J-integral evaluation and stability analysis in the unstable ductile fracture

International Nuclear Information System (INIS)

Miyoshi, Toshiro; Yoshida, Yuichiro; Shiratori, Masaki.

1984-01-01

Concerning unstable ductile fracture, which is an important problem on the structural stability of line pipes, nuclear reactor piping and so on, the research on fracture mechanics parameters which control the beginning of the stable growth and unstable growth of cracks attracts interest. At present, as the parameters, the T-modulus based on J-integral crack tip opening angle, crack opening angle averaged over crack developing part, plastic work coefficient and so on have been proposed. The research on the effectiveness and inter-relation of these parameters is divided into generation phase and application phase, and by these researches, it was reported that all T-modulus, CTOA and COA took almost constant values in relation to crack development, except initial transition period. In order to decide which parameter is most appropriate, the detailed analysis is required. In this study, the analysis of unstable ductile fracture of a central crack test piece and a small tensile test piece was carried out by finite element method, and the evaluation of J-integral in relation to crack development, J-integral resistance value when COA is assumed to be a constant, the form of an unstable fracture occurring point and the compliance dependence were examined. The method of analysis, the evaluation of J-integral, J-integral resistance value, unstable fracture occurring point and stability diagram are described. (Kako, I.)

Unstable periodic orbits and chaotic economic growth

International Nuclear Information System (INIS)

Ishiyama, K.; Saiki, Y.

2005-01-01

We numerically find many unstable periodic solutions embedded in a chaotic attractor in a macroeconomic growth cycle model of two countries with different fiscal policies, and we focus on a special type of the unstable periodic solutions. It is confirmed that chaotic behavior represented by the model is qualitatively and quantitatively related to the unstable periodic solutions. We point out that the structure of a chaotic solution is dissolved into a class of finite unstable periodic solutions picked out among a large number of periodic solutions. In this context it is essential for the unstable periodic solutions to be embedded in the chaotic attractor

Balancing for Unstable Nonlinear Systems

NARCIS (Netherlands)

Scherpen, J.M.A.

1993-01-01

A previously obtained method of balancing for stable nonlinear systems is extended to unstable nonlinear systems. The similarity invariants obtained by the concept of LQG balancing for an unstable linear system can also be obtained by considering a past and future energy function of the system. By

Unstable system with Coulomb interaction distorted near the origin

International Nuclear Information System (INIS)

Kerbikov, B.O.

1981-01-01

An unstable system with Coulomb interaction distorted at small distances is considered. The results are applicable to hadronic atoms analysis. A detailed investigation of the model which can be solved exactly is presented. This model contains the separable short-range potential with the Yamaguchi form factor. Closed expressions for the modified effective range function and the Coulomb-modified scattering length ase obtained [ru

Cosmology and unstable nuclei

International Nuclear Information System (INIS)

Schramm, D.N.

1995-01-01

Primordial nucleosynthesis has established itself as one of the three pillars of Big Bang cosmology. Many of the Big Bang Nucleosynthesis reactions involve unstable nuclei. Hence there is a tight relationship hetween the subject of this conference and cosmology. The prime role of unstable nuclei in cosmology is related to lithium synthesis and the lack of cosmological synthesis of Be and B. These nuclei will thus be focused upon. Nucleosynthesis involves comparing calculated abundances with observed abundances. In general, abundance determinations are dominated by systematic rather than statistical errors, and work on bounding systematics is crucial. The quark-hadron inspired inhomogeneous calculations now unanimously agree that only relatively small variations in Ω b are possible vis-a-vis the homogeneous model; hence the robustness of Ω b ∼0.05 is now apparent. (These calculations depend critically on unstable nuclei.) The above argues that the bulk of the baryons in the universe are not producing visible light. A comparison with the ROSAT cluster data is also shown to be consistent with the standard BBN model. Ω b ∼1 seems to be definitely excluded, so if Ω TOTAL =1, as some recent observations may hint, then non-baryonic dark matter is required. The implications of the recently reported halo microlensing events are discussed. In summary, it is argued that the physics of unstable nuclei affects the fundamental dark matter argument. ((orig.))

Physical stability of drugs after storage above and below the glass transition temperature: Relationship to glass-forming ability.

Science.gov (United States)

Alhalaweh, Amjad; Alzghoul, Ahmad; Mahlin, Denny; Bergström, Christel A S

2015-11-10

Amorphous materials are inherently unstable and tend to crystallize upon storage. In this study, we investigated the extent to which the physical stability and inherent crystallization tendency of drugs are related to their glass-forming ability (GFA), the glass transition temperature (Tg) and thermodynamic factors. Differential scanning calorimetry was used to produce the amorphous state of 52 drugs [18 compounds crystallized upon heating (Class II) and 34 remained in the amorphous state (Class III)] and to perform in situ storage for the amorphous material for 12h at temperatures 20°C above or below the Tg. A computational model based on the support vector machine (SVM) algorithm was developed to predict the structure-property relationships. All drugs maintained their Class when stored at 20°C below the Tg. Fourteen of the Class II compounds crystallized when stored above the Tg whereas all except one of the Class III compounds remained amorphous. These results were only related to the glass-forming ability and no relationship to e.g. thermodynamic factors was found. The experimental data were used for computational modeling and a classification model was developed that correctly predicted the physical stability above the Tg. The use of a large dataset revealed that molecular features related to aromaticity and π-π interactions reduce the inherent physical stability of amorphous drugs. Copyright © 2015 Elsevier B.V. All rights reserved.

Dynamical formation of a hairy black hole in a cavity from the decay of unstable solitons

International Nuclear Information System (INIS)

Sanchis-Gual, Nicolas; Font, José A; Carlos Degollado, Juan; Herdeiro, Carlos; Radu, Eugen

2017-01-01

Recent numerical relativity simulations within the Einstein–Maxwell–(charged-)Klein–Gordon (EMcKG) system have shown that the non-linear evolution of a superradiantly unstable Reissner–Nordström black hole (BH) enclosed in a cavity, leads to the formation of a BH with scalar hair. Perturbative evidence for the stability of such hairy BHs has been independently established, confirming they are the true endpoints of superradiant instability. The same EMcKG system admits also charged scalar soliton-type solutions, which can be either stable or unstable. Using numerical relativity techniques, we provide evidence that the time evolution of some of these unstable solitons leads, again, to the formation of a hairy BH. In some other cases, unstable solitons evolve into a (bald) Reissner–Nordström BH. These results establish that the system admits two distinct channels to form hairy BHs at the threshold of superradiance: growing hair from an unstable (bald) BH, or growing a horizon from an unstable (horizonless) soliton. Some parallelism with the case of asymptotically flat boson stars and Kerr BHs with scalar hair is drawn. (paper)

Dynamical formation of a hairy black hole in a cavity from the decay of unstable solitons

Science.gov (United States)

Sanchis-Gual, Nicolas; Degollado, Juan Carlos; Font, José A.; Herdeiro, Carlos; Radu, Eugen

2017-08-01

Recent numerical relativity simulations within the Einstein-Maxwell-(charged-)Klein-Gordon (EMcKG) system have shown that the non-linear evolution of a superradiantly unstable Reissner-Nordström black hole (BH) enclosed in a cavity, leads to the formation of a BH with scalar hair. Perturbative evidence for the stability of such hairy BHs has been independently established, confirming they are the true endpoints of superradiant instability. The same EMcKG system admits also charged scalar soliton-type solutions, which can be either stable or unstable. Using numerical relativity techniques, we provide evidence that the time evolution of some of these unstable solitons leads, again, to the formation of a hairy BH. In some other cases, unstable solitons evolve into a (bald) Reissner-Nordström BH. These results establish that the system admits two distinct channels to form hairy BHs at the threshold of superradiance: growing hair from an unstable (bald) BH, or growing a horizon from an unstable (horizonless) soliton. Some parallelism with the case of asymptotically flat boson stars and Kerr BHs with scalar hair is drawn.

TDP-43 inclusion bodies formed in bacteria are structurally amorphous, non-amyloid and inherently toxic to neuroblastoma cells.

Directory of Open Access Journals (Sweden)

Claudia Capitini

Full Text Available Accumulation of ubiquitin-positive, tau- and α-synuclein-negative intracellular inclusions of TDP-43 in the central nervous system represents the major hallmark correlated to amyotrophic lateral sclerosis and frontotemporal lobar degeneration with ubiquitin-positive inclusions. Such inclusions have variably been described as amorphous aggregates or more structured deposits having an amyloid structure. Following the observations that bacterial inclusion bodies generally consist of amyloid aggregates, we have overexpressed full-length TDP-43 and C-terminal TDP-43 in E. coli, purified the resulting full-length and C-terminal TDP-43 containing inclusion bodies (FL and Ct TDP-43 IBs and subjected them to biophysical analyses to assess their structure/morphology. We show that both FL and Ct TDP-43 aggregates contained in the bacterial IBs do not bind amyloid dyes such as thioflavin T and Congo red, possess a disordered secondary structure, as inferred using circular dichroism and infrared spectroscopies, and are susceptible to proteinase K digestion, thus possessing none of the hallmarks for amyloid. Moreover, atomic force microscopy revealed an irregular structure for both types of TDP-43 IBs and confirmed the absence of amyloid-like species after proteinase K treatment. Cell biology experiments showed that FL TDP-43 IBs were able to impair the viability of cultured neuroblastoma cells when added to their extracellular medium and, more markedly, when transfected into their cytosol, where they are at least in part ubiquitinated and phosphorylated. These data reveal an inherently high propensity of TDP-43 to form amorphous aggregates, which possess, however, an inherently high ability to cause cell dysfunction. This indicates that a gain of toxic function caused by TDP-43 deposits is effective in TDP-43 pathologies, in addition to possible loss of function mechanisms originating from the cellular mistrafficking of the protein.

Unstable Titan-generated Rayleigh-Taylor Lakes Impact Ice

Science.gov (United States)

Umurhan, O. M.; Korycansky, D. G.; Zahnle, K. J.

2014-12-01

The evolution of surface morphology on Titan, Triton, and other worlds is strongly influenced by the interplay of various fluid dynamical processes. Specifically, overturning instabilities can easily arise due to the special circumstances of landform evolution that probably occurred on these worlds. On Titan, large impacts that formed basins like Menrva crater (and possibly Hotei Regio) would have generated impact-melt ice lakes unstably arranged over less dense ice. Cantaloupe terrains, for example as seen on Triton, may be the result of condensation of volatiles (methane, nitrogen) leading to unstably stratified layers of different compositions and densities. In each of these cases, Rayleigh-Taylor instabilities leading to large scale diapirism may be at play. In addition to the dynamics of these instabilities, other physical effects (e.g. heat diffusion, freezing/melting, porosity, temperature dependent viscosity) likely play an important role in the evolution of these features. In this ongoing study, we examine the properties of unstably stratified fluids in which the lower less-dense ice has a temperature dependent viscosity. Surprisingly, we find that there exists an optimal disturbance length scale corresponding to the fastest growth of the Rayleigh-Taylor instability. For unstably stratified layers of water (low viscosity heavy liquid lying above an ice whose viscosity increases with depth) the fastest growing mode corresponds to 40-60 km scales with overturn times of approximately 100 days. We present a detailed numerical stability analysis in a corresponding Boussinessq model (in the creeping flow limit) incorporating thermal conduction and latent heat release and we examine the stability properties surveying a variety of parameters. We have also developed a two-dimensional numerical code (a hybrid spectral/compact-differencing scheme) to model the evolution of such systems for which we shall present preliminary numerical results depicting the outcome of

Manual control of unstable systems

Science.gov (United States)

Allen, R. W.; Hogue, J. R.; Parseghian, Z.

1986-01-01

Under certain operational regimes and failure modes, air and ground vehicles can present the human operator with a dynamically unstable or divergent control task. Research conducted over the last two decades has explored the ability of the human operator to control unstable systems under a variety of circumstances. Past research is reviewed and human operator control capabilities are summarized. A current example of automobile directional control under rear brake lockup conditions is also reviewed. A control system model analysis of the driver's steering control task is summarized, based on a generic driver/vehicle model presented at last year's Annual Manual. Results from closed course braking tests are presented that confirm the difficulty the average driver has in controlling the unstable directional dynamics arising from rear wheel lockup.

Inherently safe characteristics of nuclear reactors

International Nuclear Information System (INIS)

1989-01-01

This report is based on a detailed study which was carried out by Colenco (a company of the Motor-Columbus Group) on behalf of the Commission of the European Communities (CEC). It presents a summary of this study and concentrates more on the generic issues involved in the subject of inherent safety in nuclear power plants. It is assumed that the reader is reasonably familiar with the design outline of the systems included in the report. The report examines the role of inherent design features in achieving the safety of nuclear power plants as an alternative to the practice, which is largely followed in current reactors, of achieving safety by the addition of engineered safety features. The report examines current reactor systems to identify the extent to which their characteristics are either already inherently safe or, on the other hand, have inherent characteristics that require protective action to be taken. It then considers the advantages of introducing design changes to improve their inherent safety characteristics. Next, it looks at some new reactor types for which claims of inherent safety are made to see to what extent these claims are justified. The general question is then considered whether adoption of the inherently safe reactors would give advantages (by reducing risk in real terms or by improving the public acceptability of nuclear power) which are sufficient to offset the expected high costs and the technical risks associated with any new technology

Inherent/passive safety in fusion power plants

International Nuclear Information System (INIS)

Piet, S.J.; Crocker, J.G.

1986-01-01

The concept of inherent or passive safety for fusion energy is explored, defined, and partially quantified. Four levels of safety assurance are defined, which range from true inherent safety to passive safety to protection via active engineered safeguard systems. Fusion has the clear potential for achieving inherent or passive safety, which should be an objective of fusion research and design. Proper material choice might lead to both inherent/passive safety and high mass power density, improving both safety and economics. When inherent or passive safety is accomplished, fusion will be well on the way to achieving its ultimate potential and to be a truly superior energy source for the future

Fusion blanket inherent safety assessment

International Nuclear Information System (INIS)

Sze, D.K.; Jung, J.; Cheng, E.T.

1986-01-01

Fusion has significant potential safety advantages. There is a strong incentive for designing fusion plants to ensure that inherent safety will be achieved. Accordingly, both the Tokamak Power Systems Studies and MINIMARS have identified inherent safety as a design goal. A necessary condition is for the blanket to maintain its configuration and integrity under all credible accident conditions. A main problem is caused by afterheat removal in an accident condition. In this regard, it is highly desirable to achieve the required level of protection of the plant capital investment and limitation of radioactivity release by systems that rely only on inherent properties of matter (e.g., thermal conductivity, specific heat, etc.) and without the use of active safety equipment. This paper assesses the conditions under which inherent safety is feasible. Three types of accident conditions are evaluated for two blankets. The blankets evaluated are a self cooled vanadium/lithium blanket and a self-cooled vanadium/Flibe blanket. The accident conditions evaluated are: (1) loss-of-flow accident; (2) loss-of-coolant accident (LOCA); and (3) partial loss-of-coolant accident

Two dimensional unstable scar statistics.

Energy Technology Data Exchange (ETDEWEB)

Warne, Larry Kevin; Jorgenson, Roy Eberhardt; Kotulski, Joseph Daniel; Lee, Kelvin S. H. (ITT Industries/AES Los Angeles, CA)

2006-12-01

This report examines the localization of time harmonic high frequency modal fields in two dimensional cavities along periodic paths between opposing sides of the cavity. The cases where these orbits lead to unstable localized modes are known as scars. This paper examines the enhancements for these unstable orbits when the opposing mirrors are both convex and concave. In the latter case the construction includes the treatment of interior foci.

Myroides odoratimimus Forms Structurally Complex and Inherently Antibiotic-Resistant Biofilm in a Wound-Like in vitro Model

Directory of Open Access Journals (Sweden)

Arianna Pompilio

2017-12-01

Full Text Available Myroides odoratimimus is an aerobic, non-fermenting Gram-negative multidrug-resistant bacterium widely distributed in nature that rarely causes infections in immunocompromised patients. We recently described in a diabetic patient a case of recurrent calcaneal ulcer infection caused by a M. odoratimimus strain showing potential for biofilm formation. For the first time, we therefore evaluated the ability of M. odoratimimus to form biofilm under different pH values and glucose concentrations using an in vitro “skin-like” model, and its susceptibility to levofloxacin, meropenem, and tigecycline. The expression of some antibiotic-resistance related genes was also monitored by RT-PCR during planktonic-to-biofilm transition. Our results indicated that M. odoratimimus can produce relevant amounts of biofilm biomass, in a time-dependent manner, especially at acidic pH and regardless of glucose concentration tested. The comparative analysis of MIC and MBC values between planktonic and sessile cells showed that resistance to antibiotics increased during the planktonic-to-biofilm transition. Viable cell count indicated that none of the tested antibiotics were able to completely eradicate preformed biofilms, although meropenem and levofloxacin were the most active causing a significant, dose-independent, reduction of biofilm's viability, as also confirmed by microscopic analysis. RT-PCR showed that antibiotic-resistance related gyrA and acrB genes are over-expressed during the transition from planktonic to sessile (biofilm lifestyle. Overall, our findings showed that M. odoratimimus can form relevant amounts of inherently antibiotic-resistant biofilm under conditions relevant to wound site, therefore suggesting a role in the pathogenesis of chronic ulcer infections.

Natriuretic peptides in unstable coronary artery disease.

Science.gov (United States)

Jernberg, Tomas; James, Stefan; Lindahl, Bertil; Johnston, Nina; Stridsberg, Mats; Venge, Per; Wallentin, Lars

2004-09-01

Patients with unstable coronary artery disease (CAD), i.e., unstable angina or non-ST-elevation myocardial infarction, vary widely in clinical presentation, prognosis and response to treatment. To select appropriate therapy, early risk stratification has become increasingly important. This review focuses on the emerging role of natriuretic peptides in the early assessment of patients with unstable CAD. We conclude that levels of brain natriuretic peptide (BNP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) are strongly associated to mortality and the risk of future congestive heart failure, and carry important prognostic information independent from previously known risk factors in unstable CAD. There are some data indicating that these markers can also be helpful in the selection of appropriate therapy in these patients but further studies are needed. Before a routine use of BNP or NT-proBNP in unstable CAD can be recommended, the cost-effectiveness of adding these new markers to the currently routine markers and their impact on selection of treatment needs further evaluation. Copyright 2004 Elsevier Ltd

Numerical simulation on beam breakup unstability of linear induction accelerator

International Nuclear Information System (INIS)

Zhang Kaizhi; Wang Huacen; Lin Yuzheng

2003-01-01

A code is written to simulate BBU in induction linac according to theoretical analysis. The general form of evolution of BBU in induction linac is investigated at first, then the effect of related parameters on BBU is analyzed, for example, the alignment error, oscillation frequency of beam centroid, beam pulse shape and acceleration gradient. At last measures are put forward to damp beam breakup unstability (BBU)

Operation: Inherent Resolve

DEFF Research Database (Denmark)

Cramer-Larsen, Lars

2015-01-01

Kapitlet giver læseren indsigt i den internationale koalitions engagement mod IS igennem Operaton Inherent Resolve; herunder koalitionens strategi i forhold til IS strategi, ligesom det belyser kampagnens legalitet og folkeretlige grundlag, ligesom det giver et bud på overvejelser om kampagnens...

A Versatile Route to Unstable Diazo Compounds via Oxadiazolines and their Use in Aryl–Alkyl Cross‐Coupling Reactions

Science.gov (United States)

Greb, Andreas; Poh, Jian‐Siang; Greed, Stephanie; Battilocchio, Claudio; Pasau, Patrick; Blakemore, David C.

2017-01-01

Abstract Coupling of readily available boronic acids and diazo compounds has emerged recently as a powerful metal‐free carbon–carbon bond forming method. However, the difficulty in forming the unstable diazo compound partner in a mild fashion has hitherto limited their general use and the scope of the transformation. Here, we report the application of oxadiazolines as precursors for the generation of an unstable family of diazo compounds using flow UV photolysis and their first use in divergent protodeboronative and oxidative C(sp2)−C(sp3) cross‐coupling processes, with excellent functional‐group tolerance. PMID:29088512

Relativistic mean field theory for unstable nuclei

International Nuclear Information System (INIS)

Toki, Hiroshi

2000-01-01

We discuss the properties of unstable nuclei in the framework of the relativistic mean field (RMF) theory. We take the RMF theory as a phenomenological theory with several parameters, whose form is constrained by the successful microscopic theory (RBHF), and whose values are extracted from the experimental values of unstable nuclei. We find the outcome with the newly obtained parameter sets (TM1 and TMA) is promising in comparison with various experimental data. We calculate systematically the ground state properties of even-even nuclei up to the drip lines; about 2000 nuclei. We find that the neutron magic shells (N=82, 128) at the standard magic numbers stay at the same numbers even far from the stability line and hence provide the feature of the r-process nuclei. However, many proton magic numbers disappear at the neutron numbers far away from the magic numbers due to the deformations. We discuss how to describe giant resonances for the case of the non-linear coupling terms for the sigma and omega mesons in the relativistic RPA. We mention also the importance of the relativistic effect on the spin observables as the Gamow-Teller strength and the longitudinal and transverse spin responses. (author)

Dynamics and statistics of unstable quantum states

International Nuclear Information System (INIS)

Sokolov, V.V.; Zelevinsky, V.G.

1989-01-01

The statistical theory of spectra formulated in terms of random matrices is extended to unstable states. The energies and widths of these states are treated as real and imaginary parts of complex eigenvalues for an effective non-hermitian hamiltonian. Eigenvalue statistics are investigated under simple assumptions. If the coupling through common decay channels is weak we obtain a Wigner distribution for the level spacings and a Porter-Thomas one for the widths, with the only exception for spacings less than widths where level repulsion fades out. Meanwhile in the complex energy plane the repulsion of eigenvalues is quadratic in accordance with the T-noninvariant character of decaying systems. In the opposite case of strong coupling with the continuum, k short-lived states are formed (k is the number of open decay channels). These states accumulate almost the whole total width, the rest of the states becoming long-lived. Such a perestroika corresponds to separation of direct processes (a nuclear analogue of Dicke coherent superradiance). At small channel number, Ericson fluctuations of the cross sections are found to be suppressed. The one-channel case is considered in detail. The joint distribution of energies and widths is obtained. The average cross sections and density of unstable states are calculated. (orig.)

Electromagnetic Radiation Originating from Unstable Electron Oscillations

DEFF Research Database (Denmark)

Juul Rasmussen, Jens; Pécseli, Hans

1975-01-01

Electromagnetic oscillations in the range 300 – 700 MHz were observed from an unmagnetized argon discharge with an unstable electron velocity distribution function.......Electromagnetic oscillations in the range 300 – 700 MHz were observed from an unmagnetized argon discharge with an unstable electron velocity distribution function....

Inherently safe in situ uranium recovery

International Nuclear Information System (INIS)

Krumhansl, James Lee; Beauheim, Richard Louis; Brady, Patrick Vane; Arnold, Bill Walter; Kanney, Joseph F.; McKenna, Sean Andrew

2009-01-01

Expansion of uranium mining in the United States is a concern to some environmental groups and sovereign Native American Nations. An approach which may alleviate some problems is to develop inherently safe in situ uranium recovery ('ISR') technologies. Current ISR technology relies on chemical extraction of trace levels of uranium from aquifers that, once mined, can still contain dissolved uranium and other trace metals that are a health concern. Existing ISR operations are few in number; however, high uranium prices are driving the industry to consider expanding operations nation-wide. Environmental concerns and enforcement of the new 30 ppb uranium drinking water standard may make opening new mining operations more difficult and costly. Here we propose a technological fix: the development of inherently safe in situ recovery (ISISR) methods. The four central features of an ISISR approach are: (1) New 'green' leachants that break down predictably in the subsurface, leaving uranium, and associated trace metals, in an immobile form; (2) Post-leachant uranium/metals-immobilizing washes that provide a backup decontamination process; (3) An optimized well-field design that increases uranium recovery efficiency and minimizes excursions of contaminated water; and (4) A combined hydrologic/geochemical protocol for designing low-cost post-extraction long-term monitoring. ISISR would bring larger amounts of uranium to the surface, leave fewer toxic metals in the aquifer, and cost less to monitor safely - thus providing a 'win-win-win' solution to all stakeholders.

Prospects for inherently safe reactors

International Nuclear Information System (INIS)

Barkenbus, J.N.

1988-01-01

Public fears over nuclear safety have led some within the nuclear community to investigate the possibility of producing inherently safe nuclear reactors; that is, reactors that are transparently incapable of producing a core melt. While several promising designs of such reactors have been produced, support for large-scale research and development efforts has not been forthcoming. The prospects for commercialization of inherently safe reactors, therefore, are problematic; possible events such as further nuclear reactor accidents and superpower summits, could alter the present situation significantly. (author)

A Versatile Route to Unstable Diazo Compounds via Oxadiazolines and their Use in Aryl-Alkyl Cross-Coupling Reactions.

Science.gov (United States)

Greb, Andreas; Poh, Jian-Siang; Greed, Stephanie; Battilocchio, Claudio; Pasau, Patrick; Blakemore, David C; Ley, Steven V

2017-12-22

Coupling of readily available boronic acids and diazo compounds has emerged recently as a powerful metal-free carbon-carbon bond forming method. However, the difficulty in forming the unstable diazo compound partner in a mild fashion has hitherto limited their general use and the scope of the transformation. Here, we report the application of oxadiazolines as precursors for the generation of an unstable family of diazo compounds using flow UV photolysis and their first use in divergent protodeboronative and oxidative C(sp 2 )-C(sp 3 ) cross-coupling processes, with excellent functional-group tolerance. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pole mass, width, and propagators of unstable fermions

International Nuclear Information System (INIS)

Kniehl, B.A.; Sirlin, A.

2008-01-01

The concepts of pole mass and width are extended to unstable fermions in the general framework of parity-nonconserving gauge theories, such as the Standard Model. In contrast with the conventional on-shell definitions, these concepts are gauge independent and avoid severe unphysical singularities, properties of great importance since most fundamental fermions in nature are unstable particles. General expressions for the unrenormalized and renormalized dressed propagators of unstable fermions and their field-renormalization constants are presented. (orig.)

[THE CYTOMETRIC TECHNIQUE OF BINDING OF EOSIN-5-MALEIMIDE IN DIAGNOSTIC OF INHERENT SPHEROCYTOSIS].

Science.gov (United States)

Kuzminova, J A; Plyasunova, S A; Jogov, V V; Smetanina, N S

2016-03-01

The laboratory diagnostic of inherent spherocytosis is based on detection of spherocytes in peripheral blood, decreasing of index of sphericity, decreasing of osmotic resistance of erythrocytes. The new test of diagnostic of hereditary spherocytosis build on molecular defect was developed on the basis of binding extracellular fragments of protein of band 3 with eosin-5-maleimide (EMA-test). The study was carried out to implement comparative analysis of sensitivity and specificity of techniques applied to diagnose inherent spherocytosis. The sampling of 94 patients with various forms of anemias was analyzed All patients were applied complex clinical laboratory examination including analysis of osmotic resistance of erythrocytes, erythrocytometry and EMA-test as specific techniques of diagnostic of inherent spherocytosis. In 51 out of 94 patients (54%) decreasing of values of EMA-test was detected and in 47 patients diagnosis of inherent spherocytosis was confirmed. The standard values of EMA-test were established in 43 patients (46%) and 12 patients out of them with established diagnosis of inherent spherocytosis. Therefore, sensitivity of EMA-test made up to 79% and specificity - 80%. The most sensitive techniques of diagnostic remain osmotic resistance of erythrocytes (91%) and index of sphericity (up to 96%). But the highest specificity in this respect has EMA-test (80%). Nowadays, none of implemented techniques of diagnostic of inherent spherocytosis can be applied as a universal one. The implementation of complex examination is needed for proper diagnostic of disease.

Restrictions in the realisation of multipass unstable resonators

International Nuclear Information System (INIS)

Strakhov, S Yu

2009-01-01

Main restrictions in the realisation of multipass unstable resonators caused by intracavity losses and large-scale aberrations are considered. The influence of intracavity losses on the laser radiation power and divergence is analysed based on the numerical simulation of an unstable resonator. The efficiency criterion for the unstable multipass resonator is proposed, which is proportional to the radiation brightness and takes into account the influence of the misalignment, thermal deformation and the main parameters of the active medium and resonator on the parameters of laser radiation. (resonators)

Challenges in modeling unstable two-phase flow experiments in porous micromodels

Science.gov (United States)

Meheust, Y.; Ferrari, A.; Jimenez-Martinez, J.; Le Borgne, T.; Lunati, I.

2014-12-01

The simulation of unstable invasion patterns in porous media flow is challenging since small perturbations tend to grow in time, so that slight differences in geometry or initial conditions potentially give rise to significantly different solutions. Here we present a detailed comparison of pore scale simulations and experiments of unstable primary drainage in porous micromodels. The porous medium consists of a Hele-Shaw cell containing cylindrical obstacles. Two experimental flow cells have been constructed by soft lithography, with different degrees of heterogeneity in the grain size distribution. To model two-phase flow at the pore scale, we solve Navier-Stokes equations for mass and momentum conservation in the discretized pore space and employ the Volume of Fluid (VOF) method to track the evolution of the interface. During drainage, if the defending fluid is the most viscous, viscous forces destabilize the interface, giving rise to the formation of preferential flow paths, in the form of a branched fingering structure. We test different numerical models (a 2D vertical integrated model and a full 3D model) and different initial conditions, studying their impact on the simulated spatial distributions of the fluid phases. Although due to the unstable nature of the invasion, small discrepancies between the experimental setup and the numerical model can result in different fluids patterns (see figure), simulations show a satisfactory agreement with the structures observed experimentally. To estimate the ability of the numerical approach to reproduce unstable displacement, we compare several quantities in both the statistical and deterministic sense. We demonstrate the impact of three main sources of uncertainty : i) the uncertainty on the pore space geometry, ii) the interface initialization and ii) three dimensional effects [1]. Simulations in weakly heterogeneous geometries are found to be more challenging because uncertainties on pore neck widths are on the same

Unstable slope management program.

Science.gov (United States)

2009-08-01

This Rapid Response Project gathered information on existing unstable slope management programs, with a : focus on asset management practices in the United States and overseas. On the basis of this study, the research : team summarized and recommende...

Unstable oscillators based hyperchaotic circuit

DEFF Research Database (Denmark)

Murali, K.; Tamasevicius, A.; G. Mykolaitis, A.

1999-01-01

A simple 4th order hyperchaotic circuit with unstable oscillators is described. The circuit contains two negative impedance converters, two inductors, two capacitors, a linear resistor and a diode. The Lyapunov exponents are presented to confirm hyperchaotic nature of the oscillations in the circ...... in the circuit. The performance of the circuit is investigated by means of numerical integration of appropriate differential equations, PSPICE simulations, and hardware experiment.......A simple 4th order hyperchaotic circuit with unstable oscillators is described. The circuit contains two negative impedance converters, two inductors, two capacitors, a linear resistor and a diode. The Lyapunov exponents are presented to confirm hyperchaotic nature of the oscillations...

[Treatment aspects of unstable angina. Costs and payments for DRG].

Science.gov (United States)

Brunelli, C; Spallarossa, P; Pasdera, A; Bezante, G P; Zorzet, F; Rossettin, P

1998-01-01

Patients with unstable angina fall into a wide prognostic and therapeutic spectrum but, in general, have great access to specialty care and invasive procedures. In the modern era, in which admissions for unstable angina outnumber those for myocardial infarction, and growing economic pressures are placed on health care systems, cardiologists must re-examine clinical strategies for treating unstable angina in the light of health-cost accounting. The aims of the present study were to examine the current management of patients admitted to our cardiology department and to calculate the medical costs. A patient schedule was drawn up to prospectively register the number and type of cardiac processes carried out during hospitalization for all unstable angina patients in the period between March 1st and May 30th, 1995. Time (minutes) actually spent by both physicians and nurses for each cardiac process were carefully recorded in order to calculate the activity budget. The effective economic budget was built for each cardiac process taking into account salaries, consumable supplies, equipment service contracts, depreciation and indirect medical and non medical costs for CCU and ward. Based to the Diagnosis Related Groups (DRG) system, 53 out of 318 patients (16%) were admitted with documented or suspected unstable angina and allocated to discharge into four DRGs: DRG 140-medically treated unstable angina: 18 patients; DRG 124-unstable angina with angiography: 16 patients; DRG 122-unstable angina evolving in myocardial infarction: 6 patients; DRG 112-unstable angina with angioplasty: 13 patients. The mean cost for hospitalized patient with unstable angina was 5,574,958 Italian Liras (DRG 140 = 2,687,719; DRG 124 = 2,800,347; DRG 122 = 6,086,563; DRG 112 = 12,751,454). The difference in costs was essentially related to the procedures involved in medical care, DRGs with expensive cardiac processes having higher costs. Furthermore, these data show a deep discrepancy between

Unstable drift eigenmode in slab geometry

International Nuclear Information System (INIS)

Tsotsonis, S.; Hirose, A.

1986-01-01

The unstable Pearlstein-Berk mode of drift waves in plane, sheared slab geometry has later been shown to be stable when electron Landau resonance is rigorously treated. Based on the variational method previously developed the authors have found that in addition to the absolutely stable Pearlstein-Berk mode, there exists an absolutely unstable eigenfunction characterized by ω ≤ ω/sub chemical bonde/, and weak ''radial'' dependence. Also, the growth rate, only weakly depends on the magnetic shear and ion/electron temperature ratio

Approaches to achieving inherently safe fusion power plants

International Nuclear Information System (INIS)

Piet, S.J.

1986-01-01

Achieving inherently safe fusion facilities and conceptual designs is a challenge to the fusion community. Success should provide fusion with important competitive advantages versus other energy technologies. Inherent safety should mean a facility designed with passive safety features such that the public is protected from any acute fatalities under all credible accidental circumstances. A key aspect to inherent safety is demonstrability - the ability to prove that a deign is as safe as claimed. Three complementary approaches to achieving inherent safety are examined: toxin inventory reduction, energy source reduction and design fault tolerance. Four levels of assurance are defined, associated with uncertainty in the words ''credible' and ''demonstrable.'' Sound reasons exist for believing that inherent safety puts a modest upper bound on all accident consequences; it should be considered a part of the collection of safety and environmental issues, which also include lower consequence accidents, waste management, and effluent control

Nuclear data for unstable isotopes

International Nuclear Information System (INIS)

Sorlin, O.

1992-01-01

Nuclear Physics and Astrophysics are both entrusted with the task of understanding nucleosynthesis and energy production in the stars. At high temperatures and densities present in explosive scenarii such as the early universe, cataclysmic binary stars (nova or accretion stars), and supernovae, the nucleosynthesis proceeds throughout unstable nuclei. In order to produce and to study the most exotic isotopes that are not accessible from stable beam - stable (or radioactive) target experiments, it is necessary to develop facilities that utilize Radioactive Nuclear Beams (RNB). The existing methods for producing unstable nuclei will be described in paragraph 2. A review of the major explosive stellar processes will be made through some selected examples using RNB

Inherent optical properties of the coccolithophore: Emiliania huxleyi.

Science.gov (United States)

Zhai, Peng-Wang; Hu, Yongxiang; Trepte, Charles R; Winker, David M; Josset, Damien B; Lucker, Patricia L; Kattawar, George W

2013-07-29

A realistic nonspherical model for Emiliania huxleyi (EHUX) is built, based on electron micrographs of coccolithophore cells. The Inherent Optical Properties (IOP) of the EHUX are then calculated numerically by using the discrete dipole approximation. The coccolithophore model includes a near-spherical core with the refractive index of 1.04 + m(i)j, and a carbonate shell formed by smaller coccoliths with refractive index of 1.2 + m(i)j, where m(i) = 0 or 0.01 and j(2) = -1. The reported IOP are the Mueller scattering matrix, backscattering probability, and depolarization ratio. Our calculation shows that the Mueller matrices of coccolithophores show different angular dependence from those of coccoliths.

Generalization in adaptation to stable and unstable dynamics.

Directory of Open Access Journals (Sweden)

Abdelhamid Kadiallah

Full Text Available Humans skillfully manipulate objects and tools despite the inherent instability. In order to succeed at these tasks, the sensorimotor control system must build an internal representation of both the force and mechanical impedance. As it is not practical to either learn or store motor commands for every possible future action, the sensorimotor control system generalizes a control strategy for a range of movements based on learning performed over a set of movements. Here, we introduce a computational model for this learning and generalization, which specifies how to learn feedforward muscle activity in a function of the state space. Specifically, by incorporating co-activation as a function of error into the feedback command, we are able to derive an algorithm from a gradient descent minimization of motion error and effort, subject to maintaining a stability margin. This algorithm can be used to learn to coordinate any of a variety of motor primitives such as force fields, muscle synergies, physical models or artificial neural networks. This model for human learning and generalization is able to adapt to both stable and unstable dynamics, and provides a controller for generating efficient adaptive motor behavior in robots. Simulation results exhibit predictions consistent with all experiments on learning of novel dynamics requiring adaptation of force and impedance, and enable us to re-examine some of the previous interpretations of experiments on generalization.

On the Kalman Filter error covariance collapse into the unstable subspace

Directory of Open Access Journals (Sweden)

A. Trevisan

2011-03-01

Full Text Available When the Extended Kalman Filter is applied to a chaotic system, the rank of the error covariance matrices, after a sufficiently large number of iterations, reduces to N⁺ + N⁰ where N⁺ and N⁰ are the number of positive and null Lyapunov exponents. This is due to the collapse into the unstable and neutral tangent subspace of the solution of the full Extended Kalman Filter. Therefore the solution is the same as the solution obtained by confining the assimilation to the space spanned by the Lyapunov vectors with non-negative Lyapunov exponents. Theoretical arguments and numerical verification are provided to show that the asymptotic state and covariance estimates of the full EKF and of its reduced form, with assimilation in the unstable and neutral subspace (EKF-AUS are the same. The consequences of these findings on applications of Kalman type Filters to chaotic models are discussed.

GPU-based simulation of the two-dimensional unstable structure of gaseous oblique detonations

Energy Technology Data Exchange (ETDEWEB)

Teng, H.H.; Kiyanda, C.B.; Ng, H.D. [Department of Mechanical and Industrial Engineering, Concordia University, Montréal, QC, H3G 1M8 (Canada); Morgan, G.H.; Nikiforakis, N. [Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, CB3 0HE (United Kingdom)

2015-03-10

In this paper, the two-dimensional structure of unstable oblique detonations induced by the wedge from a supersonic combustible gas flow is simulated using the reactive Euler equations with a one-step Arrhenius chemistry model. A wide range of activation energy of the combustible mixture is considered. Computations are performed on the Graphical Processing Unit (GPU) to reduce the simulation runtimes. A large computational domain covered by a uniform mesh with high grid resolution is used to properly capture the development of instabilities and the formation of different transverse wave structures. After the initiation point, where the oblique shock transits into a detonation, an instability begins to manifest and in all cases, the left-running transverse waves first appear, followed by the subsequent emergence of right-running transverse waves forming the dual-head triple point structure. This study shows that for low activation energies, a long computational length must be carefully considered to reveal the unstable surface due to the slow growth rate of the instability. For high activation energies, the flow behind the unstable oblique detonation features the formation of unburnt gas pockets and strong vortex-pressure wave interaction resulting in a chaotic-like vortical structure.

Vowel Inherent Spectral Change

CERN Document Server

Assmann, Peter

2013-01-01

It has been traditional in phonetic research to characterize monophthongs using a set of static formant frequencies, i.e., formant frequencies taken from a single time-point in the vowel or averaged over the time-course of the vowel. However, over the last twenty years a growing body of research has demonstrated that, at least for a number of dialects of North American English, vowels which are traditionally described as monophthongs often have substantial spectral change. Vowel Inherent Spectral Change has been observed in speakers’ productions, and has also been found to have a substantial effect on listeners’ perception. In terms of acoustics, the traditional categorical distinction between monophthongs and diphthongs can be replaced by a gradient description of dynamic spectral patterns. This book includes chapters addressing various aspects of vowel inherent spectral change (VISC), including theoretical and experimental studies of the perceptually relevant aspects of VISC, the relationship between ar...

Attainment of unstable β nucleation of glycine in presence of L-tyrosine and its analytical interpretation-A combined approach

Science.gov (United States)

Renuka Devi, K.; Srinivasan, K.

2015-05-01

The ability of L-tyrosine molecules to act as a template and to facilitate the nucleation of unstable β polymorph in the solution has been revealed through in-situ nucleation study. This nucleation of β occurs along with the existing α nucleation at the critical concentration of additive in the solution. The presence of L-tyrosine molecules lowers the inherent barrier that exists for β nucleation in the solution. No nucleation of γ was observed over the entire range of concentrations studied. The molecular recognition capability and stereo selective inhibitory action of the added L-tyrosine molecules towards glycine molecule have been successfully revealed in terms of habit modification observed in the nucleated polymorphs. In the case of α polymorph, L-tyrosine induces a change in the morphology along the enantiopolar -b direction while in the case of β polymorph, habit modification from needle to plate like structure is observed. With the increase in time span, solution mediated phase transformation from β to α polymorph has been observed in the solution. Analytically the nucleation parameters of α and β polymorphs were estimated based on Classical Nucleation Theory. Form of crystallization of the nucleated polymorphs of glycine was confirmed by a powder x-ray diffraction analysis.

Study on unstable fracture characteristics of light water reactor piping

International Nuclear Information System (INIS)

Kurihara, Ryoichi

1998-08-01

Many testing studies have been conducted to validate the applicability of the leak before break (LBB) concept for the light water reactor piping in the world. It is especially important among them to clarify the condition that an inside surface crack of the piping wall does not cause an unstable fracture but ends in a stable fracture propagating only in the pipe thickness direction, even if the excessive loading works to the pipe. Pipe unstable fracture tests performed in Japan Atomic Energy Research Institute had been planned under such background, and clarified the condition for the cracked pipe to cause the unstable fracture under monotonous increase loading or cyclic loading by using test pipes with the inside circumferential surface crack. This paper examines the pipe unstable fracture by dividing it into two parts. One is the static unstable fracture that breaks the pipe with the inside circumferential surface crack by increasing load monotonously. Another is the dynamic unstable fracture that breaks the pipe by the cyclic loading. (author). 79 refs

Inherent Anticipation in the Pharmaceutical and Biotechnology Industries.

Science.gov (United States)

Goldman, Michael; Evans, Georgia; Zappia, Andrew

2015-04-15

Pharmaceutical and biotech research often involves discovering new properties of, or new methods to use, existing compositions. The doctrine of inherent anticipation, however, prevents the issuance and/or validity of a patent for discoveries deemed to have been implicitly disclosed in the prior art. This can be a barrier to patent rights in these technologies. Inherent anticipation therefore creates uncertainty for patent protection in the pharmaceutical and biotech sciences. Despite this uncertainty, Federal Circuit jurisprudence provides guidance on the boundaries of the inherent anticipation doctrine. In view of the case law, certain strategies may be employed to protect inventions that may potentially be viewed as inherent in the prior art. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.

Cold or hot, stable or unstable collective nuclear motion

International Nuclear Information System (INIS)

Chomaz, Ph.; Lacroix, D.; Jacquot, B.; Colonna, M.; Ayik, S.

1999-01-01

We present a general discussion of the mean field dynamics of finite nuclei prepared under extreme of temperature and pressure. Many features of the dynamics are carefully studied such as the collective expansion, the evaporation process, the different time-scale. We show that under the thermal pressure and the effect of the compression, the system may reach low density regions where it may become unstable. Early development of the instabilities in a dilute nuclear source in investigated using a finite temperature quantal Rpa approach for different systems. The growth rates of the unstable collective modes are determining by solving a dispersion relation. Which is obtained by parameterizing the transition density in terms of its multipole moments. Under typical conditions of a dilute finite system at moderate temperatures the dispersion relation exhibits an ultraviolet cut-off. As a result, only a finite number of multiple modes becomes unstable , and the number of the unstable collective modes increases with the size of the source. Calculations indicate that for an expanding source, unstable modes show a transition from surface to volume character. (author)

Unstable fracture of nuclear pressure vessel

International Nuclear Information System (INIS)

Urata, Kazuyoshi

1978-01-01

Unstable fracture of nuclear pressure vessel shell for light water reactors up to 1,000 MWe class is discussed in accordance with ASME Code Sec. XI. The depth of surface crack required to protect against the unstable fracture is calculated on the basis of reactor operating conditions including loss of coolant accidents. Calculated surface crack depth a is equal to tαexp(2.19(a/l)) where l is crack length and t is weld thickness. α is crack depth required to protect against the unstable fracture in terms of the ratio of crack deth to weld thickness for surface crack have infinite length. Using this α, the safety factor included for allowable defect described in Sec. XI and the effects of thickness is discussed. It is derived that allowable defect described in Sec. XI include the safety factor of two on the crack depth for crack initiation at postulated accident and the safety factor of ten for crack depth calculated from point of view of crack arrest at normal conditions. (auth.)

Sacral neuromodulation in the treatment of the unstable bladder.

Science.gov (United States)

Bosch, J L

1998-07-01

Sacral neuromodulation as a treatment for urge incontinence in patients with an unstable bladder is the subject of ongoing clinical studies. Although approximately 75% of the patients treated with a permanent sacral foramen electrode implant have experienced significant improvements, it is now also clear that there is an initial failure rate of about 25%. Recent studies have pointed out the importance of improved patient selection on the basis of sex differences, urodynamic parameters and psychological factors. Also, newer forms of test stimulation and permanent electrode implantation are being explored in an effort to improve on the present results.

Inherently safe high temperature gas-cooled reactor

International Nuclear Information System (INIS)

Yamada, Masao; Hayakawa, Hitoshi

1987-01-01

It is recognized in general that High Temperature Gas-cooled Reactors have remarkable characteristics in inherent safety and it is well known that credits of the time margin have been admitted for accident evaluation in the licensing of the currently operating prototype HTGRs (300 MWe class). Recently, more inherently safe HTGRs are being developed in various countries and drawing attention on their possibility for urban siting. The inherent safety characteristics of these HTRs differ each other depending on their design philosophy and on the features of the components/structures which constitute the plant. At first, the specific features/characteristics of the elemental components/structures of the HTRs are explained one by one and then the overall safety features/characteristics of these HTR plants are explained in connection with their design philosophy and combination of the elemental features. Taking the KWU/Interatom Modular Reactor System as an example, the particular design philosophy and safety characteristics of the inherently safe HTR are explained with a result of preliminary evaluation on the possibility of siting close to densely populated area. (author)

Unstable ductile fracture conditions in upper shelf region

International Nuclear Information System (INIS)

Nakano, Yoshifumi; Kubo, Takahiro

1985-01-01

The phenomenon of unstability of ductile fracture in the upper shelf region of a forged steel for nuclear reactor pressure vessels A508 Cl. 3 was studied with a large compliance apparatus, whose spring constants were 100, 170 and 230 kgf/mm, at the test temperatures of 100, 200 and 300 0 C and at the loading rates of 2, 20 and 200 mm/min in the crosshead speed. The main results obtained are as follows: (1) The fracture modes of the specimens consisted of (a) stable fracture, (b) unstable fracture which leads to a complete fracture rapidly and (c) quasiunstable fracture which does not lead to a complete fracture though a rapid extension of ductile crack takes place. (2) Side groove, high temperature or small spring constant made a ductile crack more unstable. (3) High temperature or large spring constant made the occurrence of quasiunstable fracture easier. (4) Quasiunstable ductile fracture took place before the maximum load, that is, at the J integral value of about 10 kgf/mm. The initiation of a microscopic ductile crack, therefore, seems to lead to quasiunstable fracture. (5) The concept that unstable ductile fracture takes place when Tsub(app) exceeds Tsub(mat) seems applicable only to the case in which unstable ductile fracture takes place after the maximum load has been exceeded. (author)

Can the inherence heuristic explain vitalistic reasoning?

Science.gov (United States)

Bastian, Brock

2014-10-01

Inherence is an important component of psychological essentialism. By drawing on vitalism as a way in which to explain this link, however, the authors appear to conflate causal explanations based on fixed features with those based on general causal forces. The disjuncture between these two types of explanatory principles highlights potential new avenues for the inherence heuristic.

Development of physiotherapy inherent requirement statements - an Australian experience.

Science.gov (United States)

Bialocerkowski, Andrea; Johnson, Amanda; Allan, Trevor; Phillips, Kirrilee

2013-04-16

The United Nations Convention on the Rights of People with Disabilities promotes equal rights of people with a disability in all aspects of their life including their education. In Australia, Disability Discrimination legislation underpins this Convention. It mandates that higher education providers must demonstrate that no discrimination has occurred and all reasonable accommodations have been considered and implemented, to facilitate access and inclusion for a student with a disability. The first step to meeting legislative requirements is to provide students with information on the inherent requirements of a course. This paper describes the steps which were taken to develop inherent requirement statements for a 4-year entry-level physiotherapy program at one Australian university. Inherent requirement statements were developed using an existing framework, which was endorsed and mandated by the University. Items which described inherencies were extracted from Australian physiotherapy professional standards and statutory regulatory requirements, and units contained in the physiotherapy program. Data were integrated into the 8 prescribed domains: ethical behaviour, behavioural stability, legal, communication, cognition, sensory abilities, strength and mobility, and sustainable performance. Statements for each domain were developed using a 5-level framework (introductory statement, description of the inherent requirement, justification for inherency, characteristics of reasonable adjustments and exemplars) and reviewed by a University Review Panel. Refinement of statements continued until no further changes were required. Fifteen physiotherapy inherent requirement statements were developed. The eight domains identified in the existing framework, developed for Nursing, were relevant to the study of physiotherapy. The inherent requirement statements developed in this study provide a transparent, defensible position on the current requirements of physiotherapy study at

A novel experimental scheme of electron scattering off unstable nuclei with a self-confining radioactive ion target (SCRIT)

International Nuclear Information System (INIS)

Wakasugi, Masanori

2005-01-01

We proposed a new experimental scheme of an electron scattering off unstable nuclei using a Self-Confining Radioactive Ion Target (SCRIT). The SCRIT is an unstable ion target formed in the electron storage ring, and is based on completely new idea. We constructed prototype of the SCRIT device and installed it in the electron storage ring KSR in Kyoto University. In the test experiment, 10 7 -Cs ions are confined in the SCRIT with the lifetime of about 2 s and the feasibility of the SCRIT as the target has been confirmed. (author)

Membrane extraction with thermodynamically unstable diphosphonic acid derivatives

Science.gov (United States)

Horwitz, E.P.; Gatrone, R.C.; Nash, K.L.

1997-10-14

Thermodynamically-unstable complexing agents which are diphosphonic acids and diphosphonic acid derivatives (or sulphur containing analogs), like carboxyhydroxymethanediphosphonic acid and vinylidene-1,1-diphosphonic acid, are capable of complexing with metal ions, and especially metal ions in the II, III, IV, V and VI oxidation states, to form stable, water-soluble metal ion complexes in moderately alkaline to highly-acidic media. However, the complexing agents can be decomposed, under mild conditions, into non-organic compounds which, for many purposes are environmentally-nondamaging compounds thereby degrading the complex and releasing the metal ion for disposal or recovery. Uses for such complexing agents as well as methods for their manufacture are also described. 1 fig.

Isotope shifts in unstable nuclei

International Nuclear Information System (INIS)

Rebel, H.

1980-05-01

Current experimental investigations of isotope shifts in atomic spectra of unstable nuclei and the resulting information about size and shape of nuclei far off stability are discussed with reference to some representative examples. (orig.)

Structure and clusters of light unstable nuclei

International Nuclear Information System (INIS)

En'yo, Yoshiko

2010-01-01

As it is known, cluster structures are often observed in light nuclei. In the recent evolution of unstable nuclear research (on nuclei having unbalanced number of neutron and proton) further new types of clusters are coming to be revealed. In this report, structures of light unstable nuclei and some of the theoretical models to describe them are reviewed. The following topics are picked up. 1. Cluster structure and theoretical models, 2. Cluster structure of unstable nuclei (low excited state). 3. Cluster structure of neutron excess beryllium isotopes. 4. Cluster gas like state in C isotope. 5. Dineutron structure of He isotopes. Numbers of strange nuclear structures of light nuclei are illustrated. Antisymmetrized molecular dynamics (AMD) is the recently developed theoretical framework which has been successfully used in heavy ion reactions and nuclear structure studies. Successful application of AMD to the isotopes of Be, B and C are illustrated. (S. Funahashi)

Analysis of Plasma Homocysteine Levels in Patients with Unstable Angina

Directory of Open Access Journals (Sweden)

José Roberto Tavares

2002-08-01

Full Text Available OBJECTIVE - To determine the prevalence of hyperhomocystinemia in patients with acute ischemic syndrome of the unstable angina type. METHODS - We prospectively studied 46 patients (24 females with unstable angina and 46 control patients (19 males, paired by sex and age, blinded to the laboratory data. Details of diets, smoking habits, medication used, body mass index, and the presence of hypertension and diabetes were recorded, as were plasma lipid and glucose levels, C-reactive protein, and lipoperoxidation in all participants. Patients with renal disease were excluded. Plasma homocysteine was estimated using high-pressure liquid chromatography. RESULTS - Plasma homocysteine levels were significantly higher in the group of patients with unstable angina (12.7±6.7 µmol/L than in the control group (8.7±4.4 µmol/L (p<0.05. Among males, homocystinemia was higher in the group with unstable angina than in the control group, but this difference was not statistically significant (14.1±5.9 µmol/L versus 11.9±4.2 µmol/L. Among females, however, a statistically significant difference was observed between the 2 groups: 11.0±7.4 µmol/L versus 6.4±2.9 µmol/L (p<0.05 in the unstable angina and control groups, respectively. Approximately 24% of the patients had unstable angina at homocysteine levels above 15 µmol/L. CONCLUSION - High homocysteine levels seem to be a relevant prevalent factor in the population with unstable angina, particularly among females.

Proton scattering from unstable nuclei

Indian Academy of Sciences (India)

Recent improvements in the intensities and optical qualities of radioactive beams have made ... The quality of the data obtained are illustrated with recent results obtained at the GANIL facility for unstable oxygen, sulfur and argon isotopes.

Cost-competitive, inherently safe LFMBR pool plant

International Nuclear Information System (INIS)

McDonald, J.S.; Brunings, J.E.; Chang, Y.I.; Hren, R.R.; Seidensticker, R.W.

1984-01-01

The Cost-Competitive, Inherently Safe LMFBR Pool Plant design was prepared in GFY 1983 under a DOE-sponsored program. This plant design was developed as a joint effort by Rockwell International and the Argonne National Laboratory with major contributions from the Bechtel Group, Inc.; Combustion engineering, Inc.; the Chicago Bridge and Iron Company; and the General Electric Company. Using current LMFBR technology, many innovative features were developed and incorporated into the design to meet the ultimate objectives of the Breeder Program, i.e., energy costs competitive with LWRs and inherent safety features to maintain the plant in a safe condition following assumed accidents without requiring operator action. This paper provides a description of the principal features that were incorporated into the design to achieve low cost and inherent safety

Symmetry energy, unstable nuclei and neutron star crusts

Energy Technology Data Exchange (ETDEWEB)

Iida, Kei [Kochi University, Department of Natural Science, Kochi (Japan); RIKEN Nishina Center, Saitama (Japan); Oyamatsu, Kazuhiro [RIKEN Nishina Center, Saitama (Japan); Aichi Shukutoku University, Department of Human Informatics, Aichi (Japan)

2014-02-15

The phenomenological approach to inhomogeneous nuclear matter is useful to describe fundamental properties of atomic nuclei and neutron star crusts in terms of the equation of state of uniform nuclear matter. We review a series of researches that we have developed by following this approach. We start with more than 200 equations of state that are consistent with empirical masses and charge radii of stable nuclei and then apply them to describe matter radii and masses of unstable nuclei, proton elastic scattering and total reaction cross sections off unstable nuclei, and nuclei in neutron star crusts including nuclear pasta. We finally discuss the possibility of constraining the density dependence of the symmetry energy from experiments on unstable nuclei and even observations of quasi-periodic oscillations in giant flares of soft gamma-ray repeaters. (orig.)

Concept of an inherently-safe high temperature gas-cooled reactor

International Nuclear Information System (INIS)

Ohashi, Hirofumi; Sato, Hiroyuki; Tachibana, Yukio; Kunitomi, Kazuhiko; Ogawa, Masuro

2012-01-01

As the challenge to ensure no harmful release of radioactive materials at the accidents by deterministic approach instead to satisfy acceptance criteria or safety goal for risk by probabilistic approach, new concept of advanced reactor, an inherently-safe high temperature gas-cooled reactor, is proposed based on the experience of the operation of the actual High Temperature Gas-cooled Reactor (HTGR) in Japan, High Temperature Engineering Test Reactor (HTTR), and the design of the commercial plant (GTHTR300), utilizing the inherent safety features of the HTGR (i.e., safety features based on physical phenomena). The safety design philosophy of the inherently-safe HTGR for the safety analysis of the radiological consequences is determined as the confinement of radioactive materials is assured by only inherent safety features without engineered safety features, AC power or prompt actions by plant personnel if the design extension conditions occur. Inherent safety features to prevent the loss or degradation of the confinement function are identified. It is proposed not to apply the probabilistic approach for the evaluation of the radiological consequences of the accidents in the safety analysis because no inherent safety features fail for the mitigation of the consequences of the accidents. Consequently, there are no event sequences to harmful release of radioactive materials if the design extension conditions occur in the inherently-safe HTGR concept. The concept and future R and D items for the inherently-safe HTGR are described in this paper.

Paradoxes of unstable electron

International Nuclear Information System (INIS)

Okun, L.B.; Zeldovich, Ya.B.

1978-01-01

The hypothesis that electron is unstable - when it is consistent with the vanishing mass of the photon- leads to a number of paradoxical statements. The lifetime of the electron is determined by emission of a huge number of longitudinal photons and exponentially depends on the amount of emitted energy. This suggests to discuss searches for charge nonconservation in experiments with high energy particles

Licensing issues for inherently safe fast reactors

International Nuclear Information System (INIS)

Kastenberg, W.E.; Lee, S.; Okrent, D.

1986-01-01

There has been considerable interest recently in a new generation of liquid metal reactor (LMR) concepts in the US. Some significant changes in regulatory philosophy will be required if the anticipated cost advantages of inherently safe designs are to be achieved. The defense in depth philosophy will need to be significantly re-evaluated in the context of inherently safe reactors. It is the purpose of this paper to begin such a re-evaluation of this regulatory philosophy

Implications of inherent safe nuclear power system

International Nuclear Information System (INIS)

Song, Yo-Taik

1987-01-01

The safety of present day nuclear power reactors and research reactors depends on a combination of design features of passive and active systems, and the alert judgement of their operators. A few inherently safe designs of nuclear reactors for power plants are currently under development. In these designs, the passive systems are emphasized, and the active systems are minimized. Also efforts are made to eliminate the potential for human failures that initiate the series of accidents. If a major system fails in these designs, the core is flooded automatically with coolants that flow by gravity, not by mechanical pumps or electromagnetic actuators. Depending on the choice of the coolants--water, liquid metal and helium gas--there are three principal types of inherently safe reactors. In this paper, these inherently safe reactor designs are reviewed and their implications are discussed. Further, future perspectives of their acceptance by nuclear industries are discussed. (author)

Signatures of unstable semiclassical trajectories in tunneling

International Nuclear Information System (INIS)

Levkov, D G; Panin, A G; Sibiryakov, S M

2009-01-01

It was found recently that processes of multidimensional tunneling are generally described at high energies by unstable semiclassical trajectories. We study two observational signatures related to the instability of trajectories. First, we find an additional power-law dependence of the tunneling probability on the semiclassical parameter as compared to the standard case of potential tunneling. The second signature is a substantial widening of the probability distribution over final-state quantum numbers. These effects are studied using a modified semiclassical technique which incorporates stabilization of the tunneling trajectories. The technique is derived from first principles. We obtain expressions for the inclusive and exclusive tunneling probabilities in the case of unstable semiclassical trajectories. We also investigate the 'phase transition' between the cases of stable and unstable trajectories across certain 'critical' values of energy. Finally, we derive the relation between the semiclassical probabilities of tunneling from the low-lying and highly excited initial states. This puts on firm ground a conjecture made previously in the semiclassical description of collision-induced tunneling in field theory

Technology which led to the westinghouse inherently safe liquid metal reactor

International Nuclear Information System (INIS)

Schmidt, J.E.; Coffield, R.D.; Doncals, R.A.; Kalinowski, J.E.; Markley, R.A.

1985-01-01

The Fast Flux Test Facility (FFTF) and the Clinch River Breeder Reactor programs resulted in an understanding of liquid metal reactor behavior that is being used to design inherent safety capability into liquid metal reactors. Technological advances give the same beneficial operating characteristics of conventional liquid metal reactors, however, the addition of inherently safe design features precludes the initiation of hypothetical core disruptive accidents. These innovative features permit inherent safety capability to be demonstrated with more than adequate margins. Also, the variety of inherent safety features provides the designers with options in selecting inherent design features for a specific reactor application

Externally perturbed unstable systems

International Nuclear Information System (INIS)

Posch, H.A.; Narnhofer, H.; Thirring, W.

1991-01-01

We discuss computer solutions of Newton's equation of motion for unstable systems in a container with time-dependent walls. An expansion leads to the formation of a cluster and a significant increase of the temperature. The question of entropy increase for expansion and compression of the system and the related problem of the feasibility of a perpetuum mobile of the second kind are investigated. (Authors)

Heteroclinic cycles between unstable attractors

NARCIS (Netherlands)

Broer, Henk; Efstathiou, Konstantinos; Subramanian, Easwar

We consider networks of pulse coupled linear oscillators with non-zero delay where the coupling between the oscillators is given by the Mirollo-Strogatz function. We prove the existence of heteroclinic cycles between unstable attractors for a network of four oscillators and for an open set of

Soleus and lateral gastrocnemius H-reflexes during standing with unstable footwear.

