Behavior of thermal breaks under seismic loads
Nguyen, Thi Thanh Huyen
2012-01-01
Nowadays sustainable constructions imply an objective of energetic performances by reducing the level of thermal conduction. The thermal-break elements, an innovative technological element is under study in several countries in Europe. If the thermal benefits have already been proved, the mechanical effects of such a wall-slab connection in a building for the seismic risk have not been assessed. To evaluate the building seismic vulnerability modifications due to these thermal breaks, experime...
Experimental investigation of dynamic pressure loads during dam break
Lobovský, Libor; Castellana, Filippo; Mas-Soler, Jordi; Souto-Iglesias, Antonio
2013-01-01
The objectives of this work are to revisit the experimental measurements on dam break flow over a dry horizontal bed and to provide a detailed insight into the dynamics of the dam break wave impacting a vertical wall downstream the dam, with emphasis on the pressure loads. The measured data are statistically analyzed and critically discussed. As a result, an extensive set of data for validation of computational tools is provided.
Experimental study of pipe reaction force and jet impingement load at the pipe break
International Nuclear Information System (INIS)
In the design of a light-water reactor nuclear power plant, the extreme loads which are caused as the result of hypothetical pipe break accident have recently become the most severe factors for the structure and equipment design of the plant. In this paper, we describe the results of experiments about reaction forces and jet impingement loads in the pipe break accident conditions. Experiments were carried out for the kinds of jets, that is steam jet and subcooled water jet. (orig.)
Domack, Marcia S.
1987-01-01
The stress corrosion behavior of the P/M aluminum alloy 7091 is evaluated in two overaged heat treatment conditions, T7E69 and T7E70, using an accelerated test technique known as the breaking load test method. The breaking load data obtained in this study indicate that P/M 7091 alloy is highly resistant to stress corrosion in both longitudinal and transverse orientations at stress levels up to 90 percent of the material yield strength. The reduction in mean breaking stress as a result of corrosive attack is smallest for the more overaged T7E70 condition. Details of the test procedure are included.
International Nuclear Information System (INIS)
Simple criteria for local and global instabilities were used to calculate leak-before-break-diagrams for load-controlled deformations. Relations between the tension and bending stresses in the uncracked pipe and the critical crack angle α/sub c/, below which complete fracture cannot occur, were developed for combined loading by internal pressure and external tension and bending. The different assumptions made for local and global instability lead to similar conclusions about the allowable crack length for leak-before-break behavior. It was not the intention of this paper to compare the conclusions with experimental results available
Pre-study of dynamic loads on the internals caused by a large pipe break in a BWR
International Nuclear Information System (INIS)
Det Norske Veritas Nuclear Technology has performed a literature study of dynamic load on a BWR (Boiling Water Reactor) internals caused by a large pipe break. The goal of the study was to improve the knowledge about the physics of phenomena occurring in the RPV (Reactor Pressure Vessel) after pipe break in the main circulation system and also to make a review of calculation methods, models and computer programs including their capabilities when calculating the dynamic loads. The report presents description of relevant parts of a BWR, initial and boundary conditions, and phenomena determining the loads - rapid depressurization and propagation of pressure wave (including none-equilibrium). Furthermore, the report generally describes possible methodologies for calculating the dynamic loads on internals after the pipe break and the experiences from calculations the dynamic loads with different methods (computer programs) including comparisons with experimental data. Fluid-Structure Interaction methodology and its importance for calculation of dynamic loads on reactor internals is discussed based on experimental data. A very intensive research program for studying and calculating the dynamic loads on internals after pipe breaks has been performed in USA and Germany during the seventies and the eighties. Several computer programs have been developed and a number of large-scale experiments have been performed to calibrate the calculation methods. In spite of the fact that all experiments were performed for PWR several experiences should be valid also for BWR. These experiences, connected mainly to capabilities of computer programs calculating dynamic loads, are discussed in the report
Design of load-to-failure tests of high-voltage insulation breaks for ITER's cryogenic network
Langeslag, S. A. E.; Rodriguez Castro, E.; Aviles Santillana, I.; Sgobba, S.; Foussat, A.
2015-12-01
The development of new generation superconducting magnets for fusion research, such as the ITER experiment, is largely based on coils wound with so-called cable-in-conduit conductors. The concept of the cable-in-conduit conductor is based on a direct cooling principle, by supercritical helium, flowing through the central region of the conductor, in close contact with the superconducting strands. Consequently, a direct connection exists between the electrically grounded helium coolant supply line and the highly energised magnet windings. Various insulated regions, constructed out of high-voltage insulation breaks, are put in place to isolate sectors with different electrical potential. In addition to high voltages and significant internal helium pressure, the insulation breaks will experience various mechanical forces resulting from differential thermal contraction phenomena and electro-magnetic loads. Special test equipment was designed, prepared and employed to assess the mechanical reliability of the insulation breaks. A binary test setup is proposed, where mechanical failure is assumed when leak rate of gaseous helium exceeds 10-9·Pa·m3/s. The test consists of a load-to-failure insulation break charging, in tension, while immersed in liquid nitrogen at the temperature of 77 K. Leak tightness during the test is monitored by measuring the leak rate of the gaseous helium, directly surrounding the insulation break, with respect to the existing vacuum inside the insulation break. The experimental setup is proven effective, and various insulation breaks performed beyond expectations.
Design of load-to-failure tests of high-voltage insulation breaks for ITER's cryogenic network
Langeslag, S A E; Aviles Santillana, I; Sgobba, S; Foussat, A
2015-01-01
The development of new generation superconducting magnets for fusion research, such as the ITER experiment, is largely based on coils wound with so-called cable-in-conduit conductors. The concept of the cable-in-conduit conductor is based on a direct cooling principle, by supercritical helium, flowing through the central region of the conductor, in close contact with the superconducting strands. Consequently, a direct connection exists between the electrically grounded helium coolant supply line and the highly energised magnet windings. Various insulated regions, constructed out of high-voltage insulation breaks, are put in place to isolate sectors with different electrical potential. In addition to high voltages and significant internal helium pressure, the insulation breaks will experience various mechanical forces resulting from differential thermal contraction phenomena and electro-magnetic loads. Special test equipment was designed, prepared and employed to assess the mechanical reliability of the insul...
Energy Technology Data Exchange (ETDEWEB)
Marcinkiewicz, Jerzy; Lindgren, Anders [Det Norske Veritas Nuclear Technology AB, Stockholm (Sweden)
2002-12-01
Det Norske Veritas Nuclear Technology has performed a literature study of dynamic load on a BWR (Boiling Water Reactor) internals caused by a large pipe break. The goal of the study was to improve the knowledge about the physics of phenomena occurring in the RPV (Reactor Pressure Vessel) after pipe break in the main circulation system and also to make a review of calculation methods, models and computer programs including their capabilities when calculating the dynamic loads. The report presents description of relevant parts of a BWR, initial and boundary conditions, and phenomena determining the loads - rapid depressurization and propagation of pressure wave (including none-equilibrium). Furthermore, the report generally describes possible methodologies for calculating the dynamic loads on internals after the pipe break and the experiences from calculations the dynamic loads with different methods (computer programs) including comparisons with experimental data. Fluid-Structure Interaction methodology and its importance for calculation of dynamic loads on reactor internals is discussed based on experimental data. A very intensive research program for studying and calculating the dynamic loads on internals after pipe breaks has been performed in USA and Germany during the seventies and the eighties. Several computer programs have been developed and a number of large-scale experiments have been performed to calibrate the calculation methods. In spite of the fact that all experiments were performed for PWR several experiences should be valid also for BWR. These experiences, connected mainly to capabilities of computer programs calculating dynamic loads, are discussed in the report.
Oum, Ji-Hyun; Seong, Changhyun; Kwon, Youngho; Ji, Jae-Hoon; Sid, Amy; Ramakrishnan, Sreejith; Ira, Grzegorz; Malkova, Anna; Sung, Patrick; Lee, Sang Eun; Shim, Eun Yong
2011-10-01
Homologous recombination repairs DNA double-strand breaks by searching for, invading, and copying information from a homologous template, typically the homologous chromosome or sister chromatid. Tight wrapping of DNA around histone octamers, however, impedes access of repair proteins to DNA damage. To facilitate DNA repair, modifications of histones and energy-dependent remodeling of chromatin are required, but the precise mechanisms by which chromatin modification and remodeling enzymes contribute to homologous DNA repair are unknown. Here we have systematically assessed the role of budding yeast RSC (remodel structure of chromatin), an abundant, ATP-dependent chromatin-remodeling complex, in the cellular response to spontaneous and induced DNA damage. RSC physically interacts with the recombination protein Rad59 and functions in homologous recombination. Multiple recombination assays revealed that RSC is uniquely required for recombination between sister chromatids by virtue of its ability to recruit cohesin at DNA breaks and thereby promoting sister chromatid cohesion. This study provides molecular insights into how chromatin remodeling contributes to DNA repair and maintenance of chromatin fidelity in the face of DNA damage.
Institute of Scientific and Technical Information of China (English)
沈保罗; 李莉; 高致文; 张昊
2012-01-01
使用WE-500型液压式万能拉伸试验机测定了IAE6半激冷合金铸铁凸轮轴的三点弯曲断裂载荷,研究了其三点弯曲断裂载荷和挠度之间的关系.研究表明:(1)不同炉次的凸轮轴的三点弯曲断裂载荷存在一定的分散性;(2)凸轮轴的三点弯曲断裂载荷与挠度之间存在正相关关系,凸轮轴中含有适量碳化物对其强度和挠度都是有益的.%The breaking load in three points bending test of the 1AE6 semi-chilled alloyed cast iron camshaft was determined by using WE-500 model hydraulic universal tensile test machine and thereby the relationship between its breaking loads and ite defections was; investigated. The resuit showed: (a )There was some dispersivity existing in the three point bonding breaking loads of camshafts of different melting heats; (b)There was a positive correlation existing between the breaking loads and deflections, and a proper amount of carbide contained in the camshaft was beneficial to both its strength and deflection.
Aguilar, Isaac-Cesar; Kagan, David
2013-01-01
The sight of a broken bat in Major League Baseball can produce anything from a humorous dribbler in the infield to a frightening pointed projectile headed for the stands. Bats usually break at the weakest point, typically in the handle. Breaking happens because the wood gets bent beyond the breaking point due to the wave sent down the bat created…
Institute of Scientific and Technical Information of China (English)
MATTHEW PLOWRIGHT; GWYNN GUILFORD
2008-01-01
@@ Resolutions are not natural - otherwise you wouldn't have to "resolve" to execute them. This year, instead of planning how to commit to a slew of unattainable goals, why not prepare for breaking your resolutions the right way?
Oum, Ji-Hyun; Seong, Changhyun; Kwon, YoungHo; Ji, Jae-Hoon; Sid, Amy; Ramakrishnan, Sreejith; Ira, Grzegorz; Malkova, Anna; Sung, Patrick; Lee, Sang Eun; Shim, Eun Yong
2011-01-01
Homologous recombination repairs DNA double-strand breaks by searching for, invading, and copying information from a homologous template, typically the homologous chromosome or sister chromatid. Tight wrapping of DNA around histone octamers, however, impedes access of repair proteins to DNA damage. To facilitate DNA repair, modifications of histones and energy-dependent remodeling of chromatin are required, but the precise mechanisms by which chromatin modification and remodeling enzymes cont...
DEFF Research Database (Denmark)
Strand, Anete Mikkala Camille
2016-01-01
storytelling to enact fruitful breakings of patterns unbecoming. The claim being, that the hamster wheel of Work-life anno 2016 needs reconfiguration and the simple yet fruitful manner by which this is done is through acknowledging the benefits of bodies, spaces and artifacts – and the benefits of actually...... taking a break, discontinuing for a moment in order to continue better, wiser and more at ease. Both within and as part of the daily routines, and – now and then – outside these routines in the majesty of nature with time to explore and redirect the course of life in companionships with fellow man...
Bali, G S; Lippert, T; Neff, H; Prkacin, Z; Schilling, K; Bali, Gunnar S; Dussel, Thomas; Lippert, Thomas; Neff, Hartmut; Prkacin, Zdravko; Schilling, Klaus
2006-01-01
We numerically investigate the transition of the static quark-antiquark string into a static-light meson-antimeson system. Improving noise reduction techniques, we are able to resolve the signature of string breaking dynamics for Nf=2 lattice QCD at zero temperature. We discuss the lattice techniques used and present results on energy levels and mixing angle of the static two-state system. We visualize the action density distribution in the region of string breaking as a function of the static colour source-antisource separation. The results can be related to properties of quarkonium systems.
Vlasić, Ignacija; Ivancić-Baće, Ivana; Imesek, Mirna; Mihaljević, Boris; Brcić-Kostić, Krunoslav
2008-09-01
The SOS response is an important mechanism which allows Escherichia coli cells to maintain genome integrity. Two key proteins in SOS regulation are LexA (repressor) and RecA (coprotease). The signal for SOS induction is generated at the level of a RecA filament. Depending on the type of DNA damage, a RecA filament is produced by specific activities (helicase, nuclease and RecA loading) of either RecBCD, RecF or a hybrid recombination pathway. It was recently demonstrated that RecA loading activity is essential for the induction of the SOS response after UV-irradiation. In this paper we studied the genetic requirements for SOS induction after introduction of a double-strand break (DSB) by the I-SceI endonuclease in a RecA loading deficient recB mutant (recB1080). We monitored SOS induction by assaying beta-galactosidase activity and compared induction of the response between strains having one or more inactivated mechanisms of RecA loading and their derivatives. We found that simultaneous inactivation of both RecA loading functions (in recB1080 recO double mutant) partially impairs SOS induction after introduction of a DSB. However, we found that the RecJ nuclease is essential for SOS induction after the introduction of a DSB in the recB1080 mutant. This result indicates that RecJ is needed to prepare ssDNA for subsequent loading of RecA protein. It implies that an additional type of RecA loading could exist in the cell. PMID:18445487
Indian Academy of Sciences (India)
Emilian Dudas
2009-01-01
We review the various mechanisms of supersymmetry breaking and its trans-mission to the observable sector. We argue that hybrid models where gauge dominates over gravity mediation, but gravity provides the main contributions to the Higgs sector masses and the neutralino mass, are able to combine the advantages and reduce the disadvantages of the two transmission mechanisms.
DEFF Research Database (Denmark)
Burcharth, Hans F.; Liu, Zhou
1999-01-01
The effect of wave short-crestedness on the horizontal wave force on a caisson is twofold. The one is the force reduction due to the reduction of point pressure on the caisson, named point-pressure reduction. The other is the force reduction due to the fact that the peak pressures do not occur...... simultaneously along the caisson, named peak-delay reduction. Model test results indicate that the point-pressure reduction can be predicted by the Goda formula. Based on linear wave theory, Battjes (1982) presented a formula for the peak-delay force reduction of short-crested waves with only one frequency...... ion of peakdelay force reduction factor for oblique long-crested and short-crested non-breaking waves are derived analytically. Theoretical formula for the maximum non-dimensional horizontally turning moment around the center of the caisson by oblique regular waves is also presented. Finally the paper...
International Nuclear Information System (INIS)
Purpose: In an experimental study, the correlation between the trabecular bone density of the different regions of the proximal femur and the fracture load in the setting of femoral neck fractures was examined. Methods: The bone mineral density 41 random proximal human femora was estimated by single-energy quanitative CT (SE-QCT). The trabecular bone density was measured at the greatest possible extracortical volume at midcapital, midneck and intertrochanteric level and in the 1 cm3 volumes of the centres of these regions in a standardised 10 mm thick slice in the middle of the femoral neck axis (in mg/ml Ca-hydroxyl apatite). The proximal femora were then isolated and mounted on a compression/bending device under two-legged stand conditions and loaded up to the point when a femoral neck fracture occurred. Results: Statistical analysis revealed a linear correlation between the trabecular bone density and the fracture load for the greater regions, with the highest value in the maximal area of the head (coefficient factor r=0.76). Conclusion: According to our data, the measurement of the trabecular bone by SE-QCT at the femoral head is a more confident adjunct than the neck or trochanteric area to predict a femoral neck fracture. (orig.)
DEFF Research Database (Denmark)
Kesting, Peter; Jørgensen, Frances
On some level, innovation begins when the current way of doing things is questioned and alternatives are sought. In cognitive terms, this can be conceptualized as the point at which an agent breaks with existing routine and returns to planning and decision-making. Thus far, however, very little...... is known about this cognitive structure or the factors that trigger the search for alternatives. In cooperation with the Danish Research Centre for Magnetic Resonance, University of Copenhagen, Denmark, we are in the process of designing an experimental study designed to gain insights into the triggers...
Peters, Kirstin
2010-01-01
A well-known result by Palamidessi tells us that {\\pi}mix (the {\\pi}-calculus with mixed choice) is more expressive than {\\pi}sep (its subset with only separate choice). The proof of this result argues with their different expressive power concerning leader election in symmetric networks. Later on, Gorla of- fered an arguably simpler proof that, instead of leader election in symmetric networks, employed the reducibility of "incestual" processes (mixed choices that include both enabled senders and receivers for the same channel) when running two copies in parallel. In both proofs, the role of breaking (ini- tial) symmetries is more or less apparent. In this paper, we shed more light on this role by re-proving the above result-based on a proper formalization of what it means to break symmetries-without referring to another layer of the distinguishing problem domain of leader election. Both Palamidessi and Gorla rephrased their results by stating that there is no uniform and reason- able encoding from {\\pi}mix i...
Hydraulic Response of Caisson Breakwaters in Multidirectional Breaking and Non-Breaking Waves
DEFF Research Database (Denmark)
Grønbech, J.; Kofoed, Jens Peter; Hald, Tue;
1998-01-01
induced loading and overtopping on caisson breakwaters situated in breaking seas. Regarding the wave forces only minor differences between breaking and non breaking waves in deep water were observed, and it was found that the prediction formula of Goda also seems to apply well for multidirectionally...... breaking waves at deep water. The study on wave overtopping showed that the 3D wave overtopping formula suggested by Franco et al., 1995b, predicts the wave overtopping reasonable well for both non breaking and breaking waves at deep water.......The present paper concerns the results and findings of a physical study on wave impacts on vertical caisson breakwaters situated in irregular, multidirectional breaking seas. The study has taken place as part of the framework programme "Dynamic of Structures" financially supported by the Danish...
A Stylistic Analysis of Break,Break,Break
Institute of Scientific and Technical Information of China (English)
李瑶
2015-01-01
Break, Break, Break is a poem by Alfred Lord Tennyson, the Poet Laureate during the Queen Victoria's reign. This exquisite little poem is wel known for the poet's grief-stricken feelings and heart-broken emotions over the premature death of his best friend, Arthur Henry Halam. Most of the previous studies on this poem focus on the emotional level to consider it as an elegy, expressing sorrow and lamentation for the death of a particular person. However, in order to have a deep understanding in general, this paper analyzes the poem based on the stylistic theory, concerning on the lexical level and the semantic level. It aims at helping the readers to cultivate a sense of appropriateness, to sharpen the understanding and appreciation of literary works and to achieve adaptation in translation.
Institute of Scientific and Technical Information of China (English)
2015-01-01
Jacky：My sister is mad at me.She refuses（拒绝）to talk to me.What can I do to break the ice？Ella：You can buy her a little gift.Break的意思是＂打破＂,ice是指＂冰块＂。冰是又冷又硬的东西,作为俗语break the ice是指＂打破沉默（僵局）＂。Jacky惹妹妹生气,妹妹不理他了,他能通过送小礼物break the ice吗？
Testing cosmological supersymmetry breaking
Kabat, D; Kabat, Daniel; Rajaraman, Arvind
2001-01-01
Banks has proposed a relation between the scale of supersymmetry breaking and the cosmological constant in de Sitter space. His proposal has a natural extension to a general FRW cosmology, in which the supersymmetry breaking scale is related to the Hubble parameter. We study one consequence of such a relation, namely that coupling constants change as the universe evolves. We find that the most straightforward extension of Banks' proposal is disfavored by experimental bounds on variation of the fine structure constant.
Martin, S P
1993-01-01
We propose a scenario in which the electroweak symmetry is spontaneously broken by an $SU(4)$ technicolor gauge interaction which also manages to break itself completely. The technicolor gauge bosons and technifermions are not confined by the technicolor force, but get large masses. Starting with a single technidoublet, one emerges with a complete standard model family of technifermions after the symmetry breaking is complete. This suggests a broad new avenue for model building. A few variations on the theme are mentioned.
Breaking wave impacts on offshore wind turbine foundations
DEFF Research Database (Denmark)
Bredmose, Henrik; Jacobsen, Niels Gjøl
2010-01-01
Extreme wave loads from breaking waves on a monopile foundation are computed within a 3D CFD model. The wave impacts are obtained by application of focused wave groups. For a fixed position of the monopile, the focus location of the wave group is varied to produce impacts with front shapes...... that for the impacts of spilling breakers the peak force gets smaller the more developed the breaking is. This is in qualitative agreement with a finding from shallow water impacts on vertical walls: the strongest wave loads are associated with breakers that hit the structure with slightly overturning front...... that varies from early stages of breaking to broken waves. The CFD results for in-line force are compared to load estimates obtained from the Morison equation. The peak loads determined with this simple method are smaller than those of the CFD solution. The computational results appear to suggest...
Energy Technology Data Exchange (ETDEWEB)
Chanowitz, M.S.
1990-09-01
The Higgs mechanism is reviewed in its most general form, requiring the existence of a new symmetry-breaking force and associated particles, which need not however be Higgs bosons. The first lecture reviews the essential elements of the Higgs mechanism, which suffice to establish low energy theorems for the scattering of longitudinally polarized W and Z gauge bosons. An upper bound on the scale of the symmetry-breaking physics then follows from the low energy theorems and partial wave unitarity. The second lecture reviews particular models, with and without Higgs bosons, paying special attention to how the general features discussed in lecture 1 are realized in each model. The third lecture focuses on the experimental signals of strong WW scattering that can be observed at the SSC above 1 TeV in the WW subenergy, which will allow direct measurement of the strength of the symmetry-breaking force. 52 refs., 10 figs.
DEFF Research Database (Denmark)
Christensen, Poul Rind; Kirketerp, Anne
2006-01-01
The paper shortly reveals the history of a small school - the KaosPilots - dedicated to educate young people to carriers as entrepreneurs. In this contribution we want to explore how the KaosPilots managed to break the waves of institutionalised concepts and practices of teaching entrepreneurship...
Model Breaking Points Conceptualized
Vig, Rozy; Murray, Eileen; Star, Jon R.
2014-01-01
Current curriculum initiatives (e.g., National Governors Association Center for Best Practices and Council of Chief State School Officers 2010) advocate that models be used in the mathematics classroom. However, despite their apparent promise, there comes a point when models break, a point in the mathematical problem space where the model cannot,…
A Comparison of Measured and Predicted Wave-Impact Pressures from Breaking and Non-breaking Waves
Fullerton, Anne M; Brewton, Susan; Brucker, Kyle A; O'Shea, Thomas T; Dommermuth, Douglas G
2014-01-01
Impact loads from waves on vessels and coastal structures are complex and may involve wave breaking, which has made these loads difficult to estimate numerically or empirically. Results from previous experiments have shown a wide range of forces and pressures measured from breaking and nonbreaking waves, with no clear trend between wave characteristics and the localized forces and pressures that they generate. In 2008, a canonical breaking wave impact data set was obtained at the Naval Surface Warfare Center, Carderock Division, by measuring the distribution of impact pressures of incident nonbreaking and breaking waves on one face of a cube. This experimental effort was sponsored by the Office of Naval Research (ONR), under the Dynamics of Interacting Platforms Program, Program Manager Dr. Ron Joslin. The effects of wave height, wavelength, face orientation, face angle, and submergence depth were investigated. Additionally, a limited number of runs were made at low forward speeds, ranging from about 0.5 to 2...
Breaking News as Radicalisation
DEFF Research Database (Denmark)
Hartley, Jannie Møller
The aim of the paper is to make explicit how the different categories are applied in the online newsroom and thus how new categories can be seen as positioning strategies in the form of radicalisations of already existing categories. Thus field theory provides us with tools to analyse how online...... journalists are using the categorisations to create hierarchies within the journalistic field in order to position themselves as specialists in what Tuchman has called developing news, aiming and striving for what today is know as breaking news and the “exclusive scoop,” as the trademark of online journalism...... provides us with the following two research questions: How does the category of breaking news fit into Tuchmans typology related to time, planning and technology? What types of stories are providing journalistic capital and how are online news stories categorised relatively within the journalistic field?...
Single sector supersymmetry breaking
Energy Technology Data Exchange (ETDEWEB)
Luty, Markus A.; Terning, John
1999-03-18
We review recent work on realistic models that break supersymmetry dynamically and give rise to composite quarks and leptons, all in a single sector. These models have a completely natural suppression of flavor-changing neutral currents, and the hierarchy of Yukawa couplings is explained by the dimensionality of composite states. The generic signatures are unification of scalar masses with different quantum numbers at the compositeness scale, and lighter gaugino, Higgsino, and third-generation sfermion masses.
DEFF Research Database (Denmark)
Hartley, Jannie Møller
2011-01-01
This chapter revisits seminal theoretical categorizations of news proposed three decades earlier by US sociologist Gaye Tuchman. By exploring the definition of ”breaking news” in the contemporary online newsrooms of three Danish news organisations, the author offers us a long overdue re......-theorization of journalistic practice in the online context and helpfully explores well-evidenced limitations to online news production, such as the relationship between original reporting and the use of ”shovelware.”...
Predicting appointment breaking.
Bean, A G; Talaga, J
1995-01-01
The goal of physician referral services is to schedule appointments, but if too many patients fail to show up, the value of the service will be compromised. The authors found that appointment breaking can be predicted by the number of days to the scheduled appointment, the doctor's specialty, and the patient's age and gender. They also offer specific suggestions for modifying the marketing mix to reduce the incidence of no-shows. PMID:10142384
Institute of Scientific and Technical Information of China (English)
1998-01-01
Many women who suffer from vaginitis have kept silent about their illness because they think it is shameful to have such a disease. The International Women’s Health Coalition (IWHC) has publicized the problem, referring to it as a "culture of silence"inherited from traditional thinking. The coalition has made attempts to improve women’s health conditions by changing people’s misconceptions about the disease. In 1997, under a grant from the American Ford Foundation, the Sichuan Provincial Women’s Federation carried out a study on women’s repro-ductive health, aimed at "breaking the silence."
Symmetries and Symmetry Breaking
Van Oers, W T H
2003-01-01
In understanding the world of matter, the introduction of symmetry principles following experimentation or using the predictive power of symmetry principles to guide experimentation is most profound. The conservation of energy, linear momentum, angular momentum, charge, and CPT involve fundamental symmetries. All other conservation laws are valid within a restricted subspace of the four interactions: the strong, the electromagnetic, the weak, and the gravitational interaction. In this paper comments are made regarding parity violation in hadronic systems, charge symmetry breaking in two nucleon and few nucleon systems, and time-reversal-invariance in hadronic systems.
DEFF Research Database (Denmark)
Konradsen, Hanne; Kirkevold, Marit; McCallin, Antoinette;
2012-01-01
and individual interviews were analyzed using the grounded theory method. The findings revealed that the main concern of the patients was feeling isolated, which was resolved using a process of interactional integration. Interactional integration begins by breaking the silence to enable the progression from......Little is known about the psychosocial effects of facial disfigurement. We present the results of a qualitative study following 15 patients who had been surgically treated for head, neck, or eye cancer over the course of their first postoperative year. Taped nurse-patient conversations...
Bootstrap Dynamical Symmetry Breaking
Directory of Open Access Journals (Sweden)
Wei-Shu Hou
2013-01-01
Full Text Available Despite the emergence of a 125 GeV Higgs-like particle at the LHC, we explore the possibility of dynamical electroweak symmetry breaking by strong Yukawa coupling of very heavy new chiral quarks Q . Taking the 125 GeV object to be a dilaton with suppressed couplings, we note that the Goldstone bosons G exist as longitudinal modes V L of the weak bosons and would couple to Q with Yukawa coupling λ Q . With m Q ≳ 700 GeV from LHC, the strong λ Q ≳ 4 could lead to deeply bound Q Q ¯ states. We postulate that the leading “collapsed state,” the color-singlet (heavy isotriplet, pseudoscalar Q Q ¯ meson π 1 , is G itself, and a gap equation without Higgs is constructed. Dynamical symmetry breaking is affected via strong λ Q , generating m Q while self-consistently justifying treating G as massless in the loop, hence, “bootstrap,” Solving such a gap equation, we find that m Q should be several TeV, or λ Q ≳ 4 π , and would become much heavier if there is a light Higgs boson. For such heavy chiral quarks, we find analogy with the π − N system, by which we conjecture the possible annihilation phenomena of Q Q ¯ → n V L with high multiplicity, the search of which might be aided by Yukawa-bound Q Q ¯ resonances.
Break WEP Faster with Statistical Analysis
Chaabouni, Rafik
2006-01-01
The Wired Equivalent Protocol is nowadays considered as unsafe. However the only academic research that tries to break WEP has been done by Fluhrer, Mantin and Shamir, who have published a report on a specific attack. Nevertheless, an unknown person under the pseudonym Korek has published 17 attacks, which are now used by both AirCrack and WepLab. For a network with average load traffic, the FMS attack would need roughfly 40 days in order to find the key (4 millions packets needed), whereas K...
DEFF Research Database (Denmark)
Hasse, Cathrine; Trentemøller, Stine
Break the Pattern! A critical enquiry into three scientific workplace cultures: Hercules, Caretakers and Worker Bees is the third publication of the international three year long project "Understanding Puzzles in the Gendered European Map" (UPGEM). By contrasting empirical findings from academic...... workplaces in the five UPGEM-countries (Denmark, Estonia, Finland, Italy and Poland) we identify three clusters of cultural patterns in physics as culture. We call these Hercules, Caretakers and Worker Bees. We also consider the influence of national cultural historical processes on the scientific culture...... (physics in culture) and discuss how physics as and in culture influence the perception of science, of work and family life, of the interplay between religion and science as well as how physics as culture can either hinder or promote the career of female scientists....
DEFF Research Database (Denmark)
Bredmose, Henrik; Peregrine, D.H.; Bullock, G.N.
2009-01-01
When an ocean wave breaks against a steep-fronted breakwater, sea wall or a similar marine structure, its impact on the structure can be very violent. This paper describes the theoretical studies that, together with field and laboratory investigations, have been carried out in order to gain...... a better understanding of the processes involved. The wave's approach towards a structure is modelled with classical irrotational flow to obtain the different types of impact profiles that may or may not lead to air entrapment. The subsequent impact is modelled with a novel compressible-flow model...... for a homogeneous mixture of incompressible liquid and ideal gas. This enables a numerical description of both trapped air pockets and the propagation of pressure shock waves through the aerated water. An exact Riemann solver is developed to permit a finite-volume solution to the flow model with smallest possible...
Electroweak breaking in supersymmetric models
Ibáñez, L E
1992-01-01
We discuss the mechanism for electroweak symmetry breaking in supersymmetric versions of the standard model. After briefly reviewing the possible sources of supersymmetry breaking, we show how the required pattern of symmetry breaking can automatically result from the structure of quantum corrections in the theory. We demonstrate that this radiative breaking mechanism works well for a heavy top quark and can be combined in unified versions of the theory with excellent predictions for the running couplings of the model. (To be published in ``Perspectives in Higgs Physics'', G. Kane editor.)
An Experimental and Computational Study of Breaking Wave Impact Forces
Fu, Thomas C; Brewton, Susan; Brucker, Kyle A; Dommermuth, Douglas G
2014-01-01
The impact forces generated by the impact of a breaking wave are poorly understood. These impulsive hydrodynamic loads to a ship's hull are of short duration relative to ship motions and buoyant wave loads and often result in extremely high pressures. The physics of breaking waves is a poorly understood, complex, multiphase phenomenon involving violent jet sprays, strong free-surface turbulence, air entrainment and bubble generation, all of which interact with the flow field and the adjacent structure. This paper will describe a set of experiments that were performed, at the Naval Surface Warfare Center, Carderock Division (NSWCCD), in 2006, to measure the hydrodynamic loads of regular nonbreaking and focused breaking waves on a 0.305 m x 0.305 m (1.0 ft x 1.0 ft) square plate and discuss the results of this study. The paper will also discuss Computational Fluid Dynamics (CFD) code predictions of breaking waves and wave impact loads. The CFD code utilized in this study is Numerical Flow Analysis (NFA).
Wave Impacts on Caisson Breakwaters Situated in Multidirectionally Breaking Seas
DEFF Research Database (Denmark)
Grønbech, J.; Burcharth, Hans F.; Frigaard, Peter;
1999-01-01
Attention has been addressed to the effects of wave obliquity and multidirectionality on the wave loads on vertical caisson breakwaters situated in non breaking seas. Within the joint European (MAST-LIP-TAW) research project, a 3D model investigation was carried out at Delft Hydraulics to assess...
Wave Impacts on Caisson Breakwaters Situated in Multidirectionally Breaking Seas
DEFF Research Database (Denmark)
Grønbech, J.; Burcharth, Hans F.; Frigaard, Peter;
1998-01-01
Attention has been addressed to the effects of wave obliquity and multidirectionality on the wave loads on vertical caisson breakwaters situated in non breaking seas. Within the joint European (MAST-LIP-TAW) research project, a 3D model investigation was carried out at Delft Hydraulics to assess...