Science.gov (United States)

Friesenbichler, Bernd; Lepers, Romuald; Maffiuletti, Nicola A

2015-05-01

Unstable footwear has been shown to increase lower extremity muscle activity, but the reflex response to perturbations induced by this intervention is unknown. Twenty healthy subjects stood in stable and unstable footwear conditions (presented randomly) while H-reflex amplitude and background muscle activity were measured in the soleus and lateral gastrocnemius (LG) muscles. Wearing unstable footwear resulted in larger H-reflexes (normalized to the maximal M-wave) for the LG (+12%; P = 0.025), but not for the soleus (+4%; P > 0.05). Background activity of both muscles was significantly higher in the unstable condition. The H-reflex facilitation observed with unstable footwear was unexpected, as challenging postural conditions usually result in reflex depression. Increased muscle activity, decreased presynaptic inhibition, and/or more forward postural position may have (over-)compensated the expected reflex depression. Differences between LG and soleus H-reflex modulation may be due to diverging motor unit recruitment thresholds. © 2015 Wiley Periodicals, Inc.

Inherent-opening-controlled pattern formation in carbon nanotube arrays

International Nuclear Information System (INIS)

Huang Xiao; Zhou, Jijie J; Sansom, Elijah; Gharib, Morteza; Haur, Sow Chorng

2007-01-01

We have introduced inherent openings into densely packed carbon nanotube arrays to study self-organized pattern formation when the arrays undergo a wetting-dewetting treatment from nanotube tips. These inherent openings, made of circular or elongated hollows in nanotube mats, serve as dewetting centres, from where liquid recedes from. As the dewetting centres initiate dry zones and the dry zones expand, surrounding nanotubes are pulled away from the dewetting centres by liquid surface tension. Among short nanotubes, the self-organized patterns are consistent with the shape of the inherent openings, i.e. slender openings lead to elongated trench-like structures, and circular holes result in relatively round nest-like arrangements. Nanotubes in a relatively high mat are more connected, like in an elastic body, than those in a short mat. Small cracks often initialize themselves in a relatively high mat, along two or more adjacent round openings; each of the cracks evolves into a trench as liquid dries up. Self-organized pattern control with inherent openings needs to initiate the dewetting process above the nanotube tips. If there is no liquid on top, inherent openings barely enlarge themselves after the wetting-dewetting treatment

Measurement of inherent optical properties in the Arabian Sea

Digital Repository Service at National Institute of Oceanography (India)

Suresh, T.; Desa, E.; Kurian, J.; Mascarenhas, A.A.M.Q.

Inherent optical properties, absorption and began attenuation were measured in situ using a reflective tube absorption meter at nint wavelength, 412, 440, 488, 510, 555, 630, 650, 676 and 715 nm, in the Arabian Sea during March. Since inherent...

Direct numerical simulation of stable and unstable turbulent thermal boundary layers

International Nuclear Information System (INIS)

Hattori, Hirofumi; Houra, Tomoya; Nagano, Yasutaka

2007-01-01

This paper presents direct numerical simulations (DNS) of stable and unstable turbulent thermal boundary layers. Since a buoyancy-affected boundary layer is often encountered in an urban environmental space where stable and unstable stratifications exist, exploring a buoyancy-affected boundary layer is very important to know the transport phenomena of the flow in an urban space. Although actual observation may qualitatively provide the characteristics of these flows, the relevant quantitative turbulent quantities are very difficult to measure. Thus, in order to quantitatively investigate a buoyancy-affected boundary layer in detail, we have here carried out for the first time time- and space-developing DNS of slightly stable and unstable turbulent thermal boundary layers. The DNS results show the quantitative turbulent statistics and structures of stable and unstable thermal boundary layers, in which the characteristic transport phenomena of thermally stratified boundary layers are demonstrated by indicating the budgets of turbulent shear stress and turbulent heat flux. Even though the input of buoyant force is not large, the influence of buoyancy is clearly revealed in both stable and unstable turbulent boundary layers. In particular, it is found that both stable and unstable thermal stratifications caused by the weak buoyant force remarkably alter the structure of near-wall turbulence

Heteroclinic cycles between unstable attractors

International Nuclear Information System (INIS)

Broer, Henk; Efstathiou, Konstantinos; Subramanian, Easwar

2008-01-01

We consider networks of pulse coupled linear oscillators with non-zero delay where the coupling between the oscillators is given by the Mirollo–Strogatz function. We prove the existence of heteroclinic cycles between unstable attractors for a network of four oscillators and for an open set of parameter values

Significance of Tc-99m pyrophosphate accumulation in unstable angina

International Nuclear Information System (INIS)

Tange, Shoichi; Kondo, Chisato; Ohta, Yoshiko; Kusakabe, Kiyoko; Shigeta, Akiko; Uchida, Tatsuro; Sumiyoshi, Tetsuya; Kaneko, Noboru; Hosoda, Saichi

1993-01-01

Tc-99m pyrophosphate (PYP) and Tl-201 simultaneous dual energy single photon emission computed tomography (SPECT) were performed in 33 patients with clinically unstable angina. According to the presence or absence of PYP accumulation in the myocardium, the patients were classified as PYP (+) group (n=22) and PYP (-) group (n=11). Clinical features, types of unstable angina, ECG changes, and serial creatine kinase (CK) data were compared in the two groups. The 'new angina at rest' type of unstable angina was more significantly common in the PYP (+) group (16/22) than the PYP (-) group (2/11). The remaining 6 patients in the PYP (+) group and 2 patients in the PYP (-) group had 'angina of effort with changing pattern'. There was a significant difference in the occurrence of ST elevation and ST depression between the group: 59% in the PYP (+) group vs. 18% in the PYP (-) group for ST elevation and 23% in the PYP (+) group vs. 64% in the PYP (-) group for ST depression. The PYP (+) group showed significant improvement in ejection fraction in the stable state (57±12%) as compared with the unstable state (62±11%), although there was no difference between the stable and unstable state in the PYP (-) group. Although wall motion abnormality index (WMI) was poorer in the PYP (+) group than the PYP (-) group, it improved to the same degree as the PYP (-) group one month later. These data suggest that the area showing PYP (+) may reflect stunned myocardium and that Tc-99m PYP accumulation may correlate with clinical features of unstable angina. (N.K.)

Development of physiotherapy inherent requirement statements – an Australian experience

Science.gov (United States)

2013-01-01

Background The United Nations Convention on the Rights of People with Disabilities promotes equal rights of people with a disability in all aspects of their life including their education. In Australia, Disability Discrimination legislation underpins this Convention. It mandates that higher education providers must demonstrate that no discrimination has occurred and all reasonable accommodations have been considered and implemented, to facilitate access and inclusion for a student with a disability. The first step to meeting legislative requirements is to provide students with information on the inherent requirements of a course. This paper describes the steps which were taken to develop inherent requirement statements for a 4-year entry-level physiotherapy program at one Australian university. Case presentation Inherent requirement statements were developed using an existing framework, which was endorsed and mandated by the University. Items which described inherencies were extracted from Australian physiotherapy professional standards and statutory regulatory requirements, and units contained in the physiotherapy program. Data were integrated into the 8 prescribed domains: ethical behaviour, behavioural stability, legal, communication, cognition, sensory abilities, strength and mobility, and sustainable performance. Statements for each domain were developed using a 5-level framework (introductory statement, description of the inherent requirement, justification for inherency, characteristics of reasonable adjustments and exemplars) and reviewed by a University Review Panel. Refinement of statements continued until no further changes were required. Fifteen physiotherapy inherent requirement statements were developed. The eight domains identified in the existing framework, developed for Nursing, were relevant to the study of physiotherapy. Conclusions The inherent requirement statements developed in this study provide a transparent, defensible position on the

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.

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.)

Thallium-201 myocardial imaging in unstable angina and variant angina

International Nuclear Information System (INIS)

Wackers, F.J.Th.; Lie, K.I.; Liem, K.L.; Sokole, E.B.; Schoot, J.B. van der

1980-01-01

It is of clinical relevance in the coronary care unit to evaluate the potential role of 201 Tl scintigraphy in patients with unstable angina. In the present chapter the authors discuss 1) the pattern of 201 Tl scintigraphy in patients with unstable angina; and 2) the potential predictive value of 201 Tl scintigraphy in identifying patients with unstable angina who have a poorer prognosis or greater tendency to subsequently develop acute myocardial infarction. All patients with unstable angina pectoris were purposely studied during the pain free period. It seemed conceivable that injecting 201 Tl during an anginal attack would result in a high percentage of scintigraphic defects and probably diminish a potential discriminative value of the method. Moreover in clinical practice the majority of patients arrive at the coronary care unit some time after the last anginal attack. If a diagnostic test performed at this time could distinguish high and low risk patients, important therapeutic decisions might be made at the earliest possible times. (Auth.)

Structural safety assessment of a tokamak-type fusion facility for a through crack to cause cooling water leakage and plasma disruption

International Nuclear Information System (INIS)

Nakahira, Masataka

2004-01-01

A tokamak-type fusion machine has inherent safety associated with plasma shutdown. A small water leak can cause a plasma disruption although there is another possibility to terminate plasma without disruption. This plasma disruption will induce electromagnetic (EM) forces acting in the vacuum vessel (VV). From a radiological safety viewpoint, the VV is designed to form a physical barrier that encloses tritium and activated dust. If the VV can sustain an unstable fracture by EM forces from a through crack to cause the small leak, the structural safety will be assured and the inherent safety will be demonstrated. Therefore, a systematic approach to assure the structural safety is developed. A new analytical model to evaluate the through crack and leak rate of cooling water is proposed, with verification by experimental leak measurements. Based on the analysis, the critical crack length to terminate plasma is evaluated as about 2mm. On the other hand, the critical crack length for unstable fracture is obtained as about 400 mm. It is concluded that EM forces induced by the small leak to terminate plasma will not cause unstable fracture of the VV; thus the inherent safety is demonstrated. (author)

Applicability of LBB concept to tokamak-type fusion machine

International Nuclear Information System (INIS)

Nakahira, Masataka

2003-12-01

A tokamak-type fusion machine has been characterized as having inherent plasma shutdown safety. An extremely small leakage of impurities such as primary cooling water, i.e., less than 0.1 g/s, will cause a plasma disruption. This plasma disruption will induce electromagnetic forces (EM forces) acting in the Vacuum Vessel (VV) and plasma-facing components. The VV forms the physical barrier that encloses tritium and activated dust. If the VV has the possibility of sustaining an unstable fracture from a through crack caused by EM forces, the structural safety will be assured and the inherent safety will be demonstrated. This paper analytically assures the Leak-Before-Break (LBB) concept as applied to the VV and is based on experimental leak rate data of a through crack having a very small opening. Based on the analysis, the critical crack length to terminate plasma is evaluated as about 2 mm. On the other hand, the critical crack length for unstable fracture is obtained as about 400 mm. It is therefore concluded that EM forces induced by small leak to terminate plasma will not cause the unstable fracture of VV, and then the inherent safety is demonstrated. (author)

On the Fate of Unstable Circumbinary Planets: Tatooine’s Close Encounters with a Death Star

Science.gov (United States)

Sutherland, Adam P.; Fabrycky, Daniel C.

2016-02-01

Circumbinary planets whose orbits become unstable may be ejected, accreted, or even captured by one of the stars. We quantify the relative rates of these channels, for a binary of secondary star’s mass fraction 0.1 with an orbit of 1 AU. The most common outcome is ejection, which happens ∼80% of the time. If binary systems form circumbinary planets readily and sloppily, this process may fill the Milky Way with free-floating planets. A significant fraction of the time, ∼20%, the unstable planet strikes the primary or secondary. We tracked whether a Jupiter-like planet would undergo tidal stripping events during close passages, and find that these events are rarely strong enough to capture the planet, although this may be observable via free-floating planets that are heated or spun-up by this process.

The representation of inherent properties.

Science.gov (United States)

Prasada, Sandeep

2014-10-01

Research on the representation of generic knowledge suggests that inherent properties can have either a principled or a causal connection to a kind. The type of connection determines whether the outcome of the storytelling process will include intuitions of inevitability and a normative dimension and whether it will ground causal explanations.

A study of unstable rock failures using finite difference and discrete element methods

Science.gov (United States)

Garvey, Ryan J.

Case histories in mining have long described pillars or faces of rock failing violently with an accompanying rapid ejection of debris and broken material into the working areas of the mine. These unstable failures have resulted in large losses of life and collapses of entire mine panels. Modern mining operations take significant steps to reduce the likelihood of unstable failure, however eliminating their occurrence is difficult in practice. Researchers over several decades have supplemented studies of unstable failures through the application of various numerical methods. The direction of the current research is to extend these methods and to develop improved numerical tools with which to study unstable failures in underground mining layouts. An extensive study is first conducted on the expression of unstable failure in discrete element and finite difference methods. Simulated uniaxial compressive strength tests are run on brittle rock specimens. Stable or unstable loading conditions are applied onto the brittle specimens by a pair of elastic platens with ranging stiffnesses. Determinations of instability are established through stress and strain histories taken for the specimen and the system. Additional numerical tools are then developed for the finite difference method to analyze unstable failure in larger mine models. Instability identifiers are established for assessing the locations and relative magnitudes of unstable failure through measures of rapid dynamic motion. An energy balance is developed which calculates the excess energy released as a result of unstable equilibria in rock systems. These tools are validated through uniaxial and triaxial compressive strength tests and are extended to models of coal pillars and a simplified mining layout. The results of the finite difference simulations reveal that the instability identifiers and excess energy calculations provide a generalized methodology for assessing unstable failures within potentially complex

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.)

On the persistence of unstable bump-on-tail electron velocity distributions in the earth's foreshock

International Nuclear Information System (INIS)

Klimas, A.J.; Fitzenreiter, R.J.

1988-01-01

Further evidence for the persistence of bump-on-tail unstable reduced velocity distribution in the Earth's electron foreshock is presented. This persistence contradicts our understanding of quasi-linear saturation of the bump-on-tail instability; the distributions should be stabilized through velocity space diffusion too quickly to allow an observation of their unstable form. A modified theory for the saturation of the bump-on-tail instability in the Earth's foreshock is proposed and examined using numerical simulation and quasi-linear theoretical techniques. It is argued the mechanism due to Filbert and Kellogg and to Cairns which is responsible for the creation of the bump-on-tail velocity distribution in the foreshock is still operative during the evolution of the bump-on-tail instability. The saturated state of the plasma must represent a balance between this creation mechanism and velocity space diffusion; the saturated state is not determined by velocity space diffusion alone. Thus the velocity distribution of the saturated stat may still appear bump-on-tail unstable to standard linear analysis which does not take the creation mechanism into account. The bump-on-tail velocity distributions in the foreshock would then represent the state of the plasma after saturation of the bump-on-tail instability, not before

An inherently safe power reactor module

International Nuclear Information System (INIS)

Salerno, L.N.

1985-01-01

General Electric's long participation in liquid metal reactor technology has led to a Power Reactor Inherently Safe Module (PRISM) concept supported by DOE contract DE-AC06-85NE37937. The reactor module is sized to maximize inherent safety features. The small size allows factory fabrication, reducing field construction and field QA/QC labor, and allows safety to be demonstrated in full scale, to support a pre-licensed standard commercial product. The module is small enough to be placed underground, and can be combined with steam and electrical generating equipment to provide a complete electrical power producing plant in the range of 400-1200 MWe. Initial assessments are that the concept has the potential to be economically competitive with existing methods of power production used by the utility industry

Monitoring Unstable Glaciers with Seismic Noise Interferometry

Science.gov (United States)

Preiswerk, L. E.; Walter, F.

2016-12-01

Gravity-driven glacier instabilities are a threat to human infrastructure in alpine terrain, and this hazard is likely to increase with future changes in climate. Seismometers have been used previously on hazardous glaciers to monitor the natural englacial seismicity. In some situations, an increase in "icequake" activity may indicate fracture growth and thus an imminent major break-off. However, without independent constraints on unstable volumes, such mere event counting is of little use. A promising new approach to monitor unstable masses in Alpine terrain is coda wave interferometry of ambient noise. While already established in the solid earth, application to glaciers is not straightforward, because the lack of inhomogeneities typically suppresses seismic coda waves in glacier ice. Only glaciers with pervasive crevasses provide enough scattering to generate long codas. This is requirement is likely met for highly dynamic unstable glaciers. Here, we report preliminary results from a temporary 5-station on-ice array of seismometers (corner frequencies: 1 Hz, array aperture: 500m) on Bisgletscher (Switzerland). The seismometers were deployed in shallow boreholes, directly above the unstable tongue of the glacier. In the frequency band 4-12 Hz, we find stable noise cross-correlations, which in principle allows monitoring on a subdaily scale. The origin and the source processes of the ambient noise in these frequencies are however uncertain. As a first step, we evaluate the stability of the sources in order to separate effects of changing source parameters from changes of englacial properties. Since icequakes occurring every few seconds may dominate the noise field, we compare their temporal and spatial occurrences with the cross-correlation functions (stability over time, the asymmetry between causal and acausal parts of the cross-correlation functions) as well as with results from beamforming to assess the influence of these transient events on the noise field.

Non-Abelian magnetized blackholes and unstable attractors

Energy Technology Data Exchange (ETDEWEB)

Mosaffa, A.E. [Institute for Studies in Theoretical Physics and Mathematics (IPM), PO Box 19395-5531, Tehran (Iran, Islamic Republic of)], E-mail: mosaffa@theory.ipm.ac.ir; Randjbar-Daemi, S. [The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11 34014, Trieste (Italy)], E-mail: seif@ictp.trieste.it; Sheikh-Jabbari, M.M. [Institute for Studies in Theoretical Physics and Mathematics (IPM), PO Box 19395-5531, Tehran (Iran, Islamic Republic of)], E-mail: jabbari@theory.ipm.ac.ir

2008-01-21

Fluctuations of non-Abelian gauge fields in a background magnetic charge contain 'tachyonic' modes which as we will show cause an instability of the background. We extend this result to the cases where the background charge (flux) is coupled to four-dimensional Einstein gravity and show that the corresponding spherically symmetric geometries, which in the absence of a cosmological constant are of the form of (colored) Reissner-Nordstroem blackholes or the AdS{sub 2}xS{sup 2}, are also unstable unless the flux assumes its smallest allowed value, in which case the configuration is stable. We discuss the relevance of these instabilities to several places in string theory including various string compactifications and the attractor mechanism. Our results for the latter imply that the attractor mechanism shown to work for the extremal Abelian charged blackholes, cannot be applied in a straightforward way to the extremal non-Abelian colored blackholes, with the exception of the minimally charged stable ones.

Weak gravitational lensing as a method to constrain unstable dark matter

International Nuclear Information System (INIS)

Wang Meiyu; Zentner, Andrew R.

2010-01-01

The nature of the dark matter remains a mystery. The possibility of an unstable dark matter particle decaying to invisible daughter particles has been explored many times in the past few decades. Meanwhile, weak gravitational lensing shear has gained a lot of attention as a probe of dark energy, though it was previously considered a dark matter probe. Weak lensing is a useful tool for constraining the stability of the dark matter. In the coming decade a number of large galaxy imaging surveys will be undertaken and will measure the statistics of cosmological weak lensing with unprecedented precision. Weak lensing statistics are sensitive to unstable dark matter in at least two ways. Dark matter decays alter the matter power spectrum and change the angular diameter distance-redshift relation. We show how measurements of weak lensing shear correlations may provide the most restrictive, model-independent constraints on the lifetime of unstable dark matter. Our results rely on assumptions regarding nonlinear evolution of density fluctuations in scenarios of unstable dark matter and one of our aims is to stimulate interest in theoretical work on nonlinear structure growth in unstable dark matter models.

Muscular outputs during dynamic bench press under stable versus unstable conditions.

Science.gov (United States)

Koshida, Sentaro; Urabe, Yukio; Miyashita, Koji; Iwai, Kanzunori; Kagimori, Aya

2008-09-01

Previous studies have suggested that resistance training exercise under unstable conditions decreases the isometric force output, yet little is known about its influence on muscular outputs during dynamic movement. The objective of this study was to investigate the effect of an unstable condition on power, force, and velocity outputs during the bench press. Twenty male collegiate athletes (mean age, 21.3 +/- 1.5 years; mean height, 167.7 +/- 7.7 cm; mean weight, 75.9 +/- 17.5 kg) participated in this study. Each subject attempted 3 sets of single bench presses with 50% of 1 repetition maximum (1RM) under a stable condition with a flat bench and an unstable condition with a Swiss ball. Acceleration data were obtained with an accelerometer attached to the center of a barbell shaft, and peak outputs of power, force, and velocity were computed. Although significant loss of the peak outputs was found under the unstable condition (p velocity outputs, compared with previous findings. Such small reduction rates of muscular outputs may not compromise the training effect. Prospective studies are necessary to confirm whether the resistance training under an unstable condition permits the improvement of dynamic performance and trunk stability.

A model for roll stall and the inherent stability modes of low aspect ratio wings at low Reynolds numbers

Science.gov (United States)

Shields, Matt

The development of Micro Aerial Vehicles has been hindered by the poor understanding of the aerodynamic loading and stability and control properties of the low Reynolds number regime in which the inherent low aspect ratio (LAR) wings operate. This thesis experimentally evaluates the static and damping aerodynamic stability derivatives to provide a complete aerodynamic model for canonical flat plate wings of aspect ratios near unity at Reynolds numbers under 1 x 105. This permits the complete functionality of the aerodynamic forces and moments to be expressed and the equations of motion to solved, thereby identifying the inherent stability properties of the wing. This provides a basis for characterizing the stability of full vehicles. The influence of the tip vortices during sideslip perturbations is found to induce a loading condition referred to as roll stall, a significant roll moment created by the spanwise induced velocity asymmetry related to the displacement of the vortex cores relative to the wing. Roll stall is manifested by a linearly increasing roll moment with low to moderate angles of attack and a subsequent stall event similar to a lift polar; this behavior is not experienced by conventional (high aspect ratio) wings. The resulting large magnitude of the roll stability derivative, Cl,beta and lack of roll damping, Cl ,rho, create significant modal responses of the lateral state variables; a linear model used to evaluate these modes is shown to accurately reflect the solution obtained by numerically integrating the nonlinear equations. An unstable Dutch roll mode dominates the behavior of the wing for small perturbations from equilibrium, and in the presence of angle of attack oscillations a previously unconsidered coupled mode, referred to as roll resonance, is seen develop and drive the bank angle? away from equilibrium. Roll resonance requires a linear time variant (LTV) model to capture the behavior of the bank angle, which is attributed to the

Development of quantitative goals for inherent safety feature design and licensing

International Nuclear Information System (INIS)

Kastenberg, W.E.; Apostolakis, G.; Dhir, V.K.; Okrent, D.

1987-01-01

There is now considerable interest in the development of advanced fast reactors whose major focus is inherent safety. The achievement of inherent safety can be viewed from several aspects. In the Integral Fast Reactor Concept the approach is to utilize the intrinsic characteristics of pool-type liquid metal fast breeder reactors (LMFBRs) and the properties of metal fuels to integrate a high degree of inherent safety into the design. The PRISM and SAFR concepts focus on other inherent safety features. The reactors discussed above represent a radical departure from existing LWR designs as well as previous LMFBR designs (e.g., CRBRP) which are based, for the most part, on the General Design Criteria found in 10CFR50 Appendix. In view of these parallel developments (advanced reactors exploiting inherent safety and the use of quantitative goals to augment licensing), there appears to be a need to perform research on the development of methods for designing, assessing, and licensing inherent safety features in advanced reactors. The objectives of such research are outlined

Estimation scheme for unstable ductile fracture of pressure vessel

International Nuclear Information System (INIS)

Takahashi, Jun; Okamura, Hiroyuki; Sakai, Shinsuke

1990-01-01

This paper presents a new scheme for the estimation of unstable ductile fracture using the J-integral. The proposed method uses a load-versus-displacement diagram which is generated using fully plastic solutions. By this method, the phenomena of the ductile fracture can be grasped visually. Thus, the parametrical survey can be executed far more easily than before. Then, using the proposed method, unstable ductile fracture is analyzed for single-edge cracked plates under both uniform tension and pure bending. In addition, several parametrical surveys are performed concerning (1) J-controlled crack growth, (2) compliance of the structure, (3) ductility of the material (i.e., J-resistance curve), and (4) scale of the structure (i.e., screening criterion). As a result, it is shown that the proposed method is especially effective for the paramtrical study of unstable ductile fracture. (author)

Thin disk laser with unstable resonator and reduced output coupler

Science.gov (United States)

Gavili, Anwar; Shayganmanesh, Mahdi

2018-05-01

In this paper, feasibility of using unstable resonator with reduced output coupling in a thin disk laser is studied theoretically. Unstable resonator is modeled by wave-optics using Collins integral and iterative method. An Yb:YAG crystal with 250 micron thickness is considered as a quasi-three level active medium and modeled by solving rate equations of energy levels populations. The amplification of laser beam in the active medium is calculated based on the Beer-Lambert law and Rigrod method. Using generalized beam parameters method, laser beam parameters like, width, divergence, M2 factor, output power as well as near and far-field beam profiles are calculated for unstable resonator. It is demonstrated that for thin disk laser (with single disk) in spite of the low thickness of the disk which leads to low gain factor, it is possible to use unstable resonator (with reduced output coupling) and achieve good output power with appropriate beam quality. Also, the behavior of output power and beam quality versus equivalent Fresnel number is investigated and optimized value of output coupling for maximum output power is achieved.

Incidence and follow-up of Braunwald subgroups in unstable angina pectoris

NARCIS (Netherlands)

van Miltenburg-van Zijl, A. J.; Simoons, M. L.; Veerhoek, R. J.; Bossuyt, P. M.

1995-01-01

OBJECTIVES. This study was performed to establish the prognosis of patients with unstable angina within the subgroups of the Braunwald classification. BACKGROUND. Among many classifications of unstable angina, the Braunwald classification is frequently used. However, the incidence and risk for each

Some cases of terrain unstability from the Dolenjska karst area

Directory of Open Access Journals (Sweden)

Magda Čarman

2010-12-01

Full Text Available The paper presents some cases of terrain unstability from the Dolenjska karst area formed in the last yearsaround Žužemberk and Dolenjske Toplice. The Dolenjska karst has its own characteristic way of development. Themain features are thick soil top, mainly composed of clay, and high and strongly fluctuating water table. Presentedare a landslide, two rockfalls and a sinkhole collapse. A landslide nearby Žužemberk was initiated in soil top. Bothrockfalls appeared in tectonically highly disturbed carbonate rocks along the Žužemberk fault. The sinkhole collapsein the area around Dolenjske Toplice developed in tectonically damaged rocks inside the Dolenjska - Notranjskahorst and during a period of heavy rain.

Informing patients of risks inherent in treatment.

Science.gov (United States)

Griffith, Richard; Tengnah, Cassam

2009-11-01

Consent to treatment lies at the heart of autonomous decision making by patients who are entitled to make a free choice about whether to accept or refuse treatment. To help patients arrive at their decision district nurses must ensure that they give sufficient information about the nature and risks inherent in the treatment to allow an informed choice to be made. This article considers how much information regarding risks needs to be disclosed. It discusses how the law requires a different level of disclosure for patients who ask no questions about risks, those who make general enquiries about risks and those who ask specific questions about the risks inherent in treatment.

Convection due to an unstable density difference across a permeable membrane

Science.gov (United States)

Puthenveettil, Baburaj A.; Arakeri, Jaywant H.

We study natural convection driven by unstable concentration differences of sodium chloride (NaCl) across a horizontal permeable membrane at Rayleigh numbers (Ra) of 1010 to 1011 and Schmidt number (Sc)=600. A layer of brine lies over a layer of distilled water, separated by the membrane, in square-cross-section tanks. The membrane is permeable enough to allow a small flow across it at higher driving potentials. Based on the predominant mode of transport across the membrane, three regimes of convection, namely an advection regime, a diffusion regime and a combined regime, are identified. The near-membrane flow in all the regimes consists of sheet plumes formed from the unstable layers of fluid near the membrane. In the advection regime observed at higher concentration differences (Bb) show a common log-normal probability density function at all Ra. We propose a phenomenology which predicts /line{lambda}_b sqrt{Z_w Z_{V_i}}, where Zw and Z_{V_i} are, respectively, the near-wall length scales in Rayleighnard convection (RBC) and due to the advection velocity. In the combined regime, which occurs at intermediate values of C/2)4/3. At lower driving potentials, in the diffusion regime, the flux scaling is similar to that in turbulent RBC.

Does the inherence heuristic take us to psychological essentialism?

Science.gov (United States)

Marmodoro, Anna; Murphy, Robin A; Baker, A G

2014-10-01

We argue that the claim that essence-based causal explanations emerge, hydra-like, from an inherence heuristic is incomplete. No plausible mechanism for the transition from concrete properties, or cues, to essences is provided. Moreover, the fundamental shotgun and storytelling mechanisms of the inherence heuristic are not clearly enough specified to distinguish them, developmentally, from associative or causal networks.

Neuromuscular adjustments of gait associated with unstable conditions

Science.gov (United States)

Ivanenko, Y. P.; d'Avella, A.; Serrao, M.; Ranavolo, A.; Draicchio, F.; Cappellini, G.; Casali, C.; Lacquaniti, F.

2015-01-01

A compact description of coordinated muscle activity is provided by the factorization of electromyographic (EMG) signals. With the use of this approach, it has consistently been shown that multimuscle activity during human locomotion can be accounted for by four to five modules, each one comprised of a basic pattern timed at a different phase of gait cycle and the weighting coefficients of synergistic muscle activations. These modules are flexible, in so far as the timing of patterns and the amplitude of weightings can change as a function of gait speed and mode. Here we consider the adjustments of the locomotor modules related to unstable walking conditions. We compared three different conditions, i.e., locomotion of healthy subjects on slippery ground (SL) and on narrow beam (NB) and of cerebellar ataxic (CA) patients on normal ground. Motor modules were computed from the EMG signals of 12 muscles of the right lower limb using non-negative matrix factorization. The unstable gait of SL, NB, and CA showed significant changes compared with controls in the stride length, stride width, range of angular motion, and trunk oscillations. In most subjects of all three unstable conditions, >70% of the overall variation of EMG waveforms was accounted for by four modules that were characterized by a widening of muscle activity patterns. This suggests that the nervous system adopts the strategy of prolonging the duration of basic muscle activity patterns to cope with unstable conditions resulting from either slippery ground, reduced support surface, or pathology. PMID:26378199

A real-life example of choosing an inherently safer process option

International Nuclear Information System (INIS)

Study, Karen

2007-01-01

While choosing an inherently safer alternative may seem straightforward, sometimes what seems to be the most obvious alternative may not provide the best risk reduction. The process designer must maintain a broad perspective to be able to recognize all potential hazards when evaluating design options. All aspects of operation such as start-up, shut-down, utility failure, as well as normal operation should be considered. Choosing the inherently safer option is best accomplished early in the option selection phase of a project; however, recycle back to the option selection phase may be needed if an option is not thoroughly evaluated early in the process. In this paper, a project to supply ammonia to a catalytic reactor will be reviewed. During the course of the project, an 'inherently safer' alternative was selected and later discarded due to issues uncovered during the detail design phase. The final option chosen will be compared to (1) the original design and (2) the initial 'inherently safer' alternative. The final option was inherently safer than both the original design and the initial 'inherently safer' alternative even though the design team initially believed that it would not be

On the representations of Poincare group associated with unstable particles

International Nuclear Information System (INIS)

Exner, RP.

1983-01-01

The problem of relativistically-covariant description of unstable particles is reexamined. We follow the approach which associates a unitary reducible representation of Poincare group with a larger isolated system, and compare it with the one ascribing a non-unitary irreducible representation to the unstable particle alone. It is shown that the problem roots in choice of the subspace Hsub(u) of the state Hilbert space which could be related to the unstable particle. Translational invariance of Hsub(u) is proved to be incompatible with unitarity of the boosts. Further we propose a concrete choice of Hsub(u) and argue that in most cases of the actual experimental arrangements, this subspace is effectively one-dimensional. A correct slow-down for decay of a moving particle is obtained

Inherently safe technologies-chemical and nuclear

International Nuclear Information System (INIS)

Weinberg, A.M.

1984-01-01

Probabilistic risk assessments show an inverse relationship between the likelihood and the consequences of nuclear and chemical plant accidents, but the Bhopal accident has change public complacency about the safety of chemical plants to such an extent that public confidence is now at the same low level as with nuclear plants. The nuclear industry's response was to strengthen its institutions and improve its technologies, but the public may not be convinced. One solution is to develop reactors which do not depend upon the active intervention of humans of electromechanical devices to deal with emergencies, but which have physical properties that limit the possible temperature and power of a reactor. The Process Inherent Ultimately Safe and the modular High-Temperature Gas-Cooled reactors are two possibilities. the chemical industry needs to develop its own inherently safe design precepts that incorporate smallness, safe processes, and hardening against sabotage. 5 references

Nonlinear Analysis of an Unstable Bench Press Bar Path and Muscle Activation.

Science.gov (United States)

Lawrence, Michael A; Leib, Daniel J; Ostrowski, Stephanie J; Carlson, Lara A

2017-05-01

Lawrence, MA, Leib, DJ, Ostrowski, SJ, and Carlson, LA. Nonlinear analysis of an unstable bench press bar path and muscle activation. J Strength Cond Res 31(5): 1206-1211, 2017-Unstable resistance exercises are typically performed to improve the ability of stabilizing muscles to maintain joint integrity under a load. The purpose of this study was to examine the effects of an unstable load (as provided by a flexible barbell and a load suspended by elastic bands) on the bar path, the primary musculature, and stabilizing musculature while bench pressing using nonlinear analyses. Fifteen resistance-trained men (age 24.2 ± 2.7 years, mass 84.1 ± 12.0 kg, height 1.77 ± 0.05 m, 9.9 ± 3.4 years of lifting experience, and bench press 1 repetition maximum (RM) 107.5 ± 25.9 kg) volunteered for this study. Subjects pressed 2 sets of 5 repetitions in both stable (total load 75% 1RM) and unstable (total load 60% 1RM) conditions using a standard barbell and a flexible Earthquake bar, respectively. Surface electromyography was used to detect muscle activity of primary movers (pectoralis major, anterior deltoid, and triceps) and bar stabilizing musculature (latissimus dorsi, middle and posterior deltoid, biceps brachii, and upper trapezius). During the unstable condition, the bar moved in more ways and was less predictable in the mediolateral and anteroposterior directions. However, the muscle activation patterns of all muscles were more constrained with the unstable barbell. These findings suggest that the unstable condition was more challenging to control, but subjects controlled the instability by contracting their muscles in a more stable pattern or "staying tight" throughout the exercise.

Can Unstable Shoe Be Used As a Safety Training Shoe for Rehabilitation Exercises?

Directory of Open Access Journals (Sweden)

Amin Gandomkar

2014-04-01

Full Text Available Objective: Unstable shoes have been recommended to osteoarthritis patients in order to reduce walking injuries. The aim of this study was to test the effect of unstable shoe on biomechanical selected variables related to injury during stanse phase of running. Materials & Methods: Twenty five healthy young male students available men (21±2.27years participated in this study. Subjects were asked to ran on the force plate in barefoot, with unstable and control shoe conditions. Active and passive joint power, peak anterior-posterior forces, active and passive vertical force, loading rate and impulse of posterior and passive vertical forces variables were recorded using synchronizing force plate and video camera and calculated in MATLAB software. A repeated measure of ANOVA used to test the hypothesis in SPSS software (version 20, p<0.05. Results: negative power at Ankle joint decreased significantly by 49%, 35% using unstable shoe compared to contol shoe and barefoot conditions respectively (P=0.02,P<0.05. Furthemore, unstable shoe decreased significantly the active ankle power compared to barefoot condition by 23% (P=0.01. Loading rate and peak of passive vertical force, impulse and peak of posterior force increased significantly in unstable shoe compared to control shoe (P<0.05. Conclusion: Unstable shoe increased some of running related injuries risk factors such as Loading rate and peak of passive vertical force, impulse and peak of posterior force. Furthemore, this shoe could decrease absorption potential shank muscles and ankle active stability compared to control shoe. However, with increase of ankle active power compared to barefoot and lower anterior force, Unstable shoe could improve the ankle joint force generation and propulsion potential.

Quantum demolition filtering and optimal control of unstable systems.

Science.gov (United States)

Belavkin, V P

2012-11-28

A brief account of the quantum information dynamics and dynamical programming methods for optimal control of quantum unstable systems is given to both open loop and feedback control schemes corresponding respectively to deterministic and stochastic semi-Markov dynamics of stable or unstable systems. For the quantum feedback control scheme, we exploit the separation theorem of filtering and control aspects as in the usual case of quantum stable systems with non-demolition observation. This allows us to start with the Belavkin quantum filtering equation generalized to demolition observations and derive the generalized Hamilton-Jacobi-Bellman equation using standard arguments of classical control theory. This is equivalent to a Hamilton-Jacobi equation with an extra linear dissipative term if the control is restricted to Hamiltonian terms in the filtering equation. An unstable controlled qubit is considered as an example throughout the development of the formalism. Finally, we discuss optimum observation strategies to obtain a pure quantum qubit state from a mixed one.

Posttest analysis of the FFTF inherent safety tests

International Nuclear Information System (INIS)

Padilla, A. Jr.; Claybrook, S.W.

1987-01-01

Inherent safety tests were performed during 1986 in the 400-MW (thermal) Fast Flux Test Facility (FFTF) reactor to demonstrate the effectiveness of an inherent shutdown device called the gas expansion module (GEM). The GEM device provided a strong negative reactivity feedback during loss-of-flow conditions by increasing the neutron leakage as a result of an expanding gas bubble. The best-estimate pretest calculations for these tests were performed using the IANUS plant analysis code (Westinghouse Electric Corporation proprietary code) and the MELT/SIEX3 core analysis code. These two codes were also used to perform the required operational safety analyses for the FFTF reactor and plant. Although it was intended to also use the SASSYS systems (core and plant) analysis code, the calibration of the SASSYS code for FFTF core and plant analysis was not completed in time to perform pretest analyses. The purpose of this paper is to present the results of the posttest analysis of the 1986 FFTF inherent safety tests using the SASSYS code

Characterization of Unstable Rock Slopes Through Passive Seismic Measurements

Science.gov (United States)

Kleinbrod, U.; Burjanek, J.; Fäh, D.

2014-12-01

Catastrophic rock slope failures have high social impact, causing significant damage to infrastructure and many casualties throughout the world each year. Both detection and characterization of rock instabilities are therefore of key importance. An analysis of ambient vibrations of unstable rock slopes might be a new alternative to the already existing methods, e.g. geotechnical displacement measurements. Systematic measurements have been performed recently in Switzerland to study the seismic response of potential rockslides concerning a broad class of slope failure mechanisms and material conditions. Small aperture seismic arrays were deployed at sites of interest for a short period of time (several hours) in order to record ambient vibrations. Each measurement setup included a reference station, which was installed on a stable part close to the instability. Recorded ground motion is highly directional in the unstable parts of the rock slope, and significantly amplified with respect to stable areas. These effects are strongest at certain frequencies, which were identified as eigenfrequencies of the unstable rock mass. In most cases the directions of maximum amplification are perpendicular to open cracks and in good agreement with the deformation directions obtained by geodetic measurements. Such unique signatures might improve our understanding of slope structure and stability. Thus we link observed vibration characteristics with available results of detailed geological characterization. This is supported by numerical modeling of seismic wave propagation in fractured media with complex topography.For example, a potential relation between eigenfrequencies and unstable rock mass volume is investigated.

Development of inherent core technologies for advanced reactor

International Nuclear Information System (INIS)

Kim, Keung Koo; Noh, J.M.; Hwang, D.H.

1999-03-01

Recently, the developed countries made their effort on developing the advanced reactor which will result in significantly enhanced safety and economy. However, they will protect the advanced reactor and its design technology with patent and proprietary right. Therefore, it is very important to develop our own key core concepts and inherent core design technologies which can form a foundation of indigenous technologies for development of the domestic advanced reactor in order to keep the superiority in the nuclear plant building market among the developing countries. In order to provide the basic technology for the core design of advanced reactor, this project is for developing the inherent core design concepts with enhanced safety and economy, and associated methodologies and technologies for core analyses. The feasibility study of constructing domestic critical facilities are performed by surveying the status and utilization of foreign facilities and by investigating the demand for domestic facilities. The research results developed in this project, such as core analysis methodologies for hexagonal core, conceptual core design based on hexagonal fuel assemblies and soluble boron core design and control strategies, will provide a technical foundation in developing core design of domestic advanced reactor. Furthermore, they will strengthen the competitiveness of Korean nuclear technology. We also expect that some of the design concepts developed in this project to improve the reactor safety and economy can be applicable to the design of advanced reactor. This will significantly reduce the public anxiety on the nuclear power plant, and will contribute to the economy of construction and operation for the future domestic reactors. Even though the critical facility will not be constructed right now, the investigation of the status and utilization of foreign critical facility will contribute to the future critical facility construction. (author). 150 refs., 34 tabs., 103

Development of inherent core technologies for advanced reactor

Energy Technology Data Exchange (ETDEWEB)

Kim, Keung Koo; Noh, J.M.; Hwang, D.H. [and others

1999-03-01

Recently, the developed countries made their effort on developing the advanced reactor which will result in significantly enhanced safety and economy. However, they will protect the advanced reactor and its design technology with patent and proprietary right. Therefore, it is very important to develop our own key core concepts and inherent core design technologies which can form a foundation of indigenous technologies for development of the domestic advanced reactor in order to keep the superiority in the nuclear plant building market among the developing countries. In order to provide the basic technology for the core design of advanced reactor, this project is for developing the inherent core design concepts with enhanced safety and economy, and associated methodologies and technologies for core analyses. The feasibility study of constructing domestic critical facilities are performed by surveying the status and utilization of foreign facilities and by investigating the demand for domestic facilities. The research results developed in this project, such as core analysis methodologies for hexagonal core, conceptual core design based on hexagonal fuel assemblies and soluble boron core design and control strategies, will provide a technical foundation in developing core design of domestic advanced reactor. Furthermore, they will strengthen the competitiveness of Korean nuclear technology. We also expect that some of the design concepts developed in this project to improve the reactor safety and economy can be applicable to the design of advanced reactor. This will significantly reduce the public anxiety on the nuclear power plant, and will contribute to the economy of construction and operation for the future domestic reactors. Even though the critical facility will not be constructed right now, the investigation of the status and utilization of foreign critical facility will contribute to the future critical facility construction. (author). 150 refs., 34 tabs., 103

Unstable pigment mutants of Chlorella vulgaris B. as induced by UV irradiation

International Nuclear Information System (INIS)

Chankova, S.; Vinarova, K.

1987-01-01

The dynamics of arising of unstable 'segregating' pigment mutants of Chlorella vulgaris B. has been investigated in dependence on the dose of UV-rays applied and the macro- and microstructural changes taking place. The mutants are found to occur with a low frequency, irrespective of the dose applied and the presence or absence of photo-reactivation. A constantly recurring process of decomposition into two subclones is observed: light green (unstable) and yellow-green (stable). The existence of two cellular populations - structurally damaged and structurally undamaged - in the light-green unstable subclone has been demonstrated. There exists a qualitative and a quantitative correlation between the structural deformations in the cell and the dose with which the unstable pigment mutants are induced. Disturbances in the cell division are observed,resulting in delayed growth rate and the formation of small colonies

Technetium-99m-pyrophosphate myocardial imaging in unstable angina

International Nuclear Information System (INIS)

Willerson, J.T.; Parkey, R.W.; Lewis, S.E.; Buja, L.M.; Bonte, F.J.

1980-01-01

The authors have found that approximately one third of patients with the syndrome of unstable angina pectoris have abnormal 99mTc-pyrophosphate myocardial scintigrams even in the absence of abnormal enzymes and electrocardiographic confirmation of the presence of acute myocardial necrosis. Thus, 99mTc-pyrophosphate myocardial imaging technique appears to represent a sensitive means to detect acute multicellular injury associated with the clinical syndrome of unstable angina pectoris even when cardiac enzymes are normal and the electrocardiogram does not definitively document the presence of acute myocardial necrosis. (Auth.)

The inherent politics of quality in public park management

DEFF Research Database (Denmark)

Lindholst, Andrej Christian; Konijnendijk, Cecil Cornelis; Fors, Hanna

2012-01-01

In this paper, we highlight and illustrate the inherent politics embedded in “quality” as a concept for managing public parks. Reflecting more generic quality concepts, contemporary quality models in park management include concepts for both operational, strategic and stakeholder management as well...... managing the park organisation itself. However, quality concepts and their application through various management models include as well as exclude the access, values and worldviews of particular interests. In this way, any particular quality concept and model embeds its own politics by inherent...... allocations of ‘who gets what, when and how’. We illustrate the inherent politics by providing a case study of a widely adopted quality model for operational management that has been adopted and implemented in Denmark as part of new public management reforms. In perspective, other quality concepts and models...

Inherent work suit buoyancy distribution: effects on lifejacket self-righting performance.

Science.gov (United States)

Barwood, Martin J; Long, Geoffrey M; Lunt, Heather; Tipton, Michael J

2014-09-01

Accidental immersion in cold water is an occupational risk. Work suits and life jackets (LJ) should work effectively in combination to keep the airway clear of the water (freeboard) and enable self-righting. We hypothesized that inherent buoyancy, in the suit or LJ, would be beneficial for enabling freeboard, but its distribution may influence LJ self-righting. Six participants consented to complete nine immersions. Suits and LJ tested were: flotation suit (FLOAT; 85 N inherent buoyancy); oilskins 1 (OS-1) and 2 (OS-2), both with no inherent buoyancy; LJs (inherent buoyancy/buoyancy after inflation/total buoyancy), LJ-1 50/150/200 N, LJ-2 0/290/290 N, LJ-3 80/190/270 N. Once dressed, the subject entered an immersion pool where uninflated freeboard, self-righting performance, and inflated freeboard were measured. Data were compared using Friedman's test to the 0.05 alpha level. All suits and LJs enabled uninflated and inflated freeboard, but differences were seen between the suits and LJs. Self-righting was achieved on 43 of 54 occasions, irrespective of suit or LJ. On all occasions that self-righting was not achieved, this occurred in an LJ that included inherent buoyancy (11/54 occasions). Of these 11 failures, 8 occurred (73% of occasions) when the FLOAT suit was being worn. LJs that included inherent buoyancy, that are certified as effective on their own, worked less effectively from the perspective of self-righting in combination with a work suit that also included inherent buoyancy. Equipment that is approved for use in the workplace should be tested in combination to ensure adequate performance in an emergency scenario.

Isolation and Purification of Unstable Iridoid Glucosides from Traditional Chinese Medicine by Preparative High Performance Liquid Chromatography Coupled with Solid-phase Extraction

Institute of Scientific and Technical Information of China (English)

LI Cun-man; XIAO Yuan-sheng; XUE Xing-ya; FENG Jia-tao; ZHANG Xiu-li; LIANG Xin-miao

2011-01-01

An efficient preparative method was successfully developed for isolation and purification of unstable components from medicinal plant extracts, using a combined method of preparative high performance liquid chro matography(HPLC) and solid-phase extraction(SPE). The aim of this study was to obtain an effective method with high preparative efficiency and importantly to avoid the transformation of unstable compounds. The preparative HPLC system was based on an LC/MS controlled four-channel autopurification system. The SPE method was per formed with a C1s packing material to trap the target compounds and to remove the acidic additive derived from the mobile phase. Using this method, the unstable iridoid glucosides(IGs) as model compounds were successfully iso lated and purified from the extract of Hedyotis diffusa Willd. Six IGs(including one new minor IG) and one nucleo tide compound were simultaneously obtained, each with a purity of ＞91% as determined by HPLC. The structures of the isolated compounds were identified by UPLC/Q-TOF MS, UV, ID and/or 2D NMR. It was demonstrated that the combination of preparative HPLC with SPE is a versatile tool for preparative purification of unstable compounds from complex natural products.

Inherent Reward and Risk (Part I): Towards a Universal Paradigm for Investment Analysis

OpenAIRE

Liang Zou

2000-01-01

In this paper, a new paradigm is developed for analyzinginvestment strategies and pricing financial assets. This paradigmassumes that any investment strategy has its own “inherent reward”and “inherent risk” that can be judged with common sense. Ijustify axiomatically the existence and uniqueness (ratio scale)of inherent reward (U) and inherent risk (D) that could beregarded as universal measures of reward and risk for any giveninvestment strategy. Incorporating the notion of “inherentefficien...

Scaling Laws for Unstable Interfaces Driven by Strong Shocks in Cylindrical Geometry

International Nuclear Information System (INIS)

Zhang, Q.; Graham, M.J.; Graham, M.J.

1997-01-01

The Richtmyer-Meshkov (RM) instability is an interfacial interface between two fluids of different densities driven by shock waves and plays an important role in the studies of inertial confinement fusion and of supernovas. So far, most of the studies are for RM unstable interfaces driven by weak or intermediate shocks in planar geometry. For experiments conducted at the Nova laser, the unstable material interface is accelerated by very strong shocks. In this Letter, we present scaling laws for the RM unstable interface driven by strong imploding and exploding shocks. copyright 1997 The American Physical Society

Crossover to potential energy landscape dominated dynamics in a model glass-forming liquid

DEFF Research Database (Denmark)

Schrøder, Thomas; Sastry, S.; Dyre, Jeppe

2000-01-01

An equilibrated model glass-forming liquid is studied by mapping successive configurations produced by molecular dynamics simulation onto a time series of inherent structures (local minima in the potential energy). Using this "inherent dynamics" approach we find direct numerical evidence for the ......An equilibrated model glass-forming liquid is studied by mapping successive configurations produced by molecular dynamics simulation onto a time series of inherent structures (local minima in the potential energy). Using this "inherent dynamics" approach we find direct numerical evidence...... for the long held view that below a crossover temperature, Tx, the liquid's dynamics can be separated into (i) vibrations around inherent structures and (ii) transitions between inherent structures [M. Goldstein, J. Chem. Phys. 51, 3728 (1969)], i.e., the dynamics become "dominated" by the potential energy...... landscape. In agreement with previous proposals, we find that Tx is within the vicinity of the mode-coupling critical temperature Tc. We further find that near Tx, transitions between inherent structures occur via cooperative, stringlike rearrangements of groups of particles moving distances substantially...

Wear Behavior of an Unstable Knee: Stabilization via Implant Design?

Directory of Open Access Journals (Sweden)

Jörn Reinders

2014-01-01

Full Text Available Background. Wear-related failures and instabilities are frequent failure mechanisms of total knee replacements. High-conforming designs may provide additional stability for the joint. This study analyzes the effects of a ligamentous insufficiency on the stability and the wear behavior of a high-conforming knee design. Methods. Two simulator wear tests were performed on a high-conforming total knee replacement design. In the first, a ligamentous-stable knee replacement with a sacrificed anterior cruciate ligament was simulated. In the second, a ligamentous-unstable knee with additionally insufficient posterior cruciate ligament and medial collateral ligament was simulated. Wear was determined gravimetrically and wear particles were analyzed. Implant kinematics was recorded during simulation. Results. Significantly higher wear rates (P≤0.001 were observed for the unstable knee (14.58±0.56 mg/106 cycles compared to the stable knee (7.97 ± 0.87 mg/106 cycles. A higher number of wear particles with only small differences in wear particle characteristics were observed. Under unstable knee conditions, kinematics increased significantly for translations and rotations (P≤0.01. This increase was mainly attributed to higher tibial posterior translation and internal rotations. Conclusion. Higher kinematics under unstable test conditions is a result of insufficient stabilization via implant design. Due to the higher kinematics, increased wear was observed in this study.

gamma. -unstable nuclei in the sdg boson model

Energy Technology Data Exchange (ETDEWEB)

Kuyucak, S.; Lac, V.S.; Morrison, I.; Barrett, B.R. (School of Physics, Univ. of Melbourne, Parkville (Australia))

1991-07-18

Following the recent Pt(p, p') experiments which indicated the need for g bosons to reproduce the E4 data, we have extended the O(6) limit of the sd boson model to include g bosons. It is shown that a {gamma}-unstable hamiltonian in the sdg model consisting of a quadrupole interaction and a g boson energy leads to results that are very similar to the O(6) limit. Deviations from the empirical energy spectrum that stem from the {gamma}-unstable nature of the hamiltonian can be improved by including a consistent hexadecapole interaction which induces triaxiality. The same hexadecapole operator can also account for the strong E4 transitions. Applications are made to the Xe and Pt isotopes. (orig.).

γ-unstable nuclei in the sdg boson model

Science.gov (United States)

Kuyucak, S.; Lac, V.-S.; Morrison, I.; Barrett, B. R.

1991-07-01

Following the recent Pt(p, p‧) experiments which indicated the need for g bosons to reproduce the E4 data, we have extended the O(6) limit of the sd boson model to include g bosons. It is shown that a γ-unstable hamiltonian in the sdg model consisting of a quadrupole interaction and a g boson energy leads to results that are very similar to the O(6) limit. Deviations from the empirical energy spectrum that stem from the γ-unstable nature of the hamiltonian can be improved by including a consistent hexadecapole interaction which induces triaxiality. The same hexadecapole operator can also account for the strong E4 transitions. Applications are made to the Xe and Pt isotopes.

Unstable magnetic moments in Ce compounds

International Nuclear Information System (INIS)

Aarts, J.

1984-01-01

The problems which are connected with the appearance or disappearance of local moments in metals are well reflected in the magnetic behaviour of Ce intermetallic compounds. This work describes experiments on two Ce compounds which are typical examples of unstable moment systems. The first of these is CeAl 2 which at low temperatures, shows coexistence of antiferromagnetic order and the Kondo effect. Measurements are presented of the magnetization and the susceptibility in different magnetic field and temperature regions. An analysis of these measurements, using a model for the crystal field effects, shows the agreement between the measurements and the calculations to be reasonably good for CeAl 2 , but this agreement becomes worse upon decreasing Ce concentration. A phenomenological description of the observations is given. The second compound reported on is CeCu 2 Si 2 , the first 'heavy-fermion' superconductor to be investigated. The superconducting state is possibly formed by the quasi-particles of a non-magnetic many body singlet state, and not simply by the (sd) conduction electrons. This being a novel phenomenon, a number of experiments were performed to test this picture and to obtain a detailed description of the behaviour of CeCu 2 Si 2 . Measurements of the Meissner volume, confirmed the superconductivity to be intrinsic. (Auth.)

Optical isotope shifts for unstable samarium isotopes

International Nuclear Information System (INIS)

Eastham, D.A.; Walker, P.M.; Griffith, J.A.R.; Evans, D.E.; Grant, I.S.; England, J.G.; Fawcett, M.J.

1984-01-01

Using a tunable dye laser beam intersecting a thermal atomic beam, optical isotope shifts and hyperfine splittings have been measured for the four unstable samarium isotopes between 144 Sm and 154 Sm, covering the well known transition region from spherical to deformed shapes. (orig.)

Unstable Systems in Relativistic Quantum Field Theory

CERN Document Server

Maiani, Luciano

1998-01-01

We show how the state of an unstable particle can be defined in terms of stable asymptotic states. This general definition is used to discuss and to solve some old problems connected with the short-time and large-time behaviour of the non-decay amplitude.

Numerical simulation of a improving virtual confocal unstable resonator with circular mirrors of spherical surfaces

International Nuclear Information System (INIS)

Wang Taichun; Fu Hanqing; Du Xiangwan

1999-01-01

Based on the analysis of advantages and disadvantages of the unstable resonator with a phase-unifying output coupler, the improving unstable resonator are designed. The numerical simulation results indicate that the improving unstable resonator overcomes disadvantages of that resonator and its far-field intensity focusing is better than the conventional resonator

Diagnostic possibilities of radionuclide investigation in patterns with stable and unstable angina pectoris

International Nuclear Information System (INIS)

Ponomareva, A.G.; Zudbinov, Yu.I.; Sokolov, O.K.; Kudinov, V.I.

1986-01-01

Myocardial radiocardiography and scintigraphy with 99m Tc-pyrophosphate was performed in 58 patients with stable angina and 60 patients with unstable angina. In patients with stable angina, positive scintigrams were mostly recorded after anginal attacks. Their central hemodynamic parameters deteriorated progressively as angina increased in severity. Patients with unstable angina typically showed myocardial accumulation of the label that was unrelated to anginal attacks and recordable by direct-projection scintigraphy. The assessment of myocardial radiocardiographic and scintigraphic data allows one to differentiate between stable and unstable angina

Effects of an unstable shoe construction on balance in women aged over 50 years

DEFF Research Database (Denmark)

Ramstrand, Nerrolyn; Thuesen, Anna Helena; Nielsen, Dennis Brandborg

2010-01-01

BACKGROUND: Shoes with an unstable sole construction are commonly used as a therapeutic tool by physiotherapists and are widely available from shoe and sporting goods retailers. The aim of this study was to investigate the effects of using an unstable shoe (Masai Barefoot Technology) on standing ....... INTERPRETATION: Results from the present study suggest that, for this group of individuals, use of unstable footwear may improve certain aspects of balance....

Diagnosis of Unstable Angina Pectoris Has Declined Markedly with the Advent of More Sensitive Troponin Assays

DEFF Research Database (Denmark)

D'Souza, Maria; Sarkisian, Laura; Saaby, Lotte

2015-01-01

]) was established in cases of a rise and/or fall of cardiac troponin I together with cardiac ischemic features. Patients with unstable chest discomfort and cardiac troponin I values below the decision limit of myocardial infarction were diagnosed as having unstable angina pectoris. The definition of acute coronary...... syndrome included unstable angina pectoris, NSTEMI, and STEMI. Mortality data were obtained from the Danish Civil Personal Registration System. RESULTS: Of 3762 consecutive patients, 516 had acute coronary syndrome. Unstable angina pectoris was present in 7%, NSTEMI in 67%, and STEMI in 26%. The NSTEMI...... patients were older, more frequently women, and had more comorbidities than patients with unstable angina pectoris and STEMI. At median follow-up of 3.2 years 195 patients had died: 14% of unstable angina pectoris, 45% of NSTEMI, and 25% of STEMI patients. Age-adjusted log-rank statistics revealed...

Trunk muscle activity increases with unstable squat movements.

Science.gov (United States)

Anderson, Kenneth; Behm, David G

2005-02-01

The objective of this study was to determine differences in electromyographic (EMG) activity of the soleus (SOL), vastus lateralis (VL), biceps femoris (BF), abdominal stabilizers (AS), upper lumbar erector spinae (ULES), and lumbo-sacral erector spinae (LSES) muscles while performing squats of varied stability and resistance. Stability was altered by doing the squat movement on a Smith machine, a free squat, and while standing on two balance discs. Fourteen male subjects performed the movements. Activities of the SOL, AS, ULES, and LSES were highest during the unstable squat and lowest with the Smith machine protocol (p squats on unstable surfaces may permit a training adaptation of the trunk muscles responsible for supporting the spinal column (i.e., erector spinae) as well as the muscles most responsible for maintaining posture (i.e., SOL).

Gamma-unstable nuclei in the sdg boson model

Science.gov (United States)

Kuyucak, S.; Lac, V.-S.; Morrison, I.; Barret, B. R.

Following the recent Pt(p,p') experiments which indicated the need for high angular momentum (g) bosons to reproduce the E4 data, we have extended the O(6) limit of the sd boson model to the sdg bosons. It is shown that a gamma-unstable Hamiltonian in the sdg model consisting of a quadrupole interaction and a g boson energy leads to results that are very similar to the O(6) limit. Deviations from the empirical energy spectrum that stem from the gamma-unstable nature of the Hamiltonian can be improved by including a consistent hexadecapole interaction which induces triaxiality. The same hexadecapole operator can also account for the strong E4 transitions to the 4(sup +) states presumed to be g boson states. Specific applications are made to the Xe and Pt isotopes.

Results of operative fixation of unstable ankle fractures in geriatric patients.

Science.gov (United States)

Pagliaro, A J; Michelson, J D; Mizel, M S

2001-05-01

It is widely accepted that operative fixation of unstable ankle fractures yields predictably good outcomes in the general population. The current literature, however reports less acceptable results in the geriatric population age 65 years and older. The current study analyzes the outcome of the surgical treatment of unstable ankle fractures in patients at least 65 years old. Twenty three patient over 65 years old were surgically treated after sustaining 21 (91%) closed and 2 (9%) open grade II unstable ankle fractures. Fractures were classified according to the Danis-Weber and Lauge-Hansen schemes. Fracture type was predominantly Weber B (21/23, 91%), or supination external rotation stage IV (21/23, 91%). Fracture union rate was 100%. There were three significant complications including a lateral wound dehiscence with delayed fibular union in an open fracture dislocation, and two below knee amputations, neither of which was directly related to the fracture treatment. There were three minor complications; one superficial wound infection and two cases of prolonged incision drainage, all of which resolved without further surgical intervention. Complications were associated with open fractures and preexisting systemic disease. These results indicate that open reduction and internal fixation of unstable ankle fractures in geriatric patients is an efficacious treatment regime that with results that are comparable to the general population.

The azimuthally anisotropic emission of unstable light nuclear in the heavy ion collisions at intermediate energy

International Nuclear Information System (INIS)

He Zhiyong; Jin Genming; Li Zuyu; Duan Limin; Dai Guangxi; Zhang Baoguo; Wu Heyu; Wen Wanxin; Qi Yujin; Luo Qingzheng

1996-01-01

The unstable light nuclei emitted in the interaction of 40 Ar on 197 Au have been detected at energy of 25 MeV/u by using particle-particle correlation measurement at small relative angle. Their in-plane and out-of-plane emission were measured for three bins of experimentally estimated impact parameter. The enhanced in-plane emission for mid-rapidity unstable nuclei is observed. This enhanced in-plane emission becomes stronger with increasing of impact parameter, but changes small with the mass of unstable nuclei. The in-plane enhancement decreases slightly with the energy of excited state of unstable nuclei. For projectile-like unstable nuclei, the in-plane emission dominates as expected

Students' Perception of Live Lectures' Inherent Disadvantages

Science.gov (United States)

Petrovic, Juraj; Pale, Predrag

2015-01-01

This paper aims to provide insight into various properties of live lectures from the perspective of sophomore engineering students. In an anonymous online survey conducted at the Faculty of Electrical Engineering and Computing, University of Zagreb, we investigated students' opinions regarding lecture attendance, inherent disadvantages of live…

Theory of elementary excitations in unstable Bose-Einstein condensates and the instability of sonic horizons

International Nuclear Information System (INIS)

Leonhardt, U.; Kiss, T.; Oehberg, P.

2003-01-01

Like classical fluids, quantum gases may suffer from hydrodynamic instabilities. Our paper develops a quantum version of the classical stability analysis in fluids, the Bogoliubov theory of elementary excitations in unstable Bose-Einstein condensates. In unstable condensates the excitation modes have complex frequencies. We derive the normalization conditions for unstable modes such that they can serve in a mode decomposition of the noncondensed component. Furthermore, we develop approximative techniques to determine the spectrum and the mode functions. Finally, we apply our theory to sonic horizons - sonic black and white holes. For sonic white holes the spectrum of unstable modes turns out to be intrinsically discrete, whereas black holes may be stable

Search for unstable photinos

International Nuclear Information System (INIS)

Mayer, P.