Break location effects on PWR small break LOCA phenomena
International Nuclear Information System (INIS)
The report presents experimental results of a small lower plenum break test of SB-PV-01 conducted at the large-Scale Test Facility (LSTF) of the Rig-of-Safety Assessment (ROSA)-IV program. This test simulates a loss-of-coolant accident (LOCA) caused by instrument tubes break (break area corresponds to 0.5% of the cold leg flow area) in a Westinghouse-type pressurized water reactor (PWR) assuming both manual actuation for all of the high pressure injection (HPI) systems and failure of the auxiliary feedwater systems. The report clarifies long-term system responses, especially the core cooling conditions related to the primary mass inventory. Also it clarifies break location effects on small break LOCA phenomena by comparing other five similar LOCA tests with break locations at cold leg, hot leg, upper head, pressurizer top (TMI-type) and SG U-tubes. It is coucluded that the lower plenum break is the severest on core heatup due to the highest break flow rate and the least primary mass recovery after the ECCS among the six tests. (author)
Energy Technology Data Exchange (ETDEWEB)
Lami, L. [Scuola Normale Superiore, I-56126 Pisa (Italy); Giovannetti, V. [NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, I-56127 Pisa (Italy)
2015-09-15
We study a set of new functionals (called entanglement–breaking indices) which characterize how many local iterations of a given (local) quantum channel are needed in order to completely destroy the entanglement between the system of interest over which the transformation is defined and an external ancilla. The possibility of contrasting the noisy effects introduced by the channel iterations via the action of intermediate (filtering) transformations is analyzed. We provide some examples in which our functionals can be exactly calculated. The differences between unitary and non-unitary filtering operations are analyzed showing that, at least for systems of dimension d larger than or equal to 3, the non-unitary choice is preferable (the gap between the performances of the two cases being divergent in some cases). For d = 2 (qubit case), on the contrary, no evidences of the presence of such gap is revealed: we conjecture that for this special case unitary filtering transformations are optimal. The scenario in which more general filtering protocols are allowed is also discussed in some detail. The case of a depolarizing noise acting on a two–qubit system is exactly solved in a general case.
Supersymmetry Breaking in Warped Geometry
Choi, Kiwoon; Kim, Do Young; Kim, Ian-Woo; Kobayashi, Tatsuo
2003-01-01
We examine the soft supersymmetry breaking parameters in supersymmetric theories on a slice of AdS_5 which generate the hierarchical Yukawa couplings by dynamically localizing the bulk matter fields in extra dimension. Such models can be regarded as the AdS dual of the recently studied 4-dimensional models which contain a supersymmetric CFT to generate the hierarchical Yukawa couplings. In such models, if supersymmetry breaking is mediated by the bulk radion superfield and/or some brane chira...
DEFF Research Database (Denmark)
Kock, Carsten Weber; Vesth, Allan
The report describes Load measurements carried out on a given wind turbine. The aim of the measurement program regarding the loads on the turbine is to verify the basic characteristics of the wind turbine and loads on the blades, the rotor and the tower, using [Ref 1], [Ref2] and [Ref 3]. Regarding...... the fatigue loads, the rotor, blades and tower moments are presented. The fatigue loads are evaluated using rainflow counting described in detail in Ref. [1]. The 1Hz equivalent load ranges are calculated at different wind speeds. All information regarding the instrumentation is collected in [ref 4] and [ref...
DEFF Research Database (Denmark)
Vesth, Allan; Kock, Carsten Weber
The report describes Load measurements carried out on a given wind turbine. The aim of the measurement program regarding the loads on the turbine is to verify the basic characteristics of the wind turbine and loads on the blades, the rotor and the tower, using [Ref 1], [Ref2] and [Ref 3]. Regardi...
DEFF Research Database (Denmark)
Kock, Carsten Weber; Vesth, Allan
The report describes Load measurements carried out on a given wind turbine. The aim of the measurement program regarding the loads on the turbine is to verify the basic characteristics of the wind turbine and loads on the blades, the rotor and the tower, using [Ref 1], [Ref2] and [Ref 3]. Regarding...
Symmetry breaking in molecular ferroelectrics.
Shi, Ping-Ping; Tang, Yuan-Yuan; Li, Peng-Fei; Liao, Wei-Qiang; Wang, Zhong-Xia; Ye, Qiong; Xiong, Ren-Gen
2016-07-11
Ferroelectrics are inseparable from symmetry breaking. Accompanying the paraelectric-to-ferroelectric phase transition, the paraelectric phase adopting one of the 32 crystallographic point groups is broken into subgroups belonging to one of the 10 ferroelectric point groups, i.e. C1, C2, C1h, C2v, C4, C4v, C3, C3v, C6 and C6v. The symmetry breaking is captured by the order parameter known as spontaneous polarization, whose switching under an external electric field results in a typical ferroelectric hysteresis loop. In addition, the responses of spontaneous polarization to other external excitations are related to a number of physical effects such as second-harmonic generation, piezoelectricity, pyroelectricity and dielectric properties. Based on these, this review summarizes recent developments in molecular ferroelectrics since 2011 and focuses on the relationship between symmetry breaking and ferroelectricity, offering ideas for exploring high-performance molecular ferroelectrics. PMID:27051889
DEFF Research Database (Denmark)
Martinelli, Luca; Lamberti, Alberto; Frigaard, Peter
2007-01-01
This paper addresses wave forces applied to vertical caisson breakwaters. Design diagrams are proposed to evaluate the reduction of the breaker wave force with increasing horizontal length of the units. A model in 1:100 scale of a typical Italian vertical breakwater was tested under...... multidirectional waves, causing mainly spilling and occasionally plunging breakers, in the CRF-LSF (Wallingford, UK) wave basin. Seven adjacent modules were instrumented with synchronized force transducers. Pulsating and breaking loads were distinguished on the basis of the frequency content and the spatial...... correlation of the force per unit length was fitted to a single or a double bell shaped distribution. The experimental autocorrelation function for pulsating loads agrees with theoretical solutions; for breaking waves it has a Taylor microscale which is approximately 7% of wavelength, only slightly dependent...
Give me a better break: Choosing workday break activities to maximize resource recovery.
Hunter, Emily M; Wu, Cindy
2016-02-01
Surprisingly little research investigates employee breaks at work, and even less research provides prescriptive suggestions for better workday breaks in terms of when, where, and how break activities are most beneficial. Based on the effort-recovery model and using experience sampling methodology, we examined the characteristics of employee workday breaks with 95 employees across 5 workdays. In addition, we examined resources as a mediator between break characteristics and well-being. Multilevel analysis results indicated that activities that were preferred and earlier in the work shift related to more resource recovery following the break. We also found that resources mediated the influence of preferred break activities and time of break on health symptoms and that resource recovery benefited person-level outcomes of emotional exhaustion, job satisfaction, and organizational citizenship behavior. Finally, break length interacted with the number of breaks per day such that longer breaks and frequent short breaks were associated with more resources than infrequent short breaks. PMID:26375961
An Analysis of Break,Break,Break Based on the Stylistic Theory
Institute of Scientific and Technical Information of China (English)
李瑶
2014-01-01
Break,Break,Break is a poem by Alfred Lord Tennyson, the Poet Laureate during the Queen Victoria's reign. This exquisite little poem is wel known for the poet’s grief-stricken feelings and heart-broken emotions over the premature death of his best friend, Arthur Henry Hal am. Most of the previous studies on this poem focus on the emotional level to consider it as an elegy, expressing sorrow and lamentation for the death of a particular person. However, in order to have a deep understanding in general, this paper analyzes the poem based on the stylistic theory, concerning on the phonological level and the grammatical level. It aims at helping the readers to cultivate a sense of appropriateness, to sharpen the understanding and appreciation of literary works and to achieve adaptation in translation.
Macner, Ashley; Steen, Paul
2011-11-01
Wet adhesion by liquid bridges in large arrays shows promise for use in lightweight, controllable on-demand devices. Applications include grab/release of wafer substrates, transport of micron-sized tiles for use in 3D printing and micro-dosing of personalized pharmaceutical drugs. By wetting and spreading, a drop can form a bridge and thereby ``grab'' a nearby solid substrate. By volume decrease or extension, the bridge can break. The breaking limit corresponds to bridge instability which can be predicted, knowing the static mechanical response of the bridge. Mechanical behaviors include force-volume (FV), pressure-volume (pV) and force-length (FL) responses. Instability crucially depends on the mode of failure - failure under constant-force or constant length are typical cases. We study single bridge equilibria for their breaking limits. FV diagrams for the pin-pin equal and pin-pin unequal radii boundary conditions for different bridge heights are measured in the laboratory. The FL response in the case of pin-pin equal radii is also measured. Results are compared to predictions of static theory. Static results are then used to compare to dynamical sequences where volume is driven quasistatically by syringe or an electro-osmotic pump. As the breaking limit is approached, the shape deformation accelerates leading to non-equilibrium shapes not captured by the static analysis.
Inflationary implications of supersymmetry breaking
Borghese, Andrea; Roest, Diederik; Zavala, Ivonne
2013-01-01
We discuss a general bound on the possibility to realise inflation in any minimal supergravity with F-terms. The derivation crucially depends on the sGoldstini, the scalar field directions that are singled out by spontaneous supersymmetry breaking. The resulting bound involves both slow-roll paramet
Strong coupling electroweak symmetry breaking
Energy Technology Data Exchange (ETDEWEB)
Barklow, T.L. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Burdman, G. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Physics; Chivukula, R.S. [Boston Univ., MA (United States). Dept. of Physics
1997-04-01
The authors review models of electroweak symmetry breaking due to new strong interactions at the TeV energy scale and discuss the prospects for their experimental tests. They emphasize the direct observation of the new interactions through high-energy scattering of vector bosons. They also discuss indirect probes of the new interactions and exotic particles predicted by specific theoretical models.
Dogan, Suzan
2016-07-01
Accretion discs are common in binary systems, and they are often found to be misaligned with respect to the binary orbit. The gravitational torque from a companion induces nodal precession in misaligned disc orbits. In this study, we first calculate whether this precession is strong enough to overcome the internal disc torques communicating angular momentum. We compare the disc precession torque with the disc viscous torque to determine whether the disc should warp or break. For typical parameters precession wins: the disc breaks into distinct planes that precess effectively independently. To check our analytical findings, we perform 3D hydrodynamical numerical simulations using the PHANTOM smoothed particle hydrodynamics code, and confirm that disc breaking is widespread and enhances accretion on to the central object. For some inclinations, the disc goes through strong Kozai cycles. Disc breaking promotes markedly enhanced and variable accretion and potentially produces high-energy particles or radiation through shocks. This would have significant implications for all binary systems: e.g. accretion outbursts in X-ray binaries and fuelling supermassive black hole (SMBH) binaries. The behaviour we have discussed in this work is relevant to a variety of astrophysical systems, for example X-ray binaries, where the disc plane may be tilted by radiation warping, SMBH binaries, where accretion of misaligned gas can create effectively random inclinations and protostellar binaries, where a disc may be misaligned by a variety of effects such as binary capture/exchange, accretion after binary formation.
Sediment transport under breaking waves
DEFF Research Database (Denmark)
Christensen, Erik Damgaard; Hjelmager Jensen, Jacob; Mayer, Stefan
2000-01-01
generated at the surface where the wave breaks as well as the turbulence generated near the bed due to the wave-motion and the undertow. In general, the levels of turbulent kinetic energy are found to be higher than experiments show. This results in an over prediction of the sediment transport. Nevertheless...
Small Break Air Ingress Experiment
Energy Technology Data Exchange (ETDEWEB)
Chang Oh; Eung Soo Kim
2011-09-01
The small break air-ingress experiment, described in this report, is designed to investigate air-ingress phenomena postulated to occur in pipes in a very high temperature gas-cooled reactor (VHTRs). During this experiment, air-ingress rates were measured for various flow and break conditions through small holes drilled into a pipe of the experimental apparatus. The holes were drilled at right angles to the pipe wall such that a direction vector drawn from the pipe centerline to the center of each hole was at right angles with respect to the pipe centerline. Thus the orientation of each hole was obtained by measuring the included angle between the direction vector of each hole with respect to a reference line anchored on the pipe centerline and pointing in the direction of the gravitational force. Using this reference system, the influence of several important parameters on the air ingress flow rate were measured including break orientation, break size, and flow velocity . The approach used to study the influence of these parameters on air ingress is based on measuring the changes in oxygen concentrations at various locations in the helium flow circulation system as a function of time using oxygen sensors (or detectors) to estimate the air-ingress rates through the holes. The test-section is constructed of a stainless steel pipe which had small holes drilled at the desired locations.
Donovan, Peter
2014-01-01
Covers the historical context and the evolution of the technically complex Allied Signals Intelligence (Sigint) activity against Japan from 1920 to 1945 Describes, explains and analyzes the code breaking techniques developed during the war in the Pacific Exposes the blunders (in code construction and use) made by the Japanese Navy that led to significant US Naval victories
DEFF Research Database (Denmark)
Driscoll, Patrick Arthur
2014-01-01
This central focus of this paper is to highlight the ways in which path dependencies and increasing returns (network effects) serve to reinforce carbon lock-in in large-scale road transportation infrastructure projects. Breaking carbon lock-in requires drastic changes in the way we plan future...
A model of intrinsic symmetry breaking
Energy Technology Data Exchange (ETDEWEB)
Ge, Li [Research Center for Quantum Manipulation, Department of Physics, Fudan University, Shanghai 200433 (China); Li, Sheng [Department of Physics, Zhejiang Normal University, Zhejiang 310004 (China); George, Thomas F., E-mail: tfgeorge@umsl.edu [Office of the Chancellor and Center for Nanoscience, Department of Chemistry and Biochemistry, University of Missouri-St. Louis, St. Louis, MO 63121 (United States); Department of Physics and Astronomy, University of Missouri-St. Louis, St. Louis, MO 63121 (United States); Sun, Xin, E-mail: xin_sun@fudan.edu.cn [Research Center for Quantum Manipulation, Department of Physics, Fudan University, Shanghai 200433 (China)
2013-11-01
Different from the symmetry breaking associated with a phase transition, which occurs when the controlling parameter is manipulated across a critical point, the symmetry breaking presented in this Letter does not need parameter manipulation. Instead, the system itself suddenly undergoes symmetry breaking at a certain time during its evolution, which is intrinsic symmetry breaking. Through a polymer model, it is revealed that the origin of the intrinsic symmetry breaking is nonlinearity, which produces instability at the instance when the evolution crosses an inflexion point, where this instability breaks the original symmetry.
Symmetries, Symmetry Breaking, Gauge Symmetries
Strocchi, Franco
2015-01-01
The concepts of symmetry, symmetry breaking and gauge symmetries are discussed, their operational meaning being displayed by the observables {\\em and} the (physical) states. For infinitely extended systems the states fall into physically disjoint {\\em phases} characterized by their behavior at infinity or boundary conditions, encoded in the ground state, which provide the cause of symmetry breaking without contradicting Curie Principle. Global gauge symmetries, not seen by the observables, are nevertheless displayed by detectable properties of the states (superselected quantum numbers and parastatistics). Local gauge symmetries are not seen also by the physical states; they appear only in non-positive representations of field algebras. Their role at the Lagrangian level is merely to ensure the validity on the physical states of local Gauss laws, obeyed by the currents which generate the corresponding global gauge symmetries; they are responsible for most distinctive physical properties of gauge quantum field ...
Renormalizable theories with symmetry breaking
Becchi, Carlo M
2016-01-01
The description of symmetry breaking proposed by K. Symanzik within the framework of renormalizable theories is generalized from the geometrical point of view. For an arbitrary compact Lie group, a soft breaking of arbitrary covariance, and an arbitrary field multiplet, the expected integrated Ward identities are shown to hold to all orders of renormalized perturbation theory provided the Lagrangian is suitably chosen. The corresponding local Ward identity which provides the Lagrangian version of current algebra through the coupling to an external, classical, Yang-Mills field, is then proved to hold up to the classical Adler-Bardeen anomaly whose general form is written down. The BPHZ renormalization scheme is used throughout in such a way that the algebraic structure analyzed in the present context may serve as an introduction to the study of fully quantized gauge theories.
Breaking GSM with rainbow Tables
Meyer, Steven
2011-01-01
Since 1998 the GSM security has been academically broken but no real attack has ever been done until in 2008 when two engineers of Pico Computing (FPGA manufacture) revealed that they could break the GSM encryption in 30 seconds with 200'000$ hardware and precomputed rainbow tables. Since then the hardware was either available for rich people only or was confiscated by government agencies. So Chris Paget and Karsten Nohl decided to react and do the same thing but in a distributed open source form (on torrent). This way everybody could "enjoy" breaking GSM security and operators will be forced to upgrade the GSM protocol that is being used by more than 4 billion users and that is more than 20 years old.
Breaking through the tranfer tunnel
Laurent Guiraud
2001-01-01
This image shows the tunnel boring machine breaking through the transfer tunnel into the LHC tunnel. Proton beams will be transferred from the SPS pre-accelerator to the LHC at 450 GeV through two specially constructed transfer tunnels. From left to right: LHC Project Director, Lyn Evans; CERN Director-General (at the time), Luciano Maiani, and Director for Accelerators, Kurt Hubner.
Leak-before-break demonstration for a typical PWR main steam pipe
International Nuclear Information System (INIS)
Currently the main steam line break evaluations of pressurized water reactor coolant systems are performed for postulated circumferential (guillotine) breaks. This results in overly conservation loading conditions. The objective of this paper is to study the local and global stability of a postulated through wall circumferential flaw in the main steam pipe of a typical pressurized water reactor. Steam leak rates are estimated and are examined in light of currently available leak rate criteria to demonstrate the leak-before-break condition. The need for additional criteria for detection of steam leaks is identified
16th Edition Breaks New Ground
Institute of Scientific and Technical Information of China (English)
Zhao Fei
2010-01-01
@@ Breaking new ground,Intertextile Shanghai Apparel Fabrics,successfully closed its doors on October 22nd,2010at the Shanghai New International Exhibition Centre,attracting a record breaking,more than 57,000 buyers.
Spontaneous Breaking of the Quantum Superposition
Pankovic, Vladan; Predojevic, Milan
2007-01-01
In this work spontaneous (non-dynamical) breaking (effective hiding) of the unitary quantum mechanical dynamical symmetry (superposition) is considered. It represents an especial but very interesting case of the general formalism of the spontaneous symmetry breaking (effective hiding). Conceptual analogies with spontaneous breaking of the gauge symmetry in Weinberg-Sallam's electro-weak interaction are pointed out. Also, consequences of the spontaneous superposition breaking in the measuremen...
BREAKING WAVE FORCES ON VERTICAL CYLINDERS
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
The breaking wave forces on vertical cylinders in shallow waters were studied by means of experimental methods. The results indicate that the breaking wave pressure is distributed exponentially with respect to water depth. An experimental formula was given using the test data. Compared with test data, the calculated breaking wave forces are in good agreement with the test data.
Electroweak symmetry breaking at photon colliders
International Nuclear Information System (INIS)
The electroweak-symmetry-breaking sector of the standard model can be weakly-coupled or can be strongly-coupled, which is characterized by some kinds of strong interaction among the Goldstone bosons of the electroweak-symmetry-breaking sector. In this paper, we summarize an investigation of probing the strong electroweak-symmetry-breaking effects at photon colliders. ((orig.))
Directory of Open Access Journals (Sweden)
Filippo Cassarà
2013-03-01
Full Text Available Recent research addressed the main role of hepcidin in the regulation of iron metabolism. However, while this mechanism could be relevant in causing iron load in Thalassemia Intermedia and Sickle-Cell Anemia, its role in Thalassemia Major (TM is marginal. This is mainly due to the high impact of transfusional requirement into the severe increase of body iron. Moreover, the damage of iron load may be worsened by infections, as HCV hepatitis, or liver and endocrinological damage. One of the most relevant associations was found between splenectomy and increase of risk for mortality due,probably, to more severe iron load. These issues suggest as morbidity and mortality of this group of patients they do not depend only by our ability in controlling heart damage but even in preventing or treating particular infections and complications. This finding is supported by the impairment of survival curves in patients with complications different from heart damage. However, because, during recent years different direct and indirect methods to detect iron overload in patients affected by secondary hemochromatosis have been implemented, our ability to maintain under control iron load is significantly improved. Anyway, the future in iron load management remains to be able to have an iron load map of our body for targeting chelation and other medical treatment according to the single organ damage.
Surface tension effects in wave breaking
Deike, Luc; Melville, W. K.; Popinet, Stephane
2014-11-01
We present a numerical study of wave breaking by solving the full Navier-Stokes equations for two-phase air-water flows using the solver Gerris. We describe a parametric study of the influence of capillary effects on wave breaking using two-dimensional simulations. The onset of wave breaking as a function of the Bond number, Bo, and the initial wave steepness S is determined and a phase diagram in terms of (S,Bo) is presented that distinguishes between non-breaking gravity waves, parasitic capillaries on a gravity wave, spilling breakers and plunging breakers. The wave energy dissipation is computed for each wave regime and is found to be in good agreement with experimental results for breaking waves. Moreover, the enhanced dissipation just by parasitic capillaries is comparable to the dissipation due to breaking. Extending the simulations to three dimensions permits studies of the generation and statistics of bubbles and spray during breaking.
Directional excitation without breaking reciprocity
Ramezani, Hamidreza; Dubois, Marc; Wang, Yuan; Shen, Y. Ron; Zhang, Xiang
2016-09-01
We propose a mechanism for directional excitation without breaking reciprocity. This is achieved by embedding an impedance matched parity-time symmetric potential in a three-port system. The amplitude distribution within the gain and loss regions is strongly influenced by the direction of the incoming field. Consequently, the excitation of the third port is contingent on the direction of incidence while transmission in the main channel is immune. Our design improves the four-port directional coupler scheme, as there is no need to implement an anechoic termination to one of the ports.
History of electroweak symmetry breaking
Kibble, T W B
2015-01-01
In this talk, I recall the history of the development of the unified electroweak theory, incorporating the symmetry-breaking Higgs mechanism, as I saw it from my standpoint as a member of Abdus Salam's group at Imperial College. I start by describing the state of physics in the years after the Second World War, explain how the goal of a unified gauge theory of weak and electromagnetic interactions emerged, the obstacles encountered, in particular the Goldstone theorem, and how they were overcome, followed by a brief account of more recent history, culminating in the historic discovery of the Higgs boson in 2012.
Leaders break ground for INFINITY
2008-01-01
Community leaders from Mississippi and Louisiana break ground for the new INFINITY at NASA Stennis Space Center facility during a Nov. 20 ceremony. Groundbreaking participants included (l to r): Gottfried Construction representative John Smith, Mississippi Highway Commissioner Wayne Brown, INFINITY board member and Apollo 13 astronaut Fred Haise, Stennis Director Gene Goldman, Studio South representative David Hardy, Leo Seal Jr. family representative Virginia Wagner, Hancock Bank President George Schloegel, Mississippi Rep. J.P. Compretta, Mississippi Band of Choctaw Indians representative Charlie Benn and Louisiana Sen. A.G. Crowe.
Spontaneous Breaking of Flavor Symmetry
Törnqvist, N A
1996-01-01
It is shown that part of the quark masses of the standard model can be generated spontaneously within the strong interactions of QCD. After the breaking of U(Nf) x U(Nf) symmetry by the vacuum, also the resulting flavor symmetric, degenerate meson mass spectrum is shown to be unstable with respect to quantum loops, for rather general models. For a C-degenerate meson spectrum the stable mass spectrum obeys the Okubo-Zweig-Iizuka rule and the approximateequal spacing rule.
Gamp, Alexander
2013-01-01
We begin by giving a description of the radio-frequency generator-cavity-beam coupled system in terms of basic quantities. Taking beam loading and cavity detuning into account, expressions for the cavity impedance as seen by the generator and as seen by the beam are derived. Subsequently methods of beam-loading compensation by cavity detuning, radio-frequency feedback and feedforward are described. Examples of digital radio-frequency phase and amplitude control for the special case of superconducting cavities are also given. Finally, a dedicated phase loop for damping synchrotron oscillations is discussed.
Boundary breaking for interdisciplinary learning
Directory of Open Access Journals (Sweden)
Adi Kidron
2015-10-01
Full Text Available The purpose of this work is to contribute to the body of knowledge on processesby which students develop interdisciplinary understanding of contents, as well as to suggest technology-enhanced means for supporting them in these processes in the context of higher education. In doing so, we suggest a rethinking of three traditional practices that tend to characterise typical higher education instruction: (1 compartmentalisation of disciplines; (2 traditional pedagogy; and (3 traditional hierarchies based on levels of expertise. Our high-level conjecture was that meaningful dialogue with peers and experts supports both the deepening of ideas in one knowledge domain and the formation of connections between ideas from several domains, both of which are required for the development of interdisciplinary understanding. We developed the Boundary Breaking for Interdisciplinary Learning (BBIL model, which harnesses technology to break boundaries between disciplines, learners and organisational levels of hierarchy. Findings indicate that 36 undergraduate students who participated in an interdisciplinary online course that implemented the BBIL model have significantly improved their interdisciplinary understanding of the course contents. This study illustrates how innovative use of available, free and low-cost technology can produce a ‘positive disruption’ in higher education instruction.
How often precipitation records break?
Papalexiou, Simon Michael; Oikonomou, Maria; Floutsakou, Athina; Bessas, Nikolaos; Mamassis, Nikos
2016-04-01
How often precipitation records break? Are there any factors that determine the average time needed for the next maximum to occur? In order to investigate these simple questions we use several hundreds of daily precipitation records (more than 100 years long each) and we study the time intervals between each successive maximum precipitation value. We investigate if the record breaking time interval is related (a) to the autocorrelation structure, (b) to probability dry, and (c) to the tail of the marginal distribution. For the last, we first, evaluate which type of tail is better fitted by choosing among three general types of tails corresponding to the distributions Pareto, Lognormal and Weibull; and second, we assess the heaviness of the tail based on the estimated shape parameter. The performance of each tail is evaluated in terms of return period values, i.e., we compare the empirical return periods of precipitation values above a threshold with the predicted ones by each of the three types of fitted tails.
Improved single sector supersymmetry breaking
Energy Technology Data Exchange (ETDEWEB)
Luty, Markus A.; Terning, John
1998-12-09
Building on recent work by N. Arkani-Hamed and the present authors, we construct realistic models that break supersymmetry dynamically and give rise to composite quarks and leptons, all in a single strongly-coupled sector. The most important improvement compared to earlier models is that the second-generation composite states correspond to dimension-2 ''meson'' operators in the ultraviolet. This leads to a higher scale for flavor physics, and gives a completely natural suppression of flavor-changing neutral currents. We also construct models in which the hierarchy of Yukawa couplings is explained by the dimensionality of composite states. These models provide an interesting and viable alternative to gravity- and gauge-mediated models. The generic signatures are unification of scalar masses with different quantum numbers at the compositeness scale, and lighter gaugino, Higgsino, and third-generation squark and slepton masses. We also analyze large classes of models that give rise to both compositeness and supersymmetry breaking, based on gauge theories with confining, fixed-point, or free-magnetic dynamics.
Strictly Anomaly Mediated Supersymmetry Breaking
Hindmarsh, Mark
2012-01-01
We consider an MSSM extension with anomaly mediation as the source of supersymmetry-breaking, and a U(1) symmetry which solves the tachyonic slepton problem, and introduces both the see-saw mechanism for neutrino masses, and the Higgs mu-term. We compare its spectra with those from so-called minimal anomaly mediated supersymmetry breaking. We find a Standard Model-like Higgs of mass 124 GeV with a gravitino mass of 120 TeV and tan(beta)=17, while a contribution to the muon anomalous magnetic moment within 2 sigma of the discrepancy between Standard Model theory and experiment favours a slightly lower gravitino mass of around 80 TeV. The model naturally produces a period of hybrid inflation, with exit to a false vacuum characterised by large Higgs vevs, the true ground state being achieved after a period of thermal inflation. The scalar spectral index is reduced to approximately 0.975, and the correct abundance of dark matter can be produced by decays of thermally-produced gravitinos, provided the gravitino ma...
Introduction to Electroweak Symmetry Breaking
Energy Technology Data Exchange (ETDEWEB)
Dawson,S.
2008-10-02
The Standard Model (SM) is the backbone of elementary particle physics-not only does it provide a consistent framework for studying the interactions of quark and leptons, but it also gives predictions which have been extensively tested experimentally. In these notes, I review the electroweak sector of the Standard Model, discuss the calculation of electroweak radiative corrections to observables, and summarize the status of SM Higgs boson searches. Despite the impressive experimental successes, however, the electroweak theory is not completely satisfactory and the mechanism of electroweak symmetry breaking is untested. I will discuss the logic behind the oft-repeated statement: 'There must be new physics at the TeV scale'. These lectures reflect my strongly held belief that upcoming results from the LHC will fundamentally change our understanding of electroweak symmetry breaking. In these lectures, I review the status of the electroweak sector of the Standard Model, with an emphasis on the importance of radiative corrections and searches for the Standard Model Higgs boson. A discussion of the special role of the TeV energy scale in electroweak physics is included.
Chiral symmetry breaking and monopoles
Di Giacomo, Adriano; Pucci, Fabrizio
2015-01-01
To understand the relation between the chiral symmetry breaking and monopoles, the chiral condensate which is the order parameter of the chiral symmetry breaking is calculated in the $\\overline{\\mbox{MS}}$ scheme at 2 [GeV]. First, we add one pair of monopoles, varying the monopole charges $m_{c}$ from zero to four, to SU(3) quenched configurations by a monopole creation operator. The low-lying eigenvalues of the Overlap Dirac operator are computed from the gauge links of the normal configurations and the configurations with additional monopoles. Next, we compare the distributions of the nearest-neighbor spacing of the low-lying eigenvalues with the prediction of the random matrix theory. The low-lying eigenvalues not depending on the scale parameter $\\Sigma$ are compared to the prediction of the random matrix theory. The results show the consistency with the random matrix theory. Thus, the additional monopoles do not affect the low-lying eigenvalues. Moreover, we discover that the additional monopoles increa...
Van den Ende, D.; Almeida, P.M.R.; Dingemans, T.J.; Van der Zwaag, S.
2007-01-01
The invention relates to a load sensor comprising a polymer matrix and a piezo-ceramic material such as PZT, em not bedded in the polymer matrix, which together form a compos not ite, wherein the polymer matrix is a liquid crystalline resin, and wherein the piezo-ceramic material is a PZT powder for
Csernus, Marilyn
Carbohydrate loading is a frequently used technique to improve performance by altering an athlete's diet. The objective is to increase glycogen stored in muscles for use in prolonged strenuous exercise. For two to three days, the athlete consumes a diet that is low in carbohydrates and high in fat and protein while continuing to exercise and…
Directory of Open Access Journals (Sweden)
F. Paredes
2012-01-01
Full Text Available It is shown that printed antennas loaded with metamaterial resonators can be designed to exhibit multiband functionality. Two different antenna types and metamaterial loading are considered: (i printed dipoles or monopoles loaded with open complementary split ring resonators (OCSRRs and (ii meander line or folded dipole antennas loaded with split ring resonators (SRRs or spiral resonators (SRs. In the first case, multiband operation is achieved by series connecting one or more OCSRRs within the dipole/monopole. Such resonators force opens at their positions, and by locating them at a quarter wavelength (at the required operating frequencies from the feeding point, it is possible to achieve multiple radiation bands. In the second case, dual-band functionality is achieved through the perturbation of the antenna characteristics caused by the presence of the metamaterial resonators. This latter strategy is specially suited to achieve conjugate matching between the antenna and the chip in radiofrequency identification (RFID tags at two of the regulated UHF-RFID bands.
Symmetry-breaking transitions in networks of nonlinear circuit elements
Energy Technology Data Exchange (ETDEWEB)
Heinrich, Martin; Dahms, Thomas; Flunkert, Valentin; Schoell, Eckehard [Institut fuer Theoretische Physik, Technische Universitaet Berlin, 10623 Berlin (Germany); Teitsworth, Stephen W, E-mail: schoell@physik.tu-berlin.d [Department of Physics, Duke University, PO Box 90305, Durham, NC 27708-0305 (United States)
2010-11-15
We investigate a nonlinear circuit consisting of N tunnel diodes in series, which shows close similarities to a semiconductor superlattice or to a neural network. Each tunnel diode is modeled by a three-variable FitzHugh-Nagumo-like system. The tunnel diodes are coupled globally through a load resistor. We find complex bifurcation scenarios with symmetry-breaking transitions that generate multiple fixed points off the synchronization manifold. We show that multiply degenerate zero-eigenvalue bifurcations occur, which lead to multistable current branches, and that these bifurcations are also degenerate with a Hopf bifurcation. These predicted scenarios of multiple branches and degenerate bifurcations are also found experimentally.
Egeland, B; Jacobvitz, D; Sroufe, L A
1988-08-01
The aim of this study was to identify variables that distinguish mothers who broke the cycle of abuse from mothers who were abused as children and who also abused their own children. Based on maternal interviews and questionnaires completed over a 64-month period, measures of mothers' past and current relationship experiences, stressful life events, and personality characteristics were obtained. Abused mothers who were able to break the abusive cycle were significantly more likely to have received emotional support from a nonabusive adult during childhood, participated in therapy during any period of their lives, and to have had a nonabusive and more stable, emotionally supportive, and satisfying relationship with a mate. Abused mothers who reenacted their maltreatment with their own children experienced significantly more life stress and were more anxious, dependent, immature, and depressed. PMID:3168615
Z'-mediated supersymmetry breaking.