1987-04-01

We have searched in e + e - -annihilation for the photino, the partner of the photon, which is predicted by supersymmetry. Photinos can be pair produced in e + e - annihilation by the exchange of a scalar electron, the partner of the electron. It was assumed that the photino is unstable and decays in a photon and a lighter supersymmetric particle. This second particle leaves the detector unobserved. In the final state one sees then two photons with missing energy and missing momentum. The data were taken with the detector CELLO at the e + e - storage ring PETRA at DESY, Hamburg. The CMS energy was between 38.3 GeV and 46.8 GeV, the total luminosity was 38.3 pb -1 . The liquid argon lead calorimeter of CELLO, the most important part for this analysis, is specialised for the measurement of electromagnetic showers. It has a good space resolution and covers 96% of the solid angle of 4π. We have selected events with 2 photons in the central calorimeter, both with an energy of more than 2 GeV. The high background due to cosmic showers was reduced by accepting only events which were correlated to the time of the e + e - annihilation. Also the direction of the showers had to point to the interaction point. The applied cuts accepted the expected events with a probability P≅0.3. No event was found which was compatible with the production of unstable photinos. One can give limits on the mass of the photino, which depend on the mass of the scalar electron and on the decay path of the photino. In the simplest case, if all photinos decay at the interaction point, photinos with masses below 21 GeV are excluded (with a mass of the scalar electron below 40 GeV). (orig.) [de

γ-unstable nuclei in the sdg boson model

International Nuclear Information System (INIS)

Kuyucak, S.; Lac, V-S.; Morrison, I.; Barret, B.R.

1991-01-01

Following the recent Pt(p,p') experiments which indicated the need for g bosons to reproduce the E4 data, we have extended the O(6) limit of the sd boson model to the sdg bosons. It is shown that a γ-unstable Hamiltonian in the sdg model consisting of a quadrupole interaction and a g boson energy leads to results that are very similar to the O(6) limit. Deviations from the empirical energy spectrum that stem from the γ-unstable nature of the Hamiltonian can be improved by including a consistent hexadecapole interaction which induces triaxiality. The same hexadecapole operator can also account for the strong E4 transitions to the 4 + states presumed to be g boson states. Specific applications are made to the Xe and Pt isotopes. 12 refs., 2 tabs., 4 figs

Mean-Field and RPA Approaches to Stable and Unstable Nuclei with Semi-Realistic Interactions

International Nuclear Information System (INIS)

Nakada, H.

2009-01-01

We have developed semi-realistic NN interactions [1, 2] by modifying the M3Y interaction [3] that was derived from the G-matrix. The modification has been made so that the saturation and the spin-orbit splittings could be reproduced. The new interactions contain finite-range LS and tensor channels, as well as Yukawa-form central channels having reasonable spin and spin-isospin properties. In order to handle such interactions in practical calculations, we have also developed new numerical methods [4-6], in which the Gaussian expansion method [7] is applied. It is noted that these methods have the following advantages: (i) we can efficiently describe the energy-dependent asymptotics of single-particle wave functions at large r, as is typified in arguments on the deformed neutron halo in 4 0M g [6], (ii) we can handle various effective interactions, including those having non-locality, and (iii) a single-set of bases is applicable to wide mass range of nuclei and therefore is suitable to systematic calculations. Thereby we can implement Hartree-Fock, Hartree-Fock-Bogolyubov and RPA calculations for stable and unstable nuclei with the semi-realistic interactions. It will be shown first that the new interactions have desired characters for the nuclear matter and for the single- and double-closed nuclei. We shall particularly focus on roles of specific channels of the effective interaction, by studying (a) 'shell evolution' and role of the spin-isospin and the tensor channels [8] in stable and unstable nuclei, and (b) the magnetic response in a fully self-consistent RPA calculation with the tensor force [9]. All these properties seem to be simultaneously and naturally reproduced by the semi-realistic interactions. Thus the semi-realistic interactions are promising in describing various aspects of nuclear structure from stable to drip-line nuclei, in a self-consistent and unified manner. Since they have microscopic origin with minimal modification, we can expect high

Energy harvesting by dynamic unstability and internal resonance for piezoelectric beam

Energy Technology Data Exchange (ETDEWEB)

Lan, Chunbo; Qin, Weiyang, E-mail: 353481781@qq.com; Deng, Wangzheng [Department of Engineering Mechanics, Northwestern Polytechnical University, Xi' an 710072 (China)

2015-08-31

We investigated the energy harvesting of a vertical beam with tip mass under vertical excitations. We applied dynamic unstability and internal resonance to improve the efficiency of harvesting. The experiments of harmonic excitation were carried out. Results show that for the beam there exist internal resonances in the dynamically unstable and the buckling bistable cases. The dynamic unstability is a determinant for strong internal resonance or mode coupling, which can be used to create a large output from piezoelectric patches. Then, the experiments of stochastic excitation were carried out. Results prove that the internal resonance or mode coupling can transfer the excitation energy to the low order modes, mainly the first and the second one. This can bring about a large output voltage. For a stochastic excitation, it is proved that there is an optimal weight of tip mass for realizing internal resonance and producing large outputs.

Infrared sensitivity of unstable vacua

International Nuclear Information System (INIS)

Krotov, Dmitry; Polyakov, Alexander M.

2011-01-01

We discover that some unstable vacua have long memory. By that we mean that even in the theories containing only massive particles, there are correllators and expectation values which grow with time. We examine the cases of instabilities caused by the constant electric fields, expanding and contracting universes and, most importantly, the global de Sitter space. In the last case the interaction leads to a remarkable UV/IR mixing and to a large back reaction. This gives reasons to believe that the cosmological constant problem could be resolved by the infrared physics.

Acoustic resonance scattering by a system of concentrically multilayered shells: the inherent background and resonance coefficients

CERN Document Server

Choi, M S; Lee, S H

1999-01-01

The inherent background coefficients that exactly describe the background amplitudes in the scattered field have been presented for the scattering of plane acoustic waves by a system of concentrically multilayered solid and/or fluid shells submerged in a fluid. The coefficients have been obtained by replacing the mechanical surface admittance function with the zero-frequency limit of the admittance function for the analogous fluid system, where the shear wave speeds in the solid layers are set to zero. By taking advantage of the concept of incoming and outgoing waves, we find the surface admittance function for the fluid system in such a form that the analytical generalization for any number of layers and the physical interpretation are very easy. The background coefficients obtained are independent of the bulk wave speeds in the system: they depend on the mass densities and the thickness of the shells. With increasing frequency, the inherent background undergoes a transition from the soft to the rigid backgr...

Concluding remarks of the International symposium on structure and reactions of unstable nuclei

International Nuclear Information System (INIS)

Mueller, A.C.

1991-01-01

A brief history of unstable beams is given, followed by a short description of the experimental facilities. The structure and reaction of unstable nuclei is discussed, and the neutron-halo nuclei are studied. Some considerations are given related to exotic-beam facilities. (K.A.) 14 refs., 2 figs

Bohr Hamiltonian with an energy-dependent γ-unstable Coulomb-like potential

Energy Technology Data Exchange (ETDEWEB)

Budaca, R. [Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest-Magurele (Romania)

2016-10-15

An exact analytical solution for the Bohr Hamiltonian with an energy-dependent Coulomb-like γ-unstable potential is presented. Due to the linear energy dependence of the potential's coupling constant, the corresponding spectrum in the asymptotic limit of the slope parameter resembles the spectral structure of the spherical vibrator, however with a different state degeneracy. The parameter free energy spectrum as well as the transition rates for this case are given in closed form and duly compared with those of the harmonic U(5) dynamical symmetry. The model wave functions are found to exhibit properties that can be associated to shape coexistence. A possible experimental realization of the model is found in few medium nuclei with a very low second 0{sup +} state known to exhibit competing prolate, oblate and spherical shapes. (orig.)

Unstable mixed convective transport in groundwater

International Nuclear Information System (INIS)

Schincariol, R.A.; Schwartz, F.W.

1990-01-01

This study is an experimental investigation of variable density groundwater flow in homogeneous and lenticular porous media. A solution of 500 mg/l Rhodamine WT dye served as the carrier for various concentrations of solute (NaCl) introduced into a two-dimensional flow tank at concentrations ranging from 1000 to 100,000 mg/l. At the scale of the experiments, mass transport depends upon both forced and free convection. In addition, density differences as low as 0.008 g/cm 3 (1000 mg/l NaCl) between a plume of dense water and ambient groundwater in homogeneous medium produces gravitational instabilities at realistic groundwater velocities. These instabilities are manifest by lobe-shaped protuberances that formed first along the bottom edge of the plume and later within the plume. As the density difference increases to 0.0015 g/cm 3 (2000 mg/l NaCl), 0.0037 g/cm 3 (5000 mg/l NaCl) or higher, this unstable mixing due to convective dispersion significantly alters the spreading process, resulting in a large degree of vertical spreading of the plume. In a lenticular medium the combination of convective dispersion and nonuniform flow due to heterogeneities results in relatively large dispersion. Scale considerations indicate that convective dispersion may provide an important component of mixing at the field scale. (Author) (30 refs., 12 figs., 3 tabs.)

The fate of unstable gauge flux compactifications

Energy Technology Data Exchange (ETDEWEB)

Burgess, C P [McMaster Univ., Hamilton, ON (Canada). Dept. of Physics and Astronomy; [Perimeter Institute for Theoretical Physics, Waterloo, ON (Canada); Parameswaran, S L [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Zavala, I [Bonn Univ. (Germany). Bethe Center for Theoretical Physics and Physikalisches Inst.

2008-12-15

Fluxes are widely used to stabilise extra dimensions, but the supporting monopolelike configurations are often unstable, particularly if they arise as gauge flux within a non-abelian gauge sector. We here seek the endpoint geometries to which this instability leads, focussing on the simplest concrete examples: sphere-monopole compactifications in six dimensions. Without gravity most monopoles in non-abelian gauge groups are unstable, decaying into the unique stable monopole in the same topological class. We show that the same is true in Einstein-YM systems, with the new twist that the decay leads to a shrinkage in the size of the extra dimensions and curves the non-compact directions: in D dimensions a Mink{sub D-2} x S{sub 2} geometry supported by an unstable monopole relaxes to AdS{sub D-2} x S{sub 2}, with the endpoint sphere smaller than the initial one. For supergravity the situation is more complicated because the dilaton obstructs such a simple evolution. The endpoint instead acquires a dilaton gradient, thereby breaking some of the spacetime symmetries. For 6D supergravity we argue that it is the 4D symmetries that break, and examine several candidates for the endpoint geometry. By using the trick of dimensional oxidation it is possible to recast the supergravity system as a higher-dimensional Einstein-YM monopole, allowing understanding of this system to guide us to the corresponding endpoint. The result is a Kasner-like geometry conformal to Mink{sub 4} times S{sub 2}, with nontrivial conformal factor and dilaton breaking the maximal 4D symmetry and generating a singularity. Yet the resulting configuration has a lower potential energy than did the initial one, and is perturbatively stable, making it a sensible candidate endpoint for the evolution. (orig.)

The fate of unstable gauge flux compactifications

International Nuclear Information System (INIS)

Burgess, C.P.; Parameswaran, S.L.; Zavala, I.

2008-12-01

Fluxes are widely used to stabilise extra dimensions, but the supporting monopolelike configurations are often unstable, particularly if they arise as gauge flux within a non-abelian gauge sector. We here seek the endpoint geometries to which this instability leads, focussing on the simplest concrete examples: sphere-monopole compactifications in six dimensions. Without gravity most monopoles in non-abelian gauge groups are unstable, decaying into the unique stable monopole in the same topological class. We show that the same is true in Einstein-YM systems, with the new twist that the decay leads to a shrinkage in the size of the extra dimensions and curves the non-compact directions: in D dimensions a Mink D-2 x S 2 geometry supported by an unstable monopole relaxes to AdS D-2 x S 2 , with the endpoint sphere smaller than the initial one. For supergravity the situation is more complicated because the dilaton obstructs such a simple evolution. The endpoint instead acquires a dilaton gradient, thereby breaking some of the spacetime symmetries. For 6D supergravity we argue that it is the 4D symmetries that break, and examine several candidates for the endpoint geometry. By using the trick of dimensional oxidation it is possible to recast the supergravity system as a higher-dimensional Einstein-YM monopole, allowing understanding of this system to guide us to the corresponding endpoint. The result is a Kasner-like geometry conformal to Mink 4 times S 2 , with nontrivial conformal factor and dilaton breaking the maximal 4D symmetry and generating a singularity. Yet the resulting configuration has a lower potential energy than did the initial one, and is perturbatively stable, making it a sensible candidate endpoint for the evolution. (orig.)

Buoyant Unstable Behavior of Initially Spherical Lean Hydrogen-Air Premixed Flames

Directory of Open Access Journals (Sweden)

Zuo-Yu Sun

2014-07-01

Full Text Available Buoyant unstable behavior in initially spherical lean hydrogen-air premixed flames within a center-ignited combustion vessel have been studied experimentally under a wide range of pressures (including reduced, normal, and elevated pressures. The experimental observations show that the flame front of lean hydrogen-air premixed flames will not give rise to the phenomenon of cellular instability when the equivalence ratio has been reduced to a certain value, which is totally different from the traditional understanding of the instability characteristics of lean hydrogen premixed flames. Accompanied by the smoothened flame front, the propagation mode of lean hydrogen premixed flames transitions from initially spherical outwardly towards upwardly when the flames expand to certain sizes. To quantitatively investigate such buoyant instability behaviors, two parameters, “float rate (ψ” and “critical flame radius (Rcr”, have been proposed in the present article. The quantitative results demonstrate that the influences of initial pressure (Pint on buoyant unstable behaviors are different. Based on the effects of variation of density difference and stretch rate on the flame front, the mechanism of such buoyant unstable behaviors has been explained by the competition between the stretch force and the results of gravity and buoyancy, and lean hydrogen premixed flames will display buoyant unstable behavior when the stretch effects on the flame front are weaker than the effects of gravity and buoyancy.

CT of hemodynamically unstable abdominal trauma

International Nuclear Information System (INIS)

Petridis, A.; Pilavaki, M.; Vafiadis, E.; Palladas, P.; Finitsis, S.; Drevelegas, A.

1999-01-01

This article is an appraisal of the use of CT in the management of patients with unstable abdominal trauma. We examined 41 patients with abdominal trauma using noncontrast dynamic CT. In 17 patients a postcontrast dynamic CT was also carried out. On CT, 25 patients had hemoperitoneum. Thirteen patients had splenic, 12 hepatic, 6 pancreatic, 8 bowel and mesenteric, 12 renal and 2 vascular injuries. Seven patients had retroperitoneal and 2 patients adrenal hematomas. All but five lesions (three renal, one pancreatic, and one splenic) were hypodense when CT was performed earlier than 8 h following the injury. Postcontrast studies (n = 17), revealed 4 splenic, 3 hepatic, 1 pancreatic, 3 renal, and 2 bowel and mesenteric injuries beyond what was found on noncontrast CT. Surgical confirmation (n = 21) was obtained in 81.81 % of splenic, 66.66 % of hepatic, 83.33 % of pancreatic, 100 % of renal, 100 % of retroperitoneal, and 85.71 % of bowel and mesenteric injuries. The majority of false diagnoses was obtained with noncontrast studies. Computed tomography is a remarkable method for evaluation and management of patients with hemodynamically unstable abdominal trauma, but only if it is revealed in the emergency room. Contrast injection, when it could be done, revealed lesions that were not suspected on initial plain scans. (orig.)

Imaging unstable plaque

International Nuclear Information System (INIS)

SRIRANJAN, Rouchelle S.; TARKIN, Jason M.; RUDD, James H.; EVANS, Nicholas R.; CHOWDHURY, Mohammed M.

2016-01-01

Recent advances in imaging technology have enabled us to utilise a range of diagnostic approaches to better characterise high-risk atherosclerotic plaque. The aim of this article is to review current and emerging techniques used to detect and quantify unstable plaque in the context of large and small arterial systems and will focus on both invasive and non-invasive imaging techniques. While the diagnosis of clinically relevant atherosclerosis still relies heavily on anatomical assessment of arterial luminal stenosis, evolving multimodal cross-sectional imaging techniques that encompass novel molecular probes can provide added information with regard to plaque composition and overall disease burden. Novel molecular probes currently being developed to track precursors of plaque rupture such as inflammation, micro-calcification, hypoxia and neoangiogenesis are likely to have translational applications beyond diagnostics and have the potential to play a part in quantifying early responses to therapeutic interventions and more accurate cardiovascular risk stratification.

Accelerator complex for unstable beams at INS

International Nuclear Information System (INIS)

Tomizawa, M.; Arai, S.; Doi, M.; Katayama, T.; Niki, K.; Tokuda, N.; Yoshizawa, M.

1992-11-01

The construction of the prototype facility of the Exotic arena in the Japan Hadron Project (JHP) is started in 1992 at the Institute for Nuclear Study (INS), University of Tokyo. The purpose of this facility is to study the various technical problems of the Exotic arena, and to perform the experiment on nuclear and astrophysics with unstable nuclear beam. The unstable nuclei produced by bombarding a thick target with 40 MeV proton beam from the existing SF cyclotron are ionized in the ion sources, mass-analyzed by an ISOL, and transported to the accelerator complex. The accelerator complex consists of a split coaxial RFQ and an interdigital H type linac. The construction of accelerator will be completed in fiscal year 1994. The development of the SCRFQ and the IH linac which is suitable to the post-accelerator of the SCRFQ are reported. Charge stripper and the beam matching between the SCRFQ and the IH linac are explained. A buncher is necessary for the matching of longitudinal phase space between the SCRFQ and the IH linac. (K.I.)

Observation and analysis of water inherent optical properties

Science.gov (United States)

Sun, Deyong; Li, Yunmei; Le, Chengfeng; Huang, Changchun

2008-03-01

Inherent optical property is an important part of water optical properties, and is the foundation of water color analytical model establishment. Through quantity filter technology (QFT) and backscattering meter BB9 (WETlabs Inc), absorption coefficients of CDOM, total suspended minerals and backscattering coefficients of total suspended minerals had been observed in Meiliang Bay of Taihu lake at summer and winter respectively. After analyzing the spectral characteristics of absorption and backscattering coefficients, the differences between two seasons had been illustrated adequately, and the reasons for the phenomena, which are related to the changes of water quality coefficient, had also been explained. So water environment states can be reflected by inherent optical properties. In addition, the relationship models between backscattering coefficients and suspended particle concentrations had been established, which can support coefficients for analytical models.

Clinical Course of Two Children with Unstable Hemoglobins : The Effect of Hydroxyurea Therapy

NARCIS (Netherlands)

Loovers, Harriet M.; Tamminga, Nienke; Mulder, Andre B.; Tamminga, Rienk Y. J.

Case reports on the effect of hydroxyurea (HU) therapy for unstable hemoglobins (Hbs) are sparse; only three adult cases have been reported. We report for the first time on the effect of HU therapy in children carrying unstable Hbs. The first case concerns a female child with a familial history of

Effect of an Unstable Load on Primary and Stabilizing Muscles During the Bench Press.

Science.gov (United States)

Ostrowski, Stephanie J; Carlson, Lara A; Lawrence, Michael A

2017-02-01

Ostrowski, SJ, Carlson, LA, and Lawrence, MA. Effect of an unstable load on primary and stabilizing muscles during the bench press. J Strength Cond Res 31(2): 430-434, 2017-Unstable resistance exercises are performed to increase activity of stabilizing muscles. The premise is that this increase in activity will yield greater strength gains than traditional resistance exercises. The purpose of this study was to determine if an unstable load increases muscle activity of stabilizing muscles during a bench press as compared with a standard bench press with a typical load. Fifteen resistance-trained males (age 24.2 ± 2.7 years, mass 84.8 ± 12.0 kg, height 1.77 ± 0.05 m, weight lifting experience 9.9 ± 3.4 years, and bench press 1 repetition maximum [1RM] 107.5 ± 25.9 kg) volunteered for this study. Subjects pressed 2 sets of 5 repetitions in both stable (75% 1RM) and unstable (60% 1RM) conditions using a standard barbell and a flexible Earthquake bar, respectively. Surface electromyography was used to detect muscle activity of primary movers (pectoralis major, anterior deltoid, and triceps) and stabilizing musculature (latissimus dorsi, middle and posterior deltoid, biceps brachii, and upper trapezius). Muscle activity was compared using a multivariate analysis of variance to determine significant (p ≤ 0.05) phase and condition differences. The right and left biceps and the left middle deltoid were significantly more active in the unstable condition. Some of the stabilizing muscles were found to be significantly more active in the unstable condition with 15% less weight. Therefore, bench pressing with an unstable load appears promising in activating stabilizing musculature compared with pressing a typical barbell.

Inherent reward & risk (Part I): Towards a universal paradigm for investment analysis

NARCIS (Netherlands)

Zou, L.

2000-01-01

In this paper, a new paradigm is developed for analyzinginvestment strategies and pricing financial assets. This paradigmassumes that any investment strategy has its own "inherent reward"and "inherent risk" that can be judged with common sense. Ijustify axiomatically the existence and uniqueness

One-dimensional unstable eigenfunction and manifold computations in delay differential equations

International Nuclear Information System (INIS)

Green, Kirk; Krauskopf, Bernd; Engelborghs, Koen

2004-01-01

In this paper we present a new numerical technique for computing the unstable eigenfunctions of a saddle periodic orbit in a delay differential equation. This is used to obtain the necessary starting data for an established algorithm for computing one-dimensional (1D) unstable manifolds of an associated saddle fixed point of a suitable Poincare map. To illustrate our method, we investigate an intermittent transition to chaos in a delay system describing a semiconductor laser subject to phase-conjugate feedback

Considerations concering the generalization of the Dirac equations to unstable fermions

International Nuclear Information System (INIS)

Kniehl, Bernd A.; Sirlin, Alberto

2014-08-01

We discuss the generalization of the Dirac equations and spinors in momentum space to free unstable spin-1/2 fermions taking into account the fundamental requirement of Lorentz covariance. We derive the generalized adjoint Dirac equations and spinors, and explain the very simple relation that exists, in our formulation, between the unstable and stable cases. As an application of the generalized spinors, we evaluate the probability density. We also discuss the behavior of the generalized Dirac equations under time reversal.

Minimal gain marching schemes: searching for unstable steady-states with unsteady solvers

Science.gov (United States)

de S. Teixeira, Renan; S. de B. Alves, Leonardo

2017-12-01

Reference solutions are important in several applications. They are used as base states in linear stability analyses as well as initial conditions and reference states for sponge zones in numerical simulations, just to name a few examples. Their accuracy is also paramount in both fields, leading to more reliable analyses and efficient simulations, respectively. Hence, steady-states usually make the best reference solutions. Unfortunately, standard marching schemes utilized for accurate unsteady simulations almost never reach steady-states of unstable flows. Steady governing equations could be solved instead, by employing Newton-type methods often coupled with continuation techniques. However, such iterative approaches do require large computational resources and very good initial guesses to converge. These difficulties motivated the development of a technique known as selective frequency damping (SFD) (Åkervik et al. in Phys Fluids 18(6):068102, 2006). It adds a source term to the unsteady governing equations that filters out the unstable frequencies, allowing a steady-state to be reached. This approach does not require a good initial condition and works well for self-excited flows, where a single nonzero excitation frequency is selected by either absolute or global instability mechanisms. On the other hand, it seems unable to damp stationary disturbances. Furthermore, flows with a broad unstable frequency spectrum might require the use of multiple filters, which delays convergence significantly. Both scenarios appear in convectively, absolutely or globally unstable flows. An alternative approach is proposed in the present paper. It modifies the coefficients of a marching scheme in such a way that makes the absolute value of its linear gain smaller than one within the required unstable frequency spectra, allowing the respective disturbance amplitudes to decay given enough time. These ideas are applied here to implicit multi-step schemes. A few chosen test cases

Relationship between the serologic status of helicobacter pylori with the presence of unstable angina

International Nuclear Information System (INIS)

Alavi, S.M.; Adel, S. M. H.; Rajabzadeh, A.

2008-01-01

To determine whether unstable angina is co-related to seropositivity to chronic Helicobacter pylori (HP) infection. It is a case control, descriptive study conducted at CCU in Razi Hospital in Ahwaz a city southwest Iran, from 2004 to 2005. We measured serum HP- lgG levels of participants in CCU in a hospital. Blood samples were drawn during study period from 96 patients (mean age 56 years) with Unstable Angina (UA) according to American Heart Association criteria and from 96 participants free of cardiovascular disease (mean age 58 years) and stored at 20 degree C. Serology results were studied in relation to UA. Using chi squared test, odds ratios (OR) and 95% confidence intervals (CI) were calculated, adjusting for age, gender, and established risk factors. Seventy nine (82.3%) of patients with unstable angina and 55(61.1%) in the control group presented a positive anti HP-lgG. Odds ratio was 3 with 95% CI: 1.9 to 4.3. There was significant relation between HP-lgG positivity and unstable angina (P 0.05). Our study revealed relationship between seropositivity of HP-lgG and unstable angina. (author)

Probabilities of inherent shutdown of unprotected events in innovative liquid metal reactors

International Nuclear Information System (INIS)

Mueller, C.J.; Wade, D.C.

1988-01-01

The uncertainty in predicting the effectiveness of inherent shutdown in innovative liquid metal cooled reactors with metallic fuel results from three broad contributing areas of uncertainty: (1) the inability to exactly predict the frequency of ATWS events with potential to challenge the safety systems and require inherent shutdown; (2) the approximation of representing all such events by a selected set of ''generic scenarios''; and (3) the inability to exactly calculate the core response to the selected generic scenarios. This paper discusses the work being done to address each of these contributing areas, identifies the design and research approaches being used at Argonne National Laboratory to reducing the key contributions to uncertainties in inherent shutdown, and presents results. The conditional probabilities (given ATWS initiation) of achieving temperatures capable of defeating inherent shutdown are shown to range from /approximately/0.1% to negligible for current designs

Ordeals of Chernobyl and the rejustification of the inherently safe reactors

International Nuclear Information System (INIS)

Lu, Y.

1989-01-01

This paper presents the necessity of developing inherently safe economic reactors (ISERs). Two characteristics which define inherent safety are discussed on the basis of various applications of such a principle in practice. Different design concepts of ISERs are then evaluated and their possible role in the future nuclear program of PRC discussed. A three-stage development strategy of ISERs in PRC is proposed

Orbit dynamics for unstable linear motion

International Nuclear Information System (INIS)

Parzen, G.

1997-01-01

A treatment is given of the orbit dynamics for linear unstable motion that allows for the zeros in the beta function and makes no assumptions about the realness of the betatron and phase functions. The phase shift per turn is shown to be related to the beta function and the number of zeros the beta function goes through per turn. The solutions of the equations of motion are found in terms of the beta function

Orbit dynamics for unstable linear motion

International Nuclear Information System (INIS)

Parzen, G.

1996-04-01

A treatment is given of the orbit dynamics for linear unstable motion that allows for the zeros in the beta function and makes no assumption about the realness of the betatron and phase functions. The phase shift per turn is shown to be related to the beta function and the number of zeros the beta function goes through per turn. The solutions of the equations of motion are found in terms of the beta function

Unstable Resonator Retrofitted Handheld Laser Designator

Science.gov (United States)

1978-06-01

retrofitted with a negative-branch unstable resona- tor laser and hybrid pump cavity in place of the conventional plane-mirror/ porro prism resonator and...directed by prism B to an expanding telescope, shared with the viewing system of the designator. The actual, unfolded resonator length is approxi...was performed based on using a plane- parallel cavity consisting of a 47% reflectivity output coupler, porro - prism reflector, and the same LiNb03

Investigation of unstable periodic space-time states in distributed active system with supercritical current

International Nuclear Information System (INIS)

Koronovskij, A.A.; Rempen, I.S.; Khramov, A.E.

2003-01-01

The set of the unstable periodic space-time states, characterizing the chaotic space-time dynamics of the electron beam with the supercritical current in the Pierce diode is discussed. The Lyapunov indicators of the revealed instable space-time states of the chaotic dynamics of the distributed self-excited system are calculated. It is shown that change in the set of the unstable periodic states in dependence on the Pierce parameter is determined by change in the various orbits stability, which is demonstrated by the values of senior Lyapunov unstable state index [ru

Detection of unstable angina by /sup 99m/technetium pyrophosphate myocardial scintigraphy

International Nuclear Information System (INIS)

Abdulla, A.M.; Canedo, M.I.; Cortez, B.C.; McGinnis, K.D.; Wilhelm, S.K.

1976-01-01

/sup 99m/Technetium stannous pyrophosphate has been shown to accumulate in acutely infarcted myocardium. To determine if the isotope is also taken up by severely ischemic, but not necrotic myocardium, we performed myocardial scintigraphic studies in 17 patients with chest pains. Seven of the patients satisfied conventional clinical, electrocardiographic, and laboratory criteria for the diagnosis of unstable angina and showed no electrocardiographic or enzymatic evidence of myocardial necrosis. Five of these seven patients with unstable angina demonstrated abnormal localized patterns, and one showed a borderline picture. Myocardial scintiscans were normal in all of a control group of ten patients with stable angina. Thus, scanning with /sup 99m/technetium stannous pyrophosphate is shown to be of value in the objective demonstration of myocardial abnormality in unstable angina

Genesis and bifurcations of unstable periodic orbits in a jet flow

International Nuclear Information System (INIS)

Uleysky, M Yu; Budyansky, M V; Prants, S V

2008-01-01

We study the origin and bifurcations of typical classes of unstable periodic orbits in a jet flow that was introduced before as a kinematic model of chaotic advection, transport and mixing of passive scalars in meandering oceanic and atmospheric currents. A method to detect and locate the unstable periodic orbits and classify them by the origin and bifurcations is developed. We consider in detail period-1 and period-4 orbits playing an important role in chaotic advection. We introduce five classes of period-4 orbits: western and eastern ballistic ones, whose origin is associated with ballistic resonances of the fourth-order, rotational ones, associated with rotational resonances of the second and fourth orders and rotational-ballistic ones associated with a rotational-ballistic resonance. It is a new kind of unstable periodic orbits that may appear in a chaotic flow with jets and/or circulation cells. Varying the perturbation amplitude, we track out the origin and bifurcations of the orbits for each class

Stabilization of switched nonlinear systems with unstable modes

CERN Document Server

Yang, Hao; Cocquempot, Vincent

2014-01-01

This book provides its reader with a good understanding of the stabilization of switched nonlinear systems (SNS), systems that are of practical use in diverse situations: design of fault-tolerant systems in space- and aircraft; traffic control; and heat propagation control of semiconductor power chips. The practical background is emphasized throughout the book; interesting practical examples frequently illustrate the theoretical results with aircraft and spacecraft given particular prominence. Stabilization of Switched Nonlinear Systems with Unstable Modes treats several different subclasses of SNS according to the characteristics of the individual system (time-varying and distributed parameters, for example), the state composition of individual modes and the degree and distribution of instability in its various modes. Achievement and maintenance of stability across the system as a whole is bolstered by trading off between individual modes which may be either stable or unstable, or by exploiting areas of part...

Spinal instrumentation for unstable C1-2 injury.

Science.gov (United States)

Mizuno, J; Nakagawa, H

1999-06-01

Seventeen patients with unstable C1-2 injuries were treated between 1990 and 1997. Various methods of instrumentation surgery were performed in 16 patients, excluding a case of atlantoaxial rotatory fixation. Posterior stabilization was carried out in 14 cases using Halifax interlaminar clamp, Sof'wire or Danek cable, or more recently, transarticular screws. Transodontoid anterior screw fixation was performed in four cases of odontoid process fractures, with posterior instrumentation in two cases because of malunion. Rigid internal fixation by instrumentation surgery for the unstable C1-2 injury avoids long-term application of a Halo brace and facilitates early rehabilitation. However, the procedure is technically demanding with the risk of neural and vascular injuries, particularly with posterior screw fixation. Sagittal reconstruction of thin-sliced computed tomography scans at the C1-2 region, neuronavigator, and intraoperative fluoroscopy are essential to allow preoperative surgical planning and intraoperative guidance.

Safety assessment in plant layout design using indexing approach: Implementing inherent safety perspective

International Nuclear Information System (INIS)

Tugnoli, Alessandro; Khan, Faisal; Amyotte, Paul; Cozzani, Valerio

2008-01-01

Layout planning plays a key role in the inherent safety performance of process plants since this design feature controls the possibility of accidental chain-events and the magnitude of possible consequences. A lack of suitable methods to promote the effective implementation of inherent safety in layout design calls for the development of new techniques and methods. In the present paper, a safety assessment approach suitable for layout design in the critical early phase is proposed. The concept of inherent safety is implemented within this safety assessment; the approach is based on an integrated assessment of inherent safety guideword applicability within the constraints typically present in layout design. Application of these guidewords is evaluated along with unit hazards and control devices to quantitatively map the safety performance of different layout options. Moreover, the economic aspects related to safety and inherent safety are evaluated by the method. Specific sub-indices are developed within the integrated safety assessment system to analyze and quantify the hazard related to domino effects. The proposed approach is quick in application, auditable and shares a common framework applicable in other phases of the design lifecycle (e.g. process design). The present work is divided in two parts: Part 1 (current paper) presents the application of inherent safety guidelines in layout design and the index method for safety assessment; Part 2 (accompanying paper) describes the domino hazard sub-index and demonstrates the proposed approach with a case study, thus evidencing the introduction of inherent safety features in layout design

Long range stress correlations in the inherent structures of liquids at rest

Energy Technology Data Exchange (ETDEWEB)

Chowdhury, Sadrul; Abraham, Sneha; Hudson, Toby; Harrowell, Peter [School of Chemistry, University of Sydney, Sydney, NSW 2006 (Australia)

2016-03-28

Simulation studies of the atomic shear stress in the local potential energy minima (inherent structures) are reported for binary liquid mixtures in 2D and 3D. These inherent structure stresses are fundamental to slow stress relaxation and high viscosity in supercooled liquids. We find that the atomic shear stress in the inherent structures (IS’s) of both liquids at rest exhibits slowly decaying anisotropic correlations. We show that the stress correlations contribute significantly to the variance of the total shear stress of the IS configurations and consider the origins of the anisotropy and spatial extent of the stress correlations.

Toxic release consequence analysis tool (TORCAT) for inherently safer design plant

International Nuclear Information System (INIS)

Shariff, Azmi Mohd; Zaini, Dzulkarnain

2010-01-01

Many major accidents due to toxic release in the past have caused many fatalities such as the tragedy of MIC release in Bhopal, India (1984). One of the approaches is to use inherently safer design technique that utilizes inherent safety principle to eliminate or minimize accidents rather than to control the hazard. This technique is best implemented in preliminary design stage where the consequence of toxic release can be evaluated and necessary design improvements can be implemented to eliminate or minimize the accidents to as low as reasonably practicable (ALARP) without resorting to costly protective system. However, currently there is no commercial tool available that has such capability. This paper reports on the preliminary findings on the development of a prototype tool for consequence analysis and design improvement via inherent safety principle by utilizing an integrated process design simulator with toxic release consequence analysis model. The consequence analysis based on the worst-case scenarios during process flowsheeting stage were conducted as case studies. The preliminary finding shows that toxic release consequences analysis tool (TORCAT) has capability to eliminate or minimize the potential toxic release accidents by adopting the inherent safety principle early in preliminary design stage.

Progress on PRISM, an inherently safe, economic, and testable advanced liquid metal reactor

International Nuclear Information System (INIS)

Tippets, F.E.; Salerno, L.N.; Boardman, C.E.; Kwant, W.; Murata, R.E.; Snyder, C.R.

1987-01-01

This paper reports progress on the design of PRISM (Power Reactor Inherently Safe Module) under the DOE-sponsored innovative reactor program now in its third year at General Electric. The purpose of this program is to develop a design for an inherently safe, reliable, and marketable liquid metal fast reactor power plant. The PRISM design approach includes the following key elements: Compact sodium-cooled pool-type reactor modules that are sized to enable factory fabrication, economical shipment to inland as well as water-side sites, and economical full-scale prototype testing for design certification; Nuclear safety-related envelope limited to the reactor modules and their service systems; Inherent, passive shutdown heat removal for loss-of-cooling events; Inherent, passive reactivity shutdown for failure-to-scram events

Operative versus nonoperative treatment of unstable lateral malleolar fractures: a randomized multicenter trial.

Science.gov (United States)

Sanders, David W; Tieszer, Christina; Corbett, Bradley

2012-03-01

To compare clinical and functional outcomes after operative and nonoperative treatment of undisplaced, unstable, isolated fibula fractures. Randomized multicenter clinical trial. Six level 1 trauma centers. Eighty-one patients with undisplaced, unstable, isolated fibula fractures as confirmed by an external rotation stress examination demonstrating an increase in medial clear space to 5 mm or greater were followed for 12 months after treatment. Forty-one patients were treated operatively by open reduction and internal fixation of the fibula. Forty patients underwent nonoperative treatment, which included the use of a short leg cast or brace and protected weight bearing for 6 weeks. Functional outcomes determined using the Olerud-Molander Ankle Score and the Short Form 36. Radiographic outcomes included measurement of union and displacement at each visit. There were no statistically significant differences in functional outcome scores or pace of recovery between the operative and nonoperative groups at any time interval (β = -0.28, 3.49; P = 0.936). Complications in the nonoperative group included 8 patients with a medial clear space ≥5 mm and 8 patients with delayed union or nonunion. In the operative group, 5 patients had a surgical site infection and 5 patients required hardware removal. Patients managed operatively had equivalent functional outcomes compared with nonoperative treatment; however, the risk of displacement and problems with union was substantially lower in patients managed with surgery.

Inherently safe aircooling for the storage of self-heating configurations of radionuclides

International Nuclear Information System (INIS)

Hame, W.; Klein, D.; Pirk, H.

1980-01-01

NUKEM developed a technical concept of a radionuclide storage facility based on aircooling, which provides that - the radionuclides, i.e. spent fuel elements, are tightly canned in steel canisters - the canned elements are put into individual cooling channels, which form the storage rack within the storage cell - the produced heat is removed from the surface of the canisters through free convection. This cooling concept shows the following advantages: - The cooling is inherently safe, as the driving force of the coolant is reliably supplied by the heat production of the system to be cooled. - The system is self-controlled and self-regulated because of the physically based correlation of heat production, heat transfer coefficients and air flow resistances. (orig.) 891 RB/orig. 892 MKO [de

Force production during squats performed with a rotational resistance device under stable versus unstable conditions.

Science.gov (United States)

Moras, Gerard; Vázquez-Guerrero, Jairo

2015-11-01

[Purpose] Force production during a squat action on a rotational resistance device (RRD) under stable and unstable conditions. [Subjects and Methods] Twenty-one healthy males were asked to perform six sets of six repetitions of squats on an RRD on either stable or unstable surfaces. The stable and unstable sets were performed on different days. Muscular outputs were obtained from a linear encoder and a strain gauge fixed to a vest. [Results] Overall, the results showed no significant differences for any of the dependent variables across exercise modes. Forcemean outputs were higher in the concentric phase than in the eccentric phase for each condition, but there were no differences in velocity, time or displacement. The forcepeak was similar in the eccentric and concentric phases of movement under both stable and unstable conditions. There were no significant differences in forcemean between sets per condition or between conditions. [Conclusion] These results suggest that performing squats with a RRD achieves similar forcemean and forcepeak under stable and unstable conditions. The forcepeak produced is also similar in concentric and eccentric phases.

Computed Tomography Angiography Evaluation of Risk Factors for Unstable Intracranial Aneurysms.

Science.gov (United States)

Wang, Guang-Xian; Gong, Ming-Fu; Wen, Li; Liu, Lan-Lan; Yin, Jin-Bo; Duan, Chun-Mei; Zhang, Dong

2018-03-19

To evaluate risk factors for instability in intracranial aneurysms (IAs) using computed tomography angiography (CTA). A total of 614 consecutive patients diagnosed with 661 IAs between August 2011 and February 2016 were reviewed. Patients and IAs were divided into stable and unstable groups. Along with clinical characteristics, IA characteristics were evaluated by CTA. Multiple logistic regression analysis was used to identify the independent risk factors associated with unstable IAs. Receiver operating characteristic (ROC) curve analysis was performed on the final model, and optimal thresholds were obtained. Patient age (odds ratio [OR], 0.946), cerebral atherosclerosis (CA; OR, 0.525), and IAs located at the middle cerebral artery (OR, 0.473) or internal carotid artery (OR, 0.512) were negatively correlated with instability, whereas IAs with irregular shape (OR, 2.157), deep depth (OR, 1.557), or large flow angle (FA; OR, 1.015) were more likely to be unstable. ROC analysis revealed threshold values of age, depth, and FA of 59.5 years, 4.25 mm, and 87.8°, respectively. The stability of IAs is significantly affected by several factors, including patient age and the presence of CA. IA shape and location also have an impact on the stability of IAs. Growth into an irregular shape, with a deep depth, and a large FA are risk factors for a change in IAs from stable to unstable. Copyright © 2018 Elsevier Inc. All rights reserved.

Mixing phases of unstable two-level systems

International Nuclear Information System (INIS)

Sokolov, V.V.; Brentano, P. von.

1993-01-01

An unstable two-level system decaying into an arbitrary number of channels is considered. It is shown that the mixing phases of the two overlapping resonances can be expressed in the terms of their partial widths and one additional universal mixing parameter. Some applications to a doublet of 2 + resonances in 8 Be and to the ρ-ω systems are considered. 18 refs

Stable and unstable crack growth in Type 304 stainless steel plate

International Nuclear Information System (INIS)

Yagawa, G.

1984-01-01

Experimental and theoretical results on stable as well as unstable fractures for Type 304 stainless steel plates with a central crack subjected to tension force are given. In the experiment using a testing machine with a special spring for high compliance, the transition points from the stable to the unstable crack growth are observed and comparisons are made between the test results and the finite element solutions. A round robin calculation for the elastic-plastic stable crack growth using one of the specimens mentioned above is also given. (orig.)

Unstable angina pectoris: the results of intracoronary administration of fibrinolytic agents

International Nuclear Information System (INIS)

Gratsianskij, N.A.; Panchenko, E.P.; Agapov, A.A.; Logutov, Yu.A.; Vladimirov, S.S.

1986-01-01

Intracoronary thrombolytic infusions were used in 10 patients with unstable angina and high risk of myocardial infarction (MI). Streptokinase (500.000 units per hour) was used in 9 patients, and urokinase, in one. Vascular recanalization was achieved in 4 cases where angiografhy, showed coronary arterial occlusion by a thrombus. Myocardial infarction developed in 8 patients (large-focal in 6 and small focal in 2) within 1 to 16 days after the thrombolytic infuson. Therefore, short-term local thrombolytic infusion fails to prevent myocardial infarction in patients with unstable angina

Boundary Between Stable and Unstable Regimes of Accretion

Directory of Open Access Journals (Sweden)

Blinova A. A.

2014-01-01

Full Text Available We investigated the boundary between stable and unstable regimes of accretion and its dependence on different parameters. Simulations were performed using a “cubed sphere" code with high grid resolution (244 grid points in the azimuthal direction, which is twice as high as that used in our earlier studies. We chose a very low viscosity value, with alpha-parameter α=0.02. We observed from the simulations that the boundary strongly depends on the ratio between magnetospheric radius rm (where the magnetic stress in the magnetosphere matches the matter stress in the disk and corotation radius rcor (where the Keplerian velocity in the disk is equal to the angular velocity of the star. For a small misalignment angle of the dipole field, Θ = 5°, accretion is unstable if rcor/rm> 1.35, and is stable otherwise. In cases of a larger misalignment angle of the dipole, Θ = 20°, instability occurs at slightly larger values, rcor/rm> 1.41

Influence of unstable footwear on lower leg muscle activity, volume change and subjective discomfort during prolonged standing.

Science.gov (United States)

Karimi, Zanyar; Allahyari, Teimour; Azghani, Mahmood Reza; Khalkhali, Hamidreza

2016-03-01

The present study was an attempt to investigate the effect of unstable footwear on lower leg muscle activity, volume change and subjective discomfort during prolonged standing. Ten healthy subjects were recruited to stand for 2 h in three footwear conditions: barefoot, flat-bottomed shoe and unstable shoe. During standing, lower leg discomfort and EMG activity of medial gastrocnemius (MG) and tibialis anterior (TA) muscles were continuously monitored. Changes in lower leg volume over standing time also were measured. Lower leg discomfort rating reduced significantly while subjects standing on unstable shoe compared to the flat-bottomed shoe and barefoot condition. For lower leg volume, less changes also were observed with unstable shoe. The activity level and variation of right MG muscle was greater with unstable shoe compared to the other footwear conditions; however regarding the left MG muscle, significant difference was found between unstable shoe and flat-bottomed shoe only for activity level. Furthermore no significant differences were observed for the activity level and variation of TA muscles (right/left) among all footwear conditions. The findings suggested that prolonged standing with unstable footwear produces changes in lower leg muscles activity and leads to less volume changes. Perceived discomfort also was lower for this type of footwear and this might mean that unstable footwear can be used as ergonomic solution for employees whose work requires prolonged standing. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

A high-power diode-laser-pumped CW Nd:YAG laser using a stable-unstable resonator

International Nuclear Information System (INIS)

Mudge, M.; Ostermeyer, P.; Veitch, J.; Munch, J.; Hamilton, M.W.

2000-01-01

Full text: The design and operation of a power-scalable diode-laser-pumped CW Nd:YAG zigzag slab laser that uses a stable-unstable resonator with a graded reflectivity mirror as an output coupler is described. We demonstrate control of the thermal lens strength in the unstable plane and weak thermal lensing in the stable plane that is independent of pump power, vital for efficient scalability. This enabled CW operation of the stable-unstable resonator with excellent near- and far-field beam quality

Memory accessibility shapes explanation: Testing key claims of the inherence heuristic account.

Science.gov (United States)

Hussak, Larisa J; Cimpian, Andrei

2018-01-01

People understand the world by constructing explanations for what they observe. It is thus important to identify the cognitive processes underlying these judgments. According to a recent proposal, everyday explanations are often constructed heuristically: Because people need to generate explanations on a moment-by-moment basis, they cannot perform an exhaustive search through the space of possible reasons, but may instead use the information that is most easily accessible in memory (Cimpian & Salomon 2014a, b). In the present research, we tested two key claims of this proposal that have so far not been investigated. First, we tested whether-as previously hypothesized-the information about an entity that is most accessible in memory tends to consist of inherent or intrinsic facts about that entity, rather than extrinsic (contextual, historical, etc.) facts about it (Studies 1 and 2). Second, we tested the implications of this difference in the memory accessibility of inherent versus extrinsic facts for the process of generating explanations: Does the fact that inherent facts are more accessible than relevant extrinsic facts give rise to an inherence bias in the content of the explanations generated (Studies 3 and 4)? The findings supported the proposal that everyday explanations are generated in part via a heuristic process that relies on easily accessible-and often inherent-information from memory.

Is the inherent potential of maize roots efficient for soil phosphorus acquisition?

Directory of Open Access Journals (Sweden)

Yan Deng

Full Text Available Sustainable agriculture requires improved phosphorus (P management to reduce the overreliance on P fertilization. Despite intensive research of root adaptive mechanisms for improving P acquisition, the inherent potential of roots for efficient P acquisition remains unfulfilled, especially in intensive agriculture, while current P management generally focuses on agronomic and environmental concerns. Here, we investigated how levels of soil P affect the inherent potential of maize (Zea mays L. roots to obtain P from soil. Responses of root morphology, arbuscular mycorrhizal colonization, and phosphate transporters were characterized and related to agronomic traits in pot and field experiments with soil P supply from deficiency to excess. Critical soil Olsen-P level for maize growth approximated 3.2 mg kg(-1, and the threshold indicating a significant environmental risk was about 15 mg kg(-1, which represented the lower and upper levels of soil P recommended in current P management. However, most root adaptations involved with P acquisition were triggered when soil Olsen-P was below 10 mg kg(-1, indicating a threshold for maximum root inherent potential. Therefore, to maintain efficient inherent potential of roots for P acquisition, we suggest that the target upper level of soil P in intensive agriculture should be reduced from the environmental risk threshold to the point maximizing the inherent potential of roots.

Is the inherent potential of maize roots efficient for soil phosphorus acquisition?

Science.gov (United States)

Deng, Yan; Chen, Keru; Teng, Wan; Zhan, Ai; Tong, Yiping; Feng, Gu; Cui, Zhenling; Zhang, Fusuo; Chen, Xinping

2014-01-01

Sustainable agriculture requires improved phosphorus (P) management to reduce the overreliance on P fertilization. Despite intensive research of root adaptive mechanisms for improving P acquisition, the inherent potential of roots for efficient P acquisition remains unfulfilled, especially in intensive agriculture, while current P management generally focuses on agronomic and environmental concerns. Here, we investigated how levels of soil P affect the inherent potential of maize (Zea mays L.) roots to obtain P from soil. Responses of root morphology, arbuscular mycorrhizal colonization, and phosphate transporters were characterized and related to agronomic traits in pot and field experiments with soil P supply from deficiency to excess. Critical soil Olsen-P level for maize growth approximated 3.2 mg kg(-1), and the threshold indicating a significant environmental risk was about 15 mg kg(-1), which represented the lower and upper levels of soil P recommended in current P management. However, most root adaptations involved with P acquisition were triggered when soil Olsen-P was below 10 mg kg(-1), indicating a threshold for maximum root inherent potential. Therefore, to maintain efficient inherent potential of roots for P acquisition, we suggest that the target upper level of soil P in intensive agriculture should be reduced from the environmental risk threshold to the point maximizing the inherent potential of roots.

CT of hemodynamically unstable abdominal trauma

Energy Technology Data Exchange (ETDEWEB)

Petridis, A.; Pilavaki, M.; Vafiadis, E.; Palladas, P.; Finitsis, S.; Drevelegas, A. [Department of Radiology, General Hospital ``G. Papanikolaou,`` Thessaloniki (Greece)

1999-03-01

This article is an appraisal of the use of CT in the management of patients with unstable abdominal trauma. We examined 41 patients with abdominal trauma using noncontrast dynamic CT. In 17 patients a postcontrast dynamic CT was also carried out. On CT, 25 patients had hemoperitoneum. Thirteen patients had splenic, 12 hepatic, 6 pancreatic, 8 bowel and mesenteric, 12 renal and 2 vascular injuries. Seven patients had retroperitoneal and 2 patients adrenal hematomas. All but five lesions (three renal, one pancreatic, and one splenic) were hypodense when CT was performed earlier than 8 h following the injury. Postcontrast studies (n = 17), revealed 4 splenic, 3 hepatic, 1 pancreatic, 3 renal, and 2 bowel and mesenteric injuries beyond what was found on noncontrast CT. Surgical confirmation (n = 21) was obtained in 81.81 % of splenic, 66.66 % of hepatic, 83.33 % of pancreatic, 100 % of renal, 100 % of retroperitoneal, and 85.71 % of bowel and mesenteric injuries. The majority of false diagnoses was obtained with noncontrast studies. Computed tomography is a remarkable method for evaluation and management of patients with hemodynamically unstable abdominal trauma, but only if it is revealed in the emergency room. Contrast injection, when it could be done, revealed lesions that were not suspected on initial plain scans. (orig.) With 6 figs., 5 tabs., 20 refs.

Small Kerr-anti-de Sitter black holes are unstable

International Nuclear Information System (INIS)

Cardoso, Vitor; Dias, Oscar J.C.

2004-01-01

Superradiance in black hole spacetimes can trigger instabilities. Here we show that, due to superradiance, small Kerr-anti-de Sitter black holes are unstable. Our demonstration uses a matching procedure, in a long wavelength approximation

Is human fracture hematoma inherently angiogenic?

LENUS (Irish Health Repository)

Street, J

2012-02-03

This study attempts to explain the cellular events characterizing the changes seen in the medullary callus adjacent to the interfragmentary hematoma during the early stages of fracture healing. It also shows that human fracture hematoma contains the angiogenic cytokine vascular endothelial growth factor and has the inherent capability to induce angiogenesis and thus promote revascularization during bone repair. Patients undergoing emergency surgery for isolated bony injury were studied. Raised circulating levels of vascular endothelial growth factor were seen in all injured patients, whereas the fracture hematoma contained significantly higher levels of vascular endothelial growth factor than did plasma from these injured patients. However, incubation of endothelial cells in fracture hematoma supernatant significantly inhibited the in vitro angiogenic parameters of endothelial cell proliferation and microtubule formation. These phenomena are dependent on a local biochemical milieu that does not support cytokinesis. The hematoma potassium concentration is cytotoxic to endothelial cells and osteoblasts. Subcutaneous transplantation of the fracture hematoma into a murine wound model resulted in new blood vessel formation after hematoma resorption. This angiogenic effect is mediated by the significant concentrations of vascular endothelial growth factor found in the hematoma. This study identifies an angiogenic cytokine involved in human fracture healing and shows that fracture hematoma is inherently angiogenic. The differences between the in vitro and in vivo findings may explain the phenomenon of interfragmentary hematoma organization and resorption that precedes fracture revascularization.

Improved inherent safety in liquid fuel reactors

International Nuclear Information System (INIS)

Taube, M.

1982-01-01

The molten salt reactor system divided into core (thermal and fast) and breeding zone (fission breeder reactor, fusion hybrid system, accelerator-spallation system) has some unique inherent safety properties: a) reduced inventory of fission products during normal operation due to on-line chemical reprocessing and in-core gas purging; b) fast removal of freshly bred fissile nuclides and fission products from the breeding zone (the so called suppressed fission system); c) pressureless fuel and primary coolant system; d) elimination of the possibility of a violent exoenergetic chemical reaction with air, water or metals; e) elimination of the possibility of gaseous hydrogen production during an accident; f) provides a non-engineered feature of dumping of fuel from the core and heat exchanger to a safe drain tank; g) presence of a large heat sink in the form of an inactive diluent salt; h) possibility of natural convection heat removal during an accident and even normal operation (by means of gas lifting); i) dissipation of the remaining decayheat by spraying water on the containment from outside, which allows to manage the worst accident; i) Even in the case of the destruction in the war by conventional or nuclear weapon the contaminated land is significantly reduced. The world-wide present activity in the field of molten salt technology is reviewed. (orig.)

Management of acute unstable acromioclavicular joint injuries.

Science.gov (United States)

Cisneros, Luis Natera; Reiriz, Juan Sarasquete

2016-12-01

Surgical management of acute unstable acromioclavicular joint injuries should be focused on realigning the torn ends of the ligaments to allow for healing potential. The most widely utilized treatment methods incorporate the use of metal hardware, which can alter the biomechanics of the acromioclavicular joint. This leads to a second surgical procedure for hardware removal once the ligaments have healed. Patients with unstable acromioclavicular joint injuries managed with arthroscopy-assisted procedures have shown good and excellent clinical outcomes, without the need for a second operation. These procedures incorporate a coracoclavicular suspension device aimed to function as an internal brace, narrowing the coracoclavicular space thus allowing for healing of the torn coracoclavicular ligaments. The lesser morbidity of a minimally invasive approach and the possibility to diagnose and treat concomitant intraarticular injuries; no obligatory implant removal, and the possibility of having a straight visualization of the inferior aspect of the base of the coracoid (convenient when placing coracoclavicular fixation systems) are the main advantages of the arthroscopic approach over classic open procedures. This article consists on a narrative review of the literature in regard to the management of acute acromioclavicular joint instability.

Patterns of Stochastic Behavior in Dynamically Unstable High-Dimensional Biochemical Networks

Directory of Open Access Journals (Sweden)

Simon Rosenfeld

2009-01-01

Full Text Available The question of dynamical stability and stochastic behavior of large biochemical networks is discussed. It is argued that stringent conditions of asymptotic stability have very little chance to materialize in a multidimensional system described by the differential equations of chemical kinetics. The reason is that the criteria of asymptotic stability (Routh- Hurwitz, Lyapunov criteria, Feinberg’s Deficiency Zero theorem would impose the limitations of very high algebraic order on the kinetic rates and stoichiometric coefficients, and there are no natural laws that would guarantee their unconditional validity. Highly nonlinear, dynamically unstable systems, however, are not necessarily doomed to collapse, as a simple Jacobian analysis would suggest. It is possible that their dynamics may assume the form of pseudo-random fluctuations quite similar to a shot noise, and, therefore, their behavior may be described in terms of Langevin and Fokker-Plank equations. We have shown by simulation that the resulting pseudo-stochastic processes obey the heavy-tailed Generalized Pareto Distribution with temporal sequence of pulses forming the set of constituent-specific Poisson processes. Being applied to intracellular dynamics, these properties are naturally associated with burstiness, a well documented phenomenon in the biology of gene expression.

Transient effects in unstable ablation fronts and mixing layers in HEDP

International Nuclear Information System (INIS)

Clarisse, J-M; Gauthier, S; Dastugue, L; Vallet, A; Schneider, N

2016-01-01

We report results obtained for two elementary unstable flow configurations relevant to high energy density physics: the ablation front instability and the Rayleigh–Taylor -instability induced mixing layer. These two flows are characterized by a transience of their perturbation dynamics. In the ablative flow case, this perturbation dynamics transience takes the form of finite-durations of successive linear-perturbation evolution phases until reaching regimes of decaying oscillations. This behaviour is observed in various regimes: weakly or strongly accelerated ablation fronts, irradiation asymmetries or initial external-surface defects, and is a result of the mean-flow unsteadiness and stretching. In the case of the Rayleigh–Taylor-instability induced mixing layer, perturbation dynamics transience manifests itself through the extinction of turbulence and mixing as the flow reaches a stable state made of two stably stratified layers of pure fluids separated by an unstratified mixing layer. A second feature, also due to compressibility, takes the form of an intense acoustic wave production, mainly localized in the heavy fluid. Finally, we point out that a systematic short-term linear-perturbation dynamics analysis should be undertaken within the framework of non-normal stability theory. (paper)

On the maximum entropy distributions of inherently positive nuclear data

Energy Technology Data Exchange (ETDEWEB)

Taavitsainen, A., E-mail: aapo.taavitsainen@gmail.com; Vanhanen, R.

2017-05-11

The multivariate log-normal distribution is used by many authors and statistical uncertainty propagation programs for inherently positive quantities. Sometimes it is claimed that the log-normal distribution results from the maximum entropy principle, if only means, covariances and inherent positiveness of quantities are known or assumed to be known. In this article we show that this is not true. Assuming a constant prior distribution, the maximum entropy distribution is in fact a truncated multivariate normal distribution – whenever it exists. However, its practical application to multidimensional cases is hindered by lack of a method to compute its location and scale parameters from means and covariances. Therefore, regardless of its theoretical disadvantage, use of other distributions seems to be a practical necessity. - Highlights: • Statistical uncertainty propagation requires a sampling distribution. • The objective distribution of inherently positive quantities is determined. • The objectivity is based on the maximum entropy principle. • The maximum entropy distribution is the truncated normal distribution. • Applicability of log-normal or normal distribution approximation is limited.

A general index of inherent risk

OpenAIRE

Schnytzer, Adi; Westreich, Sara

2009-01-01

We extend the pioneering work of Aumann and Serrano by presenting an index of inherent riskiness of a gamble having the desirable properties of their index, while being applicable to gambles with either positive or negative expectations. As such, our index provides a measure of riskiness which is of use for both risk lovers and risk aversive gamblers, and is defined for all discrete and a large class of continuous gambles. We analyze abstract properties of our index, and present in addition t...

Diagnosis of unstable angina pectoris has declined markedly with the advent of more sensitive troponin assays.

Science.gov (United States)

D'Souza, Maria; Sarkisian, Laura; Saaby, Lotte; Poulsen, Tina S; Gerke, Oke; Larsen, Torben B; Diederichsen, Axel C P; Jangaard, Nikolaj; Diederichsen, Søren Z; Hosbond, Susanne; Hove, Jens; Thygesen, Kristian; Mickley, Hans

2015-08-01

Since the arrival of the universal definition of myocardial infarction more sensitive troponin assays have been developed. How these occurrences have influenced the proportions and clinical features of the components of acute coronary syndrome have not been studied prospectively in unselected hospital patients. During 2010 we evaluated all patients in whom cardiac troponin I had been measured at a single university hospital. The diagnosis of acute myocardial infarction (ST-elevation myocardial infarction [STEMI] or non-ST-elevation myocardial infarction [NSTEMI]) was established in cases of a rise and/or fall of cardiac troponin I together with cardiac ischemic features. Patients with unstable chest discomfort and cardiac troponin I values below the decision limit of myocardial infarction were diagnosed as having unstable angina pectoris. The definition of acute coronary syndrome included unstable angina pectoris, NSTEMI, and STEMI. Mortality data were obtained from the Danish Civil Personal Registration System. Of 3762 consecutive patients, 516 had acute coronary syndrome. Unstable angina pectoris was present in 7%, NSTEMI in 67%, and STEMI in 26%. The NSTEMI patients were older, more frequently women, and had more comorbidities than patients with unstable angina pectoris and STEMI. At median follow-up of 3.2 years 195 patients had died: 14% of unstable angina pectoris, 45% of NSTEMI, and 25% of STEMI patients. Age-adjusted log-rank statistics revealed differences in mortality: NSTEMI vs unstable angina pectoris (P = .0091) and NSTEMI vs STEMI (P = .0045). The application of the universal definition together with the use of a contemporary troponin assay seems to have reduced the proportion of patients with unstable angina pectoris to the benefit of patients with NSTEMI. Despite this, NSTEMI patients have a sustained higher mortality than patients with STEMI. Copyright © 2015 Elsevier Inc. All rights reserved.