Langacker, Paul; Paz, Gil; Wang, Lian-Tao; Yavin, Itay
2008-02-01
We consider a class of models in which supersymmetry breaking is communicated dominantly via a U1' gauge interaction, which also helps solve the mu problem. Such models can emerge naturally in top-down constructions and are a version of split supersymmetry. The spectrum contains heavy sfermions, Higgsinos, exotics, and Z' approximately 10-100 TeV, light gauginos approximately 100-1000 GeV, a light Higgs boson approximately 140 GeV, and a light singlino. A specific set of U1' charges and exotics is analyzed, and we present five benchmark models. The implications for the gluino lifetime, cold dark matter, and the gravitino and neutrino masses are discussed. PMID:18352261
Dynamical centrosymmetry breaking in graphene
Carvalho, David N; Biancalana, Fabio
2016-01-01
We discover an unusual phenomenon that occurs when a graphene monolayer is illuminated by a short and intense pulse at normal incidence. Due to the pulse-induced oscillations of the Dirac cones, a dynamical breaking of the layer's centrosymmetry takes place, leading to the generation of second harmonic waves. We prove that this result can only be found by using the full Dirac equation and show that the widely used semiconductor Bloch equations fail to reproduce this and some other important physics of graphene. Our results open new windows in the understanding of nonlinear light-matter interactions in a wide variety of new 2D materials with a gapped or ungapped Dirac-like dispersion.
Symmetry Breaking in Finite Volume
Institute of Scientific and Technical Information of China (English)
LIU Chuan
2000-01-01
Spontaneous symmetry breaking is a cooperative phenomenon for systems with infinitely many degrees of freedom and it plays an essential role in quantum field theories. Lattice O(N) model is studied within the Hamiltonian approach using an adiabatic approximation. It is shown that the low-lying spectrum of the system in the broken phase can be understood by using the adiabatic, or Born-Oppenheimer approximation, which turns out to become an expansion in the inverse power of volume. In the infinite volume limit, the symmetry is broken while in the finite volume the slow rotation of the zero-momentum mode restores the symmetry and gives rise to the rotator spectrum, which has been observed in realistic Monte Carlo simulations.
Supersymmetry-breaking nonlinear sigma models
Energy Technology Data Exchange (ETDEWEB)
Imai, Takumi, E-mail: imai@yukawa.kyoto-u.ac.jp [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan); Izawa, K.-I. [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, University of Tokyo (WPI), Kashiwa 277-8583 (Japan); Nakai, Yuichiro [Department of Physics, Tohoku University, Sendai 980-8578 (Japan)
2012-10-22
We consider a novel class of constraints on chiral superfields to obtain supersymmetric nonlinear sigma models in four spacetime dimensions, which strictly combine the internal symmetry breaking with spontaneous supersymmetry breaking. The resultant massless modes can be exclusively Nambu-Goldstone bosons without their complex partners and the goldstino that is charged under the internal symmetry. The massive modes show a peculiar relation among their masses and the scales of symmetry breakings.
Mutual information and spontaneous symmetry breaking
Hamma, A.; Giampaolo, S. M.; Illuminati, F.
2015-01-01
We show that the metastable, symmetry-breaking ground states of quantum many-body Hamiltonians have vanishing quantum mutual information between macroscopically separated regions, and are thus the most classical ones among all possible quantum ground states. This statement is obvious only when the symmetry-breaking ground states are simple product states, e.g. at the factorization point. On the other hand, symmetry-breaking states are in general entangled along the entire ordered phase, and t...
van den Ende, D.; Almeida, P.M.R.; Dingemans, T.J.; Van der Zwaag, S.
2007-01-01
The invention relates to a load sensor comprising a polymer matrix and a piezo-ceramic material such as PZT, em not bedded in the polymer matrix, which together form a compos not ite, wherein the polymer matrix is a liquid crystalline resin, and wherein the piezo-ceramic material is a PZT powder forming 30-60% by volume of the composite, and wherein the PZT powder forms 40-50% by volume of the composite.
Duricic, J.; Erdik, T.; Pektas, A.O.; Van Gelder, P.H.A.J.M.
2013-01-01
The dam-break induced loads and their effects on buildings are of vital importance for assessing the vulnerability of buildings in flood-prone areas. A comprehensive methodology, for risk assessment of buildings subject to flooding, is nevertheless still missing. This research aims to take a step fo
On breaks of the Indian monsoon
Indian Academy of Sciences (India)
Sulochana Gadgil; P V Joseph
2003-12-01
For over a century, the term break has been used for spells in which the rainfall over the Indian monsoon zone is interrupted. The phenomenon of `break monsoon' is of great interest because long intense breaks are often associated with poor monsoon seasons. Such breaks have distinct circulation characteristics (heat trough type circulation) and have a large impact on rainfed agriculture.Although interruption of the monsoon rainfall is considered to be the most important feature of the break monsoon, traditionally breaks have been identified on the basis of the surface pressure and wind patterns over the Indian region. We have defined breaks (and active spells) on the basis of rainfall over the monsoon zone. The rainfall criteria are chosen so as to ensure a large overlap with the traditional breaks documented by Ramamurthy (1969) and De et al (1998). We have identified these rainbreaks for 1901-89. We have also identified active spells on the basis of rainfall over the Indian monsoon zone. We have shown that the all-India summer monsoon rainfall is significantly negatively correlated with the number of rainbreak days (correlation coefficient −0.56) and significantly positively correlated with the number of active days (correlation coefficient 0.47).Thus the interannual variation of the all-India summer monsoon rainfall is shown to be related to the number of days of rainbreaks and active spells identified here. There have been several studies of breaks (and also active spells in several cases) identified on the basis of different criteria over regions differing in spatial scales (e.g., Webster et al 1998; Krishnan et al 2000; Goswami and Mohan 2000; and Annamalai and Slingo 2001). We find that there is considerable overlap between the rainbreaks we have identified and breaks based on the traditional definition. There is some overlap with the breaks identified by Krishnan et al (2000) but little overlap with breaks identified by Webster et al (1998). Further
Beat eMeier; Zimmermann, Thomas D.
2015-01-01
In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load can affect prospective memory performance. The existence of multiple target events increases prospective load and adding complexity to the to-be-remembered action increases retrospective load. In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results s...
DNA Replication Reaches the Breaking Point
Petrini, John H.J.
2009-01-01
DNA strand breaks that result in stalled or damaged replication forks can be detrimental to the DNA replication process. In this issue, Doksani et al. (2009) examine the impact of a single double-stranded DNA break on replication in the budding yeast, Saccharomyces cerevisiae.
Four Top Production and Electroweak Symmetry Breaking
Cheung, Kingman
1995-01-01
With the recent discovery of a heavy top quark $(m_t \\approx 175 - 200$ GeV), the top quark opens an window to electroweak symmetry breaking. We propose the study of four-top, $t\\bar t t\\bar t$, production at hadronic supercolliders as a probe to electroweak symmetry breaking.
Anatomy of String Breaking in QCD
Prkacin, Z; Dussel, T; Lippert, T; Neff, H; Schilling, K; Prkacin, Zdravko; Bali, Gunnar S; Dussel, Thomas; Lippert, Thomas; Neff, Hartmut; Schilling, Klaus
2005-01-01
We investigate the string breaking mechanism in n_f=2 QCD. We discuss the lattice techniques used and present results on energy levels and mixing angle of the static BBbar|QbarQ two-state system. The string breaking is visualized, by means of an animation of the action density distribution as a function of the static colour source-antisource separation.
Electroweak Symmetry Breaking and the Higgs Boson
Pich, Antonio
2015-01-01
The first LHC run has confirmed the Standard Model as the correct theory at the electroweak scale, and the existence of a Higgs-like particle associated with the spontaneous breaking of the electroweak gauge symmetry. These lectures overview the present knowledge on the Higgs boson and discuss alternative scenarios of electroweak symmetry breaking which are already being constrained by the experimental data.
Charge-symmetry-breaking nucleon form factors
Kubis, Bastian
2009-01-01
A quantitative understanding of charge-symmetry breaking is an increasingly important ingredient for the extraction of the nucleon's strange vector form factors. We review the theoretical understanding of the charge-symmetry-breaking form factors, both for single nucleons and for Helium-4.
Miller, G A
2003-01-01
Two new experiments have detected charge-symmetry breaking, the mechanism responsible for protons and neutrons having different masses. Symmetry is a crucial concept in the theories that describe the subatomic world because it has an intimate connection with the laws of conservation. The theory of the strong interaction between quarks - quantum chromodynamics - is approximately invariant under what is called charge symmetry. In other words, if we swap an up quark for a down quark, then the strong interaction will look almost the same. This symmetry is related to the concept of sup i sospin sup , and is not the same as charge conjugation (in which a particle is replaced by its antiparticle). Charge symmetry is broken by the competition between two different effects. The first is the small difference in mass between up and down quarks, which is about 200 times less than the mass of the proton. The second is their different electric charges. The up quark has a charge of +2/3 in units of the proton charge, while ...
Automatic Prosodic Break Detection and Feature Analysis
Institute of Scientific and Technical Information of China (English)
Chong-Jia Ni; Ai-Ying Zhang; Wen-Ju Liu; Bo Xu
2012-01-01
Automatic prosodic break detection and annotation are important for both speech understanding and natural speech synthesis.In this paper,we discuss automatic prosodic break detection and feature analysis.The contributions of the paper are two aspects.One is that we use classifier combination method to detect Mandarin and English prosodic break using acoustic,lexical and syntactic evidence.Our proposed method achieves better performance on both the Mandarin prosodic annotation corpus — Annotated Speech Corpus of Chinese Discourse and the English prosodic annotation corpus —Boston University Radio News Corpus when compared with the baseline system and other researches' experimental results.The other is the feature analysis for prosodic break detection.The functions of different features,such as duration,pitch,energy,and intensity,are analyzed and compared in Mandarin and English prosodic break detection.Based on the feature analysis,we also verify some linguistic conclusions.
A laboratory study of breaking waves
Directory of Open Access Journals (Sweden)
Jaros³aw Têgowski
2004-09-01
Full Text Available This paper deals with some aspects of the wave-breaking phenomenon. The objectives were to study wave-breaking criteria, and the probability of whitecap coverage under fully controlled wave conditions. An additional task was to in vestigate the characteristic spectral features of the noise produced by breaking waves and the acoustic energy generated during wave breaking events. A controlled experiment was carried out in the Ocean Basin Laboratory at MARINTEK, Trondheim (Norway. Waves were generated by a computer-controlled multi-flap wave maker, which reproduced a realistic pattern of the sea surface for the prescribed spectra. Using wave staff recordings and photographic techniques, correlations between the breaking parameters and the radiated acoustic emissions were established.
Supersymmetry Breaking by Higher Dimension Operators
Farakos, Fotis; Kehagias, Alex; Porrati, Massimo
2014-01-01
We discuss a supersymmetry breaking mechanism for N = 1 theories triggered by higher dimensional op- erators. We consider such operators for real linear and chiral spinor superfields that break superymmetry and reduce to the Volkov-Akulov action. We also consider supersymmetry breaking induced by a higher dimensional operator of a nonminimal scalar (complex linear) multiplet. The latter differs from the stan- dard chiral multiplet in its auxiliary sector, which contains, in addition to the complex scalar auxiliary of a chiral superfield, a complex vector and two spinors auxiliaries. By adding an appropriate higher di- mension operator, the scalar auxiliary may acquire a nonzero vev triggering spontaneous supersymmetry breaking. We find that the spectrum of the theory in the supersymmetry breaking vacuum consists of a free chiral multiplet and a constraint chiral superfield describing the goldstino. Interestingly, the latter turns out to be one of the auxiliary fermions, which becomes dynamical in the supersym...
Research progress on dam-break floods
Wu, Jiansong
2011-08-01
Because of the catastrophic effects downstream of dam-break failure, more and more researchers around the world have been working on the study of dam-break flows to accurately forecast the downstream inundation mapping. With the rapid development of computer hardware and computing techniques, numerical study on dam-break flows has been a popular research subject. In the paper, the numerical methodologies used to solve the governing partial differential equations of dam-break flows are classified and summarized, and their characteristics and applications are discussed respectively. Furthermore, the fully-developed mathematical models developed in recent decades are reviewed, and also introduced the authors\\' on-going work. Finally, some possible future developments on modeling the dam-break flows and some solutions are presented and discussed. © 2011 IEEE.
Science Illiteracy: Breaking the Cycle
Lebofsky, L. A.; Lebofsky, N. R.
2003-12-01
At the University of Arizona, as at many state universities and colleges, the introductory science classes for non-science majors may be the only science classes that future K--8 teachers will take. The design of the UA's General Education program requires all future non-science certified teachers to take the General Education science classes. These classes are therefore an ideal venue for the training of the state's future teachers. Many students, often including future teachers, are ill-prepared for college, i.e., they lack basic science content knowledge, basic mathematics skills, and reading and writing skills. They also lack basic critical thinking skills and study skills. It is within this context that our future teachers are trained. How do we break the cycle of science illiteracy? There is no simple solution, and certainly not a one-size-fits-all panacea that complements every professor's style of instruction. However, there are several programs at the University of Arizona, and also principles that I apply in my own classes, that may be adaptable in other classrooms. Assessment of K--12 students' learning supports the use of inquiry-based science instruction. This approach can be incorporated in college classes. Modeling proven and productive teaching methods for the future teachers provides far more than ``just the facts,'' and all students gain from the inquiry approach. Providing authentic research opportunities employs an inquiry-based approach. Reading (outside the textbook) and writing provide feedback to students with poor writing and critical thinking skills. Using peer tutors and an instant messaging hot line gives experience to the tutors and offers "comfortable" assistance to students.
Breaking stress of neutron star crust
International Nuclear Information System (INIS)
Complete text of publication follows. The breaking stress (the maximum of the stress-strain curve) of neutron star crust is important for neutron star physics including pulsar glitches, emission of gravitational waves from static mountains, and flares from star quakes. We perform many molecular dynamic simulations of the breaking stress at different coupling parameters (inverse temperatures), strain rates and composition of matter. We describe our results with the Zhurkov model of strength. We apply this model to estimate the breaking stress for timescales ∼1 s - 1 year, which are most important for applications, but much longer than can be directly simulated. At these timescales the breaking stress depends strongly on the temperature. For coupling parameter Γ<200 matter breaks at very small stress, if it is applied for a few years. This viscoelastic creep can limit the lifetime of mountains on neutron stars. We also suggest an alternative model of timescale-independent breaking stress, which can be used to estimate an upper limit on the breaking stress. This work was partially supported by the Russian Foundation for Basic Research (grant 11-02-00253-a), by the State Program 'Leading Scientific Schools of Russian Federation' (grant NSh 3769.2010.2), by the President grant for young Russian scientists (MK-5857.2010.2), by United States DOE grant (DE-FG02-87ER40365) and by Shared University Research grants from IBM, Inc. to Indiana University.
Laguna Verde annulus pressurization loads evaluation
Energy Technology Data Exchange (ETDEWEB)
Castaneda, M. A.; Cruz, M. A.; Cardenas, J. B.; Vargas, A.; Cruz, H. J.; Mercado, J. J., E-mail: miguel.castaneda01@cfe.gob.m [Comision Federal de Electricidad, Central Nucleoelectrica de Laguna Verde, Km. 42.5 Carretera Cardel-Nautla, Veracruz (Mexico)
2010-10-15
Annulus pressurization, jet impingement, pipe whip restraint and jet thrust are phenomena related to postulated pipe ruptures. A postulated pipe rupture at the weld between recirculation, or feedwater piping and a reactor nozzle safe end, will lead to a high flow rate of flashing water/steam mixture into the annulus between the reactor pressure vessel and the biological shield wall. The total effect of the vessel and pipe inventory blowdown from the break being postulated must be accounted for in the evaluation. A recirculation line break will give rise to an angular dependent short term pressure differential around the vessel, followed by a longer term pressure buildup in the annulus. A recirculation line postulated rupture may not produce worst case conditions and reference to time intervals for only the recirculation break should be treated superficially. A postulated rupture of the feedwater piping may produce the extreme case for determining: 1) the shield wall and reactor vessel to pedestal interactions, 2) loading on the reactor vessel internals, or 3) responses for the balance of piping attached to the vessel. Recently it was identified a potential issue regarding the criteria used to determine which cases were evaluated for Annulus Pressurization (A P) loads for new loads plants. The original A P loads methodology in the late 1970 and early 1980 years separated the mass/energy release calculation from the structural response calculation based on the implicit assumption that the maximum overall mass/energy release will result in maximizing the structural response and corresponding stresses on the reactor pressure vessel, internals, and containment structures. This process did not consider the dynamic response in the primary and secondary safety related structures, components and equipment. Consequently, the A P loads used as input for design adequacy evaluations of Nuclear Steam Supply System safety related components for new loads plants might have
Dirac Neutrino Masses from Generalized Supersymmetry Breaking
International Nuclear Information System (INIS)
We demonstrate that Dirac neutrino masses in the experimentally preferred range are generated within supersymmetric gauge extensions of the standard model with a generalized supersymmetry breaking sector. If the superpotential neutrino Yukawa terms are forbidden by the gauge symmetry [such as a U(1)'], sub-eV scale effective Dirac mass terms can arise at tree level from hard supersymmetry breaking Yukawa couplings, or at one loop due to nonanalytic soft supersymmetry breaking trilinear scalar couplings. The radiative neutrino magnetic and electric dipole moments vanish at one-loop order
Search for primordial symmetry breakings in CMB
Shiraishi, Maresuke
2016-06-01
There are possibilities to violate symmetries (e.g. parity and rotational invariance) in the primordial cosmological fluctuations. Such symmetry breakings can imprint very rich signatures in late-time phenomena, which may be possible to observe. Especially, Cosmic Microwave Background (CMB) will change its face drastically, corresponding to the symmetry-breaking types, since the harmonic-space representation is very sensitive to the statistical, spin and angular dependences of cosmological perturbations. Here, we discuss (1) general responses of CMB to the symmetry breakings, (2) some theoretical models creating interesting CMB signatures, and (3) aspects of the estimation from observational data.