Correlation between relaxations and plastic deformation, and elastic model of flow in metallic glasses and glass-forming liquids

International Nuclear Information System (INIS)

Wang Weihua

2011-01-01

We study the similarity and correlations between relaxations and plastic deformation in metallic glasses (MGs) and MG-forming liquids. It is shown that the microscope plastic events, the initiation and formation of shear bands, and the mechanical yield in MGs where the atomic sites are topologically unstable induced by applied stress, can be treated as the glass to supercooled liquid state transition induced by external shear stress. On the other hand, the glass transition, the primary and secondary relaxations, plastic deformation and yield can be attributed to the free volume increase induced flow, and the flow can be modeled as the activated hopping between the inherent states in the potential energy landscape. We then propose an extended elastic model to describe the flow based on the energy landscape theory. That is, the flow activation energy density is linear proportional to the instantaneous elastic moduli, and the activation energy density ρ E is determined to be a simple expression of ρ E =(10/11)G+(1/11)K. The model indicates that both shear and bulk moduli are critical parameters accounting for both the homogeneous and inhomogeneous flows in MGs and MG-forming liquids. The elastic model is experimentally certified. We show that the elastic perspectives offers a simple scenario for the flow in MGs and MG-forming liquids and are suggestive for understanding the glass transition, plastic deformation, and nature and characteristics of MGs

Damping capacity of unstable steels on chromium-nickel-manganese base

Energy Technology Data Exchange (ETDEWEB)

Kochkin, L.I.; Rudakov, A.A. (Kirovskij Politekhnicheskij Inst. (USSR))

1982-02-01

The paper deals with results of a study on the energy scattering in OKh13N3G8, 20Kh13N3G4 and 30Kh13N3G4 unstable steels. It is shown that the development of microplastic strains most easily occurs in low-carbon steel having a two-phase structure in the initial state. The proceeding of microplastic deformations in carbon unstable steels is limited by the interstitial atom effect on the dislocation movement. It is established that in OKh13N3G8 steel the martensite ..cap alpha --> gamma..- transformation begins under the cyclic stress amplitudes below the yield point of this steel. The steels studied possess a high vibrostrength.

Unstable decay and state selection

International Nuclear Information System (INIS)

McKane, Alan; Tarlie, Martin

2001-01-01

The decay of unstable states when several metastable states are available for occupation is investigated using path-integral techniques. Specifically, a method is described that enables the probabilities with which the metastable states are occupied to be calculated by finding optimal paths, and fluctuations about them, in the weak-noise limit. The method is illustrated on a system described by two coupled Langevin equations, which are found in the study of instabilities in fluid dynamics and superconductivity. The problem involves a subtle interplay between nonlinearities and noise, and a naive approximation scheme that does not take this into account is shown to be unsatisfactory. The use of optimal paths is briefly reviewed and then applied to finding the conditional probability of ending up in one of the metastable states, having begun in the unstable state. There are several aspects of the calculation that distinguish it from most others involving optimal paths: (i) the paths do not begin and end on an attractor, and moreover, the final point is to a large extent arbitrary, (ii) the interplay between the fluctuations and the leading-order contribution are at the heart of the method, and (iii) the final result involves quantities that are not exponentially small in the noise strength. This final result, which gives the probability of a particular state being selected in terms of the parameters of the dynamics, is remarkably simple and agrees well with the results of numerical simulations. The method should be applicable to similar problems in a number of other areas, such as state selection in lasers, activationless chemical reactions, and population dynamics in fluctuating environments

Tactical supply chain planning models with inherent flexibility

DEFF Research Database (Denmark)

Esmaeilikia, Masoud; Fahimnia, Behnam; Sarkis, Joeseph

2016-01-01

Supply chains (SCs) can be managed at many levels. The use of tactical SC planning models with multiple flexibility options can help manage the usual operations efficiently and effectively, whilst improve the SC resiliency in response to inherent environmental uncertainties. This paper defines ta...

Unstable Pore-Water Flow in Intertidal Wetlands

Science.gov (United States)

Barry, D. A.; Shen, C.; Li, L.

2014-12-01

Salt marshes are important intertidal wetlands strongly influenced by interactions between surface water and groundwater. Bordered by coastal water, the marsh system undergoes cycles of inundation and exposure driven by the tide. This leads to dynamic, complex pore-water flow and solute transport in the marsh soil. Pore-water circulations occur over vastly different spatial and temporal scales with strong link to the marsh topography. These circulations control solute transport between the marsh soil and the tidal creek, and ultimately affect the overall nutrient exchange between the marsh and coastal water. The pore-water flows also dictate the soil condition, particularly aeration, which influences the marsh plant growth. Numerous studies have been carried out to examine the pore-water flow process in the marsh soil driven by tides, focusing on stable flow with the assumption of homogeneity in soil and fluid properties. This assumption, however, is questionable given the actual inhomogeneous conditions in the field. For example, the salinity of surface water in the tidal creek varies temporally and spatially due to the influence of rainfall and evapotranspiration as well as the freshwater input from upland areas to the estuary, creating density gradients across the marsh surface and within the marsh soil. Many marshes possess soil stratigraphy with low-permeability mud typically overlying high-permeability sandy deposits. Macropores such as crab burrows are commonly distributed in salt marsh sediments. All these conditions are prone to the development of non-uniform, unstable preferential pore-water flow in the marsh soil, for example, funnelling and fingering. Here we present results from laboratory experiments and numerical simulations to explore such unstable flow. In particular, the analysis aims to address how the unstable flow modifies patterns of local pore-water movement and solute transport, as well as the overall exchange between the marsh soil and

Stable or unstable tear of the anterior cruciate ligament of the knee: an MR diagnosis?

Energy Technology Data Exchange (ETDEWEB)

Dyck, Pieter van; Gielen, Jan L.; Parizel, Paul M. [University Hospital Antwerp and University of Antwerp, Department of Radiology, Edegem (Belgium); Vanhoenacker, Filip M. [University Hospital Antwerp and University of Antwerp, Department of Radiology, Edegem (Belgium); AZ St-Maarten Duffel/Mechelen, Department of Radiology, Duffel (Belgium); Wouters, Kristien [University Hospital Antwerp and University of Antwerp, Department of Scientific Coordination and Biostatistics, Edegem (Belgium); Dossche, Lieven [University Hospital Antwerp and University of Antwerp, Department of Orthopedics, Edegem (Belgium)

2012-03-15

To determine the usefulness of magnetic resonance (MR) imaging to distinguish stable from unstable tears of the anterior cruciate ligament (ACL) of the knee. MR images of 97 patients with surgically confirmed ACL tear were retrospectively reviewed. According to arthroscopic and clinical examination, these patients had 36 stable and 61 unstable (9 partial and 52 complete) ACL tears. MR images were interpreted by two blinded reviewers and scored with respect to previously reported primary and secondary MR signs of ACL injury. Based on a comprehensive assessment of all the MR findings, ACLs were categorized as being stable or unstable. MR accuracy was calculated considering only primary MR signs and considering both primary and secondary MR signs of ACL injury, separately. Accuracy of each individual primary and secondary MR sign was calculated. Considering only primary MR signs, sensitivity, specificity, and accuracy of MR were 77, 92, and 82%, respectively. Considering both primary and secondary MR signs, sensitivity, specificity, and accuracy of MR were 59, 81, and 67%, respectively. Of all MR signs, discontinuity and abnormal orientation had highest test accuracy (79 and 87%, respectively). Anterior tibial translation, uncovering of the posterior horn of the lateral meniscus, and hyperbuckled PCL were only seen in unstable ACLs (specificity 100%), but these secondary findings had low sensitivity (23%). Bone contusion around the lateral knee compartment was seen in both unstable and stable ACLs (accuracy 64%). Previously reported MR imaging signs do not allow accurate distinction between clinically stable and unstable ACL injuries. Anterior tibial translation, uncovering of the posterior horn of the lateral meniscus, and hyperbuckled PCL, if present, are helpful signs in the diagnosis of an unstable tear. The presence of bone marrow edema around the lateral knee compartment is not predictive of ACL insufficiency. (orig.)

Unstable oscillatory Pierce modes of neutralized electron beams

International Nuclear Information System (INIS)

Cary, J.R.; Lemons, D.S.

1982-01-01

Oscillatory modes of the Pierce system have been calculated. These modes are found to have growth rates comparable to the previously investigated purely growing modes. When these modes are included, it is found that the Pierce system is unstable for most values of ω/sub p/ L/V 0 >π

Flights between a neighborhoods of unstable libration points of Sun-Earth system

Science.gov (United States)

Surkova, Valerya; Shmyrov, Vasily

2018-05-01

In this paper we study the problem of constructing impulse flights between neighborhoods of unstable collinear libration points of the Sun-Earth system [1]. Such maneuvering in near-Earth space may prove to be in demand in modern space navigation. For example, such a maneuvering was done by the space vehicle GENESIS. Three test points are chosen for the implementation of the impulse control, in order to move to a neighborhood of the libration point L2. It is shown that the earlier on the exit from the vicinity of the libration point L1 impulse control was realized, the sooner the neighborhood L2 was achieved. Separated from this problem, the problem of optimal control in the neighborhood of L2 was considered and a form of stabilizing control is presented.

Long-term effects of electrical neurostimulation in patients with unstable angina : Refractory to conventional therapies

NARCIS (Netherlands)

de Vries, Jessica; DeJongste, Mike J. L.; Zijlstra, Felix; Staal, Michiel

2007-01-01

Background. Patients with unstable angina pectoris may become refractory to conventional therapies. Electrical neurostimulation with transcutaneous electrical stimulation and/or spinal cord stimulation has been shown to be effective for patients with refractory unstable angina pectoris in hospital

Emission temperatures from the decay of particle-unstable complex nuclei

International Nuclear Information System (INIS)

Nayak, T.K.

1990-01-01

Relative populations of particle-unstable states were measured for complex fragments emitted in the reaction 14 N + Ag at E/A = 35 MeV by using a position sensitive high resolution hodoscope. Experimental population probabilities of particle-unstable states were extracted by fitting the coincidence spectra of the decay products by an appropriate R-matrix or Breit-Wigner formalism. According to thermal models, the populations of excited states at freezeout are expected to follow a Boltzmann distribution weighted by the emission temperature of the system. Tests of this freezeout assumption were made by comparing the experimental population to the predictions of statistical calculations. Extensive statistical calculation which include the effect of sequential feeding from heavier particle unstable nuclei were performed to estimate the population probabilities and the ratios of population probabilities indicate emission temperatures of about 3-4 MeV. But a detailed comparison for individual fragments for a calculation with T em = 4 MeV reveals that about half of the measured population probabilities and one third of the ratios of the population probabilities differ significantly from the predictions of statistical calculations. Calculations which include rotational effects could not satisfactorily account for this discrepancy. These results suggest a possible breakdown of the assumption of local thermal equilibrium at freezeout

Finite-width effects in unstable-particle production at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Falgari, P. [Utrecht Univ. (Netherlands). Inst. for Theoretical Physics; Utrecht Univ. (Netherlands). Spinoza Inst.; Papanastasiou, A.S. [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Signer, A. [Paul Scherrer Institut, Villigen (Switzerland); Zuerich Univ. (Switzerland). Inst. for Theoretical Physics

2013-03-15

We present a general formalism for the calculation of finite-width contributions to the differential production cross sections of unstable particles at hadron colliders. In this formalism, which employs an effective-theory description of unstable-particle production and decay, the matrix element computation is organized as a gauge-invariant expansion in powers of {Gamma}{sub X}/m{sub X}, with {Gamma}{sub X} and m{sub X} the width and mass of the unstable particle. This framework allows for a systematic inclusion of off-shell and non-factorizable effects whilst at the same time keeping the computational effort minimal compared to a full calculation in the complex-mass scheme. As a proof-of-concept example, we give results for an NLO calculation of top-antitop production in the q anti q partonic channel. As already found in a similar calculation of single-top production, the finite-width effects are small for the total cross section, as expected from the naive counting {proportional_to}{Gamma}{sub t}/m{sub t}{proportional_to}1%. However, they can be sizeable, in excess of 10%, close to edges of certain kinematical distributions. The dependence of the results on the mass renormalization scheme, and its implication for a precise extraction of the top-quark mass, is also discussed.

Finite-width effects in unstable-particle production at hadron colliders

International Nuclear Information System (INIS)

Falgari, P.; Signer, A.; Zuerich Univ.

2013-03-01

We present a general formalism for the calculation of finite-width contributions to the differential production cross sections of unstable particles at hadron colliders. In this formalism, which employs an effective-theory description of unstable-particle production and decay, the matrix element computation is organized as a gauge-invariant expansion in powers of Γ X /m X , with Γ X and m X the width and mass of the unstable particle. This framework allows for a systematic inclusion of off-shell and non-factorizable effects whilst at the same time keeping the computational effort minimal compared to a full calculation in the complex-mass scheme. As a proof-of-concept example, we give results for an NLO calculation of top-antitop production in the q anti q partonic channel. As already found in a similar calculation of single-top production, the finite-width effects are small for the total cross section, as expected from the naive counting ∝Γ t /m t ∝1%. However, they can be sizeable, in excess of 10%, close to edges of certain kinematical distributions. The dependence of the results on the mass renormalization scheme, and its implication for a precise extraction of the top-quark mass, is also discussed.

Inherent Limitations in Mid-Wave and Long-Wave-IR Upconversion Detector

DEFF Research Database (Denmark)

Barh, Ajanta; Tseng, Yu-Pei; Pedersen, Christian

2017-01-01

Inherent limitations in terms of optical losses, selection of nonlinear crystal(s), detection efficiency and pumping conditions in mid-wave (3-5 µm) and long-wave (8-12 µm) infrared frequency upconversion modules are investigated in this paper.......Inherent limitations in terms of optical losses, selection of nonlinear crystal(s), detection efficiency and pumping conditions in mid-wave (3-5 µm) and long-wave (8-12 µm) infrared frequency upconversion modules are investigated in this paper....

The true quantum face of the "exponential" decay: Unstable systems in rest and in motion

Science.gov (United States)

Urbanowski, K.

2017-12-01

Results of theoretical studies and numerical calculations presented in the literature suggest that the survival probability P0(t) has the exponential form starting from times much smaller than the lifetime τ up to times t ⪢τ and that P0(t) exhibits inverse power-law behavior at the late time region for times longer than the so-called crossover time T ⪢ τ (The crossover time T is the time when the late time deviations of P0(t) from the exponential form begin to dominate). More detailed analysis of the problem shows that in fact the survival probability P0(t) can not take the pure exponential form at any time interval including times smaller than the lifetime τ or of the order of τ and it has has an oscillating form. We also study the survival probability of moving relativistic unstable particles with definite momentum . These studies show that late time deviations of the survival probability of these particles from the exponential-like form of the decay law, that is the transition times region between exponential-like and non-exponential form of the survival probability, should occur much earlier than it follows from the classical standard considerations.

Production of spin-polarized unstable nuclei by using polarized electron capture process

International Nuclear Information System (INIS)

Shimizu, S.

1998-01-01

Measurements of emitted radiation from spin polarized nuclei are used to get information on electromagnetic moment of ground state unstable nuclei together with spin or parity state of excited states of their decayed (daughter) nuclei. These data are known to be useful for experimental investigation into the structure of unstable nuclei far from the stability line. The present study aims to establish a general method applicable to 11 Be and 16 N nuclei. To produce spin polarization, a new method in which the electron spin polarization of Rb is firstly produced by laser pumping, then the electron is transferred to the unstable nuclear beam (RNB) when they passes through the Rb vapor is proposed. Finally the polarized RNB will be implanted into superfluid helium to remain with a long spin-relaxation time. Future experimental set up for the above measurement adopted in the available radioactive nuclear beam facilities is briefly described. (Ohno, S.)

Is it about "pink" or about "girls"? The inherence heuristic across social and nonsocial domains.

Science.gov (United States)

Kinzler, Katherine D; Sullivan, Kathleen R

2014-10-01

The inherence heuristic provides an intriguing and novel explanation for early thought in a variety of domains. Exploring similarities and differences in inherent reasoning across social and nonsocial domains can help us understand the role that inherent thinking plays in the development of human reasoning and the process by which more elaborate essentialist reasoning develops.

Influence of Inherent Moisture Content on the Deformation ...

African Journals Online (AJOL)

Influence of Inherent Moisture Content on the Deformation. Properties of Coconut Tissues During Mechanical Oil. Expression. *J. J. Mpagalile1 and B. Clarke2. 1Department of ... The study confirmed that moisture content has an important role in the deformation of coconut ..... A micro penetration technique for mechanical.

Exhaustive Classification of the Invariant Solutions for a Specific Nonlinear Model Describing Near Planar and Marginally Long-Wave Unstable Interfaces for Phase Transition

Science.gov (United States)

Ahangari, Fatemeh

2018-05-01

Problems of thermodynamic phase transition originate inherently in solidification, combustion and various other significant fields. If the transition region among two locally stable phases is adequately narrow, the dynamics can be modeled by an interface motion. This paper is devoted to exhaustive analysis of the invariant solutions for a modified Kuramoto-Sivashinsky equation in two spatial and one temporal dimensions is presented. This nonlinear partial differential equation asymptotically characterizes near planar interfaces, which are marginally long-wave unstable. For this purpose, by applying the classical symmetry method for this model the classical symmetry operators are attained. Moreover, the structure of the Lie algebra of symmetries is discussed and the optimal system of subalgebras, which yields the preliminary classification of group invariant solutions is constructed. Mainly, the Lie invariants corresponding to the infinitesimal symmetry generators as well as associated similarity reduced equations are also pointed out. Furthermore, the nonclassical symmetries of this nonlinear PDE are also comprehensively investigated.

Strategy switching in the stabilization of unstable dynamics.

Directory of Open Access Journals (Sweden)

Jacopo Zenzeri

Full Text Available In order to understand mechanisms of strategy switching in the stabilization of unstable dynamics, this work investigates how human subjects learn to become skilled users of an underactuated bimanual tool in an unstable environment. The tool, which consists of a mass and two hand-held non-linear springs, is affected by a saddle-like force-field. The non-linearity of the springs allows the users to determine size and orientation of the tool stiffness ellipse, by using different patterns of bimanual coordination: minimal stiffness occurs when the two spring terminals are aligned and stiffness size grows by stretching them apart. Tool parameters were set such that minimal stiffness is insufficient to provide stable equilibrium whereas asymptotic stability can be achieved with sufficient stretching, although at the expense of greater effort. As a consequence, tool users have two possible strategies for stabilizing the mass in different regions of the workspace: 1 high stiffness feedforward strategy, aiming at asymptotic stability and 2 low stiffness positional feedback strategy aiming at bounded stability. The tool was simulated by a bimanual haptic robot with direct torque control of the motors. In a previous study we analyzed the behavior of naïve users and we found that they spontaneously clustered into two groups of approximately equal size. In this study we trained subjects to become expert users of both strategies in a discrete reaching task. Then we tested generalization capabilities and mechanism of strategy-switching by means of stabilization tasks which consist of tracking moving targets in the workspace. The uniqueness of the experimental setup is that it addresses the general problem of strategy-switching in an unstable environment, suggesting that complex behaviors cannot be explained in terms of a global optimization criterion but rather require the ability to switch between different sub-optimal mechanisms.

Damping capacity of unstable steels on chromium-nickel-manganese base

International Nuclear Information System (INIS)

Kochkin, L.I.; Rudakov, A.A.

1982-01-01

The paper deals with results of a study on the energy scattering in OKh13N3G8, 20Kh13N3G4 and 30Kh13N3G4 unstable steels. It is shown that the development of microplastic strains most easily occurs in low-carbon steel having a two-phase structure in the initial state. The proceeding of microplastic deformations in carbon unstable steels is limited by the interstitial atom effect on the dislocation movement. It is established that in OKh13N3G8 steel the martensite α→γ- transformation begins under the cyclic stress amplitudes below the yield point of this steel. The steels studied possess a high vibrostrength [ru

Inherent reactor power controller for a metal-fueled ALMR

International Nuclear Information System (INIS)

Wood, R.T.; Wilson, T.L. Jr.

1990-01-01

Inherent power control for metal-fueled ALMR designs involves using reactivity thermal feedback effects to control reactor power. This paper describes how, using classical control design techniques, a control system for normal load following maneuvers was deigned for a pool-type ALMR. This design provides active control of power removal in the balance of plant, direct control of selected primary and intermediate loop temperatures, and passive control of reactor power. The inherent stability of the strong, fast reactivity feedback effects bring heat production in the core into balance with the heat removal system temperatures, which are controlled to meet power demand. A simulation of the control system successfully responded to a 10% step change in power demand by changing power at an acceptable rate without causing large temperature fluctuations or exceeding thermal limits

The effect of topography on the evolution of unstable disturbances in a baroclinic atmosphere

Science.gov (United States)

Clark, J. H. E.

1985-01-01

A two layer spectral quasi-geostrophic model is used to simulate the effects of topography on the equilibria, their stability, and the long term evolution of incipient unstable waves. The flow is forced by latitudinally dependent radiative heating. Dissipation is in the form of Rayleigh friction. An analytical solution is found for the propagating finite amplitude waves which result from baroclinic instability of the zonal winds when topography is absent. The appearance of this solution for wavelengths just longer than the Rossby radius of deformation and disappearance of ultra-long wavelengths is interpreted in terms of the Hopf bifurcation theory. Simple dynamic and thermodynamic criteria for the existence of periodic Rossby solutions are presented. A Floquet stability analysis shows that the waves are neutral. The nature of the form drag instability of high index equilibria is investigated. The proximity of the equilibrium shear to a resonant value is essential for the instability, provided the equilibrium occurs at a slightly stronger shear than resonance.

Results and implications of the EBR-II inherent safety demonstration tests

International Nuclear Information System (INIS)

Planchon, H.P.; Golden, G.H.; Sackett, J.I.; Mohr, D.; Chang, L.K.; Feldman, E.E.; Betten, P.R.

1987-01-01

On April 3, 1986 two milestone tests were conducted in Experimental Breeder Reactor-2 (EBR-II). The first test was a loss of flow without scram and the second was a loss of heat sink without scram. Both tests were initiated from 100% power and in both tests the reactor was shut down by natural processes, principally thermal expansion, without automatic scram, operator intervention or the help of special in-core devices. The temperature transients during the tests were mild, as predicted, and there was no damage to the core or reactor plant structures. In a general sense, therefore, the tests plus supporting analysis demonstrated the feasibility of inherent passive shutdown for undercooling accidents in metal-fueled LMRs. The results provide a technical basis for future experiments in EBR-II to demonstrate inherent safety for overpower accidents and provide data for validation of computer codes used for design and safety analysis of inherently safe reactor plants

Experimental evidence for inherent Lévy search behaviour in foraging animals.

Science.gov (United States)

Kölzsch, Andrea; Alzate, Adriana; Bartumeus, Frederic; de Jager, Monique; Weerman, Ellen J; Hengeveld, Geerten M; Naguib, Marc; Nolet, Bart A; van de Koppel, Johan

2015-05-22

Recently, Lévy walks have been put forward as a new paradigm for animal search and many cases have been made for its presence in nature. However, it remains debated whether Lévy walks are an inherent behavioural strategy or emerge from the animal reacting to its habitat. Here, we demonstrate signatures of Lévy behaviour in the search movement of mud snails (Hydrobia ulvae) based on a novel, direct assessment of movement properties in an experimental set-up using different food distributions. Our experimental data uncovered clusters of small movement steps alternating with long moves independent of food encounter and landscape complexity. Moreover, size distributions of these clusters followed truncated power laws. These two findings are characteristic signatures of mechanisms underlying inherent Lévy-like movement. Thus, our study provides clear experimental evidence that such multi-scale movement is an inherent behaviour rather than resulting from the animal interacting with its environment. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Thallium-201 scintigraphy in unstable angina pectoris

International Nuclear Information System (INIS)

Wackers, F.J.T.; Lie, K.I.; Liem, K.L.; Sokole, E.B.; Samson, G.; Van Der Schoot, J.B.; Durrer, D.

1978-01-01

Thallium-201 scintigraphy was performed during the pain free period in 98 patients with unstable angina. Scintiscans were positive in 39 patients, questionable in 27 patients and normal in 32 patients. Eighty-one patients responded favorably to treatment (group I). Seventeen patients had complicated courses (group II) and despite maximal treatment with propranolol either developed infarction (six patients) or continued to have angina necessitating coronary surgery (11 patients). In group I during the pain free period 26 of 81 patients had positive thallium-201 scans, whereas 20 patients had an abnormal ECG at that time; during angina 18 patients had transient ECG changes. In group II during the pain free period 13 of 17 patients had positive scans, whereas two patients had abnormal ECG at that time; during angina 12 patients showed transient ECG changes. The sensitivity to recognize group II was 76% for thallium-201 scintigraphy, 11% for ECG during the pain free period; 70% for ECG during angina; 94% for the combination of either positive scans or abnormal ECG. Thus, positive thallium-201 scans occur in patients with unstable angina, positive scans can be obtained during the pain free period, thallium-201 scans are more frequently positive in patients with complicated course

Tracer filamentation at an unstable ocean front

Science.gov (United States)

Feng, Yen Chia; Mahadevan, Amala; Thiffeault, Jean-Luc; Yecko, Philip

2017-11-01

A front, where two bodies of ocean water with different physical properties meet, can become unstable and lead to a flow with high strain rate and vorticity. Phytoplankton and other oceanic tracers are stirred into filaments by such flow fields, as can often be seen in satellite imagery. The stretching and folding of a tracer by a two-dimensional flow field has been well studied. In the ocean, however, the vertical shear of horizontal velocity is typically two orders of magnitude larger than the horizontal velocity gradient. Theoretical calculations show that vertical shear alters the way in which horizontal strain affects the tracer, resulting in thin, sloping structures in the tracer field. Using a non-hydrostatic ocean model of an unstable ocean front, we simulate tracer filamentation to identify the effect of vertical shear on the deformation of the tracer. In a complementary laboratory experiment, we generate a simple, vertically sheared strain flow and use dye and particle image velocimetry to quantify the filamentary structures in terms of the strain and shear. We identify how vertical shear alters the tracer filaments and infer how the evolution of tracers in the ocean will differ from the idealized two-dimensional paradigm. Support of NSF DMS-1418956 is acknowledged.

Velocity Spectra in the Unstable Planetary Boundary Layer

DEFF Research Database (Denmark)

Højstrup, Jørgen

1982-01-01

Models for velocity spectra of all three components in the lower half of the unstable PBL are presented. The model spectra are written as a sum of two parts, nS(n) = A(fi, z/zi)w*2 + B(f, z/zi)u*02, a mixed layer part with a stability dependence, and a surface layer part without stability...

Impacts of reactivity feedback uncertainties on inherent shutdown in innovative designs

International Nuclear Information System (INIS)

Mueller, C.J.

1986-01-01

The concept of inherent shutdown is emphasized in the approach to the design of innovative, small pool-type liquid-metal reactors (LMRs). This paper reports an evaluation of reactivity feedback uncertainties used in the analyses of anticipated transients without scram for innovative LMRs, and the associated impacts on safety margins and inherent shutdown success probabilities on unprotected loss-of-flow (LOF) events. It then assesses the ultimate importance of these uncertainties on LOF and transient overpower events in evolving metal and oxide innovative designs

Impacts of reactivity feedback uncertainties on inherent shutdown in innovative designs

International Nuclear Information System (INIS)

Mueller, C.J.

1986-01-01

The concept of ''inherent shutdown'' is emphasized in the approach to the design of innovative, small pool-type liquid metal reactors (LMRs). This paper reports an evaluation of reactivity feedback uncertainties used in the analyses of anticipated transients without scram (ATWS) for innovative LMRs, and the associated impacts on safety margins and inherent shutdown success probabilities on unprotected loss-of-flow (LOF) events. It then assesses the ultimate importance of these uncertainties on LOF and transient overpower (TOP) events in evolving metal and oxide innovative designs

The role of passive and inherent safety properties in Siemens/KWU nuclear power plants

International Nuclear Information System (INIS)

Gremm, O.

1990-01-01

In Siemens/KWU Nuclear Power Plants the applied safety concept consist of a well balanced combination of active, passive use well is inherent safety measures. In principle it is not possible to realise a safety concept exclusively with inherent and/or passive safety properties. The respective measures and arguments will be explained in detail in the presentation. In addition the Siemens/KWU safety concept with examples of the role of inherent and passive safety measures will be illustrated. (author). 9 refs, 9 figs

Unstable mass outflow from a binary system

Energy Technology Data Exchange (ETDEWEB)

Nariai, K [Tokyo Univ., Mitaka (Japan). Tokyo Astronomical Observatory; Sugimoto, D

1976-12-01

A contact binary system which fills the outer Lagrangian lobe is unstable against the mass loss from the second Lagrangian point. The effect of the mass loss on the remaining system is studied for several typical cases. It is shown that the separation between the components at the periastron decreases with a high rate in most cases; therefore, the system continues to lose mass once gas begins to flow out from the second Lagrangian point.

Treatment of Unstable Trochanteric Femur Fractures: Proximal Femur Nail Versus Proximal Femur Locking Compression Plate.

Science.gov (United States)

Singh, Ashutosh Kumar; Narsaria, Nidi; G R, Arun; Srivastava, Vivek

Unstable trochanteric femur fractures are common fractures that are difficult to manage. We conducted a prospective study to compare functional outcomes and complications of 2 different implant designs, proximal femur nail (PFN) and proximal femur locking compression plate (PFLCP), used in internal fixation of unstable trochanteric femur fractures. On hospital admission, 48 patients with unstable trochanteric fractures were randomly assigned (using a sealed envelope method) to treatment with either PFN (24 patients) or PFLCP (24 patients). Perioperative data and complications were recorded. All cases were followed up for 2 years. The groups did not differ significantly (P > .05) in operative time, reduction quality, complications, hospital length of stay, union rate, or time to union. Compared with the PFLCP group, the PFN group had shorter incisions and less blood loss. Regarding functional outcomes, there was no significant difference in mean Harris Hip Score (P = .48) or Palmer and Parker mobility score (P = .58). Both PFN and PFLCP are effective in internal fixation of unstable trochanteric femur fractures.

Stimulation of confocal unstable resonators using thin gain sheet

International Nuclear Information System (INIS)

Du Yanyi

2000-01-01

Mode calculation in unstable resonators with flowing saturable gain using the fast Fourier transform (FFT) algorithm and thin gain sheet just nearly inside the big mirror. This method is in resonators of small disturbance (ψ 0max = π/2), middle magnification (m 0 ∼= 1%)

Quantification of Inherent Respirable Dust Generation Potential (IRDGP) of South African Coals

CSIR Research Space (South Africa)

Phillips, H

2003-08-01

Full Text Available Advisory Committee Project Summary Project Title: Inherent Respirable Dust Generation Potential (IRDGP) of South African Coals-SIM020604 Author(s): H.R.Phillips and B. K. Belle Agency: University of Witwatersrand Report Date: July2003... Related Projects: Health 607, Sim 02-06-03 Category: Occupational Health Applied Research Occupational Hygiene Summary Project SIM020604 was formulated to determine the Inherent Respirable Dust Generation Potential (IRDGP) of various South...

Nonlinear dynamics exploration through normal forms

CERN Document Server

Kahn, Peter B

2014-01-01

Geared toward advanced undergraduates and graduate students, this exposition covers the method of normal forms and its application to ordinary differential equations through perturbation analysis. In addition to its emphasis on the freedom inherent in the normal form expansion, the text features numerous examples of equations, the kind of which are encountered in many areas of science and engineering. The treatment begins with an introduction to the basic concepts underlying the normal forms. Coverage then shifts to an investigation of systems with one degree of freedom that model oscillations

Photo-oxidation of histidine peptides yields high concentrations of unstable peroxides

International Nuclear Information System (INIS)

Policarpio, V.V.; Hawkins, C.L.; Davies, M.J.

2003-01-01

Oxidation of proteins by UV, and visible light in the presence of sensitizers, results in side chain modification as well as aggregation and fragmentation. In particular, singlet oxygen has been reported to oxidize Met, Trp, Tyr, Cys and His side chains in a selective manner. In this study the oxidation of histidine and its derivatives, and His-containing peptides is examined using a range of sensitizers, to determine whether peroxides are major intermediates, and the mechanism of formation of these species. Visible light-sensitised oxidation of Gly-His-Gly in the presence of oxygen and rose bengal gives unstable substrate-derived peroxides with the peroxide yield increasing with increasing photolysis time. Similar behaviour was detected with other photosensitizers, though the peroxide yields varied with the sensitizer at identical concentrations with rose bengal > aluminium phthalocyanine > hematoporphyrin IX > zinc phthalocyanine > tetrakisporphine. The peroxide yield was decreased in the presence of azide and enhanced when deuterium oxide was employed as the solvent, consistent with peroxide formation being singlet oxygen mediated. Experiments using anoxic conditions gave low yields of peroxides confirming the oxygen-dependence of these reactions. HPLC analysis showed rapid loss of the parent peptide, with subsequent formation of both stable and unstable products; these are currently being characterized by MS and NMR. Similar behavior has been observed with other His derivatives. The yield of singlet oxygen formed in these reactions has been estimated using a bleaching assay (N, N-dimethyl-4-nitrosoaniline). Quantification of singlet oxygen formation and Gly-His-Gly derived peroxide during rose bengal-mediated photooxidation indicated a conversion efficiency of the initial singlet oxygen into substrate-derived peroxides of ca. 75% indicating that peroxide formation is a highly efficient and major reaction pathway

Indispensable role of biochar-inherent mineral constituents in its environmental applications: A review.

Science.gov (United States)

Xu, Xiaoyun; Zhao, Yinghao; Sima, Jingke; Zhao, Ling; Mašek, Ondřej; Cao, Xinde

2017-10-01

Biochar typically consists of both carbon and mineral fractions, and the carbon fraction has been generally considered to determine its properties and applications. Recently, an increasing body of research has demonstrated that mineral components inherent in biochar, such as alkali or alkaline earth metals in the form of carbonates, phosphates, or oxides, could also influence the properties and thus the applications. The review articles published thus far have mainly focused on multiple environmental and agronomic applications of biochar, including carbon sequestration, soil improvement, environmental remediation, etc. This review aims to highlight the indispensable role of the mineral fraction of biochar in these different applications, especially in environmental applications. Specifically, it provides a critical review of current research findings related to the mineral composition of biochar and the effect of the mineral fraction on the physicochemical properties, contaminant sorption, carbon retention and stability, and nutrient bioavailability of biochar. Furthermore, the role of minerals in the emerging applications of biochar, as a precursor for fuel cells, supercapacitors, and photoactive components, is also summarized. Overall, inherent minerals should be fully considered while determining the most appropriate application for any given biochar. A thorough understanding of the role of biochar-bound minerals in different applications will also allow the design or selection of the most suitable biochar for specific applications based on the consideration of feedstock composition, production parameters, and post-treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Treatment options for unstable trochanteric fractures: Screw or helical proxima femoral nail.

Science.gov (United States)

Bajpai, Jeetendra; Maheshwari, Rajesh; Bajpai, Akansha; Saini, Sumit

2015-01-01

To compare treatment outcome of screw proximal femoral nail (PFN) system with that of a helical PFN. The study included 77 patients with closed unstable intertrochanteric fracture classified as AO 31A2&31A3, between June 2008 to August 2011. Inclusion criteria were: all mature skeletons above 50 years of age; closed unstable trochanteric fracture classified as AO 31A2&A3. Exclusion criteria were: immature skeleton, pathological fracture of any cause other than osteoporosis, inability to walk inde- pendently prior to injury. Patients were randomized to 2 treatment groups based on admission sequence. Forty patients were treated with screw PFN and thirty seven were treated with helical PFN. Both groups were similar in respect of time of surgery, blood loss and functional assessment and duration of hospitalization. In screw PFN group 2 patients had superficial wound infection, 1 patient had persistent hip pain and 1 patient had shortening>1 cm buttrochanteric fractures even in Indian patients where the bones are narrow and neck diameter is small. It is an implant of choice for osteoporotic and unstable trochanteric fractures.

Natural goodness and the political form of human life

Directory of Open Access Journals (Sweden)

Müller Jan

2015-01-01

Full Text Available Ethical Naturalism attempts to explain the objective normativity effective in human practices by reference to the relation between a living individual and the life-form it exhibits. This explanation falls short in the case of human beings (1 - not merely because of their essential rationality, but because the idea of normativity implicit in practice is dependent on the form of normativity’s being made explicit (2. I argue that this explicit form of normativity’s force and claim - the law in general - implies a tension between an explicit norm’s claim to absoluteness and the particularity of the situational case it is applied to. This tension may seem to produce an inherent violence corrupting the very idea of objective normativity inherent in the human form of life (3; in fact, it shows that the human form of life is essentially political. That the human form of life is essentially political does not contradict the idea of objective normativity - provided that this objectivity is not derived from a conception of “natural goodness”, but rather from the actuality of human practice and its principle, justice (4.

The use of unstable chromosome aberrations and micronuclei in the individual biomonitoring: a comparative study

International Nuclear Information System (INIS)

Fernandes, Thiago de Salazar e

2005-02-01

Biodosimetry is based on the investigation of radioinduced biological effects in order to correlate them with the absorbed dose. The quantification of unstable chromosome aberrations and micronuclei, in peripheral blood lymphocytes, are two methods commonly used in biodosimetry. In this context, the aim of this research was to compare these methods in the biomonitoring of health care professionals occupationally exposed to ionizing radiation. In parallel, the technique of C-banding was evaluated for quality control of unstable chromosome aberrations analyses. Thus, samples of peripheral blood from health care professionals of three hospitals from Recife (Brazil) were collected, and the lymphocytes cultures were carried out based on the cytogenetic classical technique. It was pointed out that analysis of micronuclei is faster than the unstable chromosome aberrations ones, which suggests the use of the former in preliminary evaluation in cases of suspected accidental exposure. C-banding technique was efficient, as confirmatory test, in the identification of dicentrics and rings during the analyses of unstable chromosome aberrations, being able to be applied in the quality control in biodosimetry. The comparison between the individual work conditions with the frequencies of unstable aberrations and micronuclei obtained from cytogenetic analysis, resulted in the change of behavior of the professionals involved in this research, with a better observance of the radioprotection standards. (author)

Exploring the Physics of Unstable Nuclei

Science.gov (United States)

Volya, Alexander

In this presentation the Continuum Shell Model (CSM) approach is advertised as a powerful theoretical tool for studying physics of unstable nuclei. The approach is illustrated using 17O as an example, which is followed by a brief presentation of the general CSM formalism. The successes of the CSM are highlighted and references are provided throughout the text. As an example, the CSM is applied perturbatively to 20O allowing one to explore the effects of continuum on positions of weakly bound states and low-lying resonances, as well as to discern some effects of threshold discontinuity.

Exploring the physics of unstable nuclei

International Nuclear Information System (INIS)

Volya, Alexander

2015-01-01

In this presentation the Continuum Shell Model (CSM) approach is advertised as a powerful theoretical tool for studying physics of unstable nuclei. The approach is illustrated using 17 O as an example, which is followed by a brief presentation of the general CSM formalism. The successes of the CSM are highlighted and references are provided throughout the text. As an example, the CSM is applied perturbatively to 20 O allowing one to explore the effects of continuum on positions of weakly bound states and low-lying resonances, as well as to discern some effects of threshold discontinuity. (author)

A STUDY OF UNSTABLE INTERTROCHANTERIC FEMORAL FRACTURES TREATED BY TROCHANTERIC FEMORAL NAIL

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Sreenivasa Neikar

2017-11-01

Full Text Available BACKGROUND Intertrochanteric fracture is one of the most common fracture of the hip especially in the elderly. The incidence of intertrochanteric fracture is rising because of the increase in number of elderly population along with superadded osteoporosis. MATERIALS AND METHODS Study included cases of unstable intertrochanteric fractures (AO and OTA Classification 31-A2 and 31-A3 fracture patterns that were operated with the short trochanteric femoral nail, which fitted into the inclusion criteria done in medical college hospital, Vijayanagara Institute of Medical Sciences, Bellary, from February 2015 to September 2016. RESULTS The age distribution was from 40 to 80 years. The largest group of patients were from 61 to 70 years. The average age was 60.5 years. The number of male patients in our series was 20 (66.7% and female was 10 (33.3%. Right side was affected in 11 cases (36.7% and left side in 19 cases (63.3%. Good reduction was achieved in 23 patients (76.7%. Acceptable reduction was achieved in 7 (23.3% patients due to severe comminution. In our study, 25 patients (83.33% had no complications. We encountered one intraoperative complication in the form of greater trochanter splintering, while inserting the nail. In our study, we encountered following postoperative complications. We noticed one case of delayed union, one case of Z effect and 2 cases of varus malunion. CONCLUSION We conclude that short trochanteric femoral nail provides good fixation for unstable intertrochanteric fractures if proper preoperative planning, good reduction and surgical technique are followed leading to high rate of bone union and minimal soft tissue damage especially for Asian patients with relatively small femora.

A chaotic system with a single unstable node

Energy Technology Data Exchange (ETDEWEB)

Sprott, J.C. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Jafari, Sajad, E-mail: sajadjafari@aut.ac.ir [Biomedical Engineering Department, Amirkabir University of Technology, Tehran 15875-4413 (Iran, Islamic Republic of); Pham, Viet-Thanh [School of Electronics and Telecommunications, Hanoi University of Science and Technology, 01 Dai Co Viet, Hanoi (Viet Nam); Hosseini, Zahra Sadat [Biomedical Engineering Department, Amirkabir University of Technology, Tehran 15875-4413 (Iran, Islamic Republic of)

2015-09-25

This paper describes an unusual example of a three-dimensional dissipative chaotic flow with quadratic nonlinearities in which the only equilibrium is an unstable node. The region of parameter space with bounded solutions is relatively small as is the basin of attraction, which accounts for the difficulty of its discovery. Furthermore, for some values of the parameters, the system has an attracting torus, which is uncommon in three-dimensional systems, and this torus can coexist with a strange attractor or with a limit cycle. The limit cycle and strange attractor exhibit symmetry breaking and attractor merging. All the attractors appear to be hidden in that they cannot be found by starting with initial conditions in the vicinity of the equilibrium, and thus they represent a new type of hidden attractor with important and potentially problematic engineering consequences. - Highlights: • An unusual example of a three-dimensional dissipative chaotic flow is introduced. • In this system the only equilibrium is an unstable node. • For some values of the parameters, the system has an attracting torus. • This torus can coexist with a strange attractor or with a limit cycle. • These properties are uncommon in three-dimensional systems.

Effect of Teriparatide on Unstable Pertrochanteric Fractures

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Tsan-Wen Huang

2015-01-01

Full Text Available We retrospectively analyzed the radiographic and clinical outcomes of unstable pertrochanteric fractures (AO/OTA 31-A2 in 44 patients who underwent dynamic hip screw (DHS fixation and compared the results with 29 patients who received teriparatide in addition to DHS fixation. A significantly shorter time for fracture healing was recorded in the teriparatide-treated group than in the control group. Rates of lag screw sliding, femoral shortening, and varus collapse were all significantly reduced in the teriparatide-treated group. There were no significant differences with regard to superficial wound infection, pneumonia, urinary tract infection, mortality, malunion, and cutting of the lag screw. The mean overall mobility scores were significantly better in the teriparatide-treated group at 3 and 6 months (P<0.001 and P<0.001, resp. but not at 12 months or the last follow-up. The pain scores were also significantly better in the teriparatide-treated group at 3 and 6 months (P=0.040 and P=0.041, resp. but not at 12 months or the last follow-up. Teriparatide improves radiographic outcomes and yields better clinical outcomes at 3 and 6 months postoperatively. The improvement in union time may be important for elderly populations with unstable pertrochanteric fractures to enable them to return to daily activities and reduce morbidity and mortality.

A comparison of locked versus nonlocked Enders rods for length unstable pediatric femoral shaft fractures.

Science.gov (United States)

Ellis, Henry Bone; Ho, Christine A; Podeszwa, David A; Wilson, Philip L

2011-12-01

Stainless steel flexible Enders rods have been used for intramedullary fixation of pediatric femur fractures with good success. Despite intraoperative anatomic alignment, length unstable femur fractures can present postoperatively with fracture shortening. The purpose of this study was to review all length unstable pediatric femoral shaft fractures in which Enders rods were used and compare those that were locked to those that were not locked. A retrospective clinical and radiographic review of all patients at a single institution undergoing flexible intramedullary fixation for length unstable femoral shaft fractures from 2001 to 2008. A length unstable fracture was defined as either a comminuted fracture or a spiral fracture longer than twice the diameter of the femoral shaft. A total of 107 length unstable femoral shaft fractures fixed with Enders rods were identified, of which 37 cases (35%) had both Enders rods "locked" through the eyelet in the distal femur with a 2.7 mm fully threaded cortical screw. Patient demographics, clinical course, complications, fracture characteristics, and radiographic outcomes were compared for the locked and nonlocked groups. There were no statistical differences between the groups in demographic data, operative variables, fracture pattern, fracture location, time to union, femoral alignment, or major complications. Shortening of the femur and nail migration measured at 1 to 6 weeks postoperatively was significantly greater for the nonlocked cases. The medial and lateral locked Enders rods moved 1.3 and 1.9 mm, respectively, and the unlocked Enders each moved 12.1 mm (P < 0.05). At final follow-up there were significantly more (P < 0.05) clinical complaints in nonlocked group, including limp, clinical shortening, and painful palpable rods. Locking Enders rods for length unstable pediatric fractures is an excellent option to prevent shortening and resulted in no additional complications, added surgical time, or increased blood loss

Risk stratification by using non-invasive radionuclide imaging in patients with unstable angina spec tories

International Nuclear Information System (INIS)

Saghari, M.

2002-01-01

Unstable angina represents a heterogeneous spectrum of clinical entities between chronic stable angina and acute myocardial infraction. Acute ischemic syndromes (including unstable angina) result from abrupt reduction in coronary flow, frequently after atherosclerotic plaque disruption and with or without associated thrombosis or vasospasm. Nuclear cardiology studies and in particular, myocardial perfusion imaging are powerful noninvasive tools for detecting and assessing the severity of acute ischemic syndromes, including unstable angina pec tories. The information derived from a nuclear cardiology study can answer unresolved clinical question and aid in subsequent patient management, specifically jeopardized myocardium detected during spontaneously occurring acute chest pain or controlled stress testing are important determinant of: 1) The need for admission to an intensive care monitoring unit 2) The need for and urgency of coronary angiography 3) The appropriate use of percutaneous or surgical coronary revascularization procedures. Extensive information suggests the stress nuclear perfusion imaging is the best validated technique for predischarge risk stratification with unstable angina patients who have been medically stabilized. Early information suggests avoidance of unecessary coronary angiography or revascularization is the cost effective strategy

Hamiltonian approach to the derivation of evolution equations for wave trains in weakly unstable media

Directory of Open Access Journals (Sweden)

N. N. Romanova

1998-01-01

Full Text Available The dynamics of weakly nonlinear wave trains in unstable media is studied. This dynamics is investigated in the framework of a broad class of dynamical systems having a Hamiltonian structure. Two different types of instability are considered. The first one is the instability in a weakly supercritical media. The simplest example of instability of this type is the Kelvin-Helmholtz instability. The second one is the instability due to a weak linear coupling of modes of different nature. The simplest example of a geophysical system where the instability of this and only of this type takes place is the three-layer model of a stratified shear flow with a continuous velocity profile. For both types of instability we obtain nonlinear evolution equations describing the dynamics of wave trains having an unstable spectral interval of wavenumbers. The transformation to appropriate canonical variables turns out to be different for each case, and equations we obtained are different for the two types of instability we considered. Also obtained are evolution equations governing the dynamics of wave trains in weakly subcritical media and in media where modes are coupled in a stable way. Presented results do not depend on a specific physical nature of a medium and refer to a broad class of dynamical systems having the Hamiltonian structure of a special form.

Unstable argininosuccinate lyase in variant forms of the urea cycle disorder argininosuccinic aciduria.

Science.gov (United States)

Hu, Liyan; Pandey, Amit V; Balmer, Cécile; Eggimann, Sandra; Rüfenacht, Véronique; Nuoffer, Jean-Marc; Häberle, Johannes

2015-09-01

Loss of function of the urea cycle enzyme argininosuccinate lyase (ASL) is caused by mutations in the ASL gene leading to ASL deficiency (ASLD). ASLD has a broad clinical spectrum ranging from life-threatening severe neonatal to asymptomatic forms. Different levels of residual ASL activity probably contribute to the phenotypic variability but reliable expression systems allowing clinically useful conclusions are not yet available. In order to define the molecular characteristics underlying the phenotypic variability, we investigated all ASL mutations that were hitherto identified in patients with late onset or mild clinical and biochemical courses by ASL expression in human embryonic kidney 293 T cells. We found residual activities >3% of ASL wild type (WT) in nine of 11 ASL mutations. Six ASL mutations (p.Arg95Cys, p.Ile100Thr, p.Val178Met, p.Glu189Gly, p.Val335Leu, and p.Arg379Cys) with residual activities ≥16% of ASL WT showed no significant or less than twofold reduced Km values, but displayed thermal instability. Computational structural analysis supported the biochemical findings by revealing multiple effects including protein instability, disruption of ionic interactions and hydrogen bonds between residues in the monomeric form of the protein, and disruption of contacts between adjacent monomeric units in the ASL tetramer. These findings suggest that the clinical and biochemical course in variant forms of ASLD is associated with relevant residual levels of ASL activity as well as instability of mutant ASL proteins. Since about 30% of known ASLD genotypes are affected by mutations studied here, ASLD should be considered as a candidate for chaperone treatment to improve mutant protein stability.

Interaction effects on the unstable discharge-energy characteristic of pump-turbine in pump mode

Science.gov (United States)

Tao, R.; Xiao, R. F.; Yang, W.; Liu, W. C.

2013-12-01

For a pump-turbine, unstable discharge-energy characteristic is an important factor for operating stability. In this study, the rotor-stator interaction effects on the pump-turbine which has the unstable discharge-energy characteristic has been studied. A series of transient CFD simulations under different discharge conditions have been conducted. Through the contrast between the simulations and experiments, it is found out that the energy decline is strongly affected by the flow loss in the adjustable vane. More importantly, the magnitude and direction of fluid flowing into the adjustable vane are varying with the impeller rotating. Disordered flow structure occurs in the adjustable vane and causes the energy losses due to the interaction effects. Based on this study, improvements on the flow uniformity at impeller outlet will help us to solve the unstable discharge-energy problem.

Liver-inherent immune system: its role in blood-stage malaria.

Science.gov (United States)

Wunderlich, Frank; Al-Quraishy, Saleh; Dkhil, Mohamed A

2014-01-01

The liver is well known as that organ which is obligately required for the intrahepatocyte development of the pre-erythrocytic stages of the malaria-causative agent Plasmodium. However, largely neglected is the fact that the liver is also a central player of the host defense against the morbidity- and mortality-causing blood stages of the malaria parasites. Indeed, the liver is equipped with a unique immune system that acts locally, however, with systemic impact. Its main "antipodal" functions are to recognize and to generate effective immunoreactivity against pathogens on the one hand, and to generate tolerance to avoid immunoreactivity with "self" and harmless substances as dietary compounds on the other hand. This review provides an introductory survey of the liver-inherent immune system: its pathogen recognition receptors including Toll-like receptors (TLRs) and its major cell constituents with their different facilities to fight and eliminate pathogens. Then, evidence is presented that the liver is also an essential organ to overcome blood-stage malaria. Finally, we discuss effector responses of the liver-inherent immune system directed against blood-stage malaria: activation of TLRs, acute phase response, phagocytic activity, cytokine-mediated pro- and anti-inflammatory responses, generation of "protective" autoimmunity by extrathymic T cells and B-1 cells, and T cell-mediated repair of liver injuries mainly produced by malaria-induced overreactions of the liver-inherent immune system.

Initial and regime situations in the decay of unstable quantum systems

International Nuclear Information System (INIS)

Rimini, A.; Zambotti, G.

1980-01-01

Two different definitions of survival probability in the decay of an unstable quantum system are considered and the equations for them are deduced from the equation for the density operator. The regime situation for the ensemble of unstable systems is studied and the density operator in such a situation is derived. The possible definitions of lifetime are discussed. If the adopted definition makes reference to all time including the early ones, then it is compulsory to specify exactly the state at the initial time. The correct equations for the survival probabilities in such conditions are derived. Two typical examples of decay experiments are considered and the influence of the initial preparation on the mean life is discussed. Numerical examples are given. (author)

Characterization of the structural collapse undergone by an unstable system of ultrasoft particles

Science.gov (United States)

Prestipino, Santi; Malescio, Gianpietro

2016-09-01

The effective repulsion between macromolecules such as polymer chains or dendrimers is everywhere finite, implying that interaction centers can even coincide. If, in addition, the large-distance attraction is sufficiently strong, then the system is driven unstable. An unstable system lacks a conventional thermodynamics since, in the infinite-size limit, it eventually collapses to a finite-size cluster (for instance, a polymer dispersion undergoes irreversible coagulation when increasing the amount of dissolved salt beyond a certain limit). Using a double-Gaussian (DG) potential for demonstration, we study the phase behavior of a system of ultrasoft particles as a function of the attraction strength η. Above a critical threshold ηc, the DG system is unstable but its collective behavior is far from trivial since two separate regions of the thermodynamic plane can be identified, based on the value taken by the average waiting time for collapse: this is finite and small on one side of the boundary, while presumably infinite in the other region. In order to make sense of this evidence, we consider a stable system of particles interacting through a DG potential augmented with a hard core (stabilized DG, or SDG potential). We provide arguments supporting the view that the boundary line of the unstable DG model is the remnant of the spinodal line of a fluid-fluid phase transition occurring in the SDG model when the hard-core diameter is sent to zero.

The effect of unstable sandals on instability in gait in healthy female subjects.

Science.gov (United States)

Price, Carina; Smith, Laura; Graham-Smith, Philip; Jones, Richard

2013-07-01

Unstable footwear generally lacks thorough peer-review published research to support concepts and marketing claims. The purpose of this study was to investigate the instability induced by four (FitFlop, Masai Barefoot Technology, Reebok Easy-Tone and Skechers Tone-Ups) commercially available unstable sandals and one stable control sandal (Earth) in walking in 15 females (mean±SD age was 29±6.7 years, mass 62.6±6.9kg and height 167.1±4.2cm). Three-dimensional motion with synchronised electromyography and kinetic data were collected. Walking speed and step length remained consistent between conditions, however double support time decreased in Masai Barefoot Technology. Centre of pressure data identified no consistent difference between the stable control and the unstable sandals, however Masai Barefoot Technology reduced the anterior-posterior range of centre of pressure. Muscle activity differed significantly at the ankle in the unstable footwear. FitFlop, Reebok and Skechers increased peroneal activity during pre-swing, whereas Masai Barefoot Technology increased medial gastrocnemius and decreased tibialis anterior activity in loading response and mid-stance. The larger rocker sole of the Masai Barefoot Technology altered gait and muscle activation with regard to braking and progression in the sagittal plane. Reebok, Skechers and FitFlop, with softer, less stable foreparts increased evertor action at toe-off, having their effect in the coronal plane. The study highlighted that any instability induced by the shoes is design-specific. Copyright © 2013 Elsevier B.V. All rights reserved.

Inherent Safety Feature of Hybrid Low Power Research Reactor during Reactivity Induced Accident

Energy Technology Data Exchange (ETDEWEB)

Kim, DongHyun; Yum, Soo Been; Hong, Sung Teak; Lim, In-Cheol [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

Hybrid low power research reactor(H-LPRR) is the new design concept of low power research reactor for critical facility as well as education and training. In the case of typical low power research reactor, the purposes of utilization are the experiments for education of nuclear engineering students, Neutron Activation Analysis(NAA) and radio-isotope production for research purpose. H-LPRR is a light-water cooled and moderated research reactor that uses rod-type LEU UO{sub 2} fuels same as those for commercial power plants. The maximum core thermal power is 70kW and, the core is placed in the bottom of open pool. There are 1 control rod and 2 shutdown rods in the core. It is designed to cool the core by natural convection, retain negative feedback coefficient for entire fuel periods and operate for 20 years without refueling. Inherent safety in H-LPRR is achieved by passive design features such as negative temperature feedback coefficient and core cooling by natural convection during normal and emergency conditions. The purpose of this study is to find out that the inherent safety characteristics of H-LPRR is able to control the power and protect the reactor from the RIA(Reactivity induced accident). RIA analysis was performed to investigate the inherent safety feature of H-LPRR. As a result, it was found that the reactor controls its power without fuel damage in the event and that the reactor remains safe states inherently. Therefore, it is believed that high degree of safety inheres in H-LPRR.

Does Unstable Employment Have an Association with Suicide Rates among the Young?

Science.gov (United States)

Kim, Chungah; Cho, Youngtae

2017-04-28

Although a growing body of literature has indicated that unemployment has a positive association with suicide, the dynamic aspects of unstable employment have not yet been considered in suicidology. This study explored the association between employment stability and completed suicide among people aged 25-34 years in 20 OECD (Organization for Economic Cooperation and Development) countries with time-series data (1994-2010). In order to consider the different aspects of unstable employment, we tested the impacts of employment protection legislation indicators as another proxy of job insecurity (employed, but unstable) apart from unemployment rates. Covariates, including economic growth rates, GDP per capita, fertility rates, and divorce rate, were controlled for. The analysis was designed to be gender- and age-specific, where observations with ages of 25-29 were separated from those with ages of 30-34. Random effect models were applied to examine changes over time in suicide rates, and other models were presented to check robustness. The results showed that it is a low level of employment protection, rather than unemployment itself, that was associated with increased suicide rates among all of the studied populations. The magnitude of the effect differed by gender.

Nd:YAG (2 omega) pumped dye laser using self-filtering unstable resonator

CERN Document Server

Rahimian, K; Hariri, H

2002-01-01

A self-filtering unstable resonator with a magnification of M=-3 in a Nd:YAG (2 omega) dye laser has been studied. The dye solution is Rhodamine 6 G in alcohol with the concentration of 5*10 sub - 3 Mol/lit. The spatial intensity distribution of the resonator has been compared has been compared with that of a plane-parallel resonator of equal length. The output energy in both configurations are comparable (20 mu J ,and 26 mu J ,respectively). A significant difference between these two resonators is the laser beam divergence, where beam divergences of 0.77 mrad for the self-filtering unstable resonator and 1.6 mrad for the plane-parallel resonator have been measured. The brightness corresponding to these two resonators are 1.5* 10 sub 1 1 and 2.2* 10 sub 1 0W.cm sub - 2.Sr sub - 1, and the pulse widths are 7 and 17 ns, respectively. These figures show clearly that laser resonator based on the self-filtering unstable resonator design an increase the laser brightness a factor of 10, with a beam divergence of a f...

Safety and efficacy of angioplasty with intracoronary stenting in patients with unstable coronary syndromes. Comparison with stable coronary syndromes

Directory of Open Access Journals (Sweden)

Luís C. L. Correia

2000-06-01

Full Text Available OBJECTIVE: To assess safety and efficacy of coronary angioplasty with stent implantation in unstable coronary syndromes. METHODS: Retrospective analysis of in-hospital and late evolution of 74 patients with unstable coronary syndromes (unstable angina or infarction without elevation of the ST segment undergoing coronary angioplasty with stent placement. These 74 patients were compared with 31 patients with stable coronary syndromes (stable angina or stable silent ischemia undergoing the same procedure. RESULTS: No death and no need for revascularization of the culprit artery occurred in the in-hospital phase. The incidences of acute non-Q-wave myocardial infarction were 1.4% and 3.2% (p=0.6 in the unstable and stable coronary syndrome groups, respectively. In the late follow-up (11.2±7.5 months, the incidences of these events combined were 5.7% in the unstable coronary syndrome group and 6.9% (p=0.8 in the stable coronary syndrome group. In the multivariate analysis, the only variable with a tendency to significance as an event predictor was diabetes mellitus (p=0.07; OR=5.2; 95% CI=0.9-29.9. CONCLUSION: The in-hospital and late evolutions of patients with unstable coronary syndrome undergoing angioplasty with intracoronary stent implantation are similar to those of the stable coronary syndrome group, suggesting that this procedure is safe and efficacious when performed in unstable coronary syndrome patients.

Hemi replacement arthroplasty for unstable inter-trochanteric fractures of femur.

Science.gov (United States)

Singh, Sudhir; Shrivastava, Chetan; Kumar, Sanjiv

2014-10-01

Unstable inter-trochanteric fracture in the geriatric population is a common injury and is associated with poor bone quality, excessive collapse, loss of fixation, and cut-out of the lag screw, are the common problems of attempts to fix these fractures. Present study is an attempt to evaluate the functional outcome of primary cemented bipolar hemiarthroplasty in unstable inter-trochanteric fractures in elderly patients. This prospective study included 25 cases with unstable inter-trochanteric fracture of femur between 60 -75 y of age in whom primary Cemented Bipolar hemi - arthroplasty was performed. The patients were followed up at six week, three month, six month and one year postoperatively and assessed using Harris Hip Score (HHS), Lower Extremity Functional Scale (LEFS), Visual analogue scale (VAS) for evaluation of outcome. The mean HHS score was 78.86+8.13 by the end of one year. Similarly mean LEFS score was 34.36+7.01 by the end of one year, whereas the mean pain score on VAS Scale by the year end was 1.04+1.02. The changes in HHS, LEFS and VAS up to six months periods are much greater which starts showing a stable trend thereafter. Fair to good scores were observed in all the patients. We compared our results with those reported by other authors and our study gave quite comparable results. We also used lower extremity function status score (LEFS) for assessment of functional ability. The purpose of its use was that while Harris Hip Score (HHS) provides information on a multitude of factors, LEFS is more patient oriented and provides the correct information about the level of activities a patient can resume post-operatively and can be offered as a self assessment tool. No significant complication except for grade I pressure sores in four patients were seen in postoperative period but they all resolved with proper nursing care by six week follow up. No patient required revision surgery. The authors believe that primary cemented bipolar hemiarthroplasty for

Nuclear Data on Unstable Nuclei for Astrophysics

International Nuclear Information System (INIS)

Smith, Michael Scott; Meyer, Richard A; Lingerfelt, Eric; Scott, J.P.; Hix, William Raphael; Ma, Zhanwen; Bardayan, Daniel W.; Blackmon, Jeff C.; Guidry, Mike W.; KOZUB, RAYMOND L.; Chae, Kyung YuK.

2004-01-01

Recent measurements with radioactive beams at ORNL's Holifield Radioactive Ion Beam Facility (HRIBF) have prompted the evaluation of a number of reactions involving unstable nuclei needed for stellar explosion studies. We discuss these evaluations, as well as the development of a new computational infrastructure to enable the rapid incorporation of the latest nuclear physics results in astrophysics models. This infrastructure includes programs that simplify the generation of reaction rates, manage rate databases, and visualize reaction rates, all hosted at a new website http://www.nucastrodata.org

Analysis of PITFL injuries in rotationally unstable ankle fractures.

Science.gov (United States)

Warner, Stephen J; Garner, Matthew R; Schottel, Patrick C; Hinds, Richard M; Loftus, Michael L; Lorich, Dean G

2015-04-01

Reduction and stabilization of the syndesmosis in unstable ankle fractures is important for ankle mortise congruity and restoration of normal tibiotalar contact forces. Of the syndesmotic ligaments, the posterior inferior tibiofibular ligament (PITFL) provides the most strength for maintaining syndesmotic stability, and previous work has demonstrated the significance of restoring PITFL function when it remains attached to a posterior malleolus fracture fragment. However, little is known regarding the nature of a PITFL injury in the absence of a posterior malleolus fracture. The goal of this study was to describe the PITFL injury pattern based on magnetic resonance imaging (MRI) and intraoperative observation. A prospective database of all operatively treated ankle fractures by a single surgeon was used to identify all supination-external rotation (SER) types III and IV ankle fracture patients with complete preoperative orthogonal ankle radiographs and MRI. All patients with a posterior malleolus fracture were excluded. Using a combination of preoperative imaging and intraoperative findings, we analyzed the nature of injuries to the PITFL. In total, 185 SER III and IV operatively treated ankle fractures with complete imaging were initially identified. Analysis of the preoperative imaging and operative reports revealed 34% (63/185) had a posterior malleolus fracture and were excluded. From the remaining 122 ankle fractures, the PITFL was delaminated from the posterior malleolus in 97% (119/122) of cases. A smaller proportion (3%; 3/122) had an intrasubstance PITFL rupture. Accurate and stable syndesmotic reduction is a significant component of restoring the ankle mortise after unstable ankle fractures. In our large cohort of rotationally unstable ankle fractures without posterior malleolus fractures, we found that most PITFL injuries occur as a delamination off the posterior malleolus. This predictable PITFL injury pattern may be used to guide new methods for

MHTGR inherent heat transfer capability

International Nuclear Information System (INIS)

Berkoe, J.M.

1992-01-01

This paper reports on the Commercial Modular High Temperature Gas-Cooled Reactor (MHTGR) which achieves improved reactor safety performance and reliability by utilizing a completely passive natural convection cooling system called the RCCS to remove decay heat in the event that all active cooling systems fail to operate. For the highly improbable condition that the RCCS were to become non-functional following a reactor depressurization event, the plant would be forced to rely upon its inherent thermo-physical characteristics to reject decay heat to the surrounding earth and ambient environment. A computational heat transfer model was created to simulate such a scenario. Plant component temperature histories were computed over a period of 20 days into the event. The results clearly demonstrate the capability of the MHTGR to maintain core integrity and provide substantial lead time for taking corrective measures

Disabilities caused by unstable mutations in Costa Rica

OpenAIRE

Morales Montero, Fernando; Cuenca Berger, Patricia; Castro Volio, Isabel

2004-01-01

Myotonic dystrophy and fragile X syndrome are two genetically determined relatively common disabilities. Both are examples of a new type of mutation mechanism called unstable or dynamic mutations, triple repeats expansions or DNA amplification. Fragile X syndrome is recognized as the main cause of hereditary mental retardation and myotonic dystrophy is considered the most common muscular dystrophy of adults. This is a prospective non randomized study of clinically affected people,...

Unstable states produced in collisions among complex nuclei

International Nuclear Information System (INIS)

Sepulveda J, D.

1978-01-01

A theory about resonant elastic dispersion is formulated and the wave function of unstable states associated with the resonances observed in the differential and total sections is studied. The object of this theory is to extend to the elastic collisions among complex nuclei interesting case, the methods and formalism of the dispersion of particles without structure by an external potential, following an idea originally formulated by H. Feshbach. (author)

Circumferential wires as a supplement to intramedullary nailing in unstable trochanteric hip fractures

DEFF Research Database (Denmark)

Ban, Ilija; Birkelund, Lasse; Palm, Henrik

2012-01-01

Fixation of unstable trochanteric fractures is challenging. Application of a circumferential wire may facilitate bone contact and avoid postoperative fracture displacement. However, the use of circumferential wires remains controversial due to possible disturbance of the blood supply to the under......Fixation of unstable trochanteric fractures is challenging. Application of a circumferential wire may facilitate bone contact and avoid postoperative fracture displacement. However, the use of circumferential wires remains controversial due to possible disturbance of the blood supply...... to the underlying bone. We evaluated the results of applied circumferential wires, concentrating mainly on complications and reoperations....

Anatomical reconstruction of unstable trochanteric fractures through posterior approach

Directory of Open Access Journals (Sweden)

Partha Saha

2015-01-01

Full Text Available Objective Unstable intertrochanteric fractures continue to be a challenge for orthopedic surgeons due to the functional limitations it results in the postoperative period. Anatomical reconstruction of the posteromedial fragment becomes difficult through conventional lateral approach, leading to excessive fracture collapse and limping. Materials and Methods: prospective, nonrandomized study was done with 40 patients. They were operated in prone position through posterior approach. Cancellous screws or SS-wires were used to fix the greater or lesser trochanteric fragments and dynamic hip screw (DHS or dynamic condylar screw (DCS for the main two fragments. Bone grafts were used to pack cavities at the posterior trochanteric regions. Results: Fracture healing occurred earlier compared to conventional lateral approach without excessive fracture collapse in majority of cases (average time to achieve union was 13.8 weeks; range: 10–18 weeks. Good functional recovery was noted with 75% 'Good' or 'Excellent' Harris Hip Scores at 24 weeks. Conclusion: Anatomical reconstruction of unstable trochanteric fractures becomes easier through posterior approach with earlier and better functional recovery.

Integral Inherently Safe Light Water Reactor (I2S-LWR)

International Nuclear Information System (INIS)

Petrovic, Bojan; Memmott, Matthew; Boy, Guy; Charit, Indrajit; Manera, Annalisa; Downar, Thomas; Lee, John; Muldrow, Lycurgus; Upadhyaya, Belle; Hines, Wesley; Haghighat, Alierza

2017-01-01

This final report summarizes results of the multi-year effort performed during the period 2/2013- 12/2016 under the DOE NEUP IRP Project ''Integral Inherently Safe Light Water Reactors (I 2 S-LWR)''. The goal of the project was to develop a concept of a 1 GWe PWR with integral configuration and inherent safety features, at the same time accounting for lessons learned from the Fukushima accident, and keeping in mind the economic viability of the new concept. Essentially (see Figure 1-1) the project aimed to implement attractive safety features, typically found only in SMRs, to a larger power (1 GWe) reactor, to address the preference of some utilities in the US power market for unit power level on the order of 1 GWe.

Non-physical practice improves task performance in an unstable, perturbed environment: Motor imagery and observational balance training

Directory of Open Access Journals (Sweden)

Wolfgang eTaube

2014-12-01

Full Text Available For consciously performed motor tasks executed in a defined and constant way, both motor imagery (MI and action observation (AO have been shown to promote motor learning. It is not known whether these forms of non-physical training also improve motor actions when these actions have to be variably applied in an unstable and unpredictable environment. The present study therefore investigated the influence of MI balance training (MI_BT and a balance training combining AO and MI (AO+MI_BT on postural control of undisturbed and disturbed upright stance on unstable ground. As spinal reflex excitability after classical (i.e., physical balance training (BT is generally decreased, we tested whether non-physical BT also has an impact on spinal reflex circuits. Thirty-six participants were randomly allocated into an MI_BT group, in which participants imagined postural exercises, an AO+MI_BT group, in which participants observed videos of other people performing balance exercises and imagined being the person in the video, and a non-active control group (CON. Before and after 4 weeks of non-physical training, balance performance was assessed on a free-moving platform during stance without perturbation and during perturbed stance. Soleus H-reflexes were recorded during stable and unstable stance. The post measurement revealed significantly decreased postural sway during undisturbed and disturbed stance after both MI_BT and AO+MI_BT. Spinal reflex excitability remained unchanged. This is the first study showing that non-physical training (MI_BT and AO+MI_BT not only promotes motor learning of ‘rigid’ postural tasks but also improves performance of highly variable and unpredictable balance actions. These findings may be relevant to improve postural control and thus reduce the risk of falls in temporarily immobilized patients.

Bench Press Upper-Body Muscle Activation Between Stable and Unstable Loads.

Science.gov (United States)

Dunnick, Dustin D; Brown, Lee E; Coburn, Jared W; Lynn, Scott K; Barillas, Saldiam R

2015-12-01

The bench press is one of the most commonly used upper-body exercises in training and is performed with many different variations, including unstable loads (ULs). Although there is much research on use of an unstable surface, there is little to none on the use of an UL. The purpose of this study was to investigate muscle activation during the bench press while using a stable load (SL) vs. UL. Twenty resistance-trained men (age = 24.1 ± 2 years; ht = 177.5 ± 5.8 cm; mass = 88.7 ± 13.7 kg) completed 2 experimental conditions (SL and UL) at 2 different intensities (60 and 80% one repetition maximum). Unstable load was achieved by hanging 16 kg kettlebells by elastic bands from the end of the bar. All trial lifts were set to a 2-second cadence with a slight pause at the bottom. Subjects had electrodes attached to 5 muscles (pectoralis major, anterior deltoid, medial deltoid, triceps brachii, and latissimus dorsi) and performed 3 isometric bench press trials to normalize electromyographic data. All 5 muscles demonstrated significantly greater activation at 80% compared with 60% load and during concentric compared with eccentric actions. These results suggest that upper body muscle activation is not different in the bench press between UL and SL. Therefore, coaches should use their preference when designing training programs.

Conventional radiation-biological dosimetry using frequencies of unstable chromosome aberrations

International Nuclear Information System (INIS)

Ramalho, Adriana T.; Costa, Maria Lucia P.; Oliveira, Monica S.

1998-01-01

Frequency of chromosome aberrations detected by conventional cytogenetics is a very useful parameter in biological radiodosimetry. It can be used for estimating absorbed doses in individuals working with radioactive sources and individuals accidentally exposed to radiation. In the first case subjects wear physical dosimeters as a routine safety habit. The laboratory at the Institute of Radioprotection and Dosimetry (IRD, Brazil) has been using conventional cytogenetic analysis to complement data obtained by physical dosimetry since 1983. Until now, more than one hundred cases were investigated where individual physical dosimeters detected occupational exposure (above the safety limits allowed). In total, only 34% of these cases were confirmed by conventional cytogenetic dosimetry. Also, conventional cytogenetic analysis following the radiation accident of Goiania (Brazil) in 1987 have been used. Peripheral lymphocytes from 129 exposed or potentially exposed individuals were analyzed for the frequencies of unstable chromosomal aberrations (dicentrics, centric rings and acentrics fragments) to estimate absorbed radiation doses. During the emergency period, doses were estimated to help immediate medical treatment using in vitro calibration curves produced before the accident. Later on, doses were assessed once more using new in vitro calibration curves. A drawback of this technique is that unstable aberrations are lost after exposure. To investigate the mean lifespan of lymphocytes containing dicentric and ring aberrations, we have followed 15 victims of the Goiania accident over all these years. Results suggest that the disappearance of unstable aberrations is dose-dependent. This could explain the variation in the results found among studies in this field

Conventional radiation-biological dosimetry using frequencies of unstable chromosome aberrations

Energy Technology Data Exchange (ETDEWEB)

Ramalho, Adriana T.; Costa, Maria Lucia P.; Oliveira, Monica S. [Institute of Radioprotection and Dosimetry (IRD), National Commission of Nuclear Energy (CNEN), Av. Salvador Allende, Cx. P. 37750, Rio de Janeiro 22.780-160 (Brazil)

1998-08-03

Frequency of chromosome aberrations detected by conventional cytogenetics is a very useful parameter in biological radiodosimetry. It can be used for estimating absorbed doses in individuals working with radioactive sources and individuals accidentally exposed to radiation. In the first case subjects wear physical dosimeters as a routine safety habit. The laboratory at the Institute of Radioprotection and Dosimetry (IRD, Brazil) has been using conventional cytogenetic analysis to complement data obtained by physical dosimetry since 1983. Until now, more than one hundred cases were investigated where individual physical dosimeters detected occupational exposure (above the safety limits allowed). In total, only 34% of these cases were confirmed by conventional cytogenetic dosimetry. Also, conventional cytogenetic analysis following the radiation accident of Goiania (Brazil) in 1987 have been used. Peripheral lymphocytes from 129 exposed or potentially exposed individuals were analyzed for the frequencies of unstable chromosomal aberrations (dicentrics, centric rings and acentrics fragments) to estimate absorbed radiation doses. During the emergency period, doses were estimated to help immediate medical treatment using in vitro calibration curves produced before the accident. Later on, doses were assessed once more using new in vitro calibration curves. A drawback of this technique is that unstable aberrations are lost after exposure. To investigate the mean lifespan of lymphocytes containing dicentric and ring aberrations, we have followed 15 victims of the Goiania accident over all these years. Results suggest that the disappearance of unstable aberrations is dose-dependent. This could explain the variation in the results found among studies in this field

Prognostic factors for survival of women with unstable spinal bone metastases from breast cancer

International Nuclear Information System (INIS)

Foerster, Robert; Bruckner, Thomas; Bostel, Tilman; Schlampp, Ingmar; Debus, Juergen; Rief, Harald

2015-01-01

Bone metastases are an important clinical issue in women with breast cancer. Particularly, unstable spinal bone metastases (SBM) are a major cause of severe morbidity and reduced quality of life (QoL) due to frequent immobilization. Radiotherapy (RT) is the major treatment modality and is capable of promoting re-ossification and improving stability. Since local therapy response is excellent, survival of these patients with unstable SBM is of high clinical importance. We therefore conducted this analysis to assess survival and to determine prognostic factors for bone survival (BS) in women with breast cancer and unstable SBM. A total population of 92 women with unstable SBM from breast cancer who were treated with RT at our department between January 2000 and January 2012 was retrospectively investigated. We calculated overall survival (OS) and BS (time between first diagnosis of bone metastases until death) with the Kaplan-Meier method and assessed prognostic factors for BS with a Cox regression model. Mean age at first diagnosis of breast cancer was 60.8 years ± SD 12.4 years. OS after 1, 2 and 5 years was 84.8, 66.3 and 50 %, respectively. BS after 1, 2 and 5 years was 62.0, 33.7 and 12 %, respectively. An age > 50 years (p < .001; HR 1.036 [CI 1.015–1.057]), the presence of a single bone metastasis (p = .002; HR 0.469 [CI 0.292–0.753]) and triple negative phenotype (p < .001; HR 1.068 [CI 0.933–1.125]) were identified as independent prognostic factors for BS. Our analysis demonstrated a short survival of women with breast cancer and unstable SBM. Age, presence of a solitary SBM and triple-negative phenotype correlated with survival. Our results may have an impact on therapeutic decisions in the future and offer a rationale for future prospective investigations

Food plant toxicants and safety - Risk assessment and regulation of inherent toxicants in plant foods

DEFF Research Database (Denmark)

Essers, A.J.A.; Alink, G.M.; Speijers, G.J.A.

1998-01-01

The ADI as a tool for risk management and regulation of food additives and pesticide residues is not readily applicable to inherent food plant toxicants: The margin between actual intake and potentially toxic levels is often small; application of the default uncertainty factors used to derive ADI...... values, particularly when extrapolating from animal data, would prohibit the utilisation of the food, which may have an overall beneficial health effect. Levels of inherent toxicants are difficult to control; their complete removal is not always wanted, due to their function for the plant or for human...... health. The health impact of the inherent toxicant is often modified by factors in the food, e.g. the bioavailability from the matrix and interaction with other inherent constituents. Risk-benefit analysis should be made for different consumption scenarios, without the use of uncertainty factors. Crucial...

Gravitationally self-bound quantum states in unstable potentials

Science.gov (United States)

Jääskeläinen, Markku

2018-04-01

Quantum mechanics at present cannot be unified with the theory of gravity at the deepest level, and to guide research towards the solution of this fundamental problem, we need to look for ways to observe or refute predictions originating from attempts to combine quantum theory with gravity. The influence of the gravitational field created by the material density given by the wave function itself gives rise to nontrivial phenomena. In this study I consider the wave function for the center-of-mass coordinate of a spherical mass distribution under the influence of the self-interaction of Newtonian gravity. I solve numerically for the ground state in the presence of an unstable potential and find that the energy of the free-space bound state can be lowered despite the nontrapping character of the potential. The center-of-mass ground state becomes increasingly localized for the used unstable potentials, although only in a limited parameter regime. The feebleness of the energy shift makes the observation of these effects demanding and requires further developments in the cooling of material particles. In addition, the influence of gravitational perturbations that are present in typical laboratory settings necessitates the use of extremely quiet and controlled environments such as those provided by recently proposed space-borne experiments.

Efficient implicit FEM simulation of sheet metal forming

NARCIS (Netherlands)

van den Boogaard, Antonius H.; Meinders, Vincent T.; Huetink, Han

2003-01-01

For the simulation of industrial sheet forming processes, the time discretisation is one of the important factors that determine the accuracy and efficiency of the algorithm. For relatively small models, the implicit time integration method is preferred, because of its inherent equilibrium check.

Development status of PIUS/ISER - a inherently safe reactor for the international use

International Nuclear Information System (INIS)

Wakabayashi, Hiroaki

1987-01-01

It is just in early 1980s that LWR-based nuclear power has become a substantial power source. Though the safety level of nuclear power is always claimed to be sufficiently high by the industry, it rests on the idea of defense in depth, the calculation by probabilistic risk assessment (PRA) or probabilistic safety assessment (PSA). The TMI-2 and Chernobyl-4 accidents occurred in the industrially most advanced countries. In this paper, an alternative way to safe nuclear power is sought in so-called inherently safe reactors (ISR) including the LWR type PIUS/ISER. With proper consideration into the design of nuclear reactor plants, those can be made basically safe through the use of passive safe mechanism for their design. In short, an ISR is a nuclear power reactor which has passive and intrinsic core cooling capability and automatic shutdown capability. As the nuclear power reactors which are currently claimed to be inherently safe, there are the process inherent and ultimately safe reactor (PIUS) of ASEA-ATOM Sweden and the inherently safe and economical reactor (ISER) of the University of Tokyo, Japan, of LWR type. The current status of the development, the reliability, and some technical problems of ISER/PIUS and the attitude of various countries toward ISER/PIUS are described. (Kako, I.)

The distribution of inherent phosphorus in fifteen water treatment ...

African Journals Online (AJOL)

The aim of this investigation was to characterise the chemical properties relevant to P-sorption/desorption processes of 15 South African WTR and to determine the inherent distribution of P within the WTR using a chemical fractionation procedure. The pH, exchangeable Ca and organic carbon content ranged from 4.77 to ...

Comparison of the effects of an eight-week push-up program using stable versus unstable surfaces.

Science.gov (United States)

Chulvi-Medrano, Iván; Martínez-Ballester, Esteban; Masiá-Tortosa, Laura

2012-12-01

Recently, the trend among physical training and rehabilitation professionals is the use of resistance exercise on unstable equipment in order to increase the effort of the agonist and stabilizing muscles. It is unknown if performing exercises on unstable surfaces provides a greater training stimulus as compared to training on a stable training surface. Therefore, the purpose of this research was to compare the effect that push-up training on stable and unstable surfaces had on strength performance in healthy young men. Thirty subjects with experience in resistance training participated in push-up training two days per week for eight weeks on one of three different surfaces: the floor (Tp), the T-Bow® (TBp) or the BOSU® (Bp). Strength, as measured by one repetition maximum (1-RM) and muscle endurance, as measured by number of pushups performed did not improve significantly (p>0.05) for any of the intervention groups. The addition of unstable surfaces in push-up training does not provide greater improvement in muscular strength and endurance than push up training performed on a stable surface in young men. 3b.

How do classical particle-field systems become unstable? - The last physics problem that Ronald Davidson studied

Science.gov (United States)

Qin, Hong

2016-10-01

Many of the classical particle-field systems in (neutral and nonneutral) plasma physics and accelerator physics become unstable when the system parameters vary. How do these instabilities happen? It turns out, very interestingly, that all conservative systems become unstable by the same mechanism, i.e, the resonance between a positive- and a negative-action modes. And this is the only route that a stable system can become unstable. In this talk, I will use several examples in plasma physics and accelerator physics with finite and infinite degrees of freedom to illustrate the basic physical picture and the rigorous theoretical structure of the process. The features at the transition between stable and unstable regions in the parameter space are the fundamental characteristics of the underlying real Hamiltonian system and complex G-Hamiltonian system. The resonance between a positive- and a negative-action modes at the transition is the Krein collision well-known to mathematicians. Research supported by the U.S. Department of Energy (DE-AC02-09CH11466).

Experiments in nonlinear dynamics using control-based continuation: Tracking stable and unstable response curves

DEFF Research Database (Denmark)

Bureau, Emil; Schilder, Frank; Santos, Ilmar

2014-01-01

We show how to implement control-based continuation in a nonlinear experiment using existing and freely available software. We demonstrate that it is possible to track the complete frequency response, including the unstable branches, for a harmonically forced impact oscillator.......We show how to implement control-based continuation in a nonlinear experiment using existing and freely available software. We demonstrate that it is possible to track the complete frequency response, including the unstable branches, for a harmonically forced impact oscillator....

Passive and inherent safety technologies for light-water nuclear reactors

International Nuclear Information System (INIS)

Forsberg, C.W.

1990-07-01

Passive/inherent safety implies a technical revolution in our approach to nuclear power safety. This direction is discussed herein for light-water reactors (LWRs) -- the predominant type of power reactor used in the world today. At Oak Ridge National Laboratory (ORNL) the approach to the development of passive/inherent safety for LWRs consists of four steps: identify and quantify safety requirements and goals; identify and quantify the technical functional requirements needed for safety; identify, invent, develop, and quantify technical options that meet both of the above requirements; and integrate safety systems into designs of economic and reliable nuclear power plants. Significant progress has been achieved in the first three steps of this program. The last step involves primarily the reactor vendors. These activities, as well as related activities worldwide, are described here. 27 refs., 7 tabs

Search for Unstable Heavy and Excited Leptons at LEP2

CERN Document Server

Abbiendi, G.; Akesson, P.F.; Alexander, G.; Allison, John; Anderson, K.J.; Arcelli, S.; Asai, S.; Ashby, S.F.; Axen, D.; Azuelos, G.; Bailey, I.; Ball, A.H.; Barberio, E.; Barlow, Roger J.; Batley, J.R.; Baumann, S.; Behnke, T.; Bell, Kenneth Watson; Bella, G.; Bellerive, A.; Bentvelsen, S.; Bethke, S.; Betts, S.; Biebel, O.; Biguzzi, A.; Bloodworth, I.J.; Bock, P.; Bohme, J.; Boeriu, O.; Bonacorsi, D.; Boutemeur, M.; Braibant, S.; Bright-Thomas, P.; Brigliadori, L.; Brown, Robert M.; Burckhart, H.J.; Capiluppi, P.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, David G.; Chrisman, D.; Ciocca, C.; Clarke, P.E.L.; Clay, E.; Cohen, I.; Conboy, J.E.; Cooke, O.C.; Couchman, J.; Couyoumtzelis, C.; Coxe, R.L.; Cuffiani, M.; Dado, S.; Dallavalle, G.Marco; Dallison, S.; Davis, R.; de Roeck, A.; Dervan, P.; Desch, K.; Dienes, B.; Dixit, M.S.; Donkers, M.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Estabrooks, P.G.; Etzion, E.; Fabbri, F.; Fanfani, A.; Fanti, M.; Faust, A.A.; Feld, L.; Ferrari, P.; Fiedler, F.; Fierro, M.; Fleck, I.; Frey, A.; Furtjes, A.; Futyan, D.I.; Gagnon, P.; Gary, J.W.; Gaycken, G.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Gingrich, D.M.; Glenzinski, D.; Goldberg, J.; Gorn, W.; Grandi, C.; Graham, K.; Gross, E.; Grunhaus, J.; Gruwe, M.; Hajdu, C.; Hanson, G.G.; Hansroul, M.; Hapke, M.; Harder, K.; Harel, A.; Hargrove, C.K.; Harin-Dirac, M.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Herten, G.; Heuer, R.D.; Hildreth, M.D.; Hill, J.C.; Hobson, P.R.; Hocker, James Andrew; Hoffman, Kara Dion; Homer, R.J.; Honma, A.K.; Horvath, D.; Hossain, K.R.; Howard, R.; Huntemeyer, P.; Igo-Kemenes, P.; Imrie, D.C.; Ishii, K.; Jacob, F.R.; Jawahery, A.; Jeremie, H.; Jimack, M.; Jones, C.R.; Jovanovic, P.; Junk, T.R.; Kanaya, N.; Kanzaki, J.; Karapetian, G.; Karlen, D.; Kartvelishvili, V.; Kawagoe, K.; Kawamoto, T.; Kayal, P.I.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Kim, D.H.; Klier, A.; Kobayashi, T.; Kobel, M.; Kokott, T.P.; Kolrep, M.; Komamiya, S.; Kowalewski, Robert V.; Kress, T.; Krieger, P.; von Krogh, J.; Kuhl, T.; Kupper, M.; Kyberd, P.; Lafferty, G.D.; Landsman, H.; Lanske, D.; Lauber, J.; Lawson, I.; Layter, J.G.; Lellouch, D.; Letts, J.; Levinson, L.; Liebisch, R.; Lillich, J.; List, B.; Littlewood, C.; Lloyd, A.W.; Lloyd, S.L.; Loebinger, F.K.; Long, G.D.; Losty, M.J.; Lu, J.; Ludwig, J.; Macchiolo, A.; Macpherson, A.; Mader, W.; Mannelli, M.; Marcellini, S.; Marchant, T.E.; Martin, A.J.; Martin, J.P.; Martinez, G.; Mashimo, T.; Mattig, Peter; McDonald, W.John; McKenna, J.; Mckigney, E.A.; McMahon, T.J.; McPherson, R.A.; Meijers, F.; Mendez-Lorenzo, P.; Merritt, F.S.; Mes, H.; Meyer, I.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Mohr, W.; Montanari, A.; Mori, T.; Nagai, K.; Nakamura, I.; Neal, H.A.; Nisius, R.; O'Neale, S.W.; Oakham, F.G.; Odorici, F.; Ogren, H.O.; Okpara, A.; Oreglia, M.J.; Orito, S.; Pasztor, G.; Pater, J.R.; Patrick, G.N.; Patt, J.; Perez-Ochoa, R.; Petzold, S.; Pfeifenschneider, P.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poli, B.; Polok, J.; Przybycien, M.; Quadt, A.; Rembser, C.; Rick, H.; Robins, S.A.; Rodning, N.; Roney, J.M.; Rosati, S.; Roscoe, K.; Rossi, A.M.; Rozen, Y.; Runge, K.; Runolfsson, O.; Rust, D.R.; Sachs, K.; Saeki, T.; Sahr, O.; Sang, W.M.; Sarkisian, E.K.G.; Sbarra, C.; Schaile, A.D.; Schaile, O.; Scharff-Hansen, P.; Schieck, J.; Schmitt, S.; Schoning, A.; Schroder, Matthias; Schumacher, M.; Schwick, C.; Scott, W.G.; Seuster, R.; Shears, T.G.; Shen, B.C.; Shepherd-Themistocleous, C.H.; Sherwood, P.; Siroli, G.P.; Skuja, A.; Smith, A.M.; Snow, G.A.; Sobie, R.; Soldner-Rembold, S.; Spagnolo, S.; Sproston, M.; Stahl, A.; Stephens, K.; Stoll, K.; Strom, David M.; Strohmer, R.; Surrow, B.; Tafirout, R.; Talbot, S.D.; Taras, P.; Tarem, S.; Teuscher, R.; Thiergen, M.; Thomas, J.; Thomson, M.A.; Torrence, E.; Towers, S.; Trefzger, T.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turner-Watson, M.F.; Ueda, I.; Van Kooten, Rick J.; Vannerem, P.; Verzocchi, M.; Voss, H.; Wackerle, F.; Waller, D.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wengler, T.; Wermes, N.; Wetterling, D.; White, J.S.; Wilson, G.W.; Wilson, J.A.; Wyatt, T.R.; Yamashita, S.; Zacek, V.; Zer-Zion, D.

2000-01-01

Searches for unstable neutral and charged heavy leptons, N and L+-, and for excited states of neutral and charged leptons, nu*, e*, mu*, and tau*, have been performed in e+e- collisions using data collected by the OPAL detector at LEP. The data analysed correspond to an integrated luminosity of about 58pb-1 at a centre-of-mass energy of 183GeV, and about 10pb-1 each at 161GeV and 172GeV. No evidence for new particles was found. Lower limits on the masses of unstable heavy and excited leptons are derived. From the analysis of charged-current, neutral-current, and photonic decays of singly produced excited leptons, upper limits are determined for the ratio of the coupling to the compositeness scale, f/Lambda, for masses up to the kinematic limit. For excited leptons, the limits are established independently of the relative values of the coupling constants f and f'.

Developing a model for hospital inherent safety assessment: Conceptualization and validation.

Science.gov (United States)

Yari, Saeed; Akbari, Hesam; Gholami Fesharaki, Mohammad; Khosravizadeh, Omid; Ghasemi, Mohammad; Barsam, Yalda; Akbari, Hamed

2018-01-01

Paying attention to the safety of hospitals, as the most crucial institute for providing medical and health services wherein a bundle of facilities, equipment, and human resource exist, is of significant importance. The present research aims at developing a model for assessing hospitals' safety based on principles of inherent safety design. Face validity (30 experts), content validity (20 experts), construct validity (268 examples), convergent validity, and divergent validity have been employed to validate the prepared questionnaire; and the items analysis, the Cronbach's alpha test, ICC test (to measure reliability of the test), composite reliability coefficient have been used to measure primary reliability. The relationship between variables and factors has been confirmed at 0.05 significance level by conducting confirmatory factor analysis (CFA) and structural equations modeling (SEM) technique with the use of Smart-PLS. R-square and load factors values, which were higher than 0.67 and 0.300 respectively, indicated the strong fit. Moderation (0.970), simplification (0.959), substitution (0.943), and minimization (0.5008) have had the most weights in determining the inherent safety of hospital respectively. Moderation, simplification, and substitution, among the other dimensions, have more weight on the inherent safety, while minimization has the less weight, which could be due do its definition as to minimize the risk.

Beneficial effect of nitrates on myocardial glucose utilization in unstable angina pectoris

International Nuclear Information System (INIS)

Araujo, L.I.; Camici, P.; Spinks, T.; Jones, T.; Maseri, A.

1987-01-01

Myocardial uptake of the glucose analog F-18-2-fluoro-2-deoxy-D-glucose (FDG) was assessed by positron emission tomography in 6 normal volunteers, 7 patients with chronic stable angina and 22 patients with unstable angina at rest in fasting conditions. Regional myocardial perfusion was assessed by rubidium-82. The study was repeated a few days later after intravenous infusion of isosorbide dinitrate. FDG uptake was similar in control subjects and patients with stable angina (0.023 +/- 0.032 vs 0.012 +/- 0.008 mol/ml/min, p less than 0.42) but was about 4-fold higher on the average in patients with unstable angina (0.084 +/- 0.047, p less than 0.01). The severity of coronary obstructions in stable and unstable angina patients was similar. The increased uptake involved the whole heart, including areas not distal to critically stenosed vessels; it was not associated with reduced myocardial perfusion and was not related to a recent episode of transient ischemia as assessed by symptoms and by Holter monitoring. After continuous infusion of nitrates, FDG uptake was consistently and significantly reduced toward normal levels both in areas perfused by critically stenosed coronary arteries and by noncritically stenosed vessels

Basis, evidences and consequences of the inherent stellar encocooning

CERN Document Server

Celis, L

2002-01-01

Based on 7093 observations with photoelectrical photometrical measurements of 191 Mira stars, the following equations (from the papers [1] to [18]) give the basis to establish the Inherent Stellar Encocooning with the spectro-photometric characteristics of the red giant variable stars, especially the Miras, which have large amplitudes (approx 50% of giant variables). The specific basis that justifies a progressive covering with ionized molecules, cold gases, dust and grains are: The relation of the visual amplitudes A sub v =A sub r +E sub A whose real luminosity separate the intrinsic pulsation and amplitude excess effects due to the presence of molecules [145] and an opaque envelope of cool gases; The relation of the visual absolute magnitudes M sub v =M sub v sub r (P)+M sub a (delta sub T sub i sub O V) which is affected by an inherent absorption and/or occultation, and; The relation that defines the probable absolute luminosity and depends on the period and the (Sa) spectral type at maximum M sub v =-2.2...

Electromagnetic form factors of hadrons

International Nuclear Information System (INIS)

Zidell, V.S.

1976-01-01

A vector meson dominance model of the electromagnetic form factors of hadrons is developed which is based on the use of unstable particle propagators. Least-square fits are made to the proton, neutron, pion and kaon form factor data in both the space and time-like regions. A good fit to the low-energy nucleon form factor data is obtained using only rho, ω, and phi dominance, and leads to a determination of the vector meson resonance parameters in good agreement with experiment. The nucleon-vector meson coupling constants obey simple sum rules indicating that there exists no hard core contribution to the form factors within theoretical uncertainties. The prediction for the electromagnetic radii of the proton is in reasonable agreement with recent experiments. The pion and kaon charge form factors as deduced from the nucleon form factors assuming vector meson universality are compared to the data. The pion form factor agrees with the data in both the space and time-like regions. The pion charge radius is in agreement with the recent Dubna result, but the isovector P-wave pion-pion phase shift calculated from the theory disagrees with experiment. A possible contribution to the form factors from a heavy rho meson is also evaluated

Fluoroscopy-guided reduction and fibular nail fixation to manage unstable ankle fractures in patients with diabetes: a retrospective cohort study.

Science.gov (United States)

Ashman, B D; Kong, C; Wing, K J; Penner, M J; Bugler, K E; White, T O; Younger, A S E

2016-09-01

Patients with diabetes are at increased risk of wound complications after open reduction and internal fixation of unstable ankle fractures. A fibular nail avoids large surgical incisions and allows anatomical reduction of the mortise. We retrospectively reviewed the results of fluoroscopy-guided reduction and percutaneous fibular nail fixation for unstable Weber type B or C fractures in 24 adult patients with type 1 or type 2 diabetes. The re-operation rate for wound dehiscence or other indications such as amputation, mortality and functional outcomes was determined. Two patients developed lateral side wound infection, one of whom underwent wound debridement. Three other patients required re-operation for removal of symptomatic hardware. No patient required a below-knee amputation. Six patients died during the study period for unrelated reasons. At a median follow-up of 12 months (7 to 38) the mean Short Form-36 Mental Component Score and Physical Component Score were 53.2 (95% confidence intervals (CI) 48.1 to 58.4) and 39.3 (95% CI 32.1 to 46.4), respectively. The mean Visual Analogue Score for pain was 3.1 (95% 1.4 to 4.9). The mean Ankle Osteoarthritis Scale total score was 32.9 (95% CI 16.0 to 49.7). Fluoroscopy-guided reduction and fibular nail fixation of unstable ankle fractures in patients with diabetes was associated with a low incidence of wound and overall complications, while providing effective surgical fixation. Cite this article: Bone Joint J 2016;98-B:1197-1201. ©2016 The British Editorial Society of Bone & Joint Surgery.

Subphotospheric fluctuations in magnetized radiative envelopes: contribution from unstable magnetosonic waves

Science.gov (United States)

Sen, Koushik; Fernández, Rodrigo; Socrates, Aristotle

2018-06-01

We examine the excitation of unstable magnetosonic waves in the radiative envelopes of intermediate- and high-mass stars with a magnetic field of ˜kG strength. Wind clumping close to the star and microturbulence can often be accounted for when including small-scale, subphotospheric density or velocity perturbations. Compressional waves - with wavelengths comparable to or shorter than the gas pressure scale height - can be destabilized by the radiative flux in optically thick media when a magnetic field is present, in a process called the radiation-driven magneto-acoustic instability (RMI). The instability does not require radiation or magnetic pressure to dominate over gas pressure, and acts independently of subsurface convection zones. Here we evaluate the conditions for the RMI to operate on a grid of stellar models covering a mass range 3-40 M⊙ at solar metallicity. For a uniform 1 kG magnetic field, fast magnetosonic modes are unstable down to an optical depth of a few tens, while unstable slow modes extend beyond the depth of the iron convection zone. The qualitative behaviour is robust to magnetic field strength variations by a factor of a few. When combining our findings with previous results for the saturation amplitude of the RMI, we predict velocity fluctuations in the range ˜0.1-10 km s-1. These amplitudes are a monotonically increasing function of the ratio of radiation to gas pressure, or alternatively, of the zero-age main sequence mass.

Force Outputs during Squats Performed Using a Rotational Inertia Device under Stable versus Unstable Conditions with Different Loads.

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Jairo Vázquez-Guerrero

Full Text Available The purpose of the study was to compare the force outputs achieved during a squat exercise using a rotational inertia device in stable versus unstable conditions with different loads and in concentric and eccentric phases. Thirteen male athletes (mean ± SD: age 23.7 ± 3.0 years, height 1.80 ± 0.08 m, body mass 77.4 ± 7.9 kg were assessed while squatting, performing one set of three repetitions with four different loads under stable and unstable conditions at maximum concentric effort. Overall, there were no significant differences between the stable and unstable conditions at each of the loads for any of the dependent variables. Mean force showed significant differences between some of the loads in stable and unstable conditions (P < 0.010 and peak force output differed between all loads for each condition (P < 0.045. Mean force outputs were greater in the concentric than in the eccentric phase under both conditions and with all loads (P < 0.001. There were no significant differences in peak force between concentric and eccentric phases at any load in either stable or unstable conditions. In conclusion, squatting with a rotational inertia device allowed the generation of similar force outputs under stable and unstable conditions at each of the four loads. The study also provides empirical evidence of the different force outputs achieved by adjusting load conditions on the rotational inertia device when performing squats, especially in the case of peak force. Concentric force outputs were significantly higher than eccentric outputs, except for peak force under both conditions. These findings support the use of the rotational inertia device to train the squatting exercise under unstable conditions for strength and conditioning trainers. The device could also be included in injury prevention programs for muscle lesions and ankle and knee joint injuries.

Force Outputs during Squats Performed Using a Rotational Inertia Device under Stable versus Unstable Conditions with Different Loads.

Science.gov (United States)

Vázquez-Guerrero, Jairo; Moras, Gerard; Baeza, Jennifer; Rodríguez-Jiménez, Sergio

2016-01-01

The purpose of the study was to compare the force outputs achieved during a squat exercise using a rotational inertia device in stable versus unstable conditions with different loads and in concentric and eccentric phases. Thirteen male athletes (mean ± SD: age 23.7 ± 3.0 years, height 1.80 ± 0.08 m, body mass 77.4 ± 7.9 kg) were assessed while squatting, performing one set of three repetitions with four different loads under stable and unstable conditions at maximum concentric effort. Overall, there were no significant differences between the stable and unstable conditions at each of the loads for any of the dependent variables. Mean force showed significant differences between some of the loads in stable and unstable conditions (P inertia device allowed the generation of similar force outputs under stable and unstable conditions at each of the four loads. The study also provides empirical evidence of the different force outputs achieved by adjusting load conditions on the rotational inertia device when performing squats, especially in the case of peak force. Concentric force outputs were significantly higher than eccentric outputs, except for peak force under both conditions. These findings support the use of the rotational inertia device to train the squatting exercise under unstable conditions for strength and conditioning trainers. The device could also be included in injury prevention programs for muscle lesions and ankle and knee joint injuries.

Robust Model-based Control of Open-loop Unstable Processes

International Nuclear Information System (INIS)

Emad, Ali

1999-01-01

This paper addresses the development of new formulations for estimating modeling errors or unmeasured disturbances to be used in Model Predictive Control (MPC) algorithms during open-loop prediction. Two different formulations were developed in this paper. One is used in MPC that directly utilizes linear models and the other in MPC that utilizes non-linear models. These estimation techniques were utilized to provide robust performance for MPC algorithms when the plant is open-loop unstable and under the influence of modeling error and/or unmeasured disturbances. For MPC that utilizes a non-linear model, the estimation technique is formulated as a fixed small size on-line optimization problem, while for linear MPC, the unmeasured disturbances are estimated via a proposed linear disturbance model. The disturbance model coefficients are identified on-line from historical estimates of plant-model mismatch. The effectiveness of incorporating these proposed estimation techniques into MPC is tested through simulated implementation on non-linear unstable exothermic fluidized bed reactor. Closed-loop simulations proved the capability of the proposed estimation methods to stabilize and, thereby, improve the MPC performance in such cases. (Author)

Monitoring cardiac output during hyperbaric oxygen treatment of haemodynamically unstable patients

DEFF Research Database (Denmark)

Hansen, Marco Bo; Treschow, Frederik; Skielboe, Martin

2013-01-01

Patients suffering from necrotizing fasciitis (NF) are often haemodynamically unstable and require extended monitoring of cardiovascular parameters; yet this is limited during hyperbaric oxygen treatment (HBOT). We aimed to evaluate the use and safety of transoesophageal Doppler (TED) monitoring ...

The effect of nonlinearity on unstable zones of Mathieu equation

Indian Academy of Sciences (India)

2017-02-09

Feb 9, 2017 ... Abstract. Mathieu equation is a well-known ordinary differential equation in which the excitation term appears as the non-constant coefficient. The mathematical modelling of many dynamic systems leads to Mathieu equation. The determination of the locus of unstable zone is important for the control of ...

Compact All Solid State Oceanic Inherent Optical Property Sensor, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Light propagation in the sea and the consequent remote sensing signals seen by aircraft and spacecraft is fundamentally governed by the inherent optical properties...

Communicating uncertainty: managing the inherent probabilistic character of hazard estimates

Science.gov (United States)

Albarello, Dario

2013-04-01

Science is much more fixing the limits of our knowledge about possible occurrences than the identification of any "truth". This is particularly true when scientific statements concern prediction of natural phenomena largely exceeding the laboratory scale as in the case of seismogenesis. In these cases, many scenarios about future occurrences result possible (plausible) and the contribution of scientific knowledge (based on the available knowledge about underlying processes or the phenomenological studies) mainly consists in attributing to each scenario a different level of likelihood (probability). In other terms, scientific predictions in the field of geosciences (hazard assessment) are inherently probabilistic. However, despite of this, many scientist (seismologists, etc.) in communicating their position in public debates tend to stress the " truth" of their statements against the fancy character of pseudo-scientific assertions: stronger is the opposition of science and pseudo-science, more hidden becomes the probabilistic character of scientific statements. The problem arises when this kind of "probabilistic" knowledge becomes the basis of any political action (e.g., to impose expensive form of risk reducing activities): in these cases the lack of any definitive "truth" requires a direct assumption of responsibility by the relevant decider (being the single citizen or the legitimate expression of a larger community) to choose among several possibilities (however characterized by different levels of likelihood). In many cases, this can be uncomfortable and strong is the attitude to delegate to the scientific counterpart the responsibility of these decisions. This "transfer" from the genuine political field to an improper scientific context is also facilitated by the lack of a diffuse culture of "probability" outside the scientific community (and in many cases inside also). This is partially the effect of the generalized adoption (by media and scientific

Inherently safe nuclear-driven internal combustion engines

International Nuclear Information System (INIS)

Alesso, P.; Chow, Tze-Show; Condit, R.; Heidrich, J.; Pettibone, J.; Streit, R.

1991-01-01

A family of nuclear driven engines is described in which nuclear energy released by fissioning of uranium or plutonium in a prompt critical assembly is used to heat a working gas. Engine performance is modeled using a code that calculates hydrodynamics, fission energy production, and neutron transport self-consistently. Results are given demonstrating a large negative temperature coefficient that produces self-shutoff of energy production. Reduced fission product inventory and the self-shutoff provide inherent nuclear safety. It is expected that nuclear engine reactor units could be scaled from 100 MW on up. 7 refs., 3 figs

Closed reduction with CT-guided screw fixation for unstable sacroiliac joint fracture-dislocation

Energy Technology Data Exchange (ETDEWEB)

Baskin, Kevin M.; Cahill, Ann Marie; Kaye, Robin D. [Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); Born, Christopher T. [Temple University Hospital/Temple Children' s Hospital, Temple Sports Medicine, Marlton, NJ (United States); Grudziak, Jan S. [Children' s Hospital of Pittsburgh, Department of Orthopedic Surgery, Pittsburgh, PA (United States); Towbin, Richard B.

2004-12-01

Unstable posterior pelvic ring fractures and dislocations are uncommon but potentially life-threatening injuries in children. Early definitive management reduces risk of immediate complications as well as chronic pain and gait dysfunction. Conventional operative therapy carries substantial risk of extensive blood loss and iatrogenic neurological and vascular injury. Minimally invasive image-guided intervention may further reduce immediate risk and improve long-term outcome. To describe CT-guided closed reduction and internal fixation (CRIF) and review outcomes of unstable fracture-dislocation of the sacroiliac (SI) joint in children. Between 2000 and 2003, three children (two girls, one boy) age 8-14 years were referred to interventional radiology for treatment of unstable SI joint fracture-dislocation not adequately treated with anterior external fixation alone. The three affected SI joints (two left, one right) were treated in a combined approach by pediatric interventional radiologists and orthopedic surgeons, using a percutaneous approach under CT guidance. Over a threaded guiding pin, 7.3 mm cannulated screws were used to achieve stable reduction of the affected SI joints. One screw was removed after slight (2 mm) migration. No neurovascular or other complications occurred. All patients had satisfactory healing with near-anatomic reduction, although recovery of the youngest was delayed by associated spinal injury. Compared to open surgical alternatives, CRIF under CT guidance reduces operating time, decreases blood loss, and allows early definitive fixation and immediate non-weight-bearing mobilization with a low rate of complication for unstable posterior pelvic ring fractures. In addition, CT-guided placement of the guide pin may allow safer screw positioning and may minimize the total number of screws needed to achieve pelvic stability. (orig.)

Cost-utility of enoxaparin compared with unfractionated heparin in unstable coronary artery disease

Directory of Open Access Journals (Sweden)

Milne Ruairidh

2001-10-01

Full Text Available Abstract Background Low molecular weight heparins hold several advantages over unfractionated heparin including convenience of administration. Enoxaparin is one such heparin licensed in the UK for use in unstable coronary artery disease (unstable stable angina and non-Q wave myocardial infarction. In these patients, two large randomised controlled trials and their meta-analysis showed small benefits for enoxaparin over unfractionated heparin at 30–43 days and potentially at one year. We found no relevant published full economic evaluations, only cost studies, one of which was conducted in the UK. The other studies, from the US, Canada and France, are difficult to interpret since their resource use and costs may not reflect UK practice. Methods We aimed to compare the benefits and costs of short-term treatment (two to eight days with enoxaparin and unfractionated heparin in unstable coronary artery disease. We used published data sources to estimate the incremental cost per quality adjusted life year (QALY, adopting a NHS perspective and using 1998 prices. Results The base case was a 0.013 QALY gain and net cost saving of £317 per person treated with enoxaparin instead of unfractionated heparin. All but one sensitivity analysis showed net savings and QALY gains, the exception (the worst case being a cost per QALY of £3,305. Best cases were a £495 saving and 0.013 QALY gain, or a £317 saving and 0.014 QALY gain per person. Conclusions Enoxaparin appears cost saving compared with unfractionated heparin in patients with unstable coronary artery disease. However, cost implications depend on local revascularisation practice.

Closed reduction with CT-guided screw fixation for unstable sacroiliac joint fracture-dislocation

International Nuclear Information System (INIS)

Baskin, Kevin M.; Cahill, Ann Marie; Kaye, Robin D.; Born, Christopher T.; Grudziak, Jan S.; Towbin, Richard B.

2004-01-01

Unstable posterior pelvic ring fractures and dislocations are uncommon but potentially life-threatening injuries in children. Early definitive management reduces risk of immediate complications as well as chronic pain and gait dysfunction. Conventional operative therapy carries substantial risk of extensive blood loss and iatrogenic neurological and vascular injury. Minimally invasive image-guided intervention may further reduce immediate risk and improve long-term outcome. To describe CT-guided closed reduction and internal fixation (CRIF) and review outcomes of unstable fracture-dislocation of the sacroiliac (SI) joint in children. Between 2000 and 2003, three children (two girls, one boy) age 8-14 years were referred to interventional radiology for treatment of unstable SI joint fracture-dislocation not adequately treated with anterior external fixation alone. The three affected SI joints (two left, one right) were treated in a combined approach by pediatric interventional radiologists and orthopedic surgeons, using a percutaneous approach under CT guidance. Over a threaded guiding pin, 7.3 mm cannulated screws were used to achieve stable reduction of the affected SI joints. One screw was removed after slight (2 mm) migration. No neurovascular or other complications occurred. All patients had satisfactory healing with near-anatomic reduction, although recovery of the youngest was delayed by associated spinal injury. Compared to open surgical alternatives, CRIF under CT guidance reduces operating time, decreases blood loss, and allows early definitive fixation and immediate non-weight-bearing mobilization with a low rate of complication for unstable posterior pelvic ring fractures. In addition, CT-guided placement of the guide pin may allow safer screw positioning and may minimize the total number of screws needed to achieve pelvic stability. (orig.)

[Usefullness of intrasacral fixation in an extremely unstable lumbosacral spine].

Science.gov (United States)

Nishiura, Tsukasa; Nishiguchi, Mitsuhisa; Kusaka, Noboru; Takayama, Kazuhiro; Maeda, Yasuhiko; Ogihara, Kotaro; Nakagawa, Minoru

2007-04-01

Intrasacral fixation technique devised by Jackson is said to provide rigid lumbosacral fixation. We treated 3 cases of lumbosacral lesions using this technique in which lumbosacral segment had become extremely unstable during surgical intervention adding to the effect of original lesions. In all cases, surgeries were performed in 2 stages, intrasacral fixation and anterior stabilization. Case 1: A 52-year-old male was diagnosed fungal discitis and spondylitis at L4 and L5. X-ray showed destruction of the vertebral bodies. L2, L3 and sacrum were fixed posteriorly using the intrasacral fixation technique. One week after the first operation, L4 and L5 vertebral bodies were replaced by long fibula grafts through the extraperitoneal approach. Case 2: A 25-year-old female with cauda equina syndrome and abnormal body form diagnosed as having spondyloptosis in which the entire vertebral body of L5 had descended below the endplate of S1. MR imaging revealed marked canal stenosis at the S1 level. In the first surgery, L5 vertebral body was resected through the transperitoneal approach. After 1 week of bed rest, posterior segments of L5 were resected, L4 was affixed to the sacrum and anterior stabilization was achieved with 2 mesh cages and lumbosacral spine was fixed using the intrasacral fixation technique. Case 3: A 64-year-old female was diagnosed as having pyogenic discitis and osteomyelitis at the L5-S1 level. In spite of successful medical treatment for infection, low back pain continued. Radiologically, L5 vertebral body was shown to have collapsed and slipped anteriorly over the sacrum. L3, L4 and sacrum were fixed by intrasacral fixation. One week after the first operation, the L5/S1 disc and the suppurtive vertebral bodies were resected through the extraperitoneal approach and anterior stabilization was performed with iliac bone grafts. At follow-up for a minimum of 6 months, initial fixation was maintained in all 3 cases and bony fusion was obtained. The

Use of unstable chromosome aberrations for biological dosimetry after the first postirradiation mitosis

International Nuclear Information System (INIS)

Doloy, M.T.; Malarbet, J.L.; Guedeney, G.; Bourguignon, M.; Leroy, A.; Reillaudou, M.; Masse, R.

1991-01-01

The loss of unstable chromosome aberrations after the first postirradiation mitosis makes their use difficult in radiation dosimetry. We describe here a method which, in a cell population observed at this stage, allows retrospective estimation of the frequencies of the unstable aberrations induced at the time of irradiation, and their use as a dosimeter. The laws controlling the behavior of unstable aberrations during mitosis were defined from a large-scale experiment on irradiated human lymphocytes. For cells undergoing the first, second, or third mitosis after irradiation, relationships were determined between the frequency, at irradiation time, of acentric fragments not arising from formation of dicentrics or rings, and the ratio of dicentrics and centric rings appearing without acentric fragments to the total number of dicentrics plus rings. On the basis of this ratio, the method described here provides an assessment of the postirradiation mitotic activity in a cell population. This assessment permitted estimation of the cell distribution and frequency of dicentrics plus centric rings, and of the frequency of acentric fragments at the time of irradiation. The use of this method for retrospective dosimetry after whole-body irradiation under various conditions of exposure is illustrated

Temperature-Driven Change in the Unstable Growth Mode on Patterned GaAs(001)

International Nuclear Information System (INIS)

Tadayyon-Eslami, T.; Phaneuf, R. J.; Kan, H.-C.; Calhoun, L. C.

2006-01-01

We observe a dramatic change in the unstable growth mode during GaAs molecular beam epitaxy on patterned GaAs(001) as the temperature is lowered through approximately 540 deg. C, roughly coincident with the preroughening temperature. Observations of the As 2 flux dependence, however, rule out thermodynamic preroughening as driving the growth mode change. Similar observations rule out the change in surface reconstruction as the cause. Instead, we find evidence that the change in the unstable growth mode can be explained by a competition between the decreased adatom collection rate on small terraces and a small anisotropic barrier to adatom diffusion downward across step bunches

On Debye radius measurement in an unstable gas discharged plasma

International Nuclear Information System (INIS)

Shvilkin, B.N.

1998-01-01

It is shown that at low concentrations of charged particles conditions can be realized in a magnetized unstable-to-drift plasma for which concentration perturbations are comparable to the concentration itself. The electron temperature is then determined by potential fluctuations, and the drift oscillation wavelength is of the order of the Debye length

Treatment of unstable trochanteric fractures : the balance between man and material

NARCIS (Netherlands)

I.B. Schipper (Inger)

2003-01-01

textabstractTreatment of unstable trochanteric fractures poses a challenge to surgeons in many ways. Accepting this challenge requires understanding of those parameters that determine the outcome. In operative fracture care at least four elements influence the outcome of treatment: the patient, the

Unstable genes unstable mind: beyond the central dogma of molecular biology.

Science.gov (United States)

Hegde, Mahabaleshwar V; Saraph, Arundhati A

2011-08-01

Schizophrenia has a polygenic mode of inheritance and an estimated heritability of over 80%, but success in understanding its genetic underpinnings to date has been modest. Unlike in trinucleotide neurodegenerative disorders, the phenomenon of genetic anticipation observed in schizophrenia or bipolar disorder has not been explained. For the first time, we provide a plausible molecular explanation of genetic anticipation and pathophysiology of schizophrenia, at least in part, with supporting evidence. We postulate that abnormally increased numbers of CAG repeats in many genes being expressed in the brain, coding for glutamine, cumulatively press for higher demand of glutamine in the respective brain cells, resulting in a metabolic crisis and dysregulation of the glutamate-glutamine cycle. This can adversely affect the functioning of both glutamate and GABA receptors, which are known to be involved in psychosis, and may also affect glutathione levels, increasing oxidative stress. The resulting psychosis (gain in function), originating from unstable genes, is described as an effect "beyond the central dogma of molecular biology". The hypothesis explains genetic anticipation, as further expansions in subsequent generations may result in increased severity and earlier occurrence. Many other well described findings provide proof of concept. This is a testable hypothesis, does not deny any known facts and opens up new avenues of research. Copyright © 2011 Elsevier Ltd. All rights reserved.

Chimera Type Behavior in Nonlocal Coupling System with Two Different Inherent Frequencies

Science.gov (United States)

Lin, Larry; Li, Ping-Cheng; Tseng, Hseng-Che

2014-03-01

From the research of Kuramoto and Strogatz, arrays of identical oscillators can display a remarkable pattern, named chimera state, in which phase-locked oscillators coexist with drifting ones in nonlocal coupling oscillator system. We consider further in this study, two groups of oscillators with different inherent frequencies and arrange them in a ring. When the difference of the inherent frequencies is within some specific parameter range, oscillators of nonlocal coupling system show two distinct chimera states. When the parameter value exceeds some threshold value, two chimera states disappear. They show different features. The statistical dynamic behavior of the system can be described by Kuramoto theory.

Probabilities of inherent shutdown of unprotected events in innovative liquid metal reactors

International Nuclear Information System (INIS)

Mueller, C.J.

1987-01-01

The uncertainty in predicting the effectiveness of inherent shutdown (ISD) in innovative designs results from three broad contributing areas of uncertainty: (1) the inability to exactly predict the frequency of ATWS events with potential to challenge the safety systems and require ISD; (2) the approximation of representing all such ATWS events by a selected set of ''generic scenarios''; and (3) the inability to exactly calculate the core response to the selected generic scenarios. In this summary, the methodology and associated results of work used to establish probabilities of failure of inherent shutdown of innovative LMRs to the unprotected loss-of-flow (LOF) accident are discussed

Inherent safety characteristics of innovative reactors

International Nuclear Information System (INIS)

Heil, J.A.

1995-11-01

The added safety value of innovative or third generation reactor designs has been evaluated in order to determine the most suitable candidate for Dutch government funded research and development support. To this end, four innovative reactor concepts, viz. PIUS (Process Inherent Ultimate Safety), PRISM (Power Reactor Innovative Small), HTR-M (High Temperature Reactor Module) and MHTGR (Modular High Temperature Gas-cooled Reactor), have been studied and their passive and inherent safety characteristics have been outlined. Also the outlook for further technological and industrial development has been considered. The results of the study confirm the perspective of the innovative reactors for reduced dependence on active safety provisions and for a further reduced vulnerability to technical failures and human errors. The accident responses to generic accident initiators, viz. reactivity and cooling accidents, and also to reactor specific accidents show that neither active safety systems nor short term operator actions are required for maintaining the reactor core in a controlled and coolable condition. Whether this gives rise to a higher total safety of the innovative reactor designs, compared to evolutionary or advanced reactors, cannot be concluded. Supplementary experimental and analytical analyses of reactor specific accidents are required to be able to assess the safety of these innovative designs in a more quantitative manner. It is believed that the safety case of innovative reactors, which are less dependent on active safety systems, can be communicated with the general public in a more transparent way. Considering the perspective for further technological and industrial development it is not expected that any of the considered innovative reactor concepts will become commercially available within the next one to two decades. However, they could be made available earlier if they would receive sufficient financial backing. Considering the added safety perspectives

Unstable footwear as a speed-dependent noise-based training gear to exercise inverted pendulum motion during walking.

Science.gov (United States)

Dierick, Frédéric; Bouché, Anne-France; Scohier, Mikaël; Guille, Clément; Buisseret, Fabien

2018-05-15

Previous research on unstable footwear has suggested that it may induce mechanical noise during walking. The purpose of this study was to explore whether unstable footwear could be considered as a noise-based training gear to exercise body center of mass (CoM) motion during walking. Ground reaction forces were collected among 24 healthy young women walking at speeds between 3 and 6 km h -1 with control running shoes and unstable rocker-bottom shoes. The external mechanical work, the recovery of mechanical energy of the CoM during and within the step cycles, and the phase shift between potential and kinetic energy curves of the CoM were computed. Our findings support the idea that unstable rocker-bottom footwear could serve as a speed-dependent noise-based training gear to exercise CoM motion during walking. At slow speed, it acts as a stochastic resonance or facilitator that reduces external mechanical work; whereas at brisk speed it acts as a constraint that increases external mechanical work and could mimic a downhill slope.

Unstable bodyweight and incident type 2 diabetes mellitus: A meta-analysis.

Science.gov (United States)

Kodama, Satoru; Fujihara, Kazuya; Ishiguro, Hajime; Horikawa, Chika; Ohara, Nobumasa; Yachi, Yoko; Tanaka, Shiro; Shimano, Hitoshi; Kato, Kiminori; Hanyu, Osamu; Sone, Hirohito

2017-07-01

The present meta-analysis aimed to clarify the association of unstable bodyweight with the risk of type 2 diabetes mellitus, an association that has been controversial among longitudinal studies. An electronic literature search using EMBASE and MEDLINE was followed up to 31 August 2016. The relative risks (RRs) of type 2 diabetes mellitus in individuals with unstable bodyweight were pooled using the inverse variance method. Eight studies were eligible for the meta-analysis. The median duration of measurements of weight change and follow-up years for ascertaining type 2 diabetes mellitus were 13.5 and 9.4 years, respectively. The pooled RR for the least vs most stable category was 1.33 (95% confidence interval 1.12-1.57). Between-study heterogeneity was statistically significant (P = 0.048). Whether type 2 diabetes mellitus was ascertained by blood testing explained 66.0% of the variance in the logarithm of RR (P = 0.02). In three studies in which blood testing was carried out, type 2 diabetes mellitus risk was not significant (RR 1.06, 95% confidence interval 0.91-1.25). Furthermore, publication bias that inflated type 2 diabetes mellitus risk was statistically detected by Egger's test (P = 0.09). Unstable bodyweight might be modestly associated with the elevated risk of type 2 diabetes mellitus; although serious biases, such as diagnostic suspicion bias and publication bias, made it difficult to assess this association. © 2017 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

Inherently safe in situ uranium recovery

Science.gov (United States)

Krumhansl, James L; Brady, Patrick V

2014-04-29

An in situ recovery of uranium operation involves circulating reactive fluids through an underground uranium deposit. These fluids contain chemicals that dissolve the uranium ore. Uranium is recovered from the fluids after they are pumped back to the surface. Chemicals used to accomplish this include complexing agents that are organic, readily degradable, and/or have a predictable lifetime in an aquifer. Efficiency is increased through development of organic agents targeted to complexing tetravalent uranium rather than hexavalent uranium. The operation provides for in situ immobilization of some oxy-anion pollutants under oxidizing conditions as well as reducing conditions. The operation also artificially reestablishes reducing conditions on the aquifer after uranium recovery is completed. With the ability to have the impacted aquifer reliably remediated, the uranium recovery operation can be considered inherently safe.

Geometries inherent to N=1 supergravities

International Nuclear Information System (INIS)

Galperin, A.S.; Ogievetsky, V.I.; Sokatchev, E.S.

1981-01-01

The first part of the talk is devoted to a consideration of linearized N=1 supergravities. The second main part deals with complex geometries inherent to different N=1 supergravities. A special attention is paid to a new version with local symmetry. It is connected to the special nonminimal case (n=0) having a remarkable property of supervolume preservation in Csup(4.4) superspace. Therefore the superdeterminant of change of variables from left to right-handed Rsup(4.4) parametrization is a dimensionless scalar. This geometric invariant has to be constrained to obtain an action. Solving such a constraint on vector and spinor prepotentials in Wess-Zumino gauge one obtains the new supergravity with 12+12 fields and local symmetry. A possible relaxation of this constraint is briefly considered (16+16 fields version) [ru

Multiphonon structure of γ-unstable or O(6) nuclei

International Nuclear Information System (INIS)

Otsuka, T.; Kim, K.H.