Computational modeling of ice cracking and break-up from helicopter blades
Shiping, Zhang
2012-06-25
In order to reduce the danger of impact onto components caused by break-up, it is important to analyze the shape of shed ice accumulated during flight. In this paper, we will present a 3D finite element method (FEM) to predict the shed ice shape by using a fluid-solid interaction (FSI) approach to determine the loads, and linear fracture mechanics to track crack propagation. Typical icing scenarios for helicopters are analyzed, and the possibility of ice break-up is investigated.
Formation of radiation-induced DNA breaks: the ratio of double-strand breaks to single-strand breaks
International Nuclear Information System (INIS)
Ionizing radiation causes the formation of strand breaks in cellular DNA, as well as other types of lesions in the chromatin of cells. Some of the earliest investigations of the molecular basis of radiation-induced damage and the implications of enzymatic repair were done by Dr. H. S. Kaplan. Because it is difficult to assay for DNA lesions in the large mammalian genome, the authors have developed a method of assaying for DNA double-strand breaks in the supercoiled nucleosome-complexed Simian virus 40 (SV40) genome, irradiated intracellularly. In this communication they present their measurements of the DNA double-strand breaks (DSBs) to single-strand breaks (SSBs) ratio obtained from the intracellularly irradiated SV40 genome. After cobalt gamma ray and X ray irradiations, this ratio is about 1/10. Their methods and results are compared with pertinent data in the literature. If the DSBs/SSBs ratio of 1/10 for cellular chromatin is correct, a substantial number of DNA double-strand breaks are formed in a mammalian cell after moderate doses (1 Gy) of radiation. The implications of different types of DNA double-strand breaks are discussed
Unconventional supersymmetry and its breaking
Energy Technology Data Exchange (ETDEWEB)
Alvarez, Pedro D., E-mail: alvarez@physics.ox.ac.uk [Centro de Estudios Científicos (CECS), Av. Arturo Prat 514, Valdivia (Chile); Universidad Andrés Bello, Av. República 440, Santiago (Chile); Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford (United Kingdom); Pais, Pablo, E-mail: pais@cecs.cl [Centro de Estudios Científicos (CECS), Av. Arturo Prat 514, Valdivia (Chile); Universidad Andrés Bello, Av. República 440, Santiago (Chile); Zanelli, Jorge, E-mail: z@cecs.cl [Centro de Estudios Científicos (CECS), Av. Arturo Prat 514, Valdivia (Chile); Universidad Andrés Bello, Av. República 440, Santiago (Chile)
2014-07-30
We present a gauge theory for a superalgebra that includes an internal gauge (G) and local Lorentz (so(1,D−1)) algebras. These two symmetries are connected by fermionic supercharges. The field content of the system includes a (non-)abelian gauge potential A, a spin-1/2 Dirac spinor ψ, the Lorentz connection ω{sup ab}, and the vielbein e{sub μ}{sup a}. The connection one-form A is in the adjoint representation of G, while ψ is in the fundamental. In contrast to standard supersymmetry and supergravity, the metric is not a fundamental field and is in the center of the superalgebra: it is not only invariant under the internal gauge group, G, and under Lorentz transformations, SO(1,D−1), but is also invariant under supersymmetry. The distinctive features of this theory that mark the difference with standard supersymmetries are: i) the number of fermionic and bosonic states is not necessarily the same; ii) there are no superpartners with equal mass; iii) although this supersymmetry originates in a local gauge theory and gravity is included, there is no gravitino; iv) fermions acquire mass from their coupling to the background or from higher order self-couplings, while bosons remain massless. In odd dimensions, the Chern–Simons (CS) form provides an action that is (quasi-)invariant under the entire superalgebra. In even dimensions, the Yang–Mills (YM) form is the only natural option and the symmetry breaks down to G⊗SO(1,D−1). In four dimensions, the construction follows the Townsend–Mac Dowell–Mansouri approach, starting with an osp(4|2)∼usp(2,2|1) connection. Due to the absence of osp(4|2)-invariant traces in four dimensions, the resulting Lagrangian is only invariant under u(1)⊕so(3,1), which includes a Nambu–Jona-Lasinio (NJL) term. In this case, the Lagrangian depends on a single dimensionful parameter that fixes Newton's constant, the cosmological constant and the NJL coupling.
Fibre break failure processes in unidirectional composites: evaluation of critical damage states.
Thionnet, A; Bunsell, A R
2016-07-13
Earlier work which successfully modelled the kinetics of fibre breakage in unidirectional composites under monotonic tensile loading has been extended to quantify the kinetics of fibre failure during both monotonic and sustained tensile loading. In both cases, failure was seen to occur when a critical density of large clusters (more than 16 fibres are broken within the representative volume element) of fibre breaks developed. However, in monotonic loading failure occurred very quickly after the first development of these large clusters, whereas under sustained loading the composite could accommodate greater levels of large clusters because of the lower applied load. This article is part of the themed issue 'Multiscale modelling of the structural integrity of composite materials'. PMID:27242295
Properties of fiber reinforced plastics about static and dynamic loadings
Kudinov, Vladimir V.; Korneeva, Natalia V.
2016-05-01
A method for investigation of impact toughness of anisotropic polymer composite materials (reinforced plastics) with the help of CM model sample in the configuration of microplastic (micro plastic) and impact pendulum-type testing machine under static and dynamic loadings has been developed. The method is called "Break by Impact" (Impact Break IB). The estimation of impact resistance CFRP by this method showed that an increase in loading velocity ~104 times the largest changes occurs in impact toughness and deformation ability of a material.
Dirac Neutrino Masses from Generalized Supersymmetry Breaking
Demir, Durmus A; Langacker, Paul
2007-01-01
We demonstrate that Dirac neutrino masses in the experimentally preferred range are generated within supersymmetric gauge extensions of the Standard Model with a generalized supersymmetry breaking sector. If the usual superpotential Yukawa couplings are forbidden by the additional gauge symmetry (such as a U(1)'), effective Dirac mass terms involving the "wrong Higgs" field can arise either at tree level due to hard supersymmetry breaking fermion Yukawa couplings, or at one-loop due to nonanalytic or "nonholomorphic" soft supersymmetry breaking trilinear scalar couplings. As both of these operators are naturally suppressed in generic models of supersymmetry breaking, the resulting neutrino masses are naturally in the sub-eV range. The neutrino magnetic and electric dipole moments resulting from the radiative mechanism also vanish at one-loop order.
Spontaneous chiral symmetry breaking in metamaterials
Liu, Mingkai; Powell, David A.; Shadrivov, Ilya V.; Lapine, Mikhail; Kivshar, Yuri S.
2014-07-01
Spontaneous chiral symmetry breaking underpins a variety of areas such as subatomic physics and biochemistry, and leads to an impressive range of fundamental phenomena. Here we show that this prominent effect is now available in artificial electromagnetic systems, enabled by the advent of magnetoelastic metamaterials where a mechanical degree of freedom leads to a rich variety of strong nonlinear effects such as bistability and self-oscillations. We report spontaneous symmetry breaking in torsional chiral magnetoelastic structures where two or more meta-molecules with opposite handedness are electromagnetically coupled, modifying the system stability. Importantly, we show that chiral symmetry breaking can be found in the stationary response of the system, and the effect is successfully demonstrated in a microwave pump-probe experiment. Such symmetry breaking can lead to a giant nonlinear polarization change, energy localization and mode splitting, which provides a new possibility for creating an artificial phase transition in metamaterials, analogous to that in ferrimagnetic domains.
Detecting Structural Breaks using Hidden Markov Models
DEFF Research Database (Denmark)
Ntantamis, Christos
Testing for structural breaks and identifying their location is essential for econometric modeling. In this paper, a Hidden Markov Model (HMM) approach is used in order to perform these tasks. Breaks are defined as the data points where the underlying Markov Chain switches from one state to anoth...... in the monetary policy of United States, the dierent functional form being variants of the Taylor (1993) rule.......Testing for structural breaks and identifying their location is essential for econometric modeling. In this paper, a Hidden Markov Model (HMM) approach is used in order to perform these tasks. Breaks are defined as the data points where the underlying Markov Chain switches from one state to another....... The estimation of the HMM is conducted using a variant of the Iterative Conditional Expectation-Generalized Mixture (ICE-GEMI) algorithm proposed by Delignon et al. (1997), that permits analysis of the conditional distributions of economic data and allows for different functional forms across regimes...
Dirac Neutrino Masses from Generalized Supersymmetry Breaking
Demir, Durmus A.; Everett, Lisa L.; Langacker, Paul
2007-01-01
We demonstrate that Dirac neutrino masses in the experimentally preferred range are generated within supersymmetric gauge extensions of the Standard Model with a generalized supersymmetry breaking sector. If the usual superpotential Yukawa couplings are forbidden by the additional gauge symmetry (such as a U(1)'), effective Dirac mass terms involving the "wrong Higgs" field can arise either at tree level due to hard supersymmetry breaking fermion Yukawa couplings, or at one-loop due to nonana...
Grand unification with large supersymmetry breaking
International Nuclear Information System (INIS)
General criteria are given for the magnitudes of mass splittings between supersymmetric partners compatible with the desired hierarchy of mass scales in GUTs. These splittings arise naturally when masses are generated radiatively from a Higgs sector breaking supersymmetry through the O'Raifeartaigh mechanism (Nucl. Phys; B96:331 (1975)). Explicit GUTs are constructed in which the supersymmetry breaking scale may easily be as large as the Planck mass. (author)
Yet another symmetry breaking to be discovered
Yoshimura, M.
2016-07-01
The discovery of spontaneous symmetry breaking in particle physics was the greatest contribution in Nambu's achievements. There is another class of symmetries that exist in low-energy nature, yet is doomed to be broken at high energy, due to a lack of protection of the gauge symmetry. I shall review our approach to searching for this class of symmetry breaking, the lepton number violation linked to the generation of the matter-antimatter asymmetry in our universe.
Breaking antidunes: Cyclic behavior due to hysteresis
DEFF Research Database (Denmark)
Deigaard, Rolf
2006-01-01
The cyclic behavior of breaking antidunes (growth, breaking of surface wave, obliteration) is investigated by use of a numerical model. The model includes the transition between supercritical and transcritical flow. As the antidune grows the flow becomes transcritical and a hydraulic jump is form...... upstream of the antidune crest. The relation between growth of the antidune and supercritical flow and between decay and transcritical flow is shown, and the significance of hysteresis in the flow conditions is investigated....
Chimera Death: Symmetry Breaking in Dynamical Networks
Zakharova, Anna; Kapeller, Marie; Schöll, Eckehard
2014-01-01
For a network of generic oscillators with nonlocal topology and symmetry-breaking coupling we establish novel partially coherent inhomogeneous spatial patterns, which combine the features of chimera states (coexisting incongruous coherent and incoherent domains) and oscillation death (oscillation suppression), which we call chimera death. We show that due to the interplay of nonlocality and breaking of rotational symmetry by the coupling two distinct scenarios from oscillatory behavior to a s...
A random fuse model for breaking processes
de Arcangelis, L.; Redner, S.; Herrmann, H. J.
1985-01-01
We introduce and study a simple idealized model to describe breaking processes by analysing the current-carrying properties of a random network consisting of insulators and fuses. By increasing the value of the external voltage applied across the network, a sequence of fuses will « burn out » and change irreversible into insultating bonds. This process terminates when a conducting path no longer exists in the network. We monitor several basic quantities during this breaking process, such as t...
Relativistic theory of string breaking in QCD
Simonov, Yu A
2011-01-01
The QCD string breaking due to quark pair creation in the vacuum confining field, possibly accompanied by vector, scalar or Nambu-Goldstone bosons, is studied nonperturbatively. The scalar light pair creation vertex occurs due to chiral symmetry breaking and has a confining form, which is computed explicitly together with subleading vector contributions. Dependence on light quark mass and flavor is specifically studied. The dominant scalar term is in good agreement with the $^3P_0$ model and experimental data.
Breaking away to South America
Anaïs Schaeffer
2011-01-01
In December 2010, Peter Dreesen of CERN’s Technology Department (TE) returned from a long trip to South America. In four months he traversed the entire Andean range, from the equator to a latitude of 55 degrees south—on a bicycle! Peter Dreesen on the Salar de Uyuni Lake, Bolivia. 11 000 kilometres is one long bike ride! And yet, that’s what Peter Dreesen did, travelling from Quito, Ecuador to Ushuaia, Argentina. Peter, an engineer in the TE Department, is no novice: the year before, he cycled from Paris to Peking, a distance of 13 500 kilometres, in just over four months. His latest voyage began last August, when he loaded his bicycle and boarded a plane for South America. In the saddle. After a week of acclimatisation at three thousand metres altitude, Peter left Quito on 6 August 2010. He arrived in Ushuaia (el fin del mundo, the end of the world, as it’s known in South America) on 12 December 2010. He recounts: “It was a bizarre sensation...
Breaking of waves in deep water
Ruiz-Chavarria, Gerardo
2013-11-01
The breaking of waves is a nonlinear phenomenon during which a fraction of the energy is dissipated. In the previous stage the wave undergoes a growth of its amplitude and the wave pattern is modified in the sense that the crests become more pronounced than the troughs. The breaking has been extensively studied in the case of waves approaching the shore. However, the wave breaking in deep water remains an open problem in fluid dynamics. In this work we study the wave breaking due to focusing of an initially parabolic wave front. To this end the evolution of wave is numerically investigated using a meshless code (Smoothed Particle Hydrodynamics). We present some results about the evolution of waves excited by a parabolic wave maker, among others, the growth induced by the focusing, the behavior around the Huygens' cusp and the process of wave breaking. Then, we compare the numerical results with the criteria given in the literature about the onset of breaking and we discuss how the energy dissipates, for example by the rise of short waves. In addition we compare the numerical results with data obtained in two different experiments made by our team. Author acknowledges DGAPA-UNAM by support under project IN116312, ``Vorticidad y ondas no lineales en fluidos.''
CP breaking in lattice chiral gauge theories
International Nuclear Information System (INIS)
The CP symmetry is not manifestly implemented for the local and doubler-free Ginsparg-Wilson operator in lattice chiral gauge theory. We precisely identify where the effects of this CP breaking appear. We show that they appear in: (I) Overall constant phase of the fermion generating functional. (II) Overall constant coefficient of the fermion generating functional. (III) Fermion propagator appearing in external fermion lines and the propagator connected to Yukawa vertices. The first effect appears from the transformation of the path integral measure and it is absorbed into a suitable definition of the constant phase factor for each topological sector; in this sense there appears no 'CP anomaly'. The second constant arises from the explicit breaking in the action and it is absorbed by the suitable weights with which topological sectors are summed. The last one in the propagator is inherent to this formulation and cannot be avoided by a mere modification of the projection operator, for example, in the framework of the Ginsparg-Wilson operator. This breaking emerges as an (almost) contact term in the propagator when the Higgs field, which is treated perturbatively, has no vacuum expectation value. In the presence of the vacuum expectation value, however, a completely new situation arises and the breaking becomes intrinsically non-local, though this breaking may still be removed in a suitable continuum limit. This non-local CP breaking is expected to persist for a non-perturbative treatment of the Higgs coupling. (author)
Loading rate effects on the fracture of Ni/Au nano-coated acrylic particles
Zhang, Z. L.; He, J. Y.; Nagao, S; Kristiansen, H.
2012-01-01
Mechanical failure of monodisperse Ni/Au coated acrylic particles has been investigated by individual compression tests using nanoindentation-based technique equipped with a flat diamond punch. We have found that both fracture property and morphology of particles depend on the compression loading rate. The breaking strain of the metal coating decreases with increasing loading rate, while the breaking stress increases. Two obvious fracture patterns with cracking in meridian or latitude directi...