1995-01-01

The multiphonon structure is shown for the O(6) limit of the Interacting Boson Model. The phonon states are created by the O(6) quadrupole operator with proper symmetrization. All the σ = N states can be described in this scheme in terms of phonon quanta and two-phonon anharmonicity, while the ground state is γ unstable. This structure is carried over into higher-lying σ < N states. (author)

Fixation of Trochanteric Fragments in Cementless Bipolar Hemiarthroplasty of Unstable Intertrochanteric Fracture: Cerclage Wiring.

Science.gov (United States)

Lee, Young-Kyun; Park, Chan Ho; Koo, Kyung-Hoi

2017-12-01

Bipolar hemiarthroplasty (HA) is an option for the treatment of unstable intertrochanteric fracture in elderly patients. There is a raising concern regarding cable-grip related complications for the fixation of trochanteric fragments. Therefore, the aim of this study was to evaluate outcome of cementless HA with fixation for the trochanteric fragments using monofilament wires in unstable intertrochanteric fracture. We reviewed 92 cementless bipolar HAs using a grit-blasted long stem design for unstable intertrochanteric fractures in 91 elderly patients with a mean age of 81.7 years. During the arthroplasty, trochanteric fracture fragments were fixed using 1 or 2 vertical wires and transverse wires. We evaluated the clinical outcomes such as abductor power, ambulatory ability and wire-related complications, and radiologic outcomes including the union of the trochanteric fragment and subsidence of stem. Sixty-two patients were followed for a minimum of 2 years (mean, 59 months) postoperatively. The mean abductor power and Koval category was 4.1 (range, 3 to 5) and 4.6 (range, 1 to 6). The wire was broken in 3 hips (4.8%) and the nonunion of the greater trochanter occurred in 1 hips (1.6%). Two stems subsided by 3 mm and 8 mm, respectively, during postoperative 6 weeks, after which the subsidence was not progressive. Cerclage wiring of the trochanter using monofilament wire leads to acceptable outcome in cementless HA for senile patients with unstable intertrochanteric fracture. Cerclage wiring using a monofilament wire is recommended for the fixation of trochanteric fragments.

Porter-Thomas distribution in unstable many-body systems

International Nuclear Information System (INIS)

Volya, Alexander

2011-01-01

We use the continuum shell model approach to explore the resonance width distribution in unstable many-body systems. The single-particle nature of a decay, the few-body character of the interaction Hamiltonian, and the collectivity that emerges in nonstationary systems due to the coupling to the continuum of reaction states are discussed. Correlations between the structures of the parent and daughter nuclear systems in the common Fock space are found to result in deviations of decay width statistics from the Porter-Thomas distribution.

Mlh1 deficiency in normal mouse colon mucosa associates with chromosomally unstable colon cancer

Science.gov (United States)

Pussila, Marjaana; Törönen, Petri; Einarsdottir, Elisabet; Katayama, Shintaro; Krjutškov, Kaarel; Holm, Liisa; Kere, Juha; Peltomäki, Päivi; Mäkinen, Markus J; Linden, Jere; Nyström, Minna

2018-01-01

Abstract Colorectal cancer (CRC) genome is unstable and different types of instabilities, such as chromosomal instability (CIN) and microsatellite instability (MSI) are thought to reflect distinct cancer initiating mechanisms. Although 85% of sporadic CRC reveal CIN, 15% reveal mismatch repair (MMR) malfunction and MSI, the hallmarks of Lynch syndrome with inherited heterozygous germline mutations in MMR genes. Our study was designed to comprehensively follow genome-wide expression changes and their implications during colon tumorigenesis. We conducted a long-term feeding experiment in the mouse to address expression changes arising in histologically normal colonic mucosa as putative cancer preceding events, and the effect of inherited predisposition (Mlh1+/−) and Western-style diet (WD) on those. During the 21-month experiment, carcinomas developed mainly in WD-fed mice and were evenly distributed between genotypes. Unexpectedly, the heterozygote (B6.129-Mlh1tm1Rak) mice did not show MSI in their CRCs. Instead, both wildtype and heterozygote CRC mice showed a distinct mRNA expression profile and shortage of several chromosomal segregation gene-specific transcripts (Mlh1, Bub1, Mis18a, Tpx2, Rad9a, Pms2, Cenpe, Ncapd3, Odf2 and Dclre1b) in their colon mucosa, as well as an increased mitotic activity and abundant numbers of unbalanced/atypical mitoses in tumours. Our genome-wide expression profiling experiment demonstrates that cancer preceding changes are already seen in histologically normal colon mucosa and that decreased expressions of Mlh1 and other chromosomal segregation genes may form a field-defect in mucosa, which trigger MMR-proficient, chromosomally unstable CRC. PMID:29701748

A simple graphical method for measuring inherent safety

International Nuclear Information System (INIS)

Gupta, J.P.; Edwards, David W.

2003-01-01

Inherently safer design (ISD) concepts have been with us for over two decades since their elaboration by Kletz [Chem. Ind. 9 (1978) 124]. Interest has really taken off globally since the early nineties after several major mishaps occurred during the eighties (Bhopal, Mexico city, Piper-alfa, Philips Petroleum, to name a few). Academic and industrial research personnel have been actively involved into devising inherently safer ways of production. The regulatory bodies have also shown deep interest since ISD makes the production safer and hence their tasks easier. Research funding has also been forthcoming for new developments as well as for demonstration projects. A natural question that arises is as to how to measure ISD characteristics of a process? Several researchers have worked on this [Trans. IChemE, Process Safety Environ. Protect. B 71 (4) (1993) 252; Inherent safety in process plant design, Ph.D. Thesis, VTT Publication Number 384, Helsinki University of Technology, Espoo, Finland, 1999; Proceedings of the Mary Kay O'Connor Process Safety Center Symposium, 2001, p. 509]. Many of the proposed methods are very elegant, yet too involved for easy adoption by the industry which is scared of yet another safety analysis regime. In a recent survey [Trans. IChemE, Process Safety Environ. Prog. B 80 (2002) 115], companies desired a rather simple method to measure ISD. Simplification is also an important characteristic of ISD. It is therefore desirable to have a simple ISD measurement procedure. The ISD measurement procedure proposed in this paper can be used to differentiate between two or more processes for the same end product. The salient steps are: Consider each of the important parameters affecting the safety (e.g., temperature, pressure, toxicity, flammability, etc.) and the range of possible values these parameters can have for all the process routes under consideration for an end product. Plot these values for each step in each process route and compare. No

Integral fast reactor concept inherent safety features

International Nuclear Information System (INIS)

Marchaterre, J.F.; Sevy, R.H.; Cahalan, J.E.

1987-01-01

The Integral Fast Reactor (IFR) is an innovative liquid-metal-cooled reactor concept being developed at Argonne National Laboratory. The two major goals of the IFT development effort are improved economics and enhanced safety. The design features that together fulfill these goals are: 1) a liquid metal (sodium) coolant, 2) a pool-type reactor primary system configuration, 3) an advanced ternary alloy metallic fuel, and 4) an integral fuel cycle. This paper reviews the design features that contribute to the safety margins inherent to the IFR concept. Special emphasis is placed on the ability of the IFR design to accommodate anticipated transients without scram (ATWS)

Inherent Error in Asynchronous Digital Flight Controls.

Science.gov (United States)

1980-02-01

operation will be eliminated. If T* is close to T, the inherent error (eA) is a small value. Then the deficiency of the basic model, which is de... tK2 at m ~VCONTR0RKIPPIL I~+ R tKT 2 TKT 5 ~I G E 1 i V OTN TRIL 2-REDN HNE IjT e UT 3 ~49__I 4.) 4 -4 - 4.-4 U 4.) k-4E-- Iz E-4 P E-44)-4. 4.)l 1s...indicate the channel failure. To reduce this deficiency , the new model computes a tolerance value equal to the maximum steady-state sample covariance of the

Integral Fast Reactor concept inherent safety features

International Nuclear Information System (INIS)

Marchaterre, J.F.; Sevy, R.H.; Cahalan, J.E.

1986-01-01

The Integral Fast Reactor (IFR) is an innovative liquid-metal-cooled reactor concept being developed at Argonne National Laboratory. The two major goals of the IFR development effort are improved economics and enhanced safety. The design features that together fulfill these goals are: (1) a liquid metal (sodium) coolant, (2) a pool-type reactor primary system configuration, (3) an advanced ternary alloy metallic fuel, and (4) an integral fuel cycle. This paper reviews the design features that contribute to the safety margins inherent to the IFR concept. Special emphasis is placed on the ability of the IFR design to accommodate anticipated transients without scram (ATWS)

Effects of constant immigration on the dynamics and persistence of stable and unstable Drosophila populations

Science.gov (United States)

Dey, Snigdhadip; Joshi, Amitabh

2013-01-01

Constant immigration can stabilize population size fluctuations but its effects on extinction remain unexplored. We show that constant immigration significantly reduced extinction in fruitfly populations with relatively stable or unstable dynamics. In unstable populations with oscillations of amplitude around 1.5 times the mean population size, persistence and constancy were unrelated. Low immigration enhanced persistence without affecting constancy whereas high immigration increased constancy without enhancing persistence. In relatively stable populations with erratic fluctuations of amplitude close to the mean population size, both low and high immigration enhanced persistence. In these populations, the amplitude of fluctuations relative to mean population size went down due to immigration, and their dynamics were altered to low-period cycles. The effects of immigration on the population size distribution and intrinsic dynamics of stable versus unstable populations differed considerably, suggesting that the mechanisms by which immigration reduced extinction risk depended on underlying dynamics in complex ways. PMID:23470546

Novel OSNR Monitoring Technique in Dense WDM Systems using Inherently Generated CW Monitoring Channels

DEFF Research Database (Denmark)

Petersen, Martin Nordal

2007-01-01

We present a simple, yet effective OSNR monitoring technique based on an inherent effect in the optical modulator. Highly accurate OSNR monitoring is demonstrated in a 40 Gb/s dense WDM system with 50 GHz channel spacing.......We present a simple, yet effective OSNR monitoring technique based on an inherent effect in the optical modulator. Highly accurate OSNR monitoring is demonstrated in a 40 Gb/s dense WDM system with 50 GHz channel spacing....

Unstable quantum states and rigged Hilbert spaces

International Nuclear Information System (INIS)

Gorini, V.; Parravicini, G.

1978-10-01

Rigged Hilbert space techniques are applied to the quantum mechanical treatment of unstable states in nonrelativistic scattering theory. A method is discussed which is based on representations of decay amplitudes in terms of expansions over complete sets of generalized eigenvectors of the interacting Hamiltonian, corresponding to complex eigenvalues. These expansions contain both a discrete and a continuum contribution. The former corresponds to eigenvalues located at the second sheet poles of the S matrix, and yields the exponential terms in the survival amplitude. The latter arises from generalized eigenvectors associated to complex eigenvalues on background contours in the complex plane, and gives the corrections to the exponential law. 27 references

16 CFR 1211.13 - Inherent force activated secondary door sensors.

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Inherent force activated secondary door sensors. 1211.13 Section 1211.13 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT... across the door so that the axis is perpendicular to the plane of the door. See Figure 6 of this part...

Search for unstable sequential neutral and charged heavy leptons in $e^{+}e^{-}$ annihilation at $\\sqrt{s}$ = 130 and 136 GeV

CERN Document Server

Acciarri, M; Adriani, O; Aguilar-Benítez, M; Ahlen, S P; Alpat, B; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alverson, G; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Antreasyan, D; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Ball, R C; Banerjee, S; Banicz, K; Barillère, R; Barone, L; Bartalini, P; Baschirotto, A; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Biasini, M; Biland, A; Bilei, G M; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böck, R K; Böhm, A; Borgia, B; Boucham, A; Bourilkov, D; Bourquin, Maurice; Brambilla, Elena; Branson, J G; Brigljevic, V; Brock, I C; Buijs, A; Bujak, A T; Burger, J D; Burger, W J; Busenitz, J K; Buytenhuijs, A O; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Caria, M; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Castello, R; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chan, A; Chang, Y H; Chaturvedi, U K; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chéreau, X J; Chiefari, G; Chien, C Y; Choi, M T; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Cohn, H O; Coignet, G; Colijn, A P; Colino, N; Commichau, V; Costantini, S; Cotorobai, F; de la Cruz, B; Dai, T S; D'Alessandro, R; De Asmundis, R; De Boeck, H; Degré, A; Deiters, K; Denes, P; De Notaristefani, F; DiBitonto, Daryl; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dorne, I; Dova, M T; Drago, E; Duchesneau, D; Duinker, P; Durán, I; Dutta, S; Easo, S; Efremenko, Yu V; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ernenwein, J P; Extermann, Pierre; Fabre, M; Faccini, R; Falciano, S; Favara, A; Fay, J; Felcini, Marta; Furetta, C; Ferguson, T; Fernández, D; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Forconi, G; Fredj, L; Freudenreich, Klaus; Galaktionov, Yu; Ganguli, S N; Gau, S S; Gentile, S; Gerald, J; Gheordanescu, N; Giagu, S; Goldfarb, S; Goldstein, J; Gong, Z F; Gougas, Andreas; Gratta, Giorgio; Grünewald, M W; Gupta, V K; Gurtu, A; Gutay, L J; Hangarter, K; Hartmann, B; Hasan, A; Hebbeker, T; Hervé, A; Van Hoek, W C; Hofer, H; Hoorani, H; Hou, S R; Hu, G; Ilyas, M M; Innocente, Vincenzo; Janssen, H; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kasser, A; Khan, R A; Kamyshkov, Yu A; Kapinos, P; Kapustinsky, J S; Karyotakis, Yu; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, J K; Kim, S C; Kim, Y G; Kinnison, W W; Kirkby, A; Kirkby, D; Kirkby, Jasper; Kittel, E W; Klimentov, A; König, A C; Köngeter, A; Korolko, I; Koutsenko, V F; Koulbardis, A; Krämer, R W; Kramer, T; Krenz, W; Kuijten, H; Kunin, A; Ladrón de Guevara, P; Landi, G; Lapoint, C; Lassila-Perini, K M; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee Jae Sik; Lee, K Y; Le Goff, J M; Leiste, R; Lenti, M; Leonardi, E; Levchenko, P M; Li Chuan; Lieb, E H; Lin, W T; Linde, Frank L; Lindemann, B; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lu, W; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Ludovici, L; Luminari, L; Lustermann, W; Ma Wen Gan; Macchiolo, A; Maity, M; Majumder, G; Malgeri, L; Malinin, A; Maña, C; Mangla, S; Marchesini, P A; Marin, A; Martin, J P; Marzano, F; Massaro, G G G; Mazumdar, K; McNally, D; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mi, Y; Mihul, A; Van Mil, A J W; Mirabelli, G; Mnich, J; Möller, M; Monteleoni, B; Moore, R; Morganti, S; Mount, R; Müller, S; Muheim, F; Nagy, E; Nahn, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Nippe, A; Nowak, H; Organtini, G; Ostonen, R; Pandoulas, D; Paoletti, S; Paolucci, P; Park, H K; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pei, Y J; Pensotti, S; Perret-Gallix, D; Petrak, S; Pevsner, A; Piccolo, D; Pieri, M; Pinto, J C; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Produit, N; Raghavan, R; Rahal-Callot, G; Rancoita, P G; Rattaggi, M; Raven, G; Razis, P A; Read, K; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Ricker, A; Riemann, S; Riemers, B C; Riles, K; Ro, S; Robohm, A; Rodin, J; Rodríguez-Calonge, F J; Roe, B P; Röhner, S; Romero, L; Rosier-Lees, S; Rosselet, P; Van Rossum, W; Roth, S; Rubio, Juan Antonio; Rykaczewski, H; Salicio, J; Sánchez, E; Santocchia, A; Sarakinos, M E; Sarkar, S; Sassowsky, M; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schmitz, P; Schneegans, M; Schöneich, B; Scholz, N; Schopper, Herwig Franz; Schotanus, D J; Schulte, R; Schultze, K; Schwenke, J; Schwering, G; Sciacca, C; Sciarrino, D; Sens, Johannes C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shukla, J; Shumilov, E; Siedenburg, T; Son, D; Sopczak, André; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Sticozzi, F; Stone, H; Stoyanov, B; Strässner, A; Strauch, K; Sudhakar, K; Sultanov, G G; Sun, L Z; Susinno, G F; Suter, H; Swain, J D; Tang, X W; Tauscher, Ludwig; Taylor, L; Ting, Samuel C C; Ting, S M; Toker, O; Tonisch, F; Tonutti, M; Tonwar, S C; Tóth, J; Tsaregorodtsev, A Yu; Tully, C; Tuchscherer, H; Tung, K L; Ulbricht, J; Uwer, U; Valente, E; Van de Walle, R T; Vetlitskii, I; Viertel, Gert M; Vivargent, M; Völkert, R; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, J C; Wang, X L; Wang, Y F; Wang, Z M; Weber, A; Wittgenstein, F; Wu, S X; Wynhoff, S; Xu, J; Xu, Z Z; Yang, B Z; Yang, C G; Yao, X Y; Ye, J B; Yeh, S C; You, J M; Zaccardelli, C; Zalite, A; Zemp, P; Zeng, Y; Zhang, Z; Zhang, Z P; Zhou, B; Zhou, Y; Zhu, G Y; Zhu, R Y; Zichichi, Antonino

1996-01-01

A search for unstable sequential neutral and charged heavy leptons has been made at center-of-mass energies 130 and 136 \\GeV\\ with the L3 detector at LEP. The neutral leptons are assumed to decay via mixing to electrons and muons. No evidence for their existence was found. We exclude unstable Dirac neutrinos for masses below 59.3 (57.9) \\GeV\\ and unstable Majorana neutrinos below 48.6 (47.2) \\GeV\\ if the neutrino couples to the electron(muon) family. We exclude unstable charged heavy leptons for masses below 61 \\GeV\\ for a wide range of the associated neutral lepton mass.

Treatment of unstable intraarticular fracture of distal radius: POP casting with external fixation.

Science.gov (United States)

ur Rahman, Obaid; Khan, Mohammad Qadeem; Rasheed, Haroon; Ahmad, Saleem

2012-04-01

To compare radiological and functional outcome of external fixation and distraction with conservative Plaster of Paris (POP) cast for unstable intra-articular fractures of the distal radius. The study was conducted on 60 patients with unstable intra-articular fracture of distal radius who reported to emergency or outpatient Orthopaedic Surgery department of Benazir Bhutto Hospital, Rawalpindi, between March and August 2007. They were divided into two equal groups: Group A and Group B, treated by Plaster of Paris cast, and external fixation with distraction respectively. The functional outcome in terms of freedom from pain, range of movement, grip power and deformity, and the radiological outcome of radial length, incongruity and radio-ulnar joint position were analysed at three months follow-up using a 3-point scoring scale. In Group A, 1 (3%) patient showed excellent result, 8 (27%) patients good results, 19 (63%) patients fair results and 2 (7%) patients poor result. In Group B, 14 (47%) patients showed excellent results, 11 (37%) patients good results, 4 (13%) patients fair results and 1 (3%) patient poor result. The outcome score of the Group B patients was significantly better compared to the Group A patients (p value advantages over conventional Plaster of Paris cast in the treatment of unstable intra-articular fractures of distal radius.

Immediate percutaneous sacroiliac screw insertion for unstable pelvic fractures: is it safe enough?

Science.gov (United States)

Acker, A; Perry, Z H; Blum, S; Shaked, G; Korngreen, A

2018-04-01

The purpose of this study was to compare the results of immediate and delayed percutaneous sacroiliac screws surgery for unstable pelvic fractures, regarding technical results and complication rate. Retrospective study. The study was conducted at the Soroka University Medical center, Beer Sheva, Israel, which is a level 1 trauma Center. 108 patients with unstable pelvic injuries were operated by the orthopedic department at the Soroka University Medical Center between the years 1999-2010. A retrospective analysis found 50 patients with immediate surgery and 58 patients with delayed surgery. Preoperative and postoperative imaging were analyzed and data was collected regarding complications. All patients were operated on by using the same technique-percutaneous fixation of sacroiliac joint with cannulated screws. The study's primary outcome measure was the safety and quality of the early operation in comparison with the late operation. A total of 156 sacroiliac screws were inserted. No differences were found between the immediate and delayed treatment groups regarding technical outcome measures (P value = 0.44) and complication rate (P value = 0.42). The current study demonstrated that immediate percutaneous sacroiliac screw insertion for unstable pelvic fractures produced equally good technical results, in comparison with the conventional delayed operation, without additional complications.

Disease resistance is related to inherent swimming performance in Atlantic salmon.

Science.gov (United States)

Castro, Vicente; Grisdale-Helland, Barbara; Jørgensen, Sven M; Helgerud, Jan; Claireaux, Guy; Farrell, Anthony P; Krasnov, Aleksei; Helland, Ståle J; Takle, Harald

2013-01-21

Like humans, fish can be classified according to their athletic performance. Sustained exercise training of fish can improve growth and physical capacity, and recent results have documented improved disease resistance in exercised Atlantic salmon. In this study we investigated the effects of inherent swimming performance and exercise training on disease resistance in Atlantic salmon.Atlantic salmon were first classified as either poor or good according to their swimming performance in a screening test and then exercise trained for 10 weeks using one of two constant-velocity or two interval-velocity training regimes for comparison against control trained fish (low speed continuously). Disease resistance was assessed by a viral disease challenge test (infectious pancreatic necrosis) and gene expression analyses of the host response in selected organs. An inherently good swimming performance was associated with improved disease resistance, as good swimmers showed significantly better survival compared to poor swimmers in the viral challenge test. Differences in mortalities between poor and good swimmers were correlated with cardiac mRNA expression of virus responsive genes reflecting the infection status. Although not significant, fish trained at constant-velocity showed a trend towards higher survival than fish trained at either short or long intervals. Finally, only constant training at high intensity had a significant positive effect on fish growth compared to control trained fish. This is the first evidence suggesting that inherent swimming performance is associated with disease resistance in fish.

Disease resistance is related to inherent swimming performance in Atlantic salmon

Directory of Open Access Journals (Sweden)

Castro Vicente

2013-01-01

Full Text Available Abstract Background Like humans, fish can be classified according to their athletic performance. Sustained exercise training of fish can improve growth and physical capacity, and recent results have documented improved disease resistance in exercised Atlantic salmon. In this study we investigated the effects of inherent swimming performance and exercise training on disease resistance in Atlantic salmon. Atlantic salmon were first classified as either poor or good according to their swimming performance in a screening test and then exercise trained for 10 weeks using one of two constant-velocity or two interval-velocity training regimes for comparison against control trained fish (low speed continuously. Disease resistance was assessed by a viral disease challenge test (infectious pancreatic necrosis and gene expression analyses of the host response in selected organs. Results An inherently good swimming performance was associated with improved disease resistance, as good swimmers showed significantly better survival compared to poor swimmers in the viral challenge test. Differences in mortalities between poor and good swimmers were correlated with cardiac mRNA expression of virus responsive genes reflecting the infection status. Although not significant, fish trained at constant-velocity showed a trend towards higher survival than fish trained at either short or long intervals. Finally, only constant training at high intensity had a significant positive effect on fish growth compared to control trained fish. Conclusions This is the first evidence suggesting that inherent swimming performance is associated with disease resistance in fish.

Capture cross sections on unstable nuclei

Science.gov (United States)

Tonchev, A. P.; Escher, J. E.; Scielzo, N.; Bedrossian, P.; Ilieva, R. S.; Humby, P.; Cooper, N.; Goddard, P. M.; Werner, V.; Tornow, W.; Rusev, G.; Kelley, J. H.; Pietralla, N.; Scheck, M.; Savran, D.; Löher, B.; Yates, S. W.; Crider, B. P.; Peters, E. E.; Tsoneva, N.; Goriely, S.

2017-09-01

Accurate neutron-capture cross sections on unstable nuclei near the line of beta stability are crucial for understanding the s-process nucleosynthesis. However, neutron-capture cross sections for short-lived radionuclides are difficult to measure due to the fact that the measurements require both highly radioactive samples and intense neutron sources. Essential ingredients for describing the γ decays following neutron capture are the γ-ray strength function and level densities. We will compare different indirect approaches for obtaining the most relevant observables that can constrain Hauser-Feshbach statistical-model calculations of capture cross sections. Specifically, we will consider photon scattering using monoenergetic and 100% linearly polarized photon beams. Challenges that exist on the path to obtaining neutron-capture cross sections for reactions on isotopes near and far from stability will be discussed.

Capture cross sections on unstable nuclei

Directory of Open Access Journals (Sweden)

Tonchev A.P.

2017-01-01

Full Text Available Accurate neutron-capture cross sections on unstable nuclei near the line of beta stability are crucial for understanding the s-process nucleosynthesis. However, neutron-capture cross sections for short-lived radionuclides are difficult to measure due to the fact that the measurements require both highly radioactive samples and intense neutron sources. Essential ingredients for describing the γ decays following neutron capture are the γ-ray strength function and level densities. We will compare different indirect approaches for obtaining the most relevant observables that can constrain Hauser-Feshbach statistical-model calculations of capture cross sections. Specifically, we will consider photon scattering using monoenergetic and 100% linearly polarized photon beams. Challenges that exist on the path to obtaining neutron-capture cross sections for reactions on isotopes near and far from stability will be discussed.

Scalar Hairy Black Holes in Four Dimensions are Unstable

Science.gov (United States)

Ganchev, Bogdan; Santos, Jorge E.

2018-04-01

We present a numerical analysis of the stability properties of the black holes with scalar hair constructed by Herdeiro and Radu. We prove the existence of a novel gauge where the scalar field perturbations decouple from the metric perturbations, and analyze the resulting quasinormal mode spectrum. We find unstable modes with characteristic growth rates which for uniformly small hair are almost identical to those of a massive scalar field on a fixed Kerr background.

Three-dimensional TDHF calculation for reactions of unstable nuclei

Energy Technology Data Exchange (ETDEWEB)

Kim, Ka-Hae; Otsuka, Takaharu [Tokyo Univ. (Japan). Dept. of Physics; Bonche, P.

1998-07-01

The fusion is studied for reactions between a stable and an unstable nuclei with neutron skin. The reactions {sup 16,28}O+{sup 40}Ca and {sup 16}O+{sup 16,28}O are taken as examples, and the three-dimensional time-dependent Hartree-Fock method with the full Skyrme interaction is used. It is confirmed that the fusion cross section in low-energy region is sensitive to the interaction used in the calculation. (author)

Scalar Hairy Black Holes in Four Dimensions are Unstable.

Science.gov (United States)

Ganchev, Bogdan; Santos, Jorge E

2018-04-27

We present a numerical analysis of the stability properties of the black holes with scalar hair constructed by Herdeiro and Radu. We prove the existence of a novel gauge where the scalar field perturbations decouple from the metric perturbations, and analyze the resulting quasinormal mode spectrum. We find unstable modes with characteristic growth rates which for uniformly small hair are almost identical to those of a massive scalar field on a fixed Kerr background.

Inherent wettability of different rock surfaces at nanoscale: a theoretical study

Science.gov (United States)

Chang, Xiao; Xue, Qingzhong; Li, Xiaofang; Zhang, Jianqiang; Zhu, Lei; He, Daliang; Zheng, Haixia; Lu, Shuangfang; Liu, Zilong

2018-03-01

Investigating the inherent wettability of rock surfaces at nanoscale is of great importance in ore floatation and oil recovery field. Using molecular dynamics simulations, we systematically study the wetting behavior of water on different rock surfaces (silica, calcite, gypsum, halite and graphite) at nanoscale. It is demonstrated that the inherent rock wettability follows the order of gypsum > calcite > halite > silica > graphite. Remarkably, we also manifest that the polarity of oil molecules can affect the water contact angles on silica surface. For example, the water contact angles on silica surface in hexane, dodecane, thiophene and toluene are 58 ± 2°, 63 ± 3°, 90 ± 1°, 118 ± 1°, respectively. Furthermore, we investigate the wetting behavior of water on heterogeneous rock surfaces and find that water molecules can move from hydrophobic surface to hydrophilic surface.

Rock slope instabilities in Norway: First systematic hazard and risk classification of 22 unstable rock slopes

Science.gov (United States)

Böhme, Martina; Hermanns, Reginald L.; Oppikofer, Thierry; Penna, Ivanna

2016-04-01

Unstable rock slopes that can cause large failures of the rock-avalanche type have been mapped in Norway for almost two decades. Four sites have earlier been characterized as high-risk objects based on expertise of few researchers. This resulted in installing continuous monitoring systems and set-up of an early-warning system for those four sites. Other unstable rock slopes have not been ranked related to their hazard or risk. There are ca. 300 other sites known of which 70 sites were installed for periodic deformation measurements using multiple techniques (Global Navigation Satellite Systems, extensometers, measurement bolts, and others). In 2012 a systematic hazard and risk classification system for unstable rock slopes was established in Norway and the mapping approach adapted to that in 2013. Now, the first 22 sites were classified for hazard, consequences and risk using this classification system. The selection of the first group of sites to be classified was based on an assumed high hazard or risk and importance given to the sites by Norwegian media and the public. Nine of the classified 22 unstable rock slopes are large sites that deform inhomogeneously or are strongly broken up in individual blocks. This suggests that different failure scenarios are possible that need to be analyzed individually. A total of 35 failure scenarios for those nine unstable rock slopes were considered. The hazard analyses were based on 9 geological parameters defined in the classification system. The classification system will be presented based on the Gamanjunni unstable rock slope. This slope has a well developed back scarp that exposes 150 m preceding displacement. The lateral limits of the unstable slope are clearly visible in the morphology and InSAR displacement data. There have been no single structures observed that allow sliding kinematically. The lower extend of the displacing rock mass is clearly defined in InSAR data and by a zone of higher rock fall activity. Yearly

Interdependency control : compensation strategies for the inherent vulnerability of critical infrastructure networks

International Nuclear Information System (INIS)

Mao, D.; Sotoodeh, M.; Monu, K.; Marti, J.R.; Srivastava, K.D.

2009-01-01

Today's increasingly interacting national critical infrastructures (NCIs) can tolerate most stochastic local disturbances. However, they are extremely fragile under global disturbances, as the latter may either push the whole system into a critical state or reveal many unexpected hidden interdependencies, inducing or triggering cascading failures among all possible layers. This robust yet fragile duality is an inherent vulnerability of modern infrastructures. It is therefore expected that weather-related disasters will be more frequent under a changing climate. This paper proposed an interdependency control strategy (ICS) that would maintain the survival of the most critical services, and compensate for this inherent vulnerability during emergency states. The paper also proposed a generalized adjacency matrix (GAM) to represent the physical interdependencies intra/inter of various infrastructure networks. The vulnerable section in the network can be identified, based on computed results of GAM, number of islands in the network, and influence domain(s) of each component. These features render ICS more effective and convincing. Last, the paper proposed a survivability index for isolated sub-networks and described relevant measures for improving this index during the four phases of emergency management. It was concluded that the proposed strategy is an effective means to reduce the inherent vulnerability and increase the resiliency of these critical infrastructures networks. 20 refs., 5 figs

The inherent catastrophic traps in retrograde CTO PCI.

Science.gov (United States)

Wu, Eugene B; Tsuchikane, Etsuo

2018-05-01

When we learn to drive, our driving instructor tells us how to check the side mirror and turn your head to check the blind spot before changing lanes. He tells us how to stop at stop signs, how to drive in slippery conditions, the safe stopping distances, and these all make our driving safe. Similarly, when we learn PCI, our mentors teach us to seat the guiding catheter co-axially, to wire the vessel safely, to deliver balloon and stents over the wire, to watch the pressure of the guiding, in order that we perform PCI safely and evade complications. In retrograde CTO PCI, there is no such published teaching. Also many individual mentors have not had the wide experience to see all the possible complications of retrograde CTO PCI and, therefore, may not be able to warn their apprentice. As the number of retrograde procedures increase worldwide, there is a corresponding increase in catastrophic complications, many of which, we as experts, can see are easily avoidable. To breach this gap in knowledge, this article describes 12 commonly met inherent traps in retrograde CTO PCI. They are inherent because by arranging our equipment in the manner to perform retrograde CTO PCI, these complications are either induced directly or happen easily. We hope this work will enhance safety of retrograde CTO PCI and avoid many catastrophic complications for our readers and operators. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Pathways for double-strand break repair in genetically unstable Z-DNA-forming sequences.

Science.gov (United States)

Kha, Diem T; Wang, Guliang; Natrajan, Nithya; Harrison, Lynn; Vasquez, Karen M

2010-05-14

DNA can adopt many structures that differ from the canonical B-form, and several of these non-canonical DNA structures have been implicated in genetic instability associated with human disease. Earlier, we found that Z-DNA causes DNA double-strand breaks (DSBs) in mammalian cells that can result in large-scale deletions and rearrangements. In contrast, the same Z-DNA-forming CG repeat in Escherichia coli resulted in only small contractions or expansions within the repeat. This difference in the Z-DNA-induced mutation spectrum between mammals and bacteria might be due to different mechanisms for DSB repair; in mammalian cells, non-homologous end-joining (NHEJ) is a major DSB repair pathway, while E. coli do not contain this system and typically use homologous recombination (HR) to process DSBs. To test the extent to which the different DSB repair pathways influenced the Z-DNA-induced mutagenesis, we engineered bacterial E.coli strains to express an inducible NHEJ system, to mimic the situation in mammalian cells. Mycobacterium tuberculosis NHEJ proteins Ku and ligase D (LigD) were expressed in E.coli cells in the presence or absence of HR, and the Z-DNA-induced mutations were characterized. We found that the presence of the NHEJ mechanism markedly shifted the mutation spectrum from small deletions/insertions to large-scale deletions (from 2% to 24%). Our results demonstrate that NHEJ plays a role in the generation of Z-DNA-induced large-scale deletions, suggesting that this pathway is associated with DNA structure-induced destabilization of genomes from prokaryotes to eukaryotes. (c) 2010 Elsevier Ltd. All rights reserved.

Computed tomography fluoroscopy-guided placement of iliosacral screws in patients with unstable posterior pelvic fractures

International Nuclear Information System (INIS)

Iguchi, Toshihiro; Ogawa, Ken-Ichi; Doi, Takeshi; Munetomo, Kazuo; Miyasho, Koji; Hiraki, Takao; Kanazawa, Susumu; Ozaki, Toshifumi

2010-01-01

The purpose of this study was to evaluate retrospectively the safety and effectiveness of the computed tomography (CT) fluoroscopy-guided placement of iliosacral screws in patients with unstable posterior pelvic fractures. Six patients (four women and two men; mean age 55.8 years; range 35-77 years) with unstable posterior pelvic fractures underwent iliosacral screw placement under CT fluoroscopy guidance between November 2007 and August 2008. Unstable pelvic ring injury (AO types B and C) was the indication for this procedure. In all the six patients except one, CT fluoroscopy-guided placement had been technically successful. In one patient, a second screw had been inserted, with a tilt to the caudal site, and slightly advanced into the extrasacral body; afterward, it could be exchanged safely for a shorter screw. Five patients and one patient underwent placement of two screws and one screw, respectively. The mean duration of the procedure was 15.0 min (range 9-30 min) per screw; the duration was 12.3 min and 18.2 min for the first and second screws, respectively. No complications requiring treatment occurred during or after the procedure. The mean clinical and radiologic follow-up period was 14 months (range 6-21 months). All pelvic injuries had healed satisfactorily, without complication, and all patients are now doing well clinically and can walk. CT fluoroscopy-guided placement of iliosacral screws is a safe and effective treatment in patients with unstable posterior pelvic fractures. (orig.)

Ankle proprioception is not targeted by exercises on an unstable surface

NARCIS (Netherlands)

Kiers, H.; Brumagne, S.; van Dieen, J.; Wees, P.J. van der; Vanhees, L.

2012-01-01

Laboratory study using a repeated measures design. The aim of this study was to determine if ankle proprioception is targeted in exercises on unstable surfaces. Lateral ankle sprain (LAS) has recurrence rates over 70%, which are believed to be due to a reduced accuracy of proprioceptive signals from

Lyapunov vectors and assimilation in the unstable subspace: theory and applications

International Nuclear Information System (INIS)

Palatella, Luigi; Carrassi, Alberto; Trevisan, Anna

2013-01-01

Based on a limited number of noisy observations, estimation algorithms provide a complete description of the state of a system at current time. Estimation algorithms that go under the name of assimilation in the unstable subspace (AUS) exploit the nonlinear stability properties of the forecasting model in their formulation. Errors that grow due to sensitivity to initial conditions are efficiently removed by confining the analysis solution in the unstable and neutral subspace of the system, the subspace spanned by Lyapunov vectors with positive and zero exponents, while the observational noise does not disturb the system along the stable directions. The formulation of the AUS approach in the context of four-dimensional variational assimilation (4DVar-AUS) and the extended Kalman filter (EKF-AUS) and its application to chaotic models is reviewed. In both instances, the AUS algorithms are at least as efficient but simpler to implement and computationally less demanding than their original counterparts. As predicted by the theory when error dynamics is linear, the optimal subspace dimension for 4DVar-AUS is given by the number of positive and null Lyapunov exponents, while the EKF-AUS algorithm, using the same unstable and neutral subspace, recovers the solution of the full EKF algorithm, but dealing with error covariance matrices of a much smaller dimension and significantly reducing the computational burden. Examples of the application to a simplified model of the atmospheric circulation and to the optimal velocity model for traffic dynamics are given. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Lyapunov analysis: from dynamical systems theory to applications’. (paper)

Plants status monitor: Modelling techniques and inherent benefits

International Nuclear Information System (INIS)

Breeding, R.J.; Lainoff, S.M.; Rees, D.C.; Prather, W.A.; Fickiessen, K.O.E.

1987-01-01

The Plant Status Monitor (PSM) is designed to provide plant personnel with information on the operational status of the plant and compliance with the plant technical specifications. The PSM software evaluates system models using a 'distributed processing' technique in which detailed models of individual systems are processed rather than by evaluating a single, plant-level model. In addition, development of the system models for PSM provides inherent benefits to the plant by forcing detailed reviews of the technical specifications, system design and operating procedures, and plant documentation. (orig.)

40 CFR 88.312-93 - Inherently Low-Emission Vehicle labeling.

Science.gov (United States)

2010-07-01

... stroke width not less than 0.5 inches (1.3 centimeters). In addition, the words “INHERENTLY LOW-EMISSION..., the words “CLEAN AIR VEHICLE” must be present in lettering no smaller than 0.8 inches (2.0 centimeters... loan to someone who has not demonstrated eligibility for expanded TCMs available to ILEVs according to...

Planktic foraminifera form their shells via metastable carbonate phases

OpenAIRE

Jacob, D. E.; Wirth, R.; Agbaje, O. B. A.; Branson, O.; Eggins, S. M.

2017-01-01

The calcium carbonate shells of planktic foraminifera provide our most valuable geochemical archive of ocean surface conditions and climate spanning the last 100 million years, and play an important role in the ocean carbon cycle. These shells are preserved in marine sediments as calcite, the stable polymorph of calcium carbonate. Here, we show that shells of living planktic foraminifers Orbulina universa and Neogloboquadrina dutertrei originally form from the unstable calcium carbonate polym...

Research of Medical Expenditure among Inpatients with Unstable Angina Pectoris in a Single Center.

Science.gov (United States)

Wu, Suo-Wei; Pan, Qi; Chen, Tong; Wei, Liang-Yu; Xuan, Yong; Wang, Qin; Li, Chao; Song, Jing-Chen

2017-07-05

With the rising incidence as well as the medical expenditure among patients with unstable angina pectoris, the research aimed to investigate the inpatient medical expenditure through the combination of diagnosis-related groups (DRGs) among patients with unstable angina pectoris in a Grade A tertiary hospital to conduct the referential standards of medical costs for the diagnosis. Single-factor analysis and multiple linear stepwise regression method were used to investigate 3933 cases between 2014 and 2016 in Beijing Hospital (China) whose main diagnosis was defined as unstable angina pectoris to determine the main factors influencing the inpatient medical expenditure, and decision tree method was adopted to establish the model of DRGs grouping combinations. The major influential factors of inpatient medical expenditure included age, operative method, therapeutic effects as well as comorbidity and complications (CCs) of the disease, and the 3933 cases were divided into ten DRGs by four factors: age, CCs, therapeutic effects, and the type of surgery with corresponding inpatient medical expenditure standards setup. Data of nonparametric test on medical costs among different groups were all significant (P angina pectoris is conducive in standardizing the diagnosis and treatment behaviors of the hospital and reducing economic burdens among patients.

Analog Electronic Implementation of Unstable Dissipative Systems of Type I with Multi-Scrolls Displaced Along Space

Science.gov (United States)

Ontañón-García, L. J.; Lozoya-Ponce, R. E.

2017-06-01

Multi-scroll Unstable Dissipative Systems (UDS) in R3 which consist of piecewise linear systems are implemented electronically by means of analog computing. The scrolling behavior of the systems can be designed to oscillate along a specific axis or into space depending on the unstable and stable manifolds. In order for a multi-scroll attractor, this switching system must present at least two unstable hyperbolic focus-saddle equilibria with the same stability index, a negative real eigenvalue and a pair of complex conjugated eigenvalues with positive real part. Then, to displace the scrolls among the axes and space different switching control laws must be designed. By taking into consideration the mathematical expressions of the switching systems, the electronic implementations are carried out by means of operational amplifiers representing the real analog physical solution of the systems, from which the voltage is measured representing the states solution.

Inherent and antigen-induced airway hyperreactivity in NC mice

Directory of Open Access Journals (Sweden)

Tetsuto Kobayashi

1999-01-01

Full Text Available In order to clarify the airway physiology of NC mice, the following experiments were carried out. To investigate inherent airway reactivity, we compared tracheal reactivity to various chemical mediators in NC, BALB/c, C57BL/6 and A/J mice in vitro. NC mice showed significantly greater reactivity to acetylcholine than BALB/c and C57BL/6 mice and a reactivity comparable to that of A/J mice, which are known as high responders. Then, airway reactivity to acetylcholine was investigated in those strains in vivo. NC mice again showed comparable airway reactivity to that seen in A/J mice and a significantly greater reactivity than that seen in BALB/c and C57BL/6 mice. To investigate the effects of airway inflammation on airway reactivity to acetylcholine in vivo, NC and BALB/c mice were sensitized to and challenged with antigen. Sensitization to and challenge with antigen induced accumulation of inflammatory cells, especially eosinophils, in lung and increased airway reactivity in NC and BALB/c mice. These results indicate that NC mice exhibit inherent and antigen-induced airway hyperreactivity. Therefore, NC mice are a suitable strain to use in investigating the mechanisms underlying airway hyperreactivity and such studies will provide beneficial information for understanding the pathophysiology of asthma.

Sensors and actuators inherent in biological species

Science.gov (United States)

Taya, Minoru; Stahlberg, Rainer; Li, Fanghong; Zhao, Ying Joyce

2007-04-01

This paper addresses examples of sensing and active mechanisms inherent in some biological species where both plants and animals cases are discussed: mechanosensors and actuators in Venus Fly Trap and cucumber tendrils, chemosensors in insects, two cases of interactions between different kingdoms, (i) cotton plant smart defense system and (ii) bird-of-paradise flower and hamming bird interaction. All these cases lead us to recognize how energy-efficient and flexible the biological sensors and actuators are. This review reveals the importance of integration of sensing and actuation functions into an autonomous system if we make biomimetic design of a set of new autonomous systems which can sense and actuate under a number of different stimuli and threats.

The inherent limits of predicting school violence.

Science.gov (United States)

Mulvey, E P; Cauffman, E

2001-10-01

The recent media hype over school shootings has led to demands for methods of identifying school shooters before they act. Despite the fact that schools remain one of the safest places for youths to be, schools are beginning to adopt identification systems to determine which students could be future killers. The methods used to accomplish this not only are unproven but are inherently limited in usefulness and often do more harm than good for both the children and the school setting. The authors' goals in the present article are to place school shootings in perspective relative to other risks of violence that children face and to provide a reasonable and scientifically defensible approach to improving the safety of schools.

Sutudy on exchange flow under the unstably stratified field

OpenAIRE

文沢, 元雄

2005-01-01

This paper deals with the exchange flow under the unstably stratified field. The author developed the effective measurement system as well as the numerical analysis program. The system and the program are applied to the helium-air exchange flow in a rectangular channel with inclination. Following main features of the exchange flow were discussed based on the calculated results.(1) Time required for establishing a quasi-steady state exchange flow.(2) The relationship between the inclination an...

Efficiency of inherent protection mechanisms for an improved HTR safety concept

Energy Technology Data Exchange (ETDEWEB)

Petersen, K.; Buescher, R.; Gerwin, H.; Schenk, W. [Kernforschungsanlage Juelich G.m.b.H. (Germany, F.R.). Inst. fuer Reaktorentwicklung

1981-01-15

For a preliminary design of a 350 MWsub(th) annular core derived from AVR-reactor the efficiency of inherent protection mechanisms is discussed. After-heat removal and auto-shut down potential are demonstrated for intact and complete failure of core heat sinks.

"A Fiber Optic Ethernet With Inherent Migration Capability To FDDI"

Science.gov (United States)

Ferris, Kenneth D.; Chan, Tammy S.

1988-12-01

A Local Area Network (LAN) designed to a standard commercial interface, the Institute of Electrical and Electronics Engineers (IEEE) 802.3 or Ethernet, has been developed using fiber optics as the physical medium. The LAN, WhisperNet, operates in an active ring and thus has an inherent low cost migration path to a Fiber Distributed Data Interface (FDDI) implementation.

Unstable Temperature Distribution in Friction Stir Welding

Directory of Open Access Journals (Sweden)

Sadiq Aziz Hussein

2014-01-01

Full Text Available In the friction stir welding process, a nonuniform and high generated temperature is undesirable. Unstable temperature and distribution affect thermal and residual stresses along the welding line, thus necessitating mitigation. This paper presents a simple method to prevent significant temperature difference along the welding line and also to help nullifying some defect types associated with this welding, such as end-hole, initial unwelded line, and deformed areas. In the experimental investigation, a heat and force thermocouple and dynamometer were utilized while couple-field thermomechanical models were used to evaluate temperature and its distribution, plastic strain, and material displacement. The suggested method generated uniform temperature distributions. Measurement results are discussed, showing a good correlation with predictions.

Antisocial personality disorder--stable and unstable subtypes.

Science.gov (United States)

Ullrich, Simone; Coid, Jeremy

2010-04-01

There have been criticisms that the criteria for antisocial personality disorder (ASPD) are over-dependent on criminal behavior. This study aimed to identify unrelated criteria of social and behavioral problems and instability, and to investigate their associations in a representative household sample of adults in the UK. Approximately one third of adults with ASPD did not fulfill any of the criteria for instability. They were less aggressive and involved in illegal activities but expressed less remorse for their behaviors. Instability in ASPD was mediated primarily through comorbid anxiety disorders and borderline personality disorder. The concept of Secondary Psychopathy, which has not generally been applied to ASPD, demonstrated many similarities to the unstable subtype.

Is the Rational Addiction model inherently impossible to estimate?

Science.gov (United States)

Laporte, Audrey; Dass, Adrian Rohit; Ferguson, Brian S

2017-07-01

The Rational Addiction (RA) model is increasingly often estimated using individual level panel data with mixed results; in particular, with regard to the implied rate of time discount. This paper suggests that the odd values of the rate of discount frequently found in the literature may in fact be a consequence of the saddle-point dynamics associated with individual level inter-temporal optimization problems. We report the results of Monte Carlo experiments estimating RA-type difference equations that seem to suggest the possibility that the presence of both a stable and an unstable root in the dynamic process may create serious problems for the estimation of RA equations. Copyright © 2016 Elsevier B.V. All rights reserved.

Accumulation of unstable periodic orbits and the stickiness in the two-dimensional piecewise linear map.

Science.gov (United States)

Akaishi, A; Shudo, A

2009-12-01

We investigate the stickiness of the two-dimensional piecewise linear map with a family of marginal unstable periodic orbits (FMUPOs), and show that a series of unstable periodic orbits accumulating to FMUPOs plays a significant role to give rise to the power law correlation of trajectories. We can explicitly specify the sticky zone in which unstable periodic orbits whose stability increases algebraically exist, and find that there exists a hierarchy in accumulating periodic orbits. In particular, the periodic orbits with linearly increasing stability play the role of fundamental cycles as in the hyperbolic systems, which allows us to apply the method of cycle expansion. We also study the recurrence time distribution, especially discussing the position and size of the recurrence region. Following the definition adopted in one-dimensional maps, we show that the recurrence time distribution has an exponential part in the short time regime and an asymptotic power law part. The analysis on the crossover time T(c)(*) between these two regimes implies T(c)(*) approximately -log[micro(R)] where micro(R) denotes the area of the recurrence region.

Stabilization and analytical tuning rule of double-loop control scheme for unstable dead-time process

Science.gov (United States)

Ugon, B.; Nandong, J.; Zang, Z.

2017-06-01

The presence of unstable dead-time systems in process plants often leads to a daunting challenge in the design of standard PID controllers, which are not only intended to provide close-loop stability but also to give good performance-robustness overall. In this paper, we conduct stability analysis on a double-loop control scheme based on the Routh-Hurwitz stability criteria. We propose to use this unstable double-loop control scheme which employs two P/PID controllers to control first-order or second-order unstable dead-time processes typically found in process industries. Based on the Routh-Hurwitz stability necessary and sufficient criteria, we establish several stability regions which enclose within them the P/PID parameter values that guarantee close-loop stability of the double-loop control scheme. A systematic tuning rule is developed for the purpose of obtaining the optimal P/PID parameter values within the established regions. The effectiveness of the proposed tuning rule is demonstrated using several numerical examples and the result are compared with some well-established tuning methods reported in the literature.

Demographic epidemiology of unstable pelvic fracture in the United States from 2000 to 2009: trends and in-hospital mortality.

Science.gov (United States)

Yoshihara, Hiroyuki; Yoneoka, Daisuke

2014-02-01

Unstable pelvic fracture is predominantly caused by high-energy blunt trauma and is associated with a high risk of mortality. The epidemiology in the United States is largely unknown. The purpose of this study was to examine the epidemiology of unstable pelvic fracture based on patient and hospital demographics in the United States during the last decade. The Nationwide Inpatient Sample was used to identify patients who were hospitalized with unstable pelvic fracture from 2000 to 2009, using the International Classification of Diseases--9th Rev.--Clinical Modification (ICD-9-CM) codes. The primary outcome parameter consisted of analyzing the temporal trends of in-hospital admissions for unstable pelvic fracture and the associated in-hospital mortality. The data were stratified by demographic variables, including age, sex, race, and hospital region in the United States. From 2000 to 2009, there were 24,059 patients in total; among these, 1,823 (7.6%) had open fractures, and 22,236 (92.4%) had closed fractures. The population growth-adjusted incidence was stable over time (p = 0.431). The incidence was the lowest in the northeastern region. The in-hospital mortality rate in patients with unstable pelvic fracture was 8.3% (21.3% for open fracture, 7.2% for closed fracture) and remained stable over time (p = 0.089). The in-hospital mortality rate was higher in several subgroups of patients, such as older patients, male patients, African-American patients, and patients in the northeastern region. During the last decade, the incidence of unstable pelvic fracture has remained stable over time in the United States. The in-hospital mortality rate in patients with unstable pelvic fracture was 8.3% and remained stable over time. The rate in patients with an open fracture was approximately three times higher than that in patients with a closed fracture. The incidence was the lowest, but the in-hospital mortality rate was the highest in the northeastern region compared with the

High energy nucleus-nucleus scattering and matter radius of unstable nucleus

International Nuclear Information System (INIS)

Sato, H.; Okuhara, Y.

1985-07-01

The interaction cross sections of high energy nucleus-nucleus scattering have been studied with the Glauber Model and Hartree-Fock like variational calculation for the nuclear structure. It is found that the experimental interaction cross sections of the light unstable nucleus-stable nucleus scatterings measured by INS-LBL collaboration are well reproduceable. (author)

Renormalization, unstable manifolds, and the fractal structure of mode locking

International Nuclear Information System (INIS)

Cvitanovic, P.; Jensen, M.H.; Kadanoff, L.P.; Procaccia, I.

1985-01-01

The apparent universality of the fractal dimension of the set of quasiperiodic windings at the onset of chaos in a wide class of circle maps is described by construction of a universal one-parameter family of maps which lies along the unstable manifold of the renormalization group. The manifold generates a universal ''devil's staircase'' whose dimension agrees with direct numerical calculations. Applications to experiments are discussed

Extension of a chaos control method to unstable trajectories on infinite- or finite-time intervals: Experimental verification

International Nuclear Information System (INIS)

Yagasaki, Kazuyuki

2007-01-01

In experiments for single and coupled pendula, we demonstrate the effectiveness of a new control method based on dynamical systems theory for stabilizing unstable aperiodic trajectories defined on infinite- or finite-time intervals. The basic idea of the method is similar to that of the OGY method, which is a well-known, chaos control method. Extended concepts of the stable and unstable manifolds of hyperbolic trajectories are used here

Magnetic resonance imaging in patients with unstable angina: comparison with acute myocardial infarction and normals

International Nuclear Information System (INIS)

Ahmad, M.; Johnson, R.F. Jr.; Fawcett, H.D.; Schreiber, M.H.

1988-01-01

The role of magnetic resonance imaging in characterizing normal, ischemic and infarcted segments of myocardium was examined in 8 patients with unstable angina, 11 patients with acute myocardial infarction, and 7 patients with stable angina. Eleven normal volunteers were imaged for comparison. Myocardial segments in short axis magnetic resonance images were classified as normal or abnormal on the basis of perfusion changes observed in thallium-201 images in 22 patients and according to the electrocariographic localization of infarction in 4 patients. T2 relaxation time was measured in 57 myocardial segments with abnormal perfusion (24 with reversible and 33 with irreversible perfusion changes) and in 25 normally perfused segments. T2 measurements in normally perfused segments of patients with acute myocardial infarction, unstable angina and stable angina were within normal range derived from T2 measurements in 48 myocardial segments of 11 normal volunteers (42 +/- 10 ms). T2 in abnormal myocardial segments of patients with stable angina also was not significantly different from normal. T2 of abnormal segments in patients with unstable angina (64 +/- 14 in reversibly ischemic and 67 +/- 21 in the irreversibly ischemic segments) was prolonged when compared to normal (p less than 0.0001) and was not significantly different from T2 in abnormal segments of patients with acute myocardial infarction (62 +/- 18 for reversibly and 66 +/- 11 for irreversibly ischemic segments). The data indicate that T2 prolongation is not specific for acute myocardial infarction and may be observed in abnormally perfused segments of patients with unstable angina

Unstable roll motions by parametric resonance in following seas. Keisu reiki shindo ni motozuku oinamichu fuantei yokoyure

Energy Technology Data Exchange (ETDEWEB)

Ishiguro, T.; Ito, A.; Mizoguchi, S. (Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan))

1991-05-01

The unstable rolling region and angle in the regular waves were studied by both tank test modeling a large container ship and theoretical calculation based on Mathieu{prime}s equation. Further research was made on the influence of metacentric height (GM) under the calm sea condition, ship speed and bilge keel dimension on the unstable rolling region. To avoid the unstable roll motion in the waves caused by the parametric resonance, the fluctuation in GM is designed to be diminished on the waves by U-shaping the hull fore and aft like a fat large ship hull, or the fluctuation in dynamic stability is done to be diminished by increasing the GM on the calm sea. However, the ship with a U-shaped hull fore and aft is large in rolling angle due to the smallness in righting arm at the large heeling angle. Generally regardless of oceanic condition and ship speed, it is impossible to establish the GM absolutely without the primary and secondary synchronizing points. To avoid the unstable roll motion with a low ship speed, it is desirable to do it by the ship speed to be as high as possible. 11 refs., 13 figs., 1 tab.

Deliberate practice theory: perceived relevance, effort, and inherent enjoyment of music practice: study II.

Science.gov (United States)

Hyllegard, Randy; Bories, Tamara L

2009-10-01

This study, based on the theory of deliberate practice, examined the practice relevance, effort, and inherent enjoyment aspects of the theory. 25 college undergraduates practiced playing a melody on an electronic keyboard for three 20-min. practice sessions. Following each session, the perceived relevance of the practice for improving performance of the melody, the effort needed to learn the melody, and the inherent enjoyment of the practice were each rated on 10-point scales. Findings were consistent with theory and similar to previous studies also involving music practice and other tasks.

Manson Chicks and Microskirted Cuties : Pornification in Thomas Pynchon's Inherent Vice

NARCIS (Netherlands)

Cook, S.J.|info:eu-repo/dai/nl/411939432

2015-01-01

Many sexual encounters in Thomas Pynchon’s fiction have occurred beyond the mainstream, generating theatres of perversity which dramatise the death wish and enact power relations from wider arenas. However, in Inherent Vice they change in nature. With the exception of scenes which use Charles Manson

Subsets of microsatellite-unstable colorectal cancers exhibit discordance between the CpG island methylator phenotype and MLH1 methylation status.

Science.gov (United States)

Kim, Jung H; Rhee, Ye-Y; Bae, Jeong-M; Kwon, Hyeong-J; Cho, Nam-Y; Kim, Mi J; Kang, Gyeong H

2013-07-01

Although the presence of MLH1 methylation in microsatellite-unstable colorectal cancer generally indicates involvement of the CpG island methylator phenotype (CIMP) in the development of the tumor, these two conditions do not always correlate. A minority of microsatellite-unstable colorectal cancers exhibit discordance between CIMP and MLH1 methylation statuses. However, the clinicopathological features of such microsatellite-unstable colorectal cancers with discrepant MLH1 methylation and CIMP statuses remain poorly studied. Microsatellite-unstable colorectal cancers (n=220) were analyzed for CIMP and MLH1 methylation statuses using the MethyLight assay. Based on the combinatorial CIMP and MLH1 methylation statuses, the microsatellite-unstable colorectal cancers were grouped into four subtypes (CIMP-high (CIMP-H) MLH1 methylation-positive (MLH1m+), CIMP-H MLH1 methylation-negative, CIMP-low/0 (CIMP-L/0) MLH1m+, and CIMP-L/0 MLH1 methylation-negative), which were compared in terms of their associations with clinicopathological and molecular features. The CIMP-L/0 MLH1 methylation-negative and CIMP-H MLH1m+ subtypes were predominant, comprising 63.6 and 24.1% of total microsatellite-unstable colorectal cancers, respectively. The discordant subtypes, CIMP-H MLH1 methylation-negative and CIMP-L/0 MLH1m+, were found in 5 and 7% of microsatellite-unstable colorectal cancers, respectively. The CIMP-H MLH1 methylation-negative subtype exhibited elevated incidence rates in male patients and was associated with larger tumor size, more frequent loss of MSH2 expression, increased frequency of KRAS mutation, and advanced cancer stage. The CIMP-L/0 MLH1m+ subtype was associated with onset at an earlier age, a predominance of MLH1 loss, and earlier cancer stage. None of the CIMP-L/0 MLH1m+ subtype patients succumbed to death during the follow-up. Our findings suggest that the discordant subtypes of colorectal cancers exhibit distinct clinicopathological and molecular features

A simplified analysis of uncertainty propagation in inherently controlled ATWS events

International Nuclear Information System (INIS)

Wade, D.C.

1987-01-01

The quasi static approach can be used to provide useful insight concerning the propagation of uncertainties in the inherent response to ATWS events. At issue is how uncertainties in the reactivity coefficients and in the thermal-hydraulics and materials properties propagate to yield uncertainties in the asymptotic temperatures attained upon inherent shutdown. The basic notion to be quantified is that many of the same physical phenomena contribute to both the reactivity increase of power reduction and the reactivity decrease of core temperature rise. Since these reactivities cancel by definition, a good deal of uncertainty cancellation must also occur of necessity. For example, if the Doppler coefficient is overpredicted, too large a positive reactivity insertion is predicted upon power reduction and collapse of the ΔT across the fuel pin. However, too large a negative reactivity is also predicted upon the compensating increase in the isothermal core average temperature - which includes the fuel Doppler effect

Problems in the assessment of inherent safety characteristics of nuclear reactors

International Nuclear Information System (INIS)

Garribba, S.F.; Vivante, C.

1988-01-01

A number of proposals are being made for an increased RD and D effort on advanced nuclear power reactors that would display outstanding safety performance. A common characteristic of the different reactor concepts would be their limited reliance upon active engineered systems under major accident conditions. However, when submitted to a more close scrutiny reactor concept options may reveal diverging safety behaviors and also development opportunities. In this respect, three issues are explored in this paper. A first question is the meaning of non-active, i.e. inherent and passive safety features. Next, is the ranking of advanced and new reactor concepts from the viewpoint of inherent and passive safety. Multiple correspondence analysis may provide a simple tool, whose use is shown for the case of HTR-500, AP600 and PRISM. Conversely, probabilistic risk assessment would allow quantitative comparisons, although lack of information and data is an obstacle. Finally, is demonstration of safety performances as a step toward market deployment of the new reactor systems

Role of FFTF in assessing structural feedbacks and inherent safety of LMR's

International Nuclear Information System (INIS)

Padilla, A.; Omberg, R.P.; O'Dell, L.D.; Harris, R.A.; Nguyen, D.H.; Waltar, A.E.

1985-03-01

The possibility of developing reactor designs with inherent safety characteristics sufficient to provide ''walk away'' safety is receiving additional emphasis in the LMR program. A key element in this effort is the recognition that LMR's possess safety characteristics above and beyond those employed in past safety review processes. Some of these additional safety characteristics are due to reactivity feedback effects caused by small structural movements during hypothetical severe design transients. The effect of these characteristics upon the behavior of the FFTF under such transients has been assessed and is discussed in this paper. The paper also presents a preliminary test matrix which might allow experimental verification of the structural reactivity feedback effects. Such experimental verification should be very useful to innovative designers seeking to optimize inherent safety. 8 refs., 1 fig., 2 tabs

Integral Inherently Safe Light Water Reactor (I²S-LWR)

Energy Technology Data Exchange (ETDEWEB)

Petrovic, Bojan [Georgia Inst. of Technology, Atlanta, GA (United States); Memmott, Matthew [Brigham Young Univ., Provo, UT (United States); Boy, Guy [Florida Inst. of Technology, Melbourne, FL (United States); Charit, Indrajit [Univ. of Idaho, Moscow, ID (United States); Manera, Annalisa [Univ. of Michigan, Ann Arbor, MI (United States); Downar, Thomas [Univ. of Michigan, Ann Arbor, MI (United States); Lee, John [Univ. of Michigan, Ann Arbor, MI (United States); Muldrow, Lycurgus [Morehouse College, Atlanta, GA (United States); Upadhyaya, Belle [Univ. of Tennessee, Knoxville, TN (United States); Hines, Wesley [Univ. of Tennessee, Knoxville, TN (United States); Haghighat, Alierza [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

2017-10-02

This final report summarizes results of the multi-year effort performed during the period 2/2013- 12/2016 under the DOE NEUP IRP Project “Integral Inherently Safe Light Water Reactors (I²S-LWR)”. The goal of the project was to develop a concept of a 1 GWe PWR with integral configuration and inherent safety features, at the same time accounting for lessons learned from the Fukushima accident, and keeping in mind the economic viability of the new concept. Essentially (see Figure 1-1) the project aimed to implement attractive safety features, typically found only in SMRs, to a larger power (1 GWe) reactor, to address the preference of some utilities in the US power market for unit power level on the order of 1 GWe.

Magnetic latch trigger for inherent shutdown assembly

International Nuclear Information System (INIS)

Sowa, E.S.

1976-01-01

An inherent shutdown assembly for a nuclear reactor is provided. A neutron absorber is held ready to be inserted into the reactor core by a magnetic latch. The latch includes a magnet whose lines of force are linked by a yoke of material whose Curie point is at the critical temperature of the reactor at which the neutron absorber is to be inserted into the reactor core. The yoke is in contact with the core coolant or fissionable material so that when the coolant or the fissionable material increase in temperature above the Curie point the yoke loses its magnetic susceptibility and the magnetic link is broken, thereby causing the absorber to be released into the reactor core. 6 claims, 3 figures

Stable, metastable and unstable solutions of a spin-1 Ising system based on the free energy surfaces

Science.gov (United States)

Keskİin, Mustafa; Özgan, Şükrü

1990-04-01

Stable, metastable and unstable solutions of a spin-1 Ising model with bilinear and biquadratic interactions are found by using the free energy surfaces. The free energy expression is obtained in the lowest approximation of the cluster variation method. All these solutions are shown in the two-dimensional phase space, especially the unstable solutions which in some cases are difficult to illustrate in the two-dimensional phase space, found by Keskin et al. recently.

${ \\mathcal P }{ \\mathcal T }$-symmetric interpretation of unstable effective potentials

CERN Document Server

Bender, Carl M.; Mavromatos, Nick E.; Sarkar, Sarben

2016-01-01

The conventional interpretation of the one-loop effective potentials of the Higgs field in the Standard Model and the gravitino condensate in dynamically broken supergravity is that these theories are unstable at large field values. A ${ \\mathcal P }{ \\mathcal T }$-symmetric reinterpretation of these models at a quantum-mechanical level eliminates these instabilities and suggests that these instabilities may also be tamed at the quantum-field-theory level.

Effectiveness of Dual-Maneuver Using K-Wire and Dingman Elevator for the Reduction of Unstable Zygomatic Arch Fracture.

Science.gov (United States)

Yoon, Hyungwoo; Kim, Jiye; Chung, Seum; Chung, Yoon-Kyu

2014-08-01

The zygoma is the most prominent portion of the face. Almost all simple zygomatic arch fractures are treated in a closed fashion with a Dingman elevator. However, the open approach should be considered for unstable zygomatic arch fractures. The coronal approach for a zygomatic arch fracture has complications. In this study, we introduce our method to reduce a special type of unstable zygomatic fracture. We retrospectively reviewed zygomatic arch view and facial bone computed tomography scans of 424 patients who visited the Wonju Severance Christian Hospital from 2007 to 2010 with zygomaticomaxillary fractures, among whom 15 patients met the inclusion criteria. We used a Dingman elevator and K-wire simultaneously to manage this type of zygomatic arch fracture. Simple medial rotation force usually collapses the posterior fractured segment, and the fracture becomes unstable. Thus, the posterior fracture segment must be concurrently elevated with a Dingman elevator through Keen's approach with rotation force applied through the K-wire. All fractures were reduced without any instability using this method. We were able to reduce unstable and difficult zygomatic arch fractures without an open incision or any external fixation device.

Drug policy in sport: hidden assumptions and inherent contradictions.

Science.gov (United States)

Smith, Aaron C T; Stewart, Bob

2008-03-01

This paper considers the assumptions underpinning the current drugs-in-sport policy arrangements. We examine the assumptions and contradictions inherent in the policy approach, paying particular attention to the evidence that supports different policy arrangements. We find that the current anti-doping policy of the World Anti-Doping Agency (WADA) contains inconsistencies and ambiguities. WADA's policy position is predicated upon four fundamental principles; first, the need for sport to set a good example; secondly, the necessity of ensuring a level playing field; thirdly, the responsibility to protect the health of athletes; and fourthly, the importance of preserving the integrity of sport. A review of the evidence, however, suggests that sport is a problematic institution when it comes to setting a good example for the rest of society. Neither is it clear that sport has an inherent or essential integrity that can only be sustained through regulation. Furthermore, it is doubtful that WADA's anti-doping policy is effective in maintaining a level playing field, or is the best means of protecting the health of athletes. The WADA anti-doping policy is based too heavily on principals of minimising drug use, and gives insufficient weight to the minimisation of drug-related harms. As a result drug-related harms are being poorly managed in sport. We argue that anti-doping policy in sport would benefit from placing greater emphasis on a harm minimisation model.

A case for inherent geometric and geodetic accuracy in remotely sensed VNIR and SWIR imaging products

Science.gov (United States)

Driver, J. M.

1982-01-01

Significant aberrations can occur in acquired images which, unless compensated on board the spacecraft, can seriously impair throughput and timeliness for typical Earth observation missions. Conceptual compensations options are advanced to enable acquisition of images with inherent geometric and geodetic accuracy. Research needs are identified which, when implemented, can provide inherently accurate images. Agressive pursuit of these research needs is recommended.

The Inherent Politics of Managing the Quality of Urban Green Spaces

DEFF Research Database (Denmark)

Lindholst, Christian; Sullivan, Sidney George; Konijnendijk van den Bosch, Cecil C.

2015-01-01

of such ‘inherent politics’ through a case study of a widespread approach to operationalizing quality in urban green space management. We conclude that adoption of any quality model has both limiting and enabling implications for public participation and decision-making and that a critical stance is needed within...

Robustness of unstable attractors in arbitrarily sized pulse-coupled networks with delay

NARCIS (Netherlands)

Broer, Hendrik; Efstathiou, Konstantinos; Subramanian, Easwar

We consider arbitrarily large networks of pulse-coupled oscillators with non-zero delay where the coupling is given by the Mirollo-Strogatz function. We prove that such systems have unstable attractors (saddle periodic orbits whose stable set has non-empty interior) in an open parameter region for

Microstructure evolution of 7050 Al alloy during age-forming

International Nuclear Information System (INIS)

Chen, Junfeng; Zou, Linchi; Li, Qiang; Chen, Yulong

2015-01-01

The microstructure evolution of the 7050 Al alloy treated by age-forming was studied using a designed device which can simulate the age-forming process. The grain shape, grain boundary misorientation and grain orientation evolution of 7050 Al alloy during age-forming have been quantitatively characterized by electron backscattering diffraction technique. The results show that age-forming produced abundant low-angle boundaries and elongated grains, which attributed to stress induced dislocation movement and grain boundary migration during the age-forming process. On the other side, the stress along rolling direction caused some unstable orientation grains to rotate towards the Brass and S orientations during the age-forming process. Hence, the intensity of the rolling texture orientation in age-formed samples is enhanced. But this effect decays gradually with increasing aging time, since stress decreases and precipitation hardening occurs during the age-forming process. - Highlights: • Quantitative analysis of grain evolution of 7050 Al alloys during age-forming • Stress induces some grain rotation of 7050 Al alloys during age-forming. • Creep leads to elongate grain of 7050 Al alloys during age-forming. • Obtains a trend on texture evolution during age-forming applied stress

Structure of Colloidal Flocs in relation to the Dynamic Properties of Unstable Suspension

Directory of Open Access Journals (Sweden)

Yasuhisa Adachi

2012-01-01

Full Text Available Dynamic behaviors of unstable colloidal dispersions are reviewed in terms of floc formation. Geometrical structure of flocs in terms of chemical conditions and formation mechanics is a key to predict macroscopic transportation properties. The rate of sedimentation and rheological properties can be described with the help of fractal dimension (D that is the function of the number of contacts between clusters (Nc. It is also well known that the application of water soluble polymers and polyelectrolytes, which are usually used as a conditioner or flocculants in colloidal dispersions, critically affects the process of flocculation. The resulted floc structure is also influenced by the application of polymer. In order to reveal the roles of the polymers, the elementary rate process of polymer reaching to colloidal interface and subsequent reconformation process into more stable adsorption state are needed to be analyzed. The properties of permeable flocs and adsorbed polymer (polyelectrolyte layers formed on the colloidal surfaces remain to be worked out in relation to inhomogeneous porous structure and electrokinetics in the future.

Finite toroidal flow generated by unstable tearing mode in a toroidal plasma

Energy Technology Data Exchange (ETDEWEB)

Hao, G. Z., E-mail: haogz@swip.ac.cn; Wang, A. K.; Xu, Y. H.; He, H. D.; Xu, M.; Qu, H. P.; Peng, X. D.; Xu, J. Q.; Qiu, X. M. [Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041 (China); Liu, Y. Q. [Culham Centre for Fusion Energy, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Sun, Y. [Institute of Plasma Physics, Chinese Academic of Sciences, P.O. Box 1126, Hefei 230031 (China); Cui, S. Y. [School of Mathematics and Statistics Science, Ludong University, Yantai 264025 (China)

2014-12-15

The neoclassical toroidal plasma viscosity torque and electromagnetic torque, generated by tearing mode (TM) in a toroidal plasma, are numerically investigated using the MARS-Q code [Liu et al., Phys. Plasmas 20, 042503 (2013)]. It is found that an initially unstable tearing mode can intrinsically drive a toroidal plasma flow resulting in a steady state solution, in the absence of the external momentum input and external magnetic field perturbation. The saturated flow is in the order of 0.5%ω{sub A} at the q=2 rational surface in the considered case, with q and ω{sub A} being the safety factor and the Alfven frequency at the magnetic axis, respectively. The generation of the toroidal flow is robust, being insensitive to the given amplitude of the perturbation at initial state. On the other hand, the flow amplitude increases with increasing the plasma resistivity. Furthermore, the initially unstable tearing mode is fully stabilized by non-linear interaction with the self-generated toroidal flow.

On the definition of entropy for quantum unstable states

International Nuclear Information System (INIS)

Civitarese, Osvaldo; Gadella, Manuel

2015-01-01

The concept of entropy is central to the formulation of the quantum statistical mechanics, and it is linked to the definition of the density operator and the associated probabilities of occupation of quantum states. The extension of this scheme to accommodate for quantum decaying states is conceptually difficult, because of the nature of these states. Here we present a way to treat quantum unstable states in the context of statistical mechanics. We focuss on the definition of the entropy and avoid the use of complex temperatures

The application of probabilistic risk assessment to inherently safe reactors

International Nuclear Information System (INIS)

Cave, L.; Kastenberg, W.E.

1987-01-01

In the development of safety goals and design criteria for 'inherently safe' reactors a question which arises is 'To what extent is PRA relevant.' To answer this question it is necessary to consider both the risk to the public and the investment risk to the utility. In this paper the factors which are likely to determine safety objectives and their allocation are presented. (orig.)

Unstable dynamics, nonequilibrium phases, and criticality in networked excitable media

International Nuclear Information System (INIS)

Franciscis, S. de; Torres, J. J.; Marro, J.

2010-01-01

Excitable systems are of great theoretical and practical interest in mathematics, physics, chemistry, and biology. Here, we numerically study models of excitable media, namely, networks whose nodes may occasionally be dormant and the connection weights are allowed to vary with the system activity on a short-time scale, which is a convenient and realistic representation. The resulting global activity is quite sensitive to stimuli and eventually becomes unstable also in the absence of any stimuli. Outstanding consequences of such unstable dynamics are the spontaneous occurrence of various nonequilibrium phases--including associative-memory phases and one in which the global activity wanders irregularly, e.g., chaotically among all or part of the dynamic attractors--and 1/f noise as the system is driven into the phase region corresponding to the most irregular behavior. A net result is resilience which results in an efficient search in the model attractor space that can explain the origin of some observed behavior in neural, genetic, and ill-condensed matter systems. By extensive computer simulation we also address a previously conjectured relation between observed power-law distributions and the possible occurrence of a ''critical state'' during functionality of, e.g., cortical networks, and describe the precise nature of such criticality in the model which may serve to guide future experiments.

Inertial and stick-slip regimes of unstable adhesive tape peeling.

Science.gov (United States)

Dalbe, Marie-Julie; Villey, Richard; Ciccotti, Matteo; Santucci, Stéphane; Cortet, Pierre-Philippe; Vanel, Loïc

2016-05-18

We present an experimental characterization of the detachment front unstable dynamics observed during the peeling of pressure sensitive adhesives. We use an experimental set-up specifically designed to control the peeling angle θ and the peeled tape length L, while peeling an adhesive tape from a flat substrate at a constant driving velocity V. High-speed imaging allows us to report the evolution of the period and amplitude of the front oscillations, as well as the relative durations of their fast and slow phases, as a function of the control parameters V, L and θ. Our study shows that, as the driving velocity or the peeling angle increases, the oscillations of the peeling front progressively evolve from genuine "stick-slip" oscillations, made of alternating long stick phases and very brief slip phases, to sinusoidal oscillations of amplitude twice the peeling velocity. We propose a model which, taking into account the peeling angle-dependent kinetic energy cost to accelerate and decelerate the peeled tape, explains the transition from the "stick-slip" to the "inertial" regime of the dynamical instability. Using independent direct measurements of the effective fracture energy of the adhesive-substrate joint, we show that our model quantitatively accounts for the two regimes of the unstable dynamics.

Suspended Particulates Concentration (PM10 under Unstable Atmospheric Conditions over Subtropical Urban Area (Qena, Egypt

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M. El-Nouby Adam

2013-01-01

Full Text Available The main purpose of this study is to evaluate the suspended particulates (PM10 in the atmosphere under unstable atmospheric conditions. The variation of PM10 was investigated and primary statistics were employed. The results show that, the PM10 concentrations values ranged from 6.00 to 646.74 μg m−3. The average value of PM10 is equal to 114.32 μg m−3. The high values were recorded in April and May (155.17 μg m−3 and 171.82 μg m−3, respectively and the low values were noted in February and December (73.86 μg m−3 and 74.05 μg m−3, respectively. The average value of PM10 of the hot season (125.35 × 10−6 g m−3 was higher than its value for the cold season (89.27 μg m−3. In addition, the effect of weather elements (air temperature, humidity and wind on the concentration of PM10 was determined. The multiple R between PM10 and these elements ranged from 0.05 to 0.47 and its value increased to reach 0.73 for the monthly average of the database used. Finally, the PM10 concentrations were grouped depending on their associated atmospheric stability class. These average values were equal to 122.80 ± 9 μg m−3 (highly unstable or convective, 109.37 ± 12 μg m−3 (moderately unstable and 104.42 ± 15 μg m−3 (slightly unstable.

Safety assessment in plant layout design using indexing approach: Implementing inherent safety perspective

International Nuclear Information System (INIS)

Tugnoli, Alessandro; Khan, Faisal; Amyotte, Paul; Cozzani, Valerio

2008-01-01

The design of layout plans requires adequate assessment tools for the quantification of safety performance. The general focus of the present work is to introduce an inherent safety perspective at different points of the layout design process. In particular, index approaches for safety assessment and decision-making in the early stages of layout design are developed and discussed in this two-part contribution. Part 1 (accompanying paper) of the current work presents an integrated index approach for safety assessment of early plant layout. In the present paper (Part 2), an index for evaluation of the hazard related to the potential of domino effects is developed. The index considers the actual consequences of possible escalation scenarios and scores or ranks the subsequent accident propagation potential. The effects of inherent and passive protection measures are also assessed. The result is a rapid quantification of domino hazard potential that can provide substantial support for choices in the early stages of layout design. Additionally, a case study concerning selection among various layout options is presented and analyzed. The case study demonstrates the use and applicability of the indices developed in both parts of the current work and highlights the value of introducing inherent safety features early in layout design

Myocardial rest iodine-123-β-methyl-iodophenyl-pentadecanoic acid scintigraphy compared with dipyridamole stress thallium-201 scintigraphy in unstable angina

International Nuclear Information System (INIS)

Misumi, Ikuo; Kimura, Yoshihiro; Hokamura, Youichi; Yamabe, Hiroshige; Ueno, Kazuhiro

1998-01-01

Twelve patients with stable angina and 12 patients with unstable angina underwent rest iodine-123-β-methyl-iodophenyl-pentadecanoic acid (BMIPP), dipyridamole stress thallium scintigraphy and delayed thallium scintigraphy. In stable angina, sensitivity for detecting ischemic segments was higher in dipyridamole thallium (74%) than rest BMIPP (48%) images (p<0.05), but there was no significant difference between the 2 images in unstable angina. In unstable angina, the incidence of segments with higher defect scores on BMIPP images than on delayed thallium images and the opposite pattern was 27 and 5 (p<0.01). In stable angina, there was no difference. The mean defect score on BMIPP (6.3±5.6) was higher than that on delayed thallium scintigraphy (2.9±2.7) and it was almost the same as on the initial dipyridamole stress test (6.5±5.2). In conclusion, BMIPP scintigraphy is safer and may be as useful in detecting myocardial ischemia in patients with unstable angina as thallium scintigraphy. (author)

Remote sensing reflectance and inherent optical properties of oceanic waters derived from above-water measurements

Science.gov (United States)

Lee, Zhongping; Carder, Kendall L.; Steward, Robert G.; Peacock, Thomas G.; Davis, Curtiss O.; Mueller, James L.

1997-02-01

Remote-sensing reflectance and inherent optical properties of oceanic properties of oceanic waters are important parameters for ocean optics. Due to surface reflectance, Rrs or water-leaving radiance is difficult to measure from above the surface. It usually is derived by correcting for the reflected skylight in the measured above-water upwelling radiance using a theoretical Fresnel reflectance value. As it is difficult to determine the reflected skylight, there are errors in the Q and E derived Rrs, and the errors may get bigger for high chl_a coastal waters. For better correction of the reflected skylight,w e propose the following derivation procedure: partition the skylight into Rayleigh and aerosol contributions, remove the Rayleigh contribution using the Fresnel reflectance, and correct the aerosol contribution using an optimization algorithm. During the process, Rrs and in-water inherent optical properties are derived at the same time. For measurements of 45 sites made in the Gulf of Mexico and Arabian Sea with chl_a concentrations ranging from 0.07 to 49 mg/m3, the derived Rrs and inherent optical property values were compared with those from in-water measurements. These results indicate that for the waters studied, the proposed algorithm performs quite well in deriving Rrs and in- water inherent optical properties from above-surface measurements for clear and turbid waters.

Unstable chromosome aberrations on peripheral blood lymphocytes from patients with cervical uterine cancer following radiotherapy

International Nuclear Information System (INIS)

Magnata, Simey de Souza Leao Pereira

2002-09-01

Absorbed dose determination is an important step for risk assessment related to an exposure to ionizing radiation. However, physical dosimetry cannot be always performed, principally in the case of retrospective estimates. In this context, the use of bioindicators (biological effects) has been proposed, which defines the so-called biological dosimetry. In particular, scoring of unstable chromosomes aberrations (dicentrics, centric rings and fragments) of peripheral blood lymphocytes, while is the most reliable biological method for estimating individual exposure to ionizing radiation. In this work, blood samples from 5 patients, with cervical uterine cancer, were evaluated after partial-body radiotherapy with a source of 69 Co. For this, conventional cytogenetic method was employed, based on Giemsa coloration and fluorescence in situ hybridization, in order to correlate the frequency of unstable chromosome aberrations of blood lymphocytes with absorbed dose, as a result of the radiotherapy. A good agreement was observed between the frequency of chromosome aberrations scored and the values of dose previously calculated by physical dosimetry during patient's radiotherapy. The results presented in this work point out the importance of concerning analyses of unstable chromosome aberrations as biological dosimeter in the investigation of partial-body exposure to ionizing radiation. (author)

An Overview of Meta-Analyses of Danhong Injection for Unstable Angina

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Xiaoxia Zhang

2015-01-01

Full Text Available Objective. To systematically collect evidence and evaluate the effects of Danhong injection (DHI for unstable angina (UA. Methods. A comprehensive search was conducted in seven electronic databases up to January 2015. The methodological and reporting quality of included studies was assessed by using AMSTAR and PRISMA. Result. Five articles were included. The conclusions suggest that DHI plus conventional medicine treatment was effective for UA pectoris treatment, could alleviate symptoms of angina and ameliorate electrocardiograms. Flaws of the original studies and systematic reviews weaken the strength of evidence. Limitations of the methodology quality include performing an incomprehensive literature search, lacking detailed characteristics, ignoring clinical heterogeneity, and not assessing publication bias and other forms of bias. The flaws of reporting systematic reviews included the following: not providing a structured summary, no standardized search strategy. For the pooled findings, researchers took statistical heterogeneity into consideration, but clinical and methodology heterogeneity were ignored. Conclusion. DHI plus conventional medicine treatment generally appears to be effective for UA treatment. However, the evidence is not hard enough due to methodological flaws in original clinical trials and systematic reviews. Furthermore, rigorous designed randomized controlled trials are also needed. The methodology and reporting quality of systematic reviews should be improved.

An Overview of Meta-Analyses of Danhong Injection for Unstable Angina.

Science.gov (United States)

Zhang, Xiaoxia; Wang, Hui; Chang, Yanxu; Wang, Yuefei; Lei, Xiang; Fu, Shufei; Zhang, Junhua

2015-01-01

Objective. To systematically collect evidence and evaluate the effects of Danhong injection (DHI) for unstable angina (UA). Methods. A comprehensive search was conducted in seven electronic databases up to January 2015. The methodological and reporting quality of included studies was assessed by using AMSTAR and PRISMA. Result. Five articles were included. The conclusions suggest that DHI plus conventional medicine treatment was effective for UA pectoris treatment, could alleviate symptoms of angina and ameliorate electrocardiograms. Flaws of the original studies and systematic reviews weaken the strength of evidence. Limitations of the methodology quality include performing an incomprehensive literature search, lacking detailed characteristics, ignoring clinical heterogeneity, and not assessing publication bias and other forms of bias. The flaws of reporting systematic reviews included the following: not providing a structured summary, no standardized search strategy. For the pooled findings, researchers took statistical heterogeneity into consideration, but clinical and methodology heterogeneity were ignored. Conclusion. DHI plus conventional medicine treatment generally appears to be effective for UA treatment. However, the evidence is not hard enough due to methodological flaws in original clinical trials and systematic reviews. Furthermore, rigorous designed randomized controlled trials are also needed. The methodology and reporting quality of systematic reviews should be improved.

Inherent safe design of advanced high temperature reactors - concepts for future nuclear power plants

International Nuclear Information System (INIS)

Hodzic, A.; Kugeler, K.

1997-01-01

This paper discusses the applicable solutions for a commercial size High Temperature Reactor (HTR) with inherent safety features. It describes the possible realization using an advanced concept which combines newly proposed design characteristics with some well known and proven HTR inherent safety features. The use of the HTR technology offers the conceivably best solution to meet the legal criteria, recently stated in Germany, for the future reactor generation. Both systems, block and pebble bed ,reactor, could be under certain design conditions self regulating in terms of core nuclear heat, mechanical stability and the environmental transfer. 23 refs., 7 figs

Nuclear structure and magnetic moment of the unstable 12B-12N mirror pair

International Nuclear Information System (INIS)

Zheng Yongnan; Zhou Dongmei; Yuan Daqing; Zuo Yi; Fan Ping; Xu Yongjun; Zhu Jiazheng; Wang Zhiqiang; Luo Hailong; Zhang Xizhen; Zhu Shengyun; Mihara, M.; Matsuta, K.; Fukuda, M.; Minamisono, T.; Suzuki, T.

2010-01-01

Magnetic moments of the A=12 unstable mirror pair nuclides 12 B and 12 N have been measured by the β-NMR technique. The experimentally measured magnetic moments are μ( 12 B)=1.00(17)μ N and μ( 12 N)=0.4571(1)μ N . The improved shell model using an SFO Hamiltonian with enhanced spin-isospin monopole proton-neutron interaction and modified single-particle energies is employed to calculate the magnetic moments of 12 B and 12 N. The calculation yields μ( 12 B)=0.929μ N and μ( 12 N)=0.452μ N and has produced a new magic number 6 for the short-lived unstable mirror pair nuclides 12 B and 12 N. (authors)

Output Error Method for Tiltrotor Unstable in Hover

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Lichota Piotr

2017-03-01

Full Text Available This article investigates unstable tiltrotor in hover system identification from flight test data. The aircraft dynamics was described by a linear model defined in Body-Fixed-Coordinate System. Output Error Method was selected in order to obtain stability and control derivatives in lateral motion. For estimating model parameters both time and frequency domain formulations were applied. To improve the system identification performed in the time domain, a stabilization matrix was included for evaluating the states. In the end, estimates obtained from various Output Error Method formulations were compared in terms of parameters accuracy and time histories. Evaluations were performed in MATLAB R2009b environment.

Effect of x-ray treatments on pathogenic bacteria, inherent microbiota, color, and texture on parsley leaves.

Science.gov (United States)

Mahmoud, Barakat S M

2012-10-01

This work is a part of systematic studies of the effect of X-ray treatments on fresh produce. The main objective of this investigation was to study the effects of X-ray treatments in reducing the concentration of artificially inoculated Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica, and Shigella flexneri, and inherent microbiota on parsley leaves. The secondary objective was to study the effects of X-ray treatments on color and texture parameters on treated parsley leaves. The Dip-inoculated method was used to inoculate parsley leaves with a mixture of two or three strains of each tested organism at 10(8) to 10(9) colony-forming unit (CFU)/mL; the inoculated parsley leaves were then air-dried and followed by treatment with different doses of X-ray (0, 0.1, 0.5, 1.0, and 1.5 kGy) at 22°C and 55-60% relative humidity. Surviving bacterial populations on parsley leaves were evaluated using a nonselective medium (tryptic soy agar) with a selective medium overlay for each bacterium: E. coli O157:H7 (CT-SMAC agar), L. monocytogenes (MOA), and S. enterica and S. flexneri (XLD). Approximately 5.8, 3.1, 5.7, and 5.2 log CFU reductions of E. coli O157:H7, L. monocytogenes, S. enterica, and Shigella flexneri were achieved by treatment with 1.0 kGy X-ray, respectively. Furthermore, the populations of E. coli O157:H7, L. monocytogenes, S. enterica, and Shigella flexneri were reduced to less than the detectable limit (1.0 log CFU/g) by treatment with 1.5 kGy X-ray. Treatment with 1.5 kGy X-ray significantly reduced the initial inherent microbiota on parsley leaves, and inherent levels were significantly (p 0.05) in color or texture of control and treated samples with 0.1-1.5 X-ray were observed. The results of investigation indicated that X-ray is an effective technology to eliminate E. coli O157:H7, L. monocytogenes, S. enterica, and Shigella flexneri, and to extend the shelf life of parsley leaves.

Inherent Conservatism in Deterministic Quasi-Static Structural Analysis

Science.gov (United States)

Verderaime, V.

1997-01-01

The cause of the long-suspected excessive conservatism in the prevailing structural deterministic safety factor has been identified as an inherent violation of the error propagation laws when reducing statistical data to deterministic values and then combining them algebraically through successive structural computational processes. These errors are restricted to the applied stress computations, and because mean and variations of the tolerance limit format are added, the errors are positive, serially cumulative, and excessively conservative. Reliability methods circumvent these errors and provide more efficient and uniform safe structures. The document is a tutorial on the deficiencies and nature of the current safety factor and of its improvement and transition to absolute reliability.

Inherent overload protection for the series resonant converter

Science.gov (United States)

King, R. J.; Stuart, T. A.

1983-01-01

The overload characteristics of the full bridge series resonant power converter are considered. This includes analyses of the two most common control methods presently in use. The first of these uses a current zero crossing detector to synchronize the control signals and is referred to as the alpha controller. The second is driven by a voltage controlled oscillator and is referred to as the gamma controller. It is shown that the gamma controller has certain reliability advantages in that it can be designed with inherent short circuit protection. Experimental results are included for an 86 kHz converter using power metal-oxide-semiconductor field-effect transistors (MOSFETs).

Inherent and antigen-induced airway hyperreactivity in NC mice

OpenAIRE

Tetsuto Kobayashi; Toru Miura; Tomoko Haba; Miyuki Sato; Masao Takei; Isao Serizawa

1999-01-01

In order to clarify the airway physiology of NC mice, the following experiments were carried out. To investigate inherent airway reactivity, we compared tracheal reactivity to various chemical mediators in NC, BALB/c, C57BL/6 and A/J mice in vitro. NC mice showed significantly greater reactivity to acetylcholine than BALB/c and C57BL/6 mice and a reactivity comparable to that of A/J mice, which are known as high responders. Then, airway reactivity to acetylcholine was investigated in those st...

Efficacy evaluation of fluoxetine combined with conventional drug treatment on unstable angina patients complicated with depression

Institute of Scientific and Technical Information of China (English)

Chun-Hua Liao

2015-01-01

Objective:To study the efficacy of fluoxetine combined with conventional drug treatment on unstable angina patients complicated with depression. Methods:120 cases of unstable angina patients with depression were randomly divided into two groups. The anti-depression group received fluoxetine combined with conventional drug therapy; the conventional group received conventional drug therapy. Then contents of monoamine neurotransmitters and their metabolites, antioxidants and inflammatory mediators of both groups were compared. Results:Serum monoamine neurotransmitters NE, 5-HT and HA levels of the anti-depression group were higher than those of the conventional group and metabolites 5-HIAA and HVA contents were lower than those of the conventional group; serum SOD, CAT, GSH and HSP-70 contents of the anti-depression group were higher than those of the conventional group, and hs-CRP, MMP9, MCP1 and HMGB1 contents were lower than those of the conventional group. Conclusion:Fluoxetine combined with conventional drug therapy can increase the contents of monoamine neurotransmitters and antioxidants, and reduce oxidative stress response and inflammatory response; it is an ideal method for treating unstable angina complicated with depression.

Unstable volatility functions: the break preserving local linear estimator

DEFF Research Database (Denmark)

Casas, Isabel; Gijbels, Irene

The objective of this paper is to introduce the break preserving local linear (BPLL) estimator for the estimation of unstable volatility functions. Breaks in the structure of the conditional mean and/or the volatility functions are common in Finance. Markov switching models (Hamilton, 1989......) and threshold models (Lin and Terasvirta, 1994) are amongst the most popular models to describe the behaviour of data with structural breaks. The local linear (LL) estimator is not consistent at points where the volatility function has a break and it may even report negative values for finite samples...

Glass Forming Ability of Amorphous Drugs Investigated by Continuous Cooling and Isothermal Transformation.

Science.gov (United States)

Blaabjerg, Lasse I; Lindenberg, Eleanor; Löbmann, Korbinian; Grohganz, Holger; Rades, Thomas

2016-09-06

The aim of this study was to investigate the glass forming ability of 12 different drugs by the determination of continuous cooling and isothermal transformation diagrams in order to elucidate if an inherent differentiation between the drugs with respect to their the glass forming ability can be made. Continuous-cooling-transformation (CCT) and time-temperature-transformation (TTT) diagrams of the drugs were developed in order to predict the critical cooling rate necessary to convert the drug from the melt into an amorphous form. While TTT diagrams overestimated the actual critical cooling rate, they allowed an inherent differentiation of glass forming ability for the investigated drugs into drugs that are extremely difficult to amorphize (>750 °C/min), drugs that require modest cooling rates (>10 °C/min), and drugs that can be made amorphous even at very slow cooling rates (>2 °C/min). Thus, the glass forming ability can be predicted by the use of TTT diagrams. In contrast to TTT diagrams, CCT diagrams may not be suitable for small organic molecules due to poor separation of exothermic events, which makes it difficult to determine the zone of recrystallization. In conclusion, this study shows that glass forming ability of drugs can be predicted by TTT diagrams.

Selection of unstable patterns and control of optical turbulence by Fourier plane filtering

DEFF Research Database (Denmark)

Mamaev, A.V.; Saffman, M.

1998-01-01

We report on selection and stabilization of transverse optical patterns in a feedback mirror experiment. Amplitude filtering in the Fourier plane is used to select otherwise unstable spatial patterns. Optical turbulence observed for nonlinearities far above the pattern formation threshold...

The Market for Academic Knowledge: Its Historical Emergence and Inherent Tensions

Science.gov (United States)

Weik, Elke

2014-01-01

This paper contributes to the discussion about the marketisation of universities by providing a historical perspective. Going back to the time when the market for academic knowledge emerged, I argue that it was created through incorporating a number of inherent tensions that have been, and still are, shaping its development. I show how these…

Detection of angina-related coronary artery in patients with unstable angina pectoris by using 123I-BMIPP myocardial scintigraphy

International Nuclear Information System (INIS)

Oka, Toshiaki; Inoue, Seiji; Asano, Ryuta; Handa, Atsushi; Iguchi, Nobuo; Sumiyoshi, Tetsuya; Hosoda, Saichi; Kobayashi, Hideki; Kusakabe, Kiyoko.

1996-01-01

To evaluate the diagnostic accuracy of detection of angina-related coronary arteries in patients with unstable angina pectoris. Twenty patients with unstable angina pectoris underwent 123 I-BMIPP scintigraphy at rest. A mean duration from last anginal attack to 123 I-BMIPP scintigraphy was 4.8±3.2 days. Seventeen of 20 angina-related coronary territories were detected by reduced 123 -BMIPP uptake. The sensitivity and specificity for detection of angina-related coronary arteries were 85% and 95%, respectively. The decrease in myocardial uptake of 123 I-BMIPP agreed with the decrease in regional wall motion by using ultrasonic echocardiography. 123 I-BMIPP scintigraphy may be useful for detection of angina-related coronary artery in a routine clinical examination in patients with unstable angina pectoris. (author)

Cemented Hemiarthroplasty in Elderly Osteoporotic Unstable Trochanteric Fractures using Fracture Window

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Thakur A

2016-03-01

Full Text Available Introduction: We would like to analyze the role of cemented hemiarthroplasty in elderly osteoporotic unstable intertrochanteric fractures through trochanteric fracture window. Materials and Methods: The study was conducted from July 2011 to July 2014. From a total of 265 consecutive patients with intertrochanteric fractures of 42 patients were selected according to inclusion criteria and results were analyzed prospectively. All patients were operated at tertiary care institute. Patients which matched the inclusion criteria were selected. 42 patients entered the study and all completed the study. Primary cemented hemiarthroplasty was done in all patients. Modified Harris Hip Score was used to assess all the patients. Results: 42 patients were included in the study with an average age of 80.7 years. Only AO/OTA type 31-A2.2 and 31-A2.3 were included, average HHS at final follow up of three years was 86.2. No revision or reoperation was done. Conclusion: In a selected cohort of patients primary prosthetic replacement in elderly osteoporotic unstable intertrochanteric fractures is good option and the surgical technique allowed us to perform it more easily.

Wind tunnel experiments on unstable self-excited vibration of sectional girders

Science.gov (United States)

Král, Radomil; Pospíšil, Stanislav; Náprstek, Jiří

2014-01-01

In this paper, a wind tunnel analysis of two degrees-of-freedom system represented by sectional girders is carried out. Besides an evaluation of the aeroelastic coefficients, the analysis is focused on the influence of the natural frequency ratio on the initiation of unstable vibration, which can be of practical interest. On the phenomenological level, the paper also discusses experimentally ascertained response regimes, with an emphasis on their stability character. The attention is paid to the memory effect in the response described by the hysteresis loop together with the separation curves determining the stability boundaries. The influence of initial disturbance on the stability is examined. Two types of cross-sections were investigated: (i) rectangular one with the aspect ratio 1:5, and (ii) bridge-like cross-section with comparable principal dimensions. For both types of cross-sections, the limits of the stability are significantly affected by an intentionally introduced initial disturbance. This holds especially with regard to the rectangular profile where the separation curves create very narrow sub-domains between a stable and an unstable response, while the bridge-like cross-section demonstrates much stable behaviour.

Utilization of Point Clouds Characteristics in Interpretation and Evaluation Geophysical Resistivity Surveying of Unstable Running Block

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Marcel Brejcha

2016-05-01

Full Text Available Close to human residences the places often abound where anthropogenic activity and external factors cause their changes. The changes can often influence their inhabitants’ life thanks to incipient dangerous places. The project of successful design of measures to ensure stability of unstable running blocks depends on chosen approaches and primary resource preparation. Utilization of modern technologies in their taking and processing is required nowadays. The paper describes the taking and processing of data for project of solution „Stabilization of unstable running block“ in a municipal settled part with efficient utilization of unusual method of processing of geophysical resistivity method.

Multi-objective optimization of a cascade refrigeration system: Exergetic, economic, environmental, and inherent safety analysis

International Nuclear Information System (INIS)

Eini, Saeed; Shahhosseini, Hamidreza; Delgarm, Navid; Lee, Moonyong; Bahadori, Alireza

2016-01-01

Highlights: • A multi-objective optimization is performed for a cascade refrigeration cycle. • The optimization problem considers inherently safe design as well as 3E analysis. • As a measure of inherent safety level a quantitative risk analysis is utilized. • A CO 2 /NH 3 cascade refrigeration system is compared with a CO 2 /C 3 H 8 system. - Abstract: Inherently safer design is the new approach to maximize the overall safety of a process plant. This approach suggests some risk reduction strategies to be implemented in the early stages of design. In this paper a multi-objective optimization was performed considering economic, exergetic, and environmental aspects besides evaluation of the inherent safety level of a cascade refrigeration system. The capital costs, the processing costs, and the social cost due to CO 2 emission were considered to be included in the economic objective function. Exergetic efficiency of the plant was considered as the second objective function. As a measure of inherent safety level, Quantitative Risk Assessment (QRA) was performed to calculate total risk level of the cascade as the third objective function. Two cases (ammonia and propane) were considered to be compared as the refrigerant of the high temperature circuit. The achieved optimum solutions from the multi–objective optimization process were given as Pareto frontier. The ultimate optimal solution from available solutions on the Pareto optimal curve was selected using Decision-Makings approaches. NSGA-II algorithm was used to obtain Pareto optimal frontiers. Also, three decision-making approaches (TOPSIS, LINMAP, and Shannon’s entropy methods) were utilized to select the final optimum point. Considering continuous material release from the major equipment in the plant, flash and jet fire scenarios were considered for the CO 2 /C 3 H 8 cycle and toxic hazards were considered for the CO 2 /NH 3 cycle. The results showed no significant differences between CO 2 /NH 3 and

The inherent inefficiency of simultaneously feasible financial transmission rights auctions

International Nuclear Information System (INIS)

Deng, Shi-Jie; Oren, Shmuel; Meliopoulos, A.P.

2010-01-01

Empirical evidence from the New York ISO shows that the clearing prices for point-to-point congestion revenue rights, also known as financial transmission rights (FTRs), resulting from centralized auctions conducted by Independent System Operators differ significantly and systematically from the realized congestion revenues that determine the accrued payoffs of these rights. The question addressed by this paper is whether such deviations are due to price discovery errors which will eventually vanish or due to inherent inefficiencies in the auction structure. We show that even with perfect foresight of average congestion rents the clearing prices for the FTRs depend on the bid quantity and therefore may not be priced correctly in the financial transmission right (FTR) auction. In particular, we prove that quantity limits on the FTR bids may cause the auction clearing prices to differ from the bid prices. This phenomenon which is inherent in the theoretical properties of the optimization algorithm used to clear the auction, is further illustrated through numerical simulations with test systems. We conclude that price discovery alone would not remedy the discrepancy between the auction prices and the realized values of the FTRs. Secondary markets or frequent reconfiguration auctions are necessary in order to achieve such convergence. (author)

The minimum attention plant inherent safety through LWR simplification

International Nuclear Information System (INIS)

Turk, R.S.; Matzie, R.A.

1987-01-01

The Minimum Attention Plant (MAP) is a unique small LWR that achieves greater inherent safety, improved operability, and reduced costs through design simplification. The MAP is a self-pressurized, indirect-cycle light water reactor with full natural circulation primary coolant flow and multiple once-through steam generators located within the reactor vessel. A fundamental tenent of the MAP design is its complete reliance on existing LWR technology. This reliance on conventional technology provides an extensive experience base which gives confidence in judging the safety and performance aspects of the design

Electromyographic activity and 6RM strength in bench press on stable and unstable surfaces.

Science.gov (United States)

Saeterbakken, Atle H; Fimland, Marius S

2013-04-01

The purpose of the study was to compare 6-repetition maximum (6RM) loads and muscle activity in bench press on 3 surfaces, namely, stable bench, balance cushion, and Swiss ball. Sixteen healthy, resistance-trained men (age 22.5 ± 2.0 years, stature 1.82 ± 6.6 m, and body mass 82.0 ± 7.8 kg) volunteered for 3 habituation/strength testing sessions and 1 experimental session. In randomized order on the 3 surfaces, 6RM strength and electromyographic activity of pectoralis major, deltoid anterior, biceps brachii, triceps brachii, rectus abdominis, oblique external and erector spinae were assessed. Relative to stable bench, the 6RM strength was approximately 93% for balance cushion (p ≤ 0.001) and approximately 92% for Swiss ball (p = 0.008); the pectoralis major electromyographic (EMG) activity was approximately 90% using the balance cushion (p = 0.080) and approximately 81% using Swiss ball (p = 0.006); the triceps EMG was approximately 79% using the balance cushion (p = 0.028) and approximately 69% using the Swiss ball (p = 0.002). Relative to balance cushion, the EMG activity in pectoralis, triceps, and erector spinae using Swiss ball was approximately 89% (p = 0.016), approximately 88% (p = 0.014) and approximately 80% (p = 0.020), respectively. In rectus abdominis, the EMG activity relative to Swiss ball was approximately 69% using stable bench (p = 0.042) and approximately 65% using the balance cushion (p = 0.046). Similar EMG activities between stable and unstable surfaces were observed for deltoid anterior, biceps brachii, and oblique external. In conclusion, stable bench press had greater 6RM strength and triceps and pectoralis EMG activity compared with the unstable surfaces. These findings have implications for athletic training and rehabilitation, because they demonstrate an inferior effect of unstable surfaces on muscle activation of prime movers and strength in bench press. If an unstable surface in bench press is desirable, a balance cushion should

A pilot study on the influence of exercising on unstable training machine on balance control and trunk muscles activity.

Science.gov (United States)

Domeika, Aurelijus; Aleknaite-Dambrauskiene, Ieva; Poskaitis, Vytautas; Zaveckas, Vidmantas; Grigas, Vytautas; Zvironiene, Ausra

2018-05-16

The main position of the working population is becoming sitting. Immobile prolonged sedentary time may cause negative effects including reduced intervertebral discs nutrition. Main ways of mitigating them are regular position changes and exercising. To evaluate influence of the short term training on unstable training machine on balance control and trunk muscles activity in patients with lower back pain. Participants (n=16) experiencing lower back pain were trained on an unstable sculling machine "Rehabili". Their balance tested by (Biodex Balance System) and rectus abdominis, externus oblique, transverse abdominis, multifidus and erector spine muscles activity (measured by surface electromyography) while sitting and standing with usual and aligned body postures both before and after six weeks of training (three 15 minutes sessions per week) were compared in between. Balance control improved after the training program. Besides, more symmetrical activation of both sides rectus and transversus abdominis muscles, as well as increased transversus abdominis muscle activation of 19% (p< 0.05), were observed. Six weeks short sessions training on unstable training machine improved balance control and increased trunk muscles activity especially in aligned body posture when standing or sitting on unstable surface.

A4 see-saw models and form dominance

International Nuclear Information System (INIS)

Chen, M-C; King, Stephen F.

2009-01-01

We introduce the idea of Form Dominance in the (type I) see-saw mechanism, according to which a particular right-handed neutrino mass eigenstate is associated with a particular physical neutrino mass eigenstate, leading to a form diagonalizable effective neutrino mass matrix. Form Dominance, which allows an arbitrary neutrino mass spectrum, may be regarded as a generalization of Constrained Sequential Dominance which only allows strongly hierarchical neutrino masses. We consider alternative implementations of the see-saw mechanism in minimal A 4 see-saw models and show that such models satisfy Form Dominance, leading to neutrino mass sum rules which predict closely spaced neutrino masses with a normal or inverted neutrino mass ordering. To avoid the partial cancellations inherent in such models we propose Natural Form Dominance, in which a different flavon is associated with each physical neutrino mass eigenstate.

The Inherent Asymmetry of DNA Replication.

Science.gov (United States)

Snedeker, Jonathan; Wooten, Matthew; Chen, Xin

2017-10-06

Semiconservative DNA replication has provided an elegant solution to the fundamental problem of how life is able to proliferate in a way that allows cells, organisms, and populations to survive and replicate many times over. Somewhat lost, however, in our admiration for this mechanism is an appreciation for the asymmetries that occur in the process of DNA replication. As we discuss in this review, these asymmetries arise as a consequence of the structure of the DNA molecule and the enzymatic mechanism of DNA synthesis. Increasing evidence suggests that asymmetries in DNA replication are able to play a central role in the processes of adaptation and evolution by shaping the mutagenic landscape of cells. Additionally, in eukaryotes, recent work has demonstrated that the inherent asymmetries in DNA replication may play an important role in the process of chromatin replication. As chromatin plays an essential role in defining cell identity, asymmetries generated during the process of DNA replication may play critical roles in cell fate decisions related to patterning and development.

Analysis of unstable secondary particles produced in jet of 30 TeV energy sum

International Nuclear Information System (INIS)

Ogata, Takeshi

1978-01-01

High energy jet shower with energy sum of about 30 TeV has been obtained in the airplane-bone emulsion chamber. The size of the emulsion chamber was 20 cm x 25 cm x 12 cm. The airplane altitude was 260 g/cm 2 , and the exposure time was 600 hours. In this experiment, two jet events were found, and one of two events, KG-7, was the largest obtained so far. Three secondary charged particles produced by high energy interaction were analysed in detail. The analysis indicated that three charged particles seemed to be created by the decay of an unstable secondary particle. The lifetime of the unstable particle was estimated to be 10 -3 - 10 -14 sec, and this particle seems to be a charm particle. (Yoshimori, M.)

Pre-failure behaviour of an unstable limestone cliff from displacement and seismic data

Directory of Open Access Journals (Sweden)

J.-L. Got

2010-04-01

Full Text Available We monitored the displacement and seismic activity of an unstable vertical rock slice in a natural limestone cliff of the southeast Vercors massif, southeast France, during the months preceding its collapse. Displacement measurements showed an average acceleration of the movement of its top, with clear increases in the displacement velocity and in the discrete seismic event production rate during periods where temperature falls, with more activity when rainfall or frost occurs. Crises of discrete seismic events produce high amplitudes in periodograms, but do not change the high frequency base noise level rate. We infer that these crises express the critical crack growth induced by water weakening (from water vapor condensation or rain of the rock strength rather than to a rapid change in applied stresses. Seismic noise analysis showed a steady increase in the high frequency base noise level and the emergence of spectral modes in the signal recorded by the sensor installed on the unstable rock slice during the weeks preceding the collapse. High frequency seismic noise base level seems to represent subcritical crack growth. It is a smooth and robust parameter whose variations are related to generalized changes in the rupture process. Drop of the seismic noise amplitude was concomitant with the emergence of spectral modes – that are compatible with high-order eigenmodes of the unstable rock slice – during the later stages of its instability. Seismic noise analysis, especially high frequency base noise level analysis may complement that of inverse displacement velocity in early-warning approaches when strong displacement fluctuations occur.

High-resolution simulations of unstable cylindrical gravity currents undergoing wandering and splitting motions in a rotating system

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Dai, Albert; Wu, Ching-Sen

2018-02-01

High-resolution simulations of unstable cylindrical gravity currents when wandering and splitting motions occur in a rotating system are reported. In this study, our attention is focused on the situation of unstable rotating cylindrical gravity currents when the ratio of Coriolis to inertia forces is larger, namely, 0.5 ≤ C ≤ 2.0, in comparison to the stable ones when C ≤ 0.3 as investigated previously by the authors. The simulations reproduce the major features of the unstable rotating cylindrical gravity currents observed in the laboratory, i.e., vortex-wandering or vortex-splitting following the contraction-relaxation motion, and good agreement is found when compared with the experimental results on the outrush radius of the advancing front and on the number of bulges. Furthermore, the simulations provide energy budget information which could not be attained in the laboratory. After the heavy fluid is released, the heavy fluid collapses and a contraction-relaxation motion is at work for approximately 2-3 revolutions of the system. During the contraction-relaxation motion of the heavy fluid, the unstable rotating cylindrical gravity currents behave similar to the stable ones. Towards the end of the contraction-relaxation motion, the dissipation rate in the system reaches a local minimum and a quasi-geostrophic equilibrium state is reached. After the quasi-geostrophic equilibrium state, vortex-wandering or vortex-splitting may occur depending on the ratio of Coriolis to inertia forces. The vortex-splitting process begins with non-axisymmetric bulges and, as the bulges grow, the kinetic energy increases at the expense of decreasing potential energy in the system. The completion of vortex-splitting is accompanied by a local maximum of dissipation rate and a local maximum of kinetic energy in the system. A striking feature of the unstable rotating cylindrical gravity currents is the persistent upwelling and downwelling motions, which are observed for both the

An efficient algorithm for calculation of the Luenberger canonical form.

Science.gov (United States)

Jordan, D.; Sridhar, B.

1973-01-01

A new algorithm is presented to obtain the Luenberger canonical form for multivariable systems. A distinct feature of the method is that the canonical form is obtained directly and, if necessary, the similarity transformation can be computed. There is a substantial reduction in the amount of computation compared to Luenberger's method. The reduced computations along with Gaussian techniques lend greater inherent accuracy and the ability to refine the solution with additional computations. An example is presented to illustrate the technique.

Investigating Resulting Residual Stresses during Mechanical Forming Process

Science.gov (United States)

Akinlabi, Stephen A.; Fatoba, Olawale S.; Mashinini, Peter M.; Akinlabi, Esther T.

2018-03-01

Most manufacturing processes such as machining, welding, heat treatment, laser forming, laser cladding and, laser metal deposition, etc. are subjected to a form of heat or energy to change the geometrical shape thus changing the inherent engineering and structural properties of the material. These changes often cause the development of locked up stresses referred to as residual stresses as a result of these activities. This study reports on the residual stresses developed due to the mechanical forming process to maintain a suitable structural integrity for the formed components. The result of the analysis through the X-ray diffraction confirmed that residual stresses were induced in the manufactured parts and further revealed that residual stresses were compressive in nature as found in the parent material but with values less than the parent material.

Spondylolysis and spondylolisthesis: prevalence of different forms of instability and clinical implications.

Science.gov (United States)

Niggemann, Pascal; Kuchta, Johannes; Beyer, Hans-Konrad; Grosskurth, D; Schulze, Thorsten; Delank, Karl-Stefan

2011-10-15

Imaging study with an evaluation of incidences and clinical correlation. To evaluate the incidence of 3 different types of instabilities in patients with spondylolysis or isthmic spondylolisthesis. Clinical findings are correlated with imaging findings, and the imaging findings are analyzed with regard to their clinical implications. Spondylolysis and isthmic spondylolisthesis are common disorders. An unstable slip is the most well-known form of instability, but other forms also exist. However, the incidence of these instabilities and their clinical implications are yet unclear. A total of 140 patients with 141 levels of spondylolysis identified by MRI (magnetic resonance imaging) were included in this study. Using positional MRI, the instability of the slip, an increased angular movement, and movement in the spondylolytic cleft were assessed. On the basis of clinical findings, the patients were classified as presenting with either radicular or nonradicular symptoms. The incidence of the instabilities was recorded and correlated with the incidence of radicular symptoms. Fifteen patients had an unstable slip (anterior instability); 35, an increased angular movement (angular instability); and 34 patients, a movement in the spondylolytic cleft (posterior instability). All forms of instability could be found together. No instability at all was found in 76 patients. Radicular symptoms were found significantly more often in patients with one or more of the described instabilities compared with patients without instability. All 3 described forms of instability are common in spondylolysis or isthmic spondylolisthesis and associated with radicular pain. This finding stresses the value of positional MRI in the evaluation of patients with spondylolysis and isthmic spondylolisthesis, especially if radicular symptoms are present.

Comparison of occipitocervical and atlantoaxial fusion in treatment of unstable Jefferson fractures

Directory of Open Access Journals (Sweden)

Yong Hu

2017-01-01

Full Text Available Background: Controversy exists regarding the management of unstable Jefferson fractures, with some surgeons performing reduction and immobilization of the patient in a halo vest and others performing open reduction and internal fixation. This study compares the clinical and radiological outcome parameters between posterior atlantoaxial fusion (AAF and occipitocervical fusion (OCF constructs in the treatment of the unstable atlas fracture. Materials and Methods: 68 consecutive patients with unstable Jefferson fractures treated by AAF or OCF between October 2004 and March 2011 were included in this retrospective evaluation from institutional databases. The authors reviewed medical records and original images. The patients were divided into two surgical groups treated with either AAF ( n = 48, F/M 30:18 and OCF ( n = 20, F/M 13:7 fusion. Blood loss, operative time, Japanese Orthopaedic Association (JOA score, visual analog scale (VAS score, atlanto-dens interval, lateral mass displacement, complications, and the bone fusion rates were recorded. Results: Five patients with incomplete paralysis (7.4% demonstrated postoperative improvement by more than 1 grade on the American Spinal Injury Association impairment scale. The JOA score of the AAF group improved from 12.5 ± 3.6 preoperatively to 15.7 ± 2.3 postoperatively, while the JOA score of the OCF group improved from 11.2 ± 3.3 preoperatively to 14.8 ± 4.2 postoperatively. The VAS score of AAF group decreased from 4.8 ± 1.5 preoperatively to 1.0 ± 0.4 postoperatively, the VAS score of the OCF group decreased from 5.4 ± 2.2 preoperatively to 1.3 ± 0.9 postoperatively. Conclusions: The OCF or AAF combined with short-term external immobilization can establish the upper cervical stability and prevent further spinal cord injury and nerve function damage.

Results of the 1986 FFTF inherent safety tests

International Nuclear Information System (INIS)

Burke, T.M.; Campbell, L.R.; Franz, G.R.; Knecht, W.L.

1987-01-01

A series of tests was recently completed at the 400-MW (thermal) Fast Flux Test Facility (FFTF) to further demonstrate the passive safety characteristics of liquid-metal-cooled fast reactors. Earlier FFTF testing of decay heat removal by sodium natural circulation was reported in 1981. The main purpose of the 1986 test series was to demonstrate passive reactor shutdown during a loss-of-flow event when several inherent shutdown devices called gas expansion modules (GEMs) were installed in the reactor. However, these tests also provide further data on the natural circulation performance of the primary system, in particular the reactor core, and thus add to the data base available for checking the validity of available analytical tools

Synthesis of unstable cyclic peroxides for chemiluminescence studies

Energy Technology Data Exchange (ETDEWEB)

Bartoloni, Fernando H.; Oliveira, Marcelo A. de; Augusto, Felipe A.; Ciscato, Luiz Francisco M.L.; Bastos, Erick L.; Baader, Wilhelm J., E-mail: wjbaader@iq.usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Quimica. Dept. de Quimica Fundamental

2012-11-15

Cyclic four-membered ring peroxides are important high-energy intermediates in a variety of chemi and bioluminescence transformations. Specifically, a-peroxy lactones (1,2-dioxetanones) have been considered as model systems for efficient firefly bioluminescence. However, the preparation of such highly unstable compounds is extremely difficult and, therefore, only few research groups have been able to study the properties of these substances. In this study, the synthesis, purification and characterization of three 1,2-dioxetanones are reported and a detailed procedure for the known synthesis of diphenoyl peroxide, another important model compound for the chemical generation of electronically excited states, is provided. For most of these peroxides, the complete spectroscopic characterization is reported here for the first time. (author)

NT-proBNP in unstable coronary artery disease--experiences from the FAST, GUSTO IV and FRISC II trials.

Science.gov (United States)

Jernberg, Tomas; James, Stefan; Lindahl, Bertil; Stridsberg, Mats; Venge, Per; Wallentin, Lars

2004-03-15

Risk stratification is important in patients with unstable coronary artery disease (CAD), i.e. unstable angina or non-ST-elevation myocardial infarction. This article focuses on the emerging role of N-terminal pro brain natriuretic peptide (NT-proBNP) and the results from the FAST, GUSTO IV and FRISC II trials. In the FAST study, NT-proBNP was measured on admission in 755 patients admitted because of symptoms suggestive of unstable CAD. Follow up was performed after 40 months. The GUSTO IV and the FRISC II-trials included patients with unstable CAD and NT-proBNP was analyzed in 6806 and 2019 patients, with follow up after 1 and 2 years, respectively. In the FAST study, patients in the 2nd, 3rd, and 4th NT-proBNP quartile had a relative risk of subsequent death of 4.2 (1.6-11.1), 10.7 (4.2-26.8) and 26.6 (10.8-65.5), respectively. In the GUSTO IV trial, increasing quartiles of NT-proBNP were related to short and long term mortality which at 1 year was; 1.8%, 3.9%, 7.7% and 19.2% (P<0.001), respectively. In multivariable analyses including well-known predictors of outcome, NT-proBNP level was independently associated to mortality in all three studies. In the FRISC II trial, the NT-proBNP level, especially if combined with a marker of inflammation, identified those with the greatest benefit from an early invasive strategy. NT-proBNP is strongly associated with mortality in patients with suspected or confirmed unstable CAD and, combined with a marker of inflammation, seems helpful in identifying those with greatest benefit from an early invasive strategy.

Comparative Emulsifying Properties of Octenyl Succinic Anhydride (OSA-Modified Starch: Granular Form vs Dissolved State.

Directory of Open Access Journals (Sweden)

María Matos

Full Text Available The emulsifying ability of OSA-modified and native starch in the granular form, in the dissolved state and a combination of both was compared. This study aims to understand mixed systems of particles and dissolved starch with respect to what species dominates at droplet interfaces and how stability is affected by addition of one of the species to already formed emulsions. It was possible to create emulsions with OSA-modified starch isolated from Quinoa as sole emulsifier. Similar droplet sizes were obtained with emulsions prepared at 7% (w/w oil content using OSA-modified starch in the granular form or molecularly dissolved but large differences were observed regarding stability. Pickering emulsions kept their droplet size constant after one month while emulsions formulated with OSA-modified starch dissolved exhibited coalescence. All emulsions stabilized combining OSA-modified starch in granular form and in solution showed larger mean droplet sizes with no significant differences with respect to the order of addition. These emulsions were unstable due to coalescence regarding presence of free oil. Similar results were obtained when emulsions were prepared by combining OSA-modified granules with native starch in solution. The degree of surface coverage of starch granules was much lower in presence of starch in solution which indicates that OSA-starch is more surface active in the dissolved state than in granular form, although it led to unstable systems compared to starch granule stabilized Pickering emulsions, which demonstrated to be extremely stable.

Making the Grade: Describing Inherent Requirements for the Initial Teacher Education Practicum

Science.gov (United States)

Sharplin, Elaine; Peden, Sanna; Marais, Ida

2016-01-01

This study explores the development, description, and illustration of inherent requirement (IR) statements to make explicit the requirements for performance on an initial teacher education (ITE) practicum. Through consultative group processes with stakeholders involved in ITE, seven IR domains were identified. From interviews with academics,…

Safety assessment in plant layout design using indexing approach: implementing inherent safety perspective. Part 1 - guideword applicability and method description.

Science.gov (United States)

Tugnoli, Alessandro; Khan, Faisal; Amyotte, Paul; Cozzani, Valerio

2008-12-15

Layout planning plays a key role in the inherent safety performance of process plants since this design feature controls the possibility of accidental chain-events and the magnitude of possible consequences. A lack of suitable methods to promote the effective implementation of inherent safety in layout design calls for the development of new techniques and methods. In the present paper, a safety assessment approach suitable for layout design in the critical early phase is proposed. The concept of inherent safety is implemented within this safety assessment; the approach is based on an integrated assessment of inherent safety guideword applicability within the constraints typically present in layout design. Application of these guidewords is evaluated along with unit hazards and control devices to quantitatively map the safety performance of different layout options. Moreover, the economic aspects related to safety and inherent safety are evaluated by the method. Specific sub-indices are developed within the integrated safety assessment system to analyze and quantify the hazard related to domino effects. The proposed approach is quick in application, auditable and shares a common framework applicable in other phases of the design lifecycle (e.g. process design). The present work is divided in two parts: Part 1 (current paper) presents the application of inherent safety guidelines in layout design and the index method for safety assessment; Part 2 (accompanying paper) describes the domino hazard sub-index and demonstrates the proposed approach with a case study, thus evidencing the introduction of inherent safety features in layout design.

Stability of unstably stratified shear flow between parallel plates

Energy Technology Data Exchange (ETDEWEB)

Fujimura, Kaoru; Kelly, R E

1987-09-01

The linear stability of unstably stratified shear flows between two horizontal parallel plates was investigated. Eigenvalue problems were solved numerically by making use of the expansion method in Chebyshev polynomials, and the critical Rayleigh numbers were obtained accurately in the Reynolds number range of (0.01, 100). It was found that the critical Rayleigh number increases with an increase of the Reynolds number. The result strongly supports previous stability analyses except for the analysis by Makino and Ishikawa (J. Jpn. Soc. Fluid Mech. 4 (1985) 148 - 158) in which a decrease of the critical Rayleigh number was obtained.

Stability of unstably stratified shear flow between parallel plates

International Nuclear Information System (INIS)

Fujimura, Kaoru; Kelly, R.E.