Directory of Open Access Journals (Sweden)
Beat eMeier
2015-06-01
Full Text Available In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load can affect prospective memory performance. The existence of multiple target events increases prospective load and adding complexity to the to-be-remembered action increases retrospective load. In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of prospective load on costs in the ongoing task for categorical targets (Experiment 2, but not for specific targets (Experiment 1. Retrospective load and ongoing task load both affected remembering the retrospective component of the prospective memory task. We suggest that prospective load can enhance costs in the ongoing task due to additional monitoring requirements. Retrospective load and ongoing task load seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially.
Break-in and Performance Issues on a single cell PBI-based PEM Fuel Cell
DEFF Research Database (Denmark)
Kær, Søren Knudsen; Jespersen, Jesper Lebæk
Depending on the application in question and the load cycle of operation, fuel cell degradation can be a serious problem. Fuel cell degradation of PBI-based MEA's and fuel cells in general is quite complex. The rate of degradation depends on several parameters, where the operating temperature...... and the current drawn from the fuel cell are of great importance. One must therefore choose the point of operation carefully in order for the fuel cell to fulfil the requirements for lifetime perform-ance of the system. Break-in of fuel cells is often done in scientific experiments to improve the performance...... of the fuel cell, even though break-in of a fuel cell implemented in a commercial application would most likely not be feasible. In the present work a commercially available PBI-based high temperature MEA is subject to a break-in procedure, as specified by the manufacturer. The cell was operated at 160 °C...
Experimental and Fe Analysis of Eccentric Loaded Welded Joint Structure
Directory of Open Access Journals (Sweden)
Harish N. Sayankar
2014-08-01
Full Text Available Arc welded structures are widely used in automobiles, constructions & power plants. As the main cause of weldment failure is design defect & overload, hence it is necessary to analyze the maximum stresses in the weldment. In this project experimentation is carried out on symmetrical and unsymmetrical eccentric loaded welded joint to determine the breaking stress in the weldment. The FE analysis & analytical estimation of breaking stress is also carried out to verify the experimental results. The stress distribution along weld size & throat thickness is evaluated and also compared with reported findings under same loading condition. Further eccentric loaded welded joint is analyzed under eccentric load by varying the gap between parent plates.
Replacement divider plate performance under LOCA loading
Energy Technology Data Exchange (ETDEWEB)
Huynk, H.M. [Quebec Hydro, Montreal, PQ (Canada); MClellan, G.H.; Schneider, W.G. [Babcock and Wilcox, Cambridge, ON (Canada)
1997-07-01
A primary divider plate in a nuclear steam generator is required to perform its partitioning function with a minimum of cross leakage, without degradation in operating performance and without loss of structural integrity resulting from normal and accident loading. The design of the replacement divider plate for normal operating conditions is discussed in some detail in reference 1 and 2. This paper describes the structural response of the replacement divider plate to the severe loading resulting from a burst primary pipe. The loads for which the divider plate structural performance must be evaluated are mild to severe differential pressure transients resulting from several postulated sizes and types of pipe break scenarios. In the unlikely event of a severe Loss of Coolant Accident (LOCA) the divider plate or parts thereof must not exit the steam generator nor completely block the outlet nozzle. For the milder LOCA loads, the integrity of the divider plate and seat bars must be maintained. Analysis for the milder LOCA loads was carried out employing a conservative approach which ignores the actual interaction between the structure and the primary fluid. For these load cases it was shown that the divider plate does not become disengaged from the seat bars. For the more severe pipe breaks, the thermal-hydraulic analysis was coupled iteratively with the structural analysis, thereby taking into account divider plate deformation, in order to obtain a better prediction of the behaviour of the divider plate. In this manner substantial reduction in divider plate response to the more severe LOCA loading was achieved. It has been shown that, for the case of a postulated large LOCA (100% reactor inlet header), the disengagement of the divider plate from the seat bars resulted in an opening smaller than 1% of the divider plate area. (author)
Modelling oil price volatility with structural breaks
International Nuclear Information System (INIS)
In this paper, we provide two main innovations: (i) we analyze oil prices of two prominent markets namely West Texas Intermediate (WTI) and Brent using the two recently developed tests by Narayan and Popp (2010) and Liu and Narayan, 2010 both of which allow for two structural breaks in the data series; and (ii) the latter method is modified to include both symmetric and asymmetric volatility models. We identify two structural breaks that occur in 1990 and 2008 which coincidentally correspond to the Iraqi/Kuwait conflict and the global financial crisis, respectively. We find evidence of persistence and leverage effects in the oil price volatility. While further extensions can be pursued, the consideration of asymmetric effects as well as structural breaks should not be jettisoned when modelling oil price volatility. - Highlights: ► We analyze oil price volatility using NP (2010) and LN (2010) tests. ► We modify the LN (2010) to account for leverage effects in oil price. ► We find two structural breaks that reflect major global crisis in the oil market. ► We find evidence of persistence and leverage effects in oil price volatility. ► Leverage effects and structural breaks are fundamental in oil price modelling.
A break in the obesity epidemic?
DEFF Research Database (Denmark)
Visscher, T L S; Heitmann, B L; Rissanen, A;
2015-01-01
Recent epidemiologic papers are presenting prevalence data suggesting breaks and decreases in obesity rates. However, before concluding that the obesity epidemic is not increasing anymore, the validity of the presented data should be discussed more thoroughly. We had a closer look into the litera......Recent epidemiologic papers are presenting prevalence data suggesting breaks and decreases in obesity rates. However, before concluding that the obesity epidemic is not increasing anymore, the validity of the presented data should be discussed more thoroughly. We had a closer look...... into the literature presented in recent reviews to address the major potential biases and distortions, and to develop insights about how to interpret the presented suggestions for a potential break in the obesity epidemic. Decreasing participation rates, the use of reported rather than measured data and small sample...... sizes, or lack of representativeness, did not seem to explain presented breaks in the obesity epidemic. Further, available evidence does not suggest that stabilization of obesity rates is seen in higher socioeconomic groups only, or that urbanization could explain a potential break in the obesity...
Chiral symmetry and chiral-symmetry breaking
Energy Technology Data Exchange (ETDEWEB)
Peskin, M.E.
1982-12-01
These lectures concern the dynamics of fermions in strong interaction with gauge fields. Systems of fermions coupled by gauge forces have a very rich structure of global symmetries, which are called chiral symmetries. These lectures will focus on the realization of chiral symmetries and the causes and consequences of thier spontaneous breaking. A brief introduction to the basic formalism and concepts of chiral symmetry breaking is given, then some explicit calculations of chiral symmetry breaking in gauge theories are given, treating first parity-invariant and then chiral models. These calculations are meant to be illustrative rather than accurate; they make use of unjustified mathematical approximations which serve to make the physics more clear. Some formal constraints on chiral symmetry breaking are discussed which illuminate and extend the results of our more explicit analysis. Finally, a brief review of the phenomenological theory of chiral symmetry breaking is presented, and some applications of this theory to problems in weak-interaction physics are discussed. (WHK)
Electrical load detection aparatus
DEFF Research Database (Denmark)
2010-01-01
A load detection technique for a load comprising multiple frequency-dependant sub-loads comprises measuring a representation of the impedance characteristic of the load; providing stored representations of a multiplicity of impedance characteristics of the load; each one of the stored representat...
Ontario Hydro's leak-before-break approach to Darlington NGS heat transport system piping
International Nuclear Information System (INIS)
The primary objective in our Leak-Before-Break studies is to show how a rational and comprehensive approach can provide an adequate measure of confidence in the assessment of piping integrity such that provision of design features (viz. pipewhip restraints, jet impingement shields) to protect against the dynamic effects of pipe rupture is not necessary. This study is one component of the overall Leak-Before-Break approach adopted at Ontario Hydro. The results of a review undertaken to evaluate the system transients or events sequences which may subject the piping to a potentially significant increase in loadings are reported. The focus in this paper is to show the approach used in deriving loadings for use in the elastic-plastic fracture mechanics analyses required to demonstrate crack stability. (author)
Enhanced breaking of heavy quark spin symmetry
Guo, Feng-Kun; Shen, Cheng-Ping
2014-01-01
Heavy quark spin symmetry is useful to make predictions on ratios of decay or production rates of systems involving heavy quarks. The breaking of spin symmetry is generally of the order of $O({\\Lambda_{\\rm QCD}/m_Q})$, with $\\Lambda_{\\rm QCD}$ the scale of QCD and $m_Q$ the heavy quark mass. In this paper, we propose a new mechanism to enhance the spin symmetry breaking. Taking the decays of the $\\Upsilon(10860)$ into the $\\chi_{bJ}\\omega\\, (J=0,1,2)$ as an example, we show that a small $S$- and $D$-wave mixing can induce a significant breaking of the spin symmetry relations for the ratios of the branching fractions of these decays, owing to an enhancement of the decays of the $D$-wave component due to nearby coupled channels.
Supersymmetry breaking induced by radiative corrections
Bajc, Borut; Mede, Timon
2012-01-01
We show that simultaneous gauge and supersymmetry breaking can be induced by radiative corrections, a la Coleman-Weinberg. A local supersymmetry-breaking minimum is induced in the effective potential of a gauge non-singlet field, in a region where the tree-level potential is almost flat. Supersymmetry breaking is then transmitted to the MSSM through gauge and chiral messenger loops, thus avoiding the suppression of gaugino masses characteristic of direct gauge mediation models. The use of a single field ensures that no dangerous tachyonic scalar masses are generated at the one-loop level. We illustrate this mechanism with an explicit example based on an SU(5) model with a single adjoint. An interesting feature of the scenario is that the GUT scale is increased with respect to standard unification, thus allowing for a larger colour Higgs triplet mass, as preferred by the experimental lower bound on the proton lifetime.
Multiscale Simulation of Breaking Wave Impacts
DEFF Research Database (Denmark)
Lindberg, Ole
errors in the fluid volume. The dam break test case shows that the incompressible and inviscid ALE-WLS model can calculate nonlinear fluid motion, fluid structure impacts and overturning waves. The propagation speed of the wetting front and impact pressures are compared to experiments and the results......The purpose of this project is to make an accurate, robust, geometric flexible and efficient model for calculation of forces on structures from nonlinear ocean waves and breaking wave impacts. Accurate prediction of the extreme forces on wind turbine foundations, breakwaters and tidal or wave power......-distance based adaptivity method and redistributed via a point position filtering method. The incompressible and inviscid ALE-WLS model is applied to the following standard validation test cases: deforming elliptical drop, small amplitude standing waves and the dam break problem. The deforming elliptical drop...
U(1) mediation of flux supersymmetry breaking
International Nuclear Information System (INIS)
We study the mediation of supersymmetry breaking triggered by background fluxes in Type II string compactifications with N = 1 supersymmetry. The mediation arises due to an U(1) vector multiplet coupling to both a hidden supersymmetry breaking flux sector and a visible D-brane sector. The required internal manifolds can be constructed by non-Kaehler resolutions of singular Calabi-Yau manifolds. The effective action encoding the U(1) coupling is then determined in terms of the global topological properties of the internal space. We investigate suitable local geometries for the hidden and visible sector in detail. This includes a systematic study of orientifold symmetries of del Pezzo surfaces realized in compact geometries after geometric transition. We construct compact examples admitting the key properties to realize flux supersymmetry breaking and U(1) mediation. Their toric realization allows us to analyze the geometry of curve classes and confirm the topological connection between the hidden and visible sector.
Workshop on electroweak symmetry breaking: proceedings
Energy Technology Data Exchange (ETDEWEB)
Hinchliffe, I. (ed.)
1984-10-01
A theoretical workshop on electroweak symmetry breaking at the Superconducting Supercollider was held at Lawrence Berkeley Laboratory, June 4-22, 1984. The purpose of the workshop was to focus theoretical attention on the ways in which experimentation at the SSC could reveal manifestations of the phenomenon responsible for electroweak symmetry breaking. This issue represents, at present, the most compelling scientific argument for the need to explore the energy region to be made accessible by the SSC, and a major aim of the workshop was to involve a broad cross section of particle theorists in the ongoing process of sharpening the requirements for both accelerator and detector design that will ensure detection and identification of meaningful signals, whatever form the electroweak symmetry breaking phenomenon should actually take. Separate entries were prepared for the data base for the papers presented.
Break-glass handling exceptional situations in access control
Petritsch, Helmut
2014-01-01
Helmut Petritsch describes the first holistic approach to Break-Glass which covers the whole life-cycle: from access control modeling (pre-access), to logging the security-relevant system state during Break-Glass accesses (at-access), and the automated analysis of Break-Glass accesses (post-access). Break-Glass allows users to override security restrictions in exceptional situations. While several Break-Glass models specific to given access control models have already been discussed in research (e.g., extending RBAC with Break-Glass), the author introduces a generic Break-Glass model. The pres
Institute of Scientific and Technical Information of China (English)
谭青; 张桂菊; 夏毅敏; 李建芳
2015-01-01
In order to study rock breaking characteristics of tunnel boring machine (TBM) disc cutter at different rock temperatures, thermodynamic rock breaking mathematical model of TBM disc cutter was established on the basis of rock temperature change by using particle flow code theory and the influence law of interaction mechanism between disc cutter and rock was also numerically simulated. Furthermore, by using the linear cutting experiment platform, rock breaking process of TBM disc cutter at different rock temperatures was well verified by the experiments. Finally, rock breaking characteristics of TBM disc cutter were differentiated and analyzed from microscale perspective. The results indicate the follows. 1) When rock temperature increases, the mechanical properties of rock such as hardness, and strength, were greatly reduced, simultaneously the microcracks rapidly grow with the cracks number increasing, which leads to rock breaking load decreasing and improves rock breaking efficiency for TBM disc cutter. 2) The higher the rock temperature, the lower the rock internal stress. The stress distribution rules coincide with the Buzin Neske stress circle rules: the maximum stress value is below the cutting edge region and then gradually decreases radiant around; stress distribution is symmetrical and the total stress of rock becomes smaller. 3) The higher the rock temperature is, the more the numbers of micro, tensile and shear cracks produced are by rock as well as the easier the rock intrusion, along with shear failure mode mainly showing. 4) With rock temperature increasing, the resistance intrusive coefficients of rock and intrusion power decrease obviously, so the specific energy consumption that TBM disc cutter achieves leaping broken also decreases subsequently. 5) The acoustic emission frequency remarkably increases along with the temperature increasing, which improves the rock breaking efficiency.
Breaking bad news in cancer patients
Directory of Open Access Journals (Sweden)
Apostolos Konstantis
2015-01-01
Full Text Available Objective: In a regional hospital, many patients are newly diagnosed with cancer. Breaking the bad news in these patients and their relatives is a tough task. Many doctors are not experienced in talking to patients about death or death-related diseases. In recent years, there have been great efforts to change the current situation. The aim of this study was to investigate the experience and education of medical personnel in breaking bad news in a secondary hospital. Materials and Methods: 59 doctors from General Hospital of Komotini, Greece were included in the study. All the doctors were in clinical specialties that treated cancer patients. A brief questionnaire was developed based on current guidelines such as Baile/SPIKES framework and the ABCDE mnemonic. Results: Residents are involved in delivering bad news less frequently than specialists. Only 21 doctors (35.59% had specific training on breaking bad news. 20 doctors (33.90% were aware of the available techniques and protocols on breaking bad news. 47 doctors (79.66% had a consistent plan for breaking bad news. 57 (96.61% delivered bad news in a quiet place, 53 (89.83% ensured no interruptions and enough time, 53 (89.83% used simple words and 54 (91.53% checked for understanding and did not rush through the news. 46 doctors (77.97% allowed relatives to determine patient′s knowledge about the disease. Conclusions: There were low rates of specific training in breaking bad news. However, the selected location, the physician′s speech and their plan were according to current guidelines.
Distribution load estimation (DLE)
Energy Technology Data Exchange (ETDEWEB)
Seppaelae, A.; Lehtonen, M. [VTT Energy, Espoo (Finland)
1998-08-01
The load research has produced customer class load models to convert the customers` annual energy consumption to hourly load values. The reliability of load models applied from a nation-wide sample is limited in any specific network because many local circumstances are different from utility to utility and time to time. Therefore there is a need to find improvements to the load models or, in general, improvements to the load estimates. In Distribution Load Estimation (DLE) the measurements from the network are utilized to improve the customer class load models. The results of DLE will be new load models that better correspond to the loading of the distribution network but are still close to the original load models obtained by load research. The principal data flow of DLE is presented
Gauge - Mediated Supersymmetry Breaking in String Compactifications
Energy Technology Data Exchange (ETDEWEB)
Diaconescu, Duiliu-Emanuel; /Rutgers U., Piscataway; Florea, Bogdan; Kachru, Shamit; Svrcek, Peter; /Stanford U., Phys. Dept. /SLAC
2006-01-04
We provide string theory examples where a toy model of a SUSY GUT or the MSSM is embedded in a compactification along with a gauge sector which dynamically breaks supersymmetry. We argue that by changing microscopic details of the model (such as precise choices of flux), one can arrange for the dominant mediation mechanism transmitting SUSY breaking to the Standard Model to be either gravity mediation or gauge mediation. Systematic improvement of such examples may lead to top-down models incorporating a solution to the SUSY flavor problem.