1987-01-01

The linear stability of unstably stratified shear flows between two horizontal parallel plates was investigated. Eigenvalue problems were solved numerically by making use of the expansion method in Chebyshev polynomials, and the critical Rayleigh numbers were obtained accurately in the Reynolds number range of [0.01, 100]. It was found that the critical Rayleigh number increases with an increase of the Reynolds number. The result strongly supports previous stability analyses except for the analysis by Makino and Ishikawa [J. Jpn. Soc. Fluid Mech. 4 (1985) 148 - 158] in which a decrease of the critical Rayleigh number was obtained. (author)

UNSTABLE PLANETARY SYSTEMS EMERGING OUT OF GAS DISKS

International Nuclear Information System (INIS)

Matsumura, Soko; Thommes, Edward W.; Chatterjee, Sourav; Rasio, Frederic A.

2010-01-01

The discovery of over 400 extrasolar planets allows us to statistically test our understanding of the formation and dynamics of planetary systems via numerical simulations. Traditional N-body simulations of multiple-planet systems without gas disks have successfully reproduced the eccentricity (e) distribution of the observed systems by assuming that the planetary systems are relatively closely packed when the gas disk dissipates, so that they become dynamically unstable within the stellar lifetime. However, such studies cannot explain the small semimajor axes a of extrasolar planetary systems, if planets are formed, as the standard planet formation theory suggests, beyond the ice line. In this paper, we numerically study the evolution of three-planet systems in dissipating gas disks, and constrain the initial conditions that reproduce the observed a and e distributions simultaneously. We adopt initial conditions that are motivated by the standard planet formation theory, and self-consistently simulate the disk evolution and planet migration, by using a hybrid N-body and one-dimensional gas disk code. We also take into account eccentricity damping, and investigate the effect of saturation of corotation resonances on the evolution of planetary systems. We find that the a distribution is largely determined in a gas disk, while the e distribution is determined after the disk dissipation. We also find that there may be an optimum disk mass which leads to the observed a-e distribution. Our simulations generate a larger fraction of planetary systems trapped in mean-motion resonances (MMRs) than the observations, indicating that the disk's perturbation to the planetary orbits may be important to explain the observed rate of MMRs. We also find a much lower occurrence of planets on retrograde orbits than the current observations of close-in planets suggest.

Nonlinear particle-wave kinetics in weakly unstable plasmas

International Nuclear Information System (INIS)

Breizman, B.N.; Berk, H.L.; Pekker, M.S.

1996-01-01

With the motivation to address the behavior of the fusion produced alpha particles in a thermonuclear reactor, a theory is developed for predicting the wave saturation levels and particle transport in weakly unstable systems with a discrete number of modes in the presence of energetic particle sources and sinks. Conditions are established for either steady state or bursting nonlinear scenarios when several modes are excited for cases where there is and there is not resonance overlap. Depending on parameters, the particles can undergo benign relaxation, with only a small fraction of the available free energy released to waves and with no global transport, or the particles can experience rapid global transport caused by a substantial conversion of their free energy into wave energy. When the resonance condition of the particle-wave interaction is varied adiabatically, the particles trapped in a wave are found to form phase space holes or clumps that enhance the particle-wave energy exchange. This mechanism, which has been experimentally observed when there is frequency chirping, causes increased saturation levels of instabilities. If resonance sweeping is imposed externally, the particle free energy can even be tapped in stable systems where background dissipation suppresses linear instability. Externally applied resonance sweeping can be important for alpha particle energy channeling, as well as for understanding fishbone and some Alfven wave instability experiments. Near instability threshold, that is when the destabilizing drive just exceeds the background dissipation, a more sophisticated analysis is developed to predict the correct saturation. To leading order, this problem reduces to an integral equation for the wave amplitude with a temporally non local cubic term. This equation has a self-similar solution that blows-up in a finite time

Predicting welding distortion in a panel structure with longitudinal stiffeners using inherent deformations obtained by inverse analysis method.

Science.gov (United States)

Liang, Wei; Murakawa, Hidekazu

2014-01-01

Welding-induced deformation not only negatively affects dimension accuracy but also degrades the performance of product. If welding deformation can be accurately predicted beforehand, the predictions will be helpful for finding effective methods to improve manufacturing accuracy. Till now, there are two kinds of finite element method (FEM) which can be used to simulate welding deformation. One is the thermal elastic plastic FEM and the other is elastic FEM based on inherent strain theory. The former only can be used to calculate welding deformation for small or medium scale welded structures due to the limitation of computing speed. On the other hand, the latter is an effective method to estimate the total welding distortion for large and complex welded structures even though it neglects the detailed welding process. When the elastic FEM is used to calculate the welding-induced deformation for a large structure, the inherent deformations in each typical joint should be obtained beforehand. In this paper, a new method based on inverse analysis was proposed to obtain the inherent deformations for weld joints. Through introducing the inherent deformations obtained by the proposed method into the elastic FEM based on inherent strain theory, we predicted the welding deformation of a panel structure with two longitudinal stiffeners. In addition, experiments were carried out to verify the simulation results.

Identification and characterization of passive safety system and inherent safety feature building blocks for advanced light-water reactors

International Nuclear Information System (INIS)

Forsberg, C.W.

1989-01-01

Oak Ridge National Laboratory (ORNL) is investigating passive and inherent safety options for Advanced Light-Water Reactors (ALWRs). A major activity in 1989 includes identification and characterization of passive safety system and inherent safety feature building blocks, both existing and proposed, for ALWRs. Preliminary results of this work are reported herein. This activity is part of a larger effort by the US Department of Energy, reactor vendors, utilities, and others in the United States to develop improved LWRs. The Advanced Boiling Water Reactor (ABWR) program and the Advanced Pressurized Water Reactor (APWR) program have as goals improved, commercially available LWRs in the early 1990s. The Advanced Simplified Boiling Water Reactor (ASBWR) program and the AP-600 program are developing more advanced reactors with increased use of passive safety systems. It is planned that these reactors will become commercially available in the mid 1990s. The ORNL program is an exploratory research program for LWRs beyond the year 2000. Desired long-term goals for such reactors include: (1) use of only passive and inherent safety, (2) foolproof against operator errors, (3) malevolence resistance against internal sabotage and external assault and (4) walkaway safety. The acronym ''PRIME'' [Passive safety, Resilient operation, Inherent safety, Malevolence resistance, and Extended (walkaway) safety] is used to summarize these desired characteristics. Existing passive and inherent safety options are discussed in this document

Inherent safety, ethics and human error.

Science.gov (United States)

Papadaki, Maria

2008-02-11

stated. The reason this article is presented here is that I believe that often, complex accidents, similarly to insignificant ones, often demonstrate an attitude which can be characterized as "inherently unsafe". I take the view that the enormous human potential and the human ability to minimize accidents needs to become a focal point towards inherent safety. Restricting ourselves to human limitations and how we could "treat" or prevent humans from not making accidents needs to be re-addressed. The purpose of this presentation is to highlight observations and provoke a discussion on how we could possibly improve the understanding of safety related issues. I do not intent to reject or criticize existing methodologies. (The entire presentation is strongly influenced by Trevor Kletz's work although our views are often different.).

Distinct Short-Range Order Is Inherent to Small Amorphous Calcium Carbonate Clusters (<2 nm)

Energy Technology Data Exchange (ETDEWEB)

Sun, Shengtong [Physical Chemistry, University of Konstanz, Universitätsstrasse 10 78457 Konstanz Germany; School of Chemical Engineering, State Key Laboratory of Chemical Engineering, Shanghai Key Laboratory of Multiphase Materials Chemical Engineering, East China University of Science and Technology, 130 Meilong Road Shanghai 200237 P.R. China; Chevrier, Daniel M. [Department of Chemistry and Institute for Research in Materials, Dalhousie University, Halifax Nova Scotia B3H 4R2 Canada; Zhang, Peng [Department of Chemistry and Institute for Research in Materials, Dalhousie University, Halifax Nova Scotia B3H 4R2 Canada; Gebauer, Denis [Physical Chemistry, University of Konstanz, Universitätsstrasse 10 78457 Konstanz Germany; Cölfen, Helmut [Physical Chemistry, University of Konstanz, Universitätsstrasse 10 78457 Konstanz Germany

2016-09-09

Amorphous intermediate phases are vital precursors in the crystallization of many biogenic minerals. While inherent short-range orders have been found in amorphous calcium carbonates (ACCs) relating to different crystalline forms, it has never been clarified experimentally whether such orders already exist in very small clusters less than 2 nm in size. Here, we studied the stability and structure of 10,12-pentacosadiynoic acid (PCDA) protected ACC clusters with a core size of ca. 1.4 nm consisting of only seven CaCO₃ units. Ligand concentration and structure are shown to be key factors in stabilizing the ACC clusters. More importantly, even in such small CaCO₃ entities, a proto-calcite short-range order can be identified but with a relatively high degree of disorder that arises from the very small size of the CaCO₃ core. Our findings support the notion of a structural link between prenucleation clusters, amorphous intermediates, and final crystalline polymorphs, which appears central to the understanding of polymorph selection.

Inherent optical properties of pollen particles: a case study for the morning glory pollen.

Science.gov (United States)

Liu, Chao; Yin, Yan

2016-01-25

Biological aerosols, such as bacteria, fungal spores, and pollens, play an important role on various atmospheric processes, whereas their inherent optical property is one of the most uncertainties that limit our ability to assess their effects on weather and climate. A numerical model with core-shell structure, hexagonal grids and barbs is developed to represent one kind of realistic pollen particles, and their inherent optical properties are simulated using a pseudo-spectral time domain method. Both the hexagonal grids and barbs substantially affect the modeled pollen optical properties. Results based on the realistic particle model are compared with two equivalent spherical approximations, and the significant differences indicate the importance of considering pollen geometries for their optical properties.

[Clinical significance of early percutaneous coronary intervention in patients with Braunwald III-B type unstable angina pectoris].

Science.gov (United States)

Nozaki, Katsuhiro; Nakao, Koichi; Horiuchi, Kenji; Kasanuki, Hiroshi; Honda, Takashi

2003-06-01

To assess the efficacy of early invasive strategy for the treatment of Braunwald III-B type unstable angina pectoris. This study included 573 consecutive patients of whom 267 underwent percutaneous coronary intervention (PCI) (312 lesions). The patients were divided into two groups, 95 treated with the early invasive strategy of coronary angiography within 24 hr of admission (Group PCI-I) and the remaining 172 treated with the early conservative strategy of coronary angiography 24 hr after admission (Group PCI-C). No significant differences were noted in the baseline characteristics of the two groups except for ST segment elevation on electrocardiography at presentation, which occurred significantly less frequently in Group PCI-C (36.8% vs 8.1%, p strategy for unstable angina pectoris were almost equivalent to those of the early conservative strategy, despite more frequent ST segmental elevation at admission in Group PCI-I. These findings suggest that the early invasive strategy for unstable angina pectoris may be acceptable even in the current Japanese clinical setting without the use of GP IIb/IIIa receptor antagonist, low molecular weight heparin or clopidogrel.

A compact, inherently safe liquid metal reactor plant concept for terrestrial defense power applications

International Nuclear Information System (INIS)

Magee, P.M.; Dubberley, A.E.; Lutz, D.E.; Palmer, R.S.

1987-01-01

A compact, inherently safe, liquid metal reactor concept based on the GE PRISM innovative LMR design has been developed for terrestrial defense power applications in the 2-50 MWe range. The concept uses a small, sodium-cooled, U-5%Zr metal fueled reactor contained within two redundant steel vessels. The core is designed to operate at a low power density and temperature (925 F) and can operate 30 years without refueling. One two primary coolant loops, depending upon the plant size, transport heat from the core to sodium-to-air, double-wall heat exchangers. Power is produced by a gas turbine operated in a closed ''bottoming'' cycle that employs intercoolers between the compressor stages and a recuperator. Inherent safety is provided by passive means only; operator action is not required to ensure plant safety even for events normally considered Beyond Design Basis Accidents. In addition to normal shutdown heat removal via the sodium-to-air heat exchangers, the design utilizes an inherently passive radiant vessel auxiliary cooling system similar to that designed for PRISM. The use of an air cycle gas turbine eliminates the cost and complexity of the sodium-water reactor pressure relief system required for a steam cycle sodium-cooled reactor

Possibility of a pressurized water reactor concept with highly inherent heat removal following capability

International Nuclear Information System (INIS)

Araya, Fumimasa; Murao, Yoshio

1995-01-01

If the core power inherently follows change in heat removal rate from the primary coolant system within small thermal expansion of the coolant which can be absorbed in a practical size of pressurizer, reactor systems may have more safety and load following capability. In order to know possibility and necessary conditions of a concept on reactor core and primary coolant system of a pressurized water reactor (PWR) with such 'highly inherent heat removal following capability', transient analyses on an ordinary two-loop PWR have been performed for a transient due to 50% change in heat removal with the RETRAN-02 code. The possibility of a PWR concept with the highly inherent heat removal following capability has been demonstrated under the conditions of the absolute value of ratio of the coolant density reactivity coefficient to the Doppler reactivity coefficient more than 10x10 3 kg·cm 3 which is two to three times larger than that at beginning of cycle (BOC) in an ordinary PWR and realized by elimination of the chemical shim, the 12% lower average linear heat generation rate of 17.9 kW/m, and the 1.5 times larger pressurizer volume than those of the ordinary PWR. (author)

On the persistence of unstable bump-on-tail electron velocity distributions in the earth's foreshock

Science.gov (United States)

Klimas, Alexander J.; Fitzenreiter, Richard J.

1988-01-01

This paper presents further evidence for the persistence of bump-on-tail unstable reduced velocity distributions in the earth's electron foreshock, which contradicts the understanding of quasi-linear saturation of the bump-on-tail instability. A modified theory for the saturation of the bump-on-tail instability in the earth's foreshock is proposed to explain the mechanism of this persistence, and the predictions are compared to the results of a numerical simulation of the electron plasma in the foreshock. The results support the thesis that quasi-linear saturation of the bump-on-tail instability is modified in the foreshock, due to the driven nature of the region, so that at saturation the stabilized velocity distribution still appears bump-on-tail unstable to linear plasma analysis.

A framework for identifying plant species to be used as 'ecological engineers' for fixing soil on unstable slopes.

Science.gov (United States)

Ghestem, Murielle; Cao, Kunfang; Ma, Wenzhang; Rowe, Nick; Leclerc, Raphaëlle; Gadenne, Clément; Stokes, Alexia

2014-01-01

Major reforestation programs have been initiated on hillsides prone to erosion and landslides in China, but no framework exists to guide managers in the choice of plant species. We developed such a framework based on the suitability of given plant traits for fixing soil on steep slopes in western Yunnan, China. We examined the utility of 55 native and exotic species with regard to the services they provided. We then chose nine species differing in life form. Plant root system architecture, root mechanical and physiological traits were then measured at two adjacent field sites. One site was highly unstable, with severe soil slippage and erosion. The second site had been replanted 8 years previously and appeared to be physically stable. How root traits differed between sites, season, depth in soil and distance from the plant stem were determined. Root system morphology was analysed by considering architectural traits (root angle, depth, diameter and volume) both up- and downslope. Significant differences between all factors were found, depending on species. We estimated the most useful architectural and mechanical traits for physically fixing soil in place. We then combined these results with those concerning root physiological traits, which were used as a proxy for root metabolic activity. Scores were assigned to each species based on traits. No one species possessed a suite of highly desirable traits, therefore mixtures of species should be used on vulnerable slopes. We also propose a conceptual model describing how to position plants on an unstable site, based on root system traits.

A framework for identifying plant species to be used as 'ecological engineers' for fixing soil on unstable slopes.

Directory of Open Access Journals (Sweden)

Murielle Ghestem

Full Text Available Major reforestation programs have been initiated on hillsides prone to erosion and landslides in China, but no framework exists to guide managers in the choice of plant species. We developed such a framework based on the suitability of given plant traits for fixing soil on steep slopes in western Yunnan, China. We examined the utility of 55 native and exotic species with regard to the services they provided. We then chose nine species differing in life form. Plant root system architecture, root mechanical and physiological traits were then measured at two adjacent field sites. One site was highly unstable, with severe soil slippage and erosion. The second site had been replanted 8 years previously and appeared to be physically stable. How root traits differed between sites, season, depth in soil and distance from the plant stem were determined. Root system morphology was analysed by considering architectural traits (root angle, depth, diameter and volume both up- and downslope. Significant differences between all factors were found, depending on species. We estimated the most useful architectural and mechanical traits for physically fixing soil in place. We then combined these results with those concerning root physiological traits, which were used as a proxy for root metabolic activity. Scores were assigned to each species based on traits. No one species possessed a suite of highly desirable traits, therefore mixtures of species should be used on vulnerable slopes. We also propose a conceptual model describing how to position plants on an unstable site, based on root system traits.

Correction of aggregative thrombocytes activity in patients with unstable angina by THz irradiation of nitrogen oxide occurrence at in vitro conditions

Directory of Open Access Journals (Sweden)

Vyacheslav F. Kirichuk

2013-11-01

Full Text Available There had been shown a normalizing effect of THz radiation of MEAS (molecular emission and absorption spectrum of 400 GHz nitrogen oxide occurrence on aggregation parameters of thrombocytes in patients with unstable angina at in vitro conditions. 180 patients with an unstable angina had been involved in to the research.

Experimental Demonstration of the Fermi-Pasta-Ulam Recurrence in a Modulationally Unstable Optical Wave

International Nuclear Information System (INIS)

Van Simaeys, G.; Emplit, Ph.; Haelterman, M.

2001-01-01

Through a detailed spectral analysis of the propagation of square-shaped laser pulses in optical fibers, we provide the experimental demonstration of the Fermi-Pasta-Ulam recurrence phenomenon in modulationally unstable optical waves ruled by the nonlinear Schroedinger equation

The Kuramoto–Sivashinsky equation. A Local Attractor Filled with Unstable Periodic Solutions

Directory of Open Access Journals (Sweden)

Anatoli N. Kulikov

2018-01-01

Full Text Available A periodic boundary value problem is considered for one version of the KuramotoSivashinsky equation, which is widely known in mathematical physics. Local bifurcations in a neighborhood of the spatially homogeneous equilibrium points in the case when they change stability are studied. It is shown that the loss of stability of homogeneous equilibrium points leads to the appearance of a two-dimensional attractor on which all solutions are periodic functions of time, except one spatially inhomogeneous state. A spectrum of frequencies of the given family of periodic solutions fills the entire number line, and they are all unstable in a sense of Lyapunov definition in the metric of the phase space (space of initial conditions of the corresponding initial boundary value problem. It is chosen the Sobolev space as the phase space. For the periodic solutions which fill the two-dimensional attractor, the asymptotic formulas are given. In order to analyze the bifurcation problem it was used analysis methods for infinite-dimensional dynamical systems: the integral (invariant manifold method, the Poincare normal form theory, and asymptotic methods. The analysis of bifurcations for periodic boundary value problem was reduced to analysing the structure of the neighborhood of the zero solution of the homogeneous Dirichlet boundary value problem for the considered equation. 

Superluminal warp drives are semiclassically unstable

Energy Technology Data Exchange (ETDEWEB)

Finazzi, S; Liberati, S [SISSA, via Beirut 2-4, Trieste 34151, Italy and INFN sezione di Trieste (Italy); Barcelo, C, E-mail: finazzi@sissa.i, E-mail: liberati@sissa.i, E-mail: carlos@iaa.e [Instituto de Astrofisica de AndalucIa, CSIC, Camino Bajo de Huetor 50, 18008 Granada (Spain)

2010-04-01

Warp drives are very interesting configurations of General Relativity: they provide a way to travel at superluminal speeds, albeit at the cost of requiring exotic matter to build them. Even if one succeeded in providing the necessary exotic matter, it would still be necessary to check whether they would survive to the switching on of quantum effects. Semiclassical corrections to warp-drive geometries created out of an initially flat spacetime have been analyzed in a previous work by the present authors in special locations, close to the wall of the bubble and in its center. Here, we present an exact numerical analysis of the renormalized stress-energy tensor (RSET) in the whole bubble. We find that the the RSET will exponentially grow in time close to the front wall of the superluminal bubble, after some transient terms have disappeared, hence strongly supporting our previous conclusion that the warp-drive geometries are unstable against semiclassical back-reaction. This result seems to implement the chronology protection conjecture, forbiddig the set up of a structure potentially dangerous for causality.

[Kirschner wire transfixation of unstable ankle fractures: indication, surgical technique and outcomes].

Science.gov (United States)

Marvan, J; Džupa, V; Bartoška, R; Kachlík, D; Krbec, M; Báča, V

2015-01-01

PURPOSE OF THE STUDY The aim of the study was to assess treatment outcomes in patients undergoing K-wire transfixation of unstable ankle fractures and compare the results with those of patients in whom it was possible to perform primary one-stage osteosynthesis. MATERIAL AND METHODS Between 2009 and 2012, a total of 358 patients (191 women and 167 men) had surgery for unstable ankle fracture. At 1-year follow-up, their subjective feelings, objective findings and ankle radiographs were evaluated. The fractures were categorised according to the Weber classification. A patient group treated by one-stage osteosynthesis, a group with definitive transfixation and a group of patients in whom temporary transfixation was converted to definitive osteosynthesis were assessed and compared. RESULTS The group treated by one-stage osteosynthesis included 278 patients with an average age of 47 years; the group of 20 patients with definitive transfixation had an average age of 67 years, and the group of 60 patients who had temporary transfixation with subsequent conversion to internal osteosynthesis were 55 years on average. In the group with one-stage osteosynthesis, 223 (80%) ankle fractures on post-injury radiographs were associated with minor joint dislocations and 55 (20%) with major dislocations. On the other hand, the radiographs of the patients treated by temporary transfixation and delayed open reduction with internal fixation showed major dislocations in 38 (63%) and minor dislocations in the rest of the patients (37%); the difference between the two groups was statistically significant (pfractures were most frequent in the group with temporary transfixation (60%) and least frequent in the group with primary osteosynthesis (44%); also this difference was statistically significant (p=0.032). At one-year follow-up, in the group with one-stage osteosynthesis, 220 patients (79%) had no radiographic signs of posttraumatic ankle osteoarthritis while, in the group with temporary

Low frequency noise in the unstable contact region of Au-to-Au microcontact for microelectromechanical system switches

Science.gov (United States)

Qiu, Haodong; Wang, Hong; Ke, Feixiang

2014-06-01

The noise behavior of Au-to-Au microcontact for microelectromechanical system switches has been experimentally studied in the unstable contact region. The results suggest that the electrical conduction remains nonmetallic at the initial stage during contact formation due to the existence of alien films, and traps in the alien layer located at the contact interface could play an important role in determining the conduction noise. The conduction fluctuation induced by electron trapping-detrapping associated with the hydrocarbon layer is found to be an intrinsic noise source contributing to the low frequency noise in the unstable contact region.

Low frequency noise in the unstable contact region of Au-to-Au microcontact for microelectromechanical system switches

Energy Technology Data Exchange (ETDEWEB)

Qiu, Haodong; Wang, Hong, E-mail: ewanghong@ntu.edu.sg [NOVITAS, Nanoelectronics Centre of Excellence, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Ke, Feixiang [Temasek Laboratories at Nanyang Technological University, Research Techno Plaza, Singapore 637553 (Singapore)

2014-06-23

The noise behavior of Au-to-Au microcontact for microelectromechanical system switches has been experimentally studied in the unstable contact region. The results suggest that the electrical conduction remains nonmetallic at the initial stage during contact formation due to the existence of alien films, and traps in the alien layer located at the contact interface could play an important role in determining the conduction noise. The conduction fluctuation induced by electron trapping-detrapping associated with the hydrocarbon layer is found to be an intrinsic noise source contributing to the low frequency noise in the unstable contact region.

Low frequency noise in the unstable contact region of Au-to-Au microcontact for microelectromechanical system switches

International Nuclear Information System (INIS)

Qiu, Haodong; Wang, Hong; Ke, Feixiang

2014-01-01

The noise behavior of Au-to-Au microcontact for microelectromechanical system switches has been experimentally studied in the unstable contact region. The results suggest that the electrical conduction remains nonmetallic at the initial stage during contact formation due to the existence of alien films, and traps in the alien layer located at the contact interface could play an important role in determining the conduction noise. The conduction fluctuation induced by electron trapping-detrapping associated with the hydrocarbon layer is found to be an intrinsic noise source contributing to the low frequency noise in the unstable contact region.

Factors contributing to inherent varus alignment of lower limb in normal Asian adults: role of tibial plateau inclination.

Science.gov (United States)

Shetty, Gautam M; Mullaji, Arun; Bhayde, Sagar; Nha, Kyung Wook; Oh, Hyoung Keun

2014-03-01

This prospective study aimed to evaluate radiographically, mechanical or hip-knee-ankle (HKA) axis in healthy, asymptomatic, Asian (Indian and Korean) adults between 20 and 40 years of age to determine the incidence of inherent varus (mechanical limb alignment of >3° varus) and the factors influencing it. Three hundred and eighty-eight lower limbs were evaluated using full length, standing hip-to-ankle radiographs in 198 healthy, asymptomatic, Asian (Indian and Korean) adults between 20 and 40 years of age to assess the hip-knee-ankle (HKA) angle, medial proximal tibial angle (MPTA), femoral bowing and femoral neck-shaft angle to determine the incidence of inherent varus (mechanical limb alignment of >3° varus) and the factors influencing it. Overall, the mean HKA angle was 177.6°±2.6° with 34.5% of limbs in inherent varus (mean HKA angle 174.9°±1.8°). The incidence of inherent varus was significantly higher (p=0.01) in males (40%) compared to females (28%) but similar among Indian (34%) and Korean subjects (35%). The hip-knee-ankle (HKA) angle showed significant positive correlation (r=0.82, palignment of the lower limb is fairly common among asymptomatic, Asian adults. These results raise several pertinent questions regarding the role of inherent varus in the aetiopathogenesis of knee osteoarthritis and in lower limb realignment procedures. © 2013 Elsevier B.V. All rights reserved.

Augmentation of proximal femoral nail in unstable trochanteric fractures

Directory of Open Access Journals (Sweden)

Gadegone Wasudeo M.

2017-01-01

Full Text Available Introduction: Biomechanically proximal femoral nail (PFN is a better choice of implant, still it is associated with screw breakage, cut out of screw through femoral head, Z effect, reverse Z effect, and lateral migration of screws. The purpose of this study is to evaluate the results of augmented PFN in terms of prevention of postoperative complications and failure rates in unstable trochanteric fractures. Material and methods: We carried out a prospective study of 82 cases with unstable trochanteric femoral fractures from April 2010 to December 2015. Forty-two females and 40 males in the age group between 58 and 81 years were included in this study. There were 45 cases of AO 31 A2 (2.2, 2.3 and 37 cases of AO 31 A3 (3.1, 3.2, 3.3. Fractures were fixed by PFN with augmentation by an additional screw from trochanter to inferior quadrant of femoral head or cerclage wire to strengthen the lateral trochanteric wall. Results: The bone healing is observed in all the cases in the mean period of 14.2 weeks. Nine patients developed complications, including lateral migration of neck screws (n = 5, Z effect (n = 1, infection (n = 2, and breakage of distal interlocking bolt in one case. Removal of screws was required in five cases. Patients were followed up for a mean of 8.4 months. At the end of follow-up the Salvati and Wilson hip function was 32 (out of 40 in 88% of patients. Conclusion: The stabilization of lateral trochanteric wall with additional screw or cerclage wire increases the stability of construct.

Angular Stable Miniplate Fixation of Chronic Unstable Scaphoid Nonunion.

Science.gov (United States)

Schormans, Philip M J; Brink, Peter R G; Poeze, Martijn; Hannemann, Pascal F W

2018-02-01

Background  Around 5 to 15% of all scaphoid fractures result in nonunion. Treatment of long-lasting scaphoid nonunion remains a challenge for the treating surgeon. Healing of scaphoid nonunion is essential for prevention of scaphoid nonunion advanced collapse and the subsequent predictable pattern of radiocarpal osteoarthritis. Purpose  The purpose of this study was to investigate the feasibility of fixation of the scaphoid nonunion with a volar angular stable miniplate and cancellous bone grafting. We hypothesized that this technique could be successful, even in patients with previous surgery for nonunion and in patients with a long duration of nonunion. Patients and Methods  A total of 21 patients enrolled in a single-center prospective cohort study. Healing of nonunion was assessed on multiplanar computed tomography scan of the wrist at a 3-month interval. Functional outcome was assessed by measuring grip strength, range of motion, and by means of the patient-rated wrist and hand evaluation (PRWHE) questionnaire. Results  During follow-up, 19 out of 21 patients (90%) showed radiological healing of the nonunion. The range of motion did not improve significantly. Postoperative PRWHE scores decreased by 34 points. Healing occurred regardless of the length of time of the nonunion (range: 6-183 months) and regardless of previous surgery (38% of patients). Conclusion  Volar angular stable miniplate fixation with autologous cancellous bone grafting is a successful technique for the treatment of chronic unstable scaphoid nonunion, even in patients with long-lasting nonunion and in patients who underwent previous surgery for a scaphoid fracture. Rotational interfragmentary stability might be an important determining factor for the successful treatment of unstable scaphoid nonunion. Level of Evidence  Level IV.

Growth of fingers at an unstable diffusing interface in a porous medium or hele-shaw cell

Energy Technology Data Exchange (ETDEWEB)

Wooding, R A

1969-11-27

Waves at an unstable horizontal interface, between 2 fluids moving vertically through a saturated porous medium, are observed to grow rapidly to become fingers (i.e., the amplitude greatly exceeds the wavelength). For a diffusing interface, in experiments using a Hele-Shaw cell, the mean amplitude taken over many fingers grows approx. as (time)U2D, followed by a transition to a growth proportional to time. Correspondingly, the mean wave number decreases approx. as (time)U-1/2D. Because of the rapid increase in amplitude, longitudinal dispersion ultimately becomes negligible relative to wave growth. To represent the observed quantities at large time, the transport equation is suitably weighted and averaged over the horizontal plane. Hyperbolic equations result, and the ascending and descending zones containing the fronts of the fingers are replaced by discontinuities. These averaged equations form an open set, but closure is achieved by assuming a law for the mean wave number based on similarity. (22 refs.)

Pipeline modeling and assessment in unstable slopes

Energy Technology Data Exchange (ETDEWEB)

Caceres, Carlos Nieves [Oleoducto Central S.A., Bogota, Cundinamarca (Colombia); Ordonez, Mauricio Pereira [SOLSIN S.A.S, Bogota, Cundinamarca (Colombia)

2010-07-01

The OCENSA pipeline system is vulnerable to geotechnical problems such as faults, landslides or creeping slopes, which are well-known in the Andes Mountains and tropical countries like Colombia. This paper proposes a methodology to evaluate the pipe behaviour during the soil displacements of slow landslides. Three different cases of analysis are examined, according to site characteristics. The process starts with a simplified analytical model and develops into 3D finite element numerical simulations applied to the on-site geometry of soil and pipe. Case 1 should be used when the unstable site is subject to landslides impacting significant lengths of pipeline, pipeline is straight, and landslide is simple from the geotechnical perspective. Case 2 should be used when pipeline is straight and landslide is complex (creeping slopes and non-conventional stabilization solutions). Case 3 should be used if the pipeline presents vertical or horizontal bends.

Modeling of supermodes in coupled unstable resonators

International Nuclear Information System (INIS)

Townsend, S.S.

1986-01-01

A general formalism describing the supermodes of an array of N identical, circulantly coupled resonators is presented. The symmetry of the problem results in a reduction of the N coupled integral equations to N decoupled integral equations. Each independent integral equation defines a set of single-resonator modes derived for a hypothetical resonator whose geometry resembles a member of the real array with the exception that all coupling beams are replaced by feedback beams, each with a prescribed constant phase. A given array supermode consists of a single equivalent resonator mode appearing repetitively in each resonator with a prescribed relative phase between individual resonators. The specific array design chosen for example is that of N adjoint coupled confocal unstable resonators. The impact of coupling on the computer modeling of this system is discussed and computer results for the cases of two- and four-laser coupling are presented

An inherently parallel method for solving discretized diffusion equations

International Nuclear Information System (INIS)

Eccleston, B.R.; Palmer, T.S.

1999-01-01

A Monte Carlo approach to solving linear systems of equations is being investigated in the context of the solution of discretized diffusion equations. While the technique was originally devised decades ago, changes in computer architectures (namely, massively parallel machines) have driven the authors to revisit this technique. There are a number of potential advantages to this approach: (1) Analog Monte Carlo techniques are inherently parallel; this is not necessarily true to today's more advanced linear equation solvers (multigrid, conjugate gradient, etc.); (2) Some forms of this technique are adaptive in that they allow the user to specify locations in the problem where resolution is of particular importance and to concentrate the work at those locations; and (3) These techniques permit the solution of very large systems of equations in that matrix elements need not be stored. The user could trade calculational speed for storage if elements of the matrix are calculated on the fly. The goal of this study is to compare the parallel performance of Monte Carlo linear solvers to that of a more traditional parallelized linear solver. The authors observe the linear speedup that they expect from the Monte Carlo algorithm, given that there is no domain decomposition to cause significant communication overhead. Overall, PETSc outperforms the Monte Carlo solver for the test problem. The PETSc parallel performance improves with larger numbers of unknowns for a given number of processors. Parallel performance of the Monte Carlo technique is independent of the size of the matrix and the number of processes. They are investigating modifications to the scheme to accommodate matrix problems with positive off-diagonal elements. They are also currently coding an on-the-fly version of the algorithm to investigate the solution of very large linear systems

Kangaroo mother care for clinically unstable neonates weighing ≤2000 g: Is it feasible at a hospital in Uganda?

Science.gov (United States)

Morgan, Melissa C; Nambuya, Harriet; Waiswa, Peter; Tann, Cally; Elbourne, Diana; Seeley, Janet; Allen, Elizabeth; Lawn, Joy E

2018-06-01

Kangaroo mother care (KMC) for stable neonates ≤2000 g (g) is associated with decreased mortality, sepsis, hypothermia, and length of stay compared to conventional care. The World Health Organization states that KMC "should be initiated… as soon as newborns are clinically stable " [12]. However, the majority of deaths occur in unstable neonates. We aimed to determine the proportion of admitted neonates meeting proposed instability criteria, assess the feasibility of providing KMC to unstable neonates, and evaluate the acceptability of this intervention to parents and providers at Jinja Regional Referral Hospital in Uganda. This was a mixed-methods study. We recorded data including birthweight, chronological age, and treatments administered from medical charts, and calculated the percentage of clinically unstable neonates, defined as the need for ≥2 medical therapies in the first 48 hours of admission. We enrolled a sample of neonates meeting pre-defined instability criteria. Mothers were counselled to provide KMC as close to continuously as possible. We calculated the median duration of KMC per episode and per day. To explore acceptability, we conducted semi-structured interviews with parents and newborn unit care providers, and analysed data using the thematic content approach. We included 254 neonates in the audit, 10 neonates in the feasibility sub-study, and 20 participants in the acceptability sub-study. Instability criteria were easily implementable, identifying 89% of neonates as unstable in the audit. The median duration of individual KMC episodes ranged from 115 to 134 minutes. The median daily duration ranged from 4.5 to 9.7 hours. Seventy-five percent of interviewees felt KMC could be used in neonates concurrently receiving other medical therapies. Barriers included lack of resources (beds/space, monitoring devices), privacy issues, inadequate education, and difficulties motivating mothers to devote time to KMC. Recommendations included staff

Quantification of the inherent uncertainty in the relaxation modulus and creep compliance of asphalt mixes

Science.gov (United States)

Kassem, Hussein A.; Chehab, Ghassan R.; Najjar, Shadi S.

2017-08-01

Advanced material characterization of asphalt concrete is essential for realistic and accurate performance prediction of flexible pavements. However, such characterization requires rigorous testing regimes that involve mechanical testing of a large number of laboratory samples at various conditions and set-ups. Advanced measurement instrumentation in addition to meticulous and accurate data analysis and analytical representation are also of high importance. Such steps as well as the heterogeneous nature of asphalt concrete (AC) constitute major factors of inherent variability. Thus, it is imperative to model and quantify the variability of the needed asphalt material's properties, mainly the linear viscoelastic response functions such as: relaxation modulus, E(t), and creep compliance, D(t). The objective of this paper is to characterize the inherent uncertainty of both E(t) and D(t) over the time domain of their master curves. This is achieved through a probabilistic framework using Monte Carlo simulations and First Order approximations, utilizing E^{*} data for six AC mixes with at least eight replicates per mix. The study shows that the inherent variability, presented by the coefficient of variation (COV), in E(t) and D(t) is low at small reduced times, and increases with the increase in reduced time. At small reduced times, the COV in E(t) and D(t) are similar in magnitude; however, differences become significant at large reduced times. Additionally, the probability distributions and COVs of E(t) and D(t) are mix dependent. Finally, a case study is considered in which the inherent uncertainty in D(t) is forward propagated to assess the effect of variability on the predicted number of cycles to fatigue failure of an asphalt mix.

The functional outcome of surgically treated unstable pelvic ring fractures by open reduction, internal fixation

Directory of Open Access Journals (Sweden)

Kaykhosro Mardanpour

2011-07-01

Full Text Available Background:Unstable Pelvic fracture,a result of high energy antero-posterior compression injury, has been managed based on internal fixation and open reduction. The mode of fixation in Unstable Pelvic fracture has, however, been a subject of controversy and some authors have proposed a need to address the issue of partial breach of the pelvic ring elements in these injuries. This study was performed to evaluate the functional and radiological results of treatment of pelvic ring fractures by open reduction, internal fixation. Methods: Thirty eight patients with unstable pelvic fractures, treated from 2002 to2008 were retrospectively reviewed. The mean age of patients’ was 37 years old (range 20 to 67. Twenty six patients were men and 12 women. The most common cause was a road traffic accident (N=37, 97%. There were 11 type-C and 27 type-B fractures according to Tile’s classification. Thirty six patients sustained additional injuries. The most prevalent additional injuries were lower extremity fractures. Open reduction, internal fixation as a definite management was applied for all patients. Quality of reduction was graded according to the grades proposed by Matta and Majeed’s score was used to assess the clinical outcome. The mean period of follow-up was 25 months (ranged from 6 to 109 months. About 81.6% of patients had either good or excellent radiological reduction. Results: The functional outcome was excellent in 66%, good in 15%, fair in 11% and poor in 7% of the patients. There were 4 postoperative infections. No sexual function problem was reported. Nerve deficits recovered completely in 2 and partially in 3 of 11 patients with preoperative neurologic deficiency. There was no significant relation between functional outcome and the site of fracture Conclusion: Unstable pelvic ring fracture injuries should be managed surgically by rigid stabilization that must be carried out as soon as the general ndition of the patient permits, and

Randomised, double-blind trial of intravenous diltiazem versus glyceryl trinitrate for unstable angina pectoris

NARCIS (Netherlands)

Gobel, EJAM; Hautvast, RWM; vanGilst, WH; Spanjaard, JN; Hillege, HL; DeJongste, MJL; Molhoek, GP; Lie, KI

1995-01-01

The effect of dihydropyridines in patients with unstable angina is discouraging. To find out the effect of the non- dihydropyridine-like calcium-channel blocker diltiazem, a randomised, double-blind trial was conducted comparing diltiazem with glyceryl trinitrate. both given intravenously, in 129

Development of atomic-beam resonance method to measure the nuclear moments of unstable nuclei

Energy Technology Data Exchange (ETDEWEB)

Sugimoto, T., E-mail: sugimoto@ribf.riken.jp [SPring-8 (Japan); Asahi, K. [Tokyo Institute of Technology, Department of Physics (Japan); Kawamura, H.; Murata, J. [Rikkyo University, Department of Physics (Japan); Nagae, D.; Shimada, K. [Tokyo Institute of Technology, Department of Physics (Japan); Ueno, H.; Yoshimi, A. [RIKEN Nishina Center (Japan)

2008-01-15

We have been working on the development of a new technique of atomic-beam resonance method to measure the nuclear moments of unstable nuclei. In the present study, an ion-guiding system to be used as an atomic-beam source have been developed.

Robust Output Model Predictive Control of an Unstable Rijke Tube

Directory of Open Access Journals (Sweden)

Fabian Jarmolowitz

2012-01-01

Full Text Available This work investigates the active control of an unstable Rijke tube using robust output model predictive control (RMPC. As internal model a polytopic linear system with constraints is assumed to account for uncertainties. For guaranteed stability, a linear state feedback controller is designed using linear matrix inequalities and used within a feedback formulation of the model predictive controller. For state estimation a robust gain-scheduled observer is developed. It is shown that the proposed RMPC ensures robust stability under constraints over the considered operating range.

Disease resistance is related to inherent swimming performance in Atlantic salmon

OpenAIRE

Castro, Vicente; Grisdale-Helland, Barbara; Jørgensen, Sven Martin; Helgerud, Jan; Claireaux, Guy; Farrell, Anthony P.; Krasnov, Aleksei; Helland, Ståle; Takle, Harald Rune

2013-01-01

Background Like humans, fish can be classified according to their athletic performance. Sustained exercise training of fish can improve growth and physical capacity, and recent results have documented improved disease resistance in exercised Atlantic salmon. In this study we investigated the effects of inherent swimming performance and exercise training on disease resistance in Atlantic salmon. Atlantic salmon were first classified as either poor or good according to their swimming per...

Effect of temperature on crack initiation in gas formed structures

Energy Technology Data Exchange (ETDEWEB)

Gohari, S.; Vrcelj, Z.; Sharifi, S.; Sharifishourabi, G.; Abadi, R. [Universiti Teknlogi Malaysia, Skudai (Malaysia)

2013-12-15

In the gas forming process, the work piece is formed by applying gas pressure. However, the gas pressure and the accompanying gas temperature can result in crack initiation and unstable crack growth. Thus, it is vital to determine the critical values of applied gas pressure and temperature to avoid crack and fracture failure. We studied the mechanism of fracture using an experimental approach and finite element simulations of a perfect aluminum sheet containing no inclusions and voids. The definition of crack was based on ductile damage mechanics. For inspection of initiation of crack and rupture in gas-metal forming, the ABAQUS/EXPLICIT simulation was used. In gas forming, the applied load is the pressure applied rather than the punching force. The results obtained from both the experimental approach and finite element simulations were compared. The effects of various parameters, such as temperature and gas pressure value on crack initiation, were taken into account.

Searching for Models Exhibiting High Circularly Polarized Luminescence: the Electroactive Inherently Chiral Oligothiophenes.

Science.gov (United States)

Benincori, Tiziana; Appoloni, Giulio; Mussini, Patrizia Romana; Arnaboldi, Serena; Cirilli, Roberto; Quartapelle Procopio, Elsa; Panigati, Monica; Abbate, Sergio; Mazzeo, Giuseppe; Longhi, Giovanna

2018-05-02

Two new inherently chiral oligothiophenes characterized by the atropisomeric 3,3'-bithianaphtene scaffold functionalized with fused ring bithiophene derivatives, namely 4H-cyclopenta [2,1-b3:4b']dithiophene (CPDT) and dithieno[3,3-b:2',3'-d]pyrrole (DTP), were synthesized. The racemates were fully characterized and resolved into antipodes by enantioselective HPLC. The enantiomers were analyzed through different chiroptical techniques: electronic circular dichroism (ECD) and vibrational circular dichroism (VCD) were employed to attribute the absolute configuration (AC). Comparison of experimental and calculated VCD spectra confirmed the DFT calculated conformational characteristics. The compound functionalized with two CPDT units was oxidized with FeCl3 and ECD and CPL of the resulting material were measured. Circularly Polarized Luminescence (CPL) was measured in order to verify if inherently chiral oligothiophenes could be promising systems for chiral photonics applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Differences of inherent optical properties of inland lake water body in typical seasons].

Science.gov (United States)

Sun, De-Yong; Li, Yun-Mei; Wang, Qiao; Le, Cheng-Fen; Huang, Chang-Chun; Wang, Li-Zhen

2008-05-01

Inherent optical property is one of the important properties of water body, which lays the foundation for the establishment of water color analytical models. By using quantity filter technology (QFT) and BB9 backscattering meter, the absorption coefficients of chromophoric dissolved organic matter (CDOM) and total suspended matters (TSM) and the backscattering coefficient of TSM in the water body at Meiliang Bay of Taihu Lake were measured in summer and winter. Based on the spectral comparison of the absorption and backscattering coefficients, their differences between the two seasons were demonstrated, and the reasons that caused these differences were also explored in the context of their relations to the changes in water quality. Consequently, water environment condition could be revealed by using the inherent optical property. The relationship between the backscattering coefficient and the TSM concentration was established, which could provide supporting coefficients to the analytical models to be developed.

Inherent uncertainties in meteorological parameters for wind turbine design

Science.gov (United States)

Doran, J. C.

1982-01-01

Major difficulties associated with meteorological measurments such as the inability to duplicate the experimental conditions from one day to the next are discussed. This lack of consistency is compounded by the stochastic nature of many of the meteorological variables of interest. Moreover, simple relationships derived in one location may be significantly altered by topographical or synoptic differences encountered at another. The effect of such factors is a degree of inherent uncertainty if an attempt is made to describe the atmosphere in terms of universal laws. Some of these uncertainties and their causes are examined, examples are presented and some implications for wind turbine design are suggested.

A STUDY OF PRIMARY CEMENTED BIPOLAR HEMIARTHROPLASTY OF HIP IN ELDERLY PATIENTS WITH OSTEOPOROTIC, UNSTABLE INTERTROCHANTERIC FRACTURE

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Maheshwar

2015-08-01

Full Text Available BACKGROUND: Intertrochanteric fractures are a major cause of morbidity and mortality in geriatric population. Osteoporosis contributes significantly to the comminution and instability in such fractures. Internal fixations in unstable intertrochanteric fractures are a ssociated with high rates of implant failures and gross restriction of hip movements. This study was undertaken to evaluate the efficacy of cemented bipolar hemiart h roplasty in elderly patients with osteoporotic, unstable intertrochanteric fractures. PATIE NTS AND METHODS: 52 patients aged above 60 years with unstable, comminuted intertrochanteric fractures with Singh’s index < 4 were operated with primary cemented bipolar hemireplacement arthroplasty. All the patients were mobilized early with full weight b earing in the post - operative period as permitted. 50 patients were evaluated for the functional outcome with Harris Hip score. RESULTS: The average age of patients was 65 years with female predominance (64%. Left side (56% was commonly involved and the c ommonest mode of injury was due to a trivial fall at home. Hypertension (30% was the commonest co - morbid condition. Limb shortening was the commonest complication (8%. The mean ± S.D. of the Harris Hip score was 85.6 ± 10.59 with a range from 56 to 96. Resul ts were excellent in 62%, good in 22%, fair in 12% and poor in 4% of cases. CONCLUSION: Elderly osteoporotic patients with comminuted, unstable intertrochanteric fractures have an increased prevalence of unsatisfactory functional results with conventional internal fixation devices. Primary cemented bipolar hemiarthroplasty with anatomical reconstruction of the trochanters allows early mobilization, improved functional outcome with relatively low incidence of associated complications.

Are autobiographical memories inherently social? Evidence from an fMRI study.

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Linda Wilbers

Full Text Available The story of our lifetime - our narrative self - is constructed from our autobiographical memories. A central claim of social psychology is that this narrative self is inherently social: When we construct our lives, we do so in a real or imagined interaction. This predicts that self-referential processes which are involved in recall of autobiographical memories overlap with processes involved in social interactions. Indeed, previous functional MRI studies indicate that regions in the medial prefrontal cortex (mPFC are activated during autobiographical memory recall and virtual communication. However, no fMRI study has investigated recall of autobiographical memories in a real-life interaction. We developed a novel paradigm in which participants overtly reported self-related and other-related memories to an experimenter, whose non-verbal reactions were being filmed and online displayed to the participants in the scanner. We found that recall of autobiographical vs. non-autobiographical memories was associated with activation of the mPFC, as was recall in the social as compared to a non-social control condition; however, both contrasts involved different non-overlapping regions within the mPFC. These results indicate that self-referential processes involved in autobiographical memory recall are different from processes supporting social interactions, and argue against the hypothesis that autobiographical memories are inherently social.

Inherent safety features of the HTTR revealed in the accident condition

International Nuclear Information System (INIS)

Kunitomi, K.; Shinozaki, M.; Baba, O.; Saito, S.

1992-01-01

The High Temperature Engineering Test Reactor (HTTR) being constructed by JAERI (Japan Atomic Energy Research Institute) is a graphite-moderated and helium-cooled reactor with an outlet gas temperature of 950degC. The inherent safety characteristics in the HTTR prevent temperature increase of reactor fuels and fission product release from the reactor core in postulated accident conditions. The reactor core can be cooled by a Vessel Cooling System (VCS) indirectly, even in the case that no forced cooling is expected during the accident such as primary pipe break. The VCS consists of independent water cooling loop and cooling panel around the reactor pressure vessel. The cooling panel whose temperature of 60-90degC cools the reactor pressure vessel by radiation and removes the decay heat from the core indirectly. Furthermore, even if failure of VCS is assumed during this accident as a severe accident, the reactor core is remained safe despite the temperature increase of biological concrete shield around the reactor pressure vessel. This paper describes the inherent safety features of the HTTR specially focused on the accident condition without forced cooling. The detailed analytical results of such an accident are described together with clarifying the role of the VCS. (author)

Brown dwarfs forming in discs: Where to look for them?

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Stamatellos D.

2011-07-01

Full Text Available A large fraction of the observed brown dwarfs may form by gravitational fragmentation of unstable discs. This model reproduces the brown dwarf desert, and provides an explanation for the existence of planetary-mass objects and for the binary properties of low-mass objects. We have performed an ensemble of radiative hydrodynamic simulations and determined the statistical properties of the low-mass objects produced by gravitational fragmentation of discs. We suggest that there is a population of brown dwarfs loosely bound on wide orbits (100–5000 AU around Sun-like stars that surveys of brown dwarf companions should target. Our simulations also indicate that planetary-mass companions to Sun-like stars are unlikely to form by disc fragmentation.

Analysis of unstable chromosome alterations frequency induced by neutron-gamma mixed field radiation

Energy Technology Data Exchange (ETDEWEB)

Souza, Priscilla L.G.; Brandao, Jose Odinilson de C.; Vale, Carlos H.F.P.; Santos, Joelan A.L.; Vilela, Eudice C.; Lima, Fabiana F. [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil)], e-mail: psouza@cnen.gov.br, e-mail: jodinilson@cnen.gov.br; Calixto, Merilane S.; Santos, Neide [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Genetica

2009-07-01

Nowadays monitoring chromosome alterations in peripheral blood lymphocytes have been used to access the radiation absorbed dose in individuals exposed accidental or occupationally to gamma radiation. However there are not many studies based on the effects of mixed field neutron-gamma. The radiobiology of neutrons has great importance because in nuclear factories worldwide there are several hundred thousand individuals monitored as potentially receiving doses of neutron. In this paper it was observed the frequencies of unstable chromosome alterations induced by a gamma-neutron mixed field. Blood was obtained from one healthy donor and exposed to mixed field neutron-gamma sources {sup 241}AmBe (20 Ci) at the Neutron Calibration Laboratory (NCL-CRCN/NE-PE-Brazil). The chromosomes were observed at metaphase, following colcemid accumulation and 1000 well-spread metaphases were analyzed for the presence of chromosome alterations by two experienced scorers. The results suggest that there is the possibility of a directly proportional relationship between absorbed dose of neutron-gamma mixed field radiation and the frequency of unstable chromosome alterations analyzed in this paper. (author)

Minimally invasive surgical treatment for unstable fractures of the proximal phalanx: intramedullary screw

Directory of Open Access Journals (Sweden)

Marcio Aurélio Aita

2016-02-01

Full Text Available ABSTRACT OBJECTIVE: To analyze the clinical-functional parameters and quality of life of patients undergoing minimally invasive surgical treatment for extra-articular fractures of the proximal phalanx, using an intramedullary screw (Acutrak(r. METHODS: Between January 2011 and September 2014, a prospective study was conducted on 41 patients (48 fingers with unstable extra-articular fractures of the proximal phalanx, who underwent minimally invasive surgical treatment using an intramedullary screw (Acutrak(r. These patients were evaluated 12 months after the surgery by means of the DASH quality-of-life questionnaire, VAS pain scale, measurement of range of motion (ROM, in degrees and radiographic assessment. RESULTS: All the patients achieved adequate reduction and consolidation of their fractures. There were statistically significant improvements in quality of life on the DASH scale, pain on the VAS scale and range of motion. CONCLUSION: The minimally invasive technique for treating unstable extra-articular fractures of the proximal phalanx using an intramedullary screw (Acutrak(r is effective and safe, and it presents satisfactory clinical-functional results.

Analysis of unstable chromosome alterations frequency induced by neutron-gamma mixed field radiation

International Nuclear Information System (INIS)

Souza, Priscilla L.G.; Brandao, Jose Odinilson de C.; Vale, Carlos H.F.P.; Santos, Joelan A.L.; Vilela, Eudice C.; Lima, Fabiana F.; Calixto, Merilane S.; Santos, Neide

2009-01-01

Nowadays monitoring chromosome alterations in peripheral blood lymphocytes have been used to access the radiation absorbed dose in individuals exposed accidental or occupationally to gamma radiation. However there are not many studies based on the effects of mixed field neutron-gamma. The radiobiology of neutrons has great importance because in nuclear factories worldwide there are several hundred thousand individuals monitored as potentially receiving doses of neutron. In this paper it was observed the frequencies of unstable chromosome alterations induced by a gamma-neutron mixed field. Blood was obtained from one healthy donor and exposed to mixed field neutron-gamma sources 241 AmBe (20 Ci) at the Neutron Calibration Laboratory (NCL-CRCN/NE-PE-Brazil). The chromosomes were observed at metaphase, following colcemid accumulation and 1000 well-spread metaphases were analyzed for the presence of chromosome alterations by two experienced scorers. The results suggest that there is the possibility of a directly proportional relationship between absorbed dose of neutron-gamma mixed field radiation and the frequency of unstable chromosome alterations analyzed in this paper. (author)

Qualitative Data Gathering Challenges in a Politically Unstable Rural Environment: A Zimbabwean Experience

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Tabitha Grace Mukeredzi

2012-02-01

Full Text Available Gaining access to participants in rural, politically unstable settings demands authority and consent not only from the participants and immediate line managers, but also from other players with interests in the research sites. This paper discusses data gathering experiences and challenges encountered during fieldwork for a PhD amidst a politically volatile situation in Zimbabwe in mid-2008. The article highlights the challenges encountered, how the researcher overcame some of them, and was stymied by others. Specifically, political challenges related to gaining access to schools and participants, which created time constraints and frustrations, fears and anxieties for the researcher. Issues of poor topography and interview space also emerged as other challenges. The paper proposes that the snags and surprises, the feelings of frustration, fear and anger that go with researching participants in politically unstable settings should not stall the research process but instead, handled with flexibility and patience, and used as motivation to continue. The experiences not only enhance the researcher's own reflexivity and reflectivity but also provide insights into the human conditions and actions as viewed from multiple perspectives.

Large Eddy Simulation of Unstably Stratified Turbulent Flow over Urban-Like Building Arrays

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Bobin Wang

2013-01-01

Full Text Available Thermal instability induced by solar radiation is the most common condition of urban atmosphere in daytime. Compared to researches under neutral conditions, only a few numerical works studied the unstable urban boundary layer and the effect of buoyancy force is unclear. In this paper, unstably stratified turbulent boundary layer flow over three-dimensional urban-like building arrays with ground heating is simulated. Large eddy simulation is applied to capture main turbulence structures and the effect of buoyancy force on turbulence can be investigated. Lagrangian dynamic subgrid scale model is used for complex flow together with a wall function, taking into account the large pressure gradient near buildings. The numerical model and method are verified with the results measured in wind tunnel experiment. The simulated results satisfy well with the experiment in mean velocity and temperature, as well as turbulent intensities. Mean flow structure inside canopy layer varies with thermal instability, while no large secondary vortex is observed. Turbulent intensities are enhanced, as buoyancy force contributes to the production of turbulent kinetic energy.

Metastable and unstable cellular solidification of colloidal suspensions

Science.gov (United States)

Deville, Sylvain; Maire, Eric; Bernard-Granger, Guillaume; Lasalle, Audrey; Bogner, Agnès; Gauthier, Catherine; Leloup, Jérôme; Guizard, Christian

2009-12-01

Colloidal particles are often seen as big atoms that can be directly observed in real space. They are therefore becoming increasingly important as model systems to study processes of interest in condensed-matter physics such as melting, freezing and glass transitions. The solidification of colloidal suspensions has long been a puzzling phenomenon with many unexplained features. Here, we demonstrate and rationalize the existence of instability and metastability domains in cellular solidification of colloidal suspensions, by direct in situ high-resolution X-ray radiography and tomography observations. We explain such interface instabilities by a partial Brownian diffusion of the particles leading to constitutional supercooling situations. Processing under unstable conditions leads to localized and global kinetic instabilities of the solid/liquid interface, affecting the crystal morphology and particle redistribution behaviour.

Inherent security benefits of underground dry storage of nuclear materials

International Nuclear Information System (INIS)

Moore, R.D.; Zahn, T.

1997-07-01

This paper, augmented by color slides and handouts, will examine the inherent security benefits of underground dry storage of nuclear materials. Specific items to be presented include: the successful implementation of this type of storage configuration at Argonne National Laboratory - West; facility design concepts with security as a primary consideration; physical barriers achieved by container design; detection, assessment, and monitoring capabilities; and open-quotes self protectionclose quotes strategies. This is a report on the security features of such a facility. The technical operational aspects of the facility are beyond the scope of this paper

A boundary integral approach to unstable solidification

International Nuclear Information System (INIS)

Strain, J.

1989-01-01

We consider the supercooled Stefan problem with a general anisotropic curvature- and velocity-dependent boundary condition on the moving interface. We present numerical methods, based on an integral equation formulation and including a new algorithm for moving curves with curvature-dependent velocity. These methods compute a periodic interface with O(Δt) accuracy, where Δt is the time step. Previous work has been limited to short time spans and achieved slightly less than O(Δt 1/2 ) accuracy. Accurate numerical results are seen to agree with the predictions of linear stability theory. This agreement has eluded previous authors, because their numerical methods suffered from grid effects and their linear stability theory was incorrect. We study the long-time evolution of an unstable interface. Our computations exhibit the beginnings of a sidebranching instability when the boundary condition includes anisotropy and tip-splitting in the isotropic case. copyright 1989 Academic Press, Inc

Research of Medical Expenditure among Inpatients with Unstable Angina Pectoris in a Single Center

Directory of Open Access Journals (Sweden)

Suo-Wei Wu

2017-01-01

Conclusions: The classification of DRGs by adopting the type of surgery as the main branch node to develop cost control standards in inpatient treatment of unstable angina pectoris is conducive in standardizing the diagnosis and treatment behaviors of the hospital and reducing economic burdens among patients.

Coherent production on nuclei and measurements of total cross sections for unstable particles

International Nuclear Information System (INIS)

Czyz, W.; Zielinski, M.

1980-01-01

The Koelbig-Margolis Formula is fitted to some explicity nonperturbative models of diffractive production. It is shown that, in spite of the fact that the standard procedure of fitting the integrated cross sections may give acceptable fits, thus obtained ''cross sections of unstable particles'', grossly disagree with the ''true'' cross sections known exactly from the models. (author)

Prognostic value of thallium-201 myocardial perfusion imaging in patients with unstable angina who respond to medical treatment

International Nuclear Information System (INIS)

Brown, K.A.

1991-01-01

Although the prognostic value of thallium-201 imaging is well established, its ability to risk stratify patients who present with unstable angina is unclear. Fifty-two consecutive patients admitted with unstable angina who responded to medical treatment and underwent stress thallium-201 imaging within 1 week of discharge were studied. Patients were followed up for 39 +/- 11 months. Cardiac events included cardiac death (n = 3), nonfatal myocardial infarction (n = 4) and admission for unstable angina or revascularization (n = 17). The ability of thallium-201 data (redistribution, fixed defects, normal) to predict cardiac events was compared with clinical data (age, gender, prior myocardial infarction, anginal syndrome, rest and stress electrocardiogram) and cardiac catheterization data using logistic regression. Thallium-201 redistribution was the only significant predictor of cardiac death or nonfatal myocardial infarction (p less than 0.05). The number of myocardial segments with thallium-201 redistribution (p less than 0.0005) and a history of prior myocardial infarction (p less than 0.05) were the only significant predictors of all cardiac events. Cardiac death or nonfatal myocardial infarction occurred more frequently in patients with thallium-201 redistribution (6 [26%] of 23) than in those without redistribution (1 [3%] of 29, p less than 0.05). Similarly, total cardiac events developed more frequently in patients with thallium-201 redistribution (p less than 0.001). Stress thallium-201 imaging has important prognostic value in patients admitted with unstable angina who respond to medical therapy and can identify subgroups at high versus low risk for future cardiac events

W nano-fuzzes: A metastable state formed due to large-flux He"+ irradiation at an elevated temperature

International Nuclear Information System (INIS)

Wu, Yunfeng; Liu, Lu; Lu, Bing; Ni, Weiyuan; Liu, Dongping

2016-01-01

W nano-fuzzes have been formed due to the large-flux and low-energy (200eV) He"+ irradiation at W surface temperature of 1480 °C. Microscopic evolution of W nano-fuzzes during annealing or low-energy (200 eV) He"+ bombardments has been observed using scanning electron microscopy and thermal desorption spectroscopy. Our measurements show that both annealing and He"+ bombardments can significantly alter the structure of W nano-fuzzes. W nano-fuzzes are thermally unstable due to the He release during annealing, and they are easily sputtered during He"+ bombardments. The current study shows that W nano-fuzzes act as a metastable state during low-energy and large-flux He"+ irradiation at an elevated temperature. - Highlights: • W nano-fuzzes microscopic evolution during annealing or He"+ irradiated have been measured. • W nano-fuzzes are thermally unstable due to He release during annealing. • He are released from the top layer of W fuzzes by annealing. • Metastable W nano-fuzzes are formed due to He"+ irradiation at an elevated temperature.

Robustness of unstable attractors in arbitrarily sized pulse-coupled networks with delay

International Nuclear Information System (INIS)

Broer, Henk; Efstathiou, Konstantinos; Subramanian, Easwar

2008-01-01

We consider arbitrarily large networks of pulse-coupled oscillators with non-zero delay where the coupling is given by the Mirollo–Strogatz function. We prove that such systems have unstable attractors (saddle periodic orbits whose stable set has non-empty interior) in an open parameter region for three or more oscillators. The evolution operator of the system can be discontinuous and we propose an improved model with continuous evolution operator