R-Parity Breaking in Minimal Supergravity
Díaz, M A
1997-01-01
We consider the Minimal Supergravity Model with universality of scalar and gaugino masses plus an extra bilinear term in the superpotential which breaks R-Parity and lepton number. We explicitly check the consistency of this model with the radiative breaking of the electroweak symmetry. A neutrino mass is radiatively induced, and large Higgs-Lepton mixings are compatible with its experimental bound. We also study briefly the lightest Higgs mass. This one-parameter extension of SUGRA-MSSM is the simplest way of introducing R-parity violation.
Polarimetric contrast microscopy by orthogonality breaking
International Nuclear Information System (INIS)
We report the design and first implementation of an active polarimetric imaging system based on the recently introduced concept of polarimetric sensing by orthogonality breaking, which involves a specific crossed-polarization dual-frequency illumination. We describe the laser source architecture and microscope set-up devoted to visible imaging at 488 nm, as well as the specific homodyne detection chain required for orthogonality breaking measurements. The first polarimetric images obtained with this non-conventional approach are presented. The polarimetric contrasts observed validate the polarimetric sensitivity of the technique. (fast track communication)
DEFF Research Database (Denmark)
Alward, Randy; Carley, Kathleen M.; Madsen, Fredrik Huitfeldt;
2006-01-01
, action" (OODA) loop. The break out group discussed vulnerability presentation needs common across various application domains, particularly in support of network discovery and network analysis tasks in those domains. Finally, the break out group wished to determine whether there is a means...... of characterizing a vulnerability. This would take into account the potential for the vulnerability to be exploited as well as the potential impact on the operations supported by the network, and on the network structure itself, of a successful exploit of that vulnerability....
Effective dissipation: breaking time-reversal symmetry
Brown, Aidan I
2016-01-01
At molecular scales, fluctuations play a significant role and prevent biomolecular processes from always proceeding in a preferred direction, raising the question of how limited amounts of free energy can be dissipated to obtain directed progress. We examine the system and process characteristics that efficiently break time-reversal symmetry at fixed energy loss; in particular for a simple model of a molecular machine, an intermediate energy barrier produces unusually high asymmetry for a given dissipation. Such insight into symmetry-breaking factors that produce particularly high time asymmetry suggests generalizations to a broader class of systems.
Chiral Symmetry Breaking from Center Vortices
Höllwieser, Roman; Schweigler, Thomas; Heller, Urs M
2014-01-01
We analyze the creation of near-zero modes from would-be zero modes of various topological charge contributions from classical center vortices in SU(2) lattice gauge theory. We show that colorful spherical vortex and instanton configurations have very similar Dirac eigenmodes and also vortex intersections are able to give rise to a finite density of near-zero modes, leading to chiral symmetry breaking via the Banks-Casher formula. We discuss the influence of the magnetic vortex fluxes on quarks and how center vortices may break chiral symmetry.
A convenient way to find an electrical insulation break of MA cores in J-PARC synchrotrons
International Nuclear Information System (INIS)
We employ Magnetic Alloy core loaded RF cavities for the Japan Proton Accelerator Research Complex synchrotrons to achieve a high accelerating voltage. To improve the electrical insulation of MA cores, we conceptualized a convenient way to find an electrical insulation break by measuring the DC resistance in the radial directions of MA cores. We call it the radial resistance method. This radial resistance method gives information of the radial location and degree of the electrical insulation breaks of MA cores. We checked the validity of the radial resistance method by comparing with a high power test result. The areas where the radial resistance method indicated the electrical insulation breaks corresponded with the areas that were damaged due to the electrical insulation breaks during the high power test. We modified the core manufacturing process by evaluating the electrical insulation of MA cores from the radial resistance data, and thus we could improve the electrical insulation of MA cores.
Numerical Study on Breaking Criteria for Solitary Waves
Institute of Scientific and Technical Information of China (English)
Chung-ren CHOU; Ruey-syan SHIH; John Z. YIM
2003-01-01
Studies of the breaking criteria for solitary waves on a slope are presented in this paper. The boundary element method is used to model the processes of shoaling and breaking of solitary waves on various slopes. Empirical formulae that can be used to characterize the breaking of solitary waves are presented. These include the breaking index, the wave height, the water depth, and the maximum particle velocity at the point of breaking. Comparisons with the results of other researches are given.
Distribution load estimation - DLE
Energy Technology Data Exchange (ETDEWEB)
Seppaelae, A. [VTT Energy, Espoo (Finland)
1996-12-31
The load research project has produced statistical information in the form of load models to convert the figures of annual energy consumption to hourly load values. The reliability of load models is limited to a certain network because many local circumstances are different from utility to utility and time to time. Therefore there is a need to make improvements in the load models. Distribution load estimation (DLE) is the method developed here to improve load estimates from the load models. The method is also quite cheap to apply as it utilises information that is already available in SCADA systems
DEFF Research Database (Denmark)
Dyrbye, Claes; Hansen, Svend Ole
pressure to structural response) and design criteria. Starting with an introduction of the wind load chain, the book moves on to meteorological considerations, atmospheric boundary layer, static wind load, dynamic wind load and scaling laws used in wind-tunnel tests. The dynamic wind load covers vibrations......Wind loads have to be taken into account when designing civil engineering structures. The wind load on structures can be systematised by means of the wind load chain: wind climate (global), terrain (wind at low height), aerodynamic response (wind load to pressure), mechanical response (wind...
Two-stage optimization method for efficient power converter design including light load operation
R. Yu; Ling, BWK; Pong, BMH; Lam, J
2012-01-01
Power converter efficiency is always a hot topic for switch mode power supplies. Nowadays, high efficiency is required over a wide load range, e.g., 20, 50, and 100 load. Computer-aided design optimization is developed in this research study, to optimize off-line power converter efficiency from light load to full load. A two-stage optimization method to optimize power converter efficiency from light load to full load is proposed. The optimization procedure first breaks the converter design va...
Vertical load capacities of roof truss cross members
Institute of Scientific and Technical Information of China (English)
Gearhart David F.; Mohamed Khaled Morsy
2016-01-01
Trusses used for roof support in coal mines are constructed of two grouted bolts installed at opposing forty-five degree angles into the roof and a cross member that ties the angled bolts together. The load on the cross member is vertical, which is transverse to the longitudinal axis, and therefore the cross member is loaded in the weakest direction. Laboratory tests were conducted to determine the vertical load capacity and deflection of three different types of cross members. Single-point load tests, with the load applied in the center of the specimen and double-point load tests, with a span of 2.4 m, were con-ducted. For the single-point load configuration, the yield of the 25 mm solid bar cross member was nom-inally 98 kN of vertical load, achieved at 42 cm of deflection. For cable cross members, yield was not achieved even after 45 cm of deflection. Peak vertical loads were about 89 kN for 17 mm cables and 67 kN for the 15 mm cables. For the double-point load configurations, the 25 mm solid bar cross mem-bers yielded at 150 kN of vertical load and 25 cm of deflection. At 25 cm of deflection individual cable strands started breaking at 133 and 111 kN of vertical load for the 17 and 15 mm cable cross members respectively.
Symmetry Breaking for Black-Scholes Equations
Institute of Scientific and Technical Information of China (English)
YANG Xuan-Liu; ZHANG Shun-Li; QU Chang-Zheng
2007-01-01
Black-Scholes equation is used to model stock option pricing. In this paper, optimal systems with one to four parameters of Lie point symmetries for Black-Scholes equation and its extension are obtained. Their symmetry breaking interaction associated with the optimal systems is also studied. As a result, symmetry reductions and corresponding solutions for the resulting equations are obtained.
Symmetry Breaking for Black-Scholes Equations
Yang, Xuan-Liu; Zhang, Shun-Li; Qu, Chang-Zheng
2007-06-01
Black-Scholes equation is used to model stock option pricing. In this paper, optimal systems with one to four parameters of Lie point symmetries for Black-Scholes equation and its extension are obtained. Their symmetry breaking interaction associated with the optimal systems is also studied. As a result, symmetry reductions and corresponding solutions for the resulting equations are obtained.
Symmetry Breaking for Black-Scholes Equations
International Nuclear Information System (INIS)
Black-Scholes equation is used to model stock option pricing. In this paper, optimal systems with one to four parameters of Lie point symmetries for Black-Scholes equation and its extension are obtained. Their symmetry breaking interaction associated with the optimal systems is also studied. As a result, symmetry reductions and corresponding solutions for the resulting equations are obtained.
Viable Gravity-Mediated Supersymmetry Breaking
Kribs, Graham D; Roy, Tuhin S
2010-01-01
We present a complete, viable model of gravity-mediated supersymmetry breaking that is safe from all flavor constraints. The central new idea is to employ a supersymmetry breaking sector without singlets, but with D-terms comparable to F-terms, causing supersymmetry breaking to be dominantly communicated through U(1)_R-symmetric operators. We construct a visible sector that is an extension of the MSSM where an \\emph{accidental} U(1)_R symmetry emerges naturally. Gauginos acquire Dirac masses from gravity-mediated D-terms, and tiny Majorana masses from anomaly-mediated contributions. Contributions to soft breaking scalar (mass)^2 arise from flavor-arbitrary gravity-induced F-terms plus one-loop finite flavor-blind contributions from Dirac gaugino masses. Renormalization group evolution of the gluino causes it to naturally increase nearly an order of magnitude larger than the squark masses. This hierarchy, combined with an accidentially U(1)_R-symmetric visible sector, nearly eliminates all flavor violation con...
Where large deep-ocean waves break
van Haren, H.; Climatoribus, A.; Gostiaux, L.
2015-01-01
Underwater topography like seamounts causes the breaking of large “internal waves” with associated turbulent mixing strongly affecting the redistribution of sediment. Here ocean turbulence is characterized and quantified in the lowest 100?m of the water column at three nearby sites above the slope o
Lifshitz-sector mediated SUSY breaking
International Nuclear Information System (INIS)
We propose a novel mechanism of SUSY breaking by coupling a Lorentz-invariant supersymmetric matter sector to non-supersymmetric gravitational interactions with Lifshitz scaling. The improved UV properties of Lifshitz propagators moderate the otherwise uncontrollable ultraviolet divergences induced by gravitational loops. This ensures that both the amount of induced Lorentz violation and SUSY breaking in the matter sector are controlled by ΛHL2/MP2, the ratio of the Hořava-Lifshitz cross-over scale ΛHL to the Planck scale MP. This ratio can be kept very small, providing a novel way of explicitly breaking supersymmetry without reintroducing fine-tuning. We illustrate our idea by considering a model of scalar gravity with Hořava-Lifshitz scaling coupled to a supersymmetric Wess-Zumino matter sector, in which we compute the two-loop SUSY breaking corrections to the masses of the light scalars due to the gravitational interactions and the heavy fields
Fragmentation in DNA double-strand breaks
International Nuclear Information System (INIS)
DNA double strand breaks are important lesions induced by irradiations. Random breakage model or quantification supported by this concept is suitable to analyze DNA double strand break data induced by low LET radiation, but deviation from random breakage model is more evident in high LET radiation data analysis. In this work we develop a new method, statistical fragmentation model, to analyze the fragmentation process of DNA double strand breaks. After charged particles enter the biological cell, they produce ionizations along their tracks, and transfer their energies to the cells and break the cellular DNA strands into fragments. The probable distribution of the fragments is obtained under the condition in which the entropy is maximum. Under the approximation E≅E0 + E1l + E2l2, the distribution functions are obtained as exp(αl + βl2). There are two components, the one proportional to exp(βl2), mainly contributes to the low mass fragment yields, the other component, proportional to exp(αl), decreases slowly as the mass of the fragments increases. Numerical solution of the constraint equations provides parameters α and β. Experimental data, especially when the energy deposition is higher, support the statistical fragmentation model. (authors)
Density Functional Simulation of a Breaking Nanowire
DEFF Research Database (Denmark)
Nakamura, A.; Brandbyge, Mads; Hansen, Lars Bruno;
1999-01-01
We study the deformation and breaking of an atomic-sized sodium wire using density functional simulations. The wire deforms through sudden atomic rearrangements and smoother atomic displacements. The conductance of the wire exhibits plateaus at integer values in units of 2e(2)/h corresponding...
Dynamical Symmetry Breaking in RN Quantum Gravity
Directory of Open Access Journals (Sweden)
A. T. Kotvytskiy
2011-01-01
Full Text Available We show that in the RN gravitation model, there is no dynamical symmetry breaking effect in the formalism of the Schwinger-Dyson equation (in flat background space-time. A general formula for the second variation of the gravitational action is obtained from the quantum corrections hμν (in arbitrary background metrics.
Physical implications of dynamical symmetry breaking
International Nuclear Information System (INIS)
Some model-independent physical implications of a class of hypercolorbased theories of dynamical symmetry-breaking are described and discussed. The role which e+e- colliders can play, in distinguishing between such theories and the canonical methodology, is underlined
Achromatic Breaks for Swift GRBs: Any Evidence?
S. Covino(INAF - Oss. Astronomico di Brera); Malesani, D.; Tagliaferri, G.; Vergani, S.D.; Chincarini, G.; Kann, D. A.; A. Moretti(Fermilab, Batavia, IL, USA); Stella, L.
2006-01-01
The availability of multi-wavelength high-quality data of gamma-ray burst afterglows in the Swift era, contrary to the expectations, did not allow us to fully confirm yet one of the most fundamental features of the standard afterglow picture: the presence of an achromatic break in the decaying light curve. We briefly review the most interesting cases identified so far.
Supersymmetry Breaking and the Cosmological Constant
Banks, T
2014-01-01
I review three attempts to explain the small value of the cosmological constant, and their connection to SUSY breaking. They are The String Landscape, Supersymmetric Large Extra Dimensions (SLED), and the Holographic Space-time Formalism invented by Fischler and myself.
DEFF Research Database (Denmark)
2009-01-01
A load testing circuit a circuit tests the load impedance of a load connected to an amplifier. The load impedance includes a first terminal and a second terminal, the load testing circuit comprising a signal generator providing a test signal of a defined bandwidth to the first terminal of the load...... impedance, an energy-storing element being connected to the second terminal of the load impedance and providing an output signal, and a measuring unit that measures the output signal or compares the output signal with a reference....
Nonlinear Mechanism of Bed Load Transport
Institute of Scientific and Technical Information of China (English)
XU Haijue; BAI Yuchuan; NG Chiu-On
2009-01-01
From the group movement of the bed load within the bottom layer, details of the nonlinear dynamic characteristics of bed load movement are discussed in this paper. Whether the sediment is initiated into motion cor-responds to whether the constant term in the equation is equal to zero. If constant term is zero and no dispersive force is considered, the equation represents the traditional Shields initiation curve, and if constant term is zero with-out the dispersive force being considered, then a new Shields curve which is much lower than the traditional one is got, The fixed point of the equation corresponds to the equilibrium sediment transport of bed load. In the mutation analysis, we have found that the inflection point is the demarcation point of breaking. In theory, the breaking point corresponds to the dividing boundary line, across which the bed form changes from flat bed to sand ripple or sand dune. Compared with the experimental data of Chatou Hydraulic Lab in France, the conclusions are verified.
International Nuclear Information System (INIS)
Mosquitofish (Gambusia affines) were collected from a small pond on the US DOE reservation that is contaminated with 137Cs, 90Sr and other radionuclides. Fish from non-contaminated populations were also collected. DNA was isolated from both the liver and the blood and examined for DNA single- and double-strand breaks by gel electrophoresis. In general, both single- and double-strand DNA breaks were more prevalent in fish from radionuclide-contaminated sites than from uncontaminated sites. In addition, there were more double-strand than single-strand breaks in DNA from contaminated fish, and more strand breaks in blood cell than in liver DNA. Also, fecundity and number of malformed embryos were determined in fish from all sites. It was found that, for fish from the contaminated site, the number of DNA strand breaks was negatively correlated with fecundity, and that females with malformed embryos in their broods had more DNA strand breaks than did females with no malformed embryos. These findings have implications for both ecological risk assessment and evolutionary ecology
Fractional Branes and Dynamical Supersymmetry Breaking
Franco, S; Saad, F; Uranga, Angel M; Franco, Sebastian; Hanany, Amihay; Saad, Fouad; Uranga, Angel M.
2006-01-01
We study the dynamics of fractional branes at toric singularities, including cones over del Pezzo surfaces and the recently constructed Y^{p,q} theories. We find that generically the field theories on such fractional branes show dynamical supersymmetry breaking, due to the appearance of non-perturbative superpotentials. In special cases, one recovers the known cases of supersymmetric infrared behaviors, associated to SYM confinement (mapped to complex deformations of the dual geometries, in the gauge/string correspondence sense) or N=2 fractional branes. In the supersymmetry breaking cases, when the dynamics of closed string moduli at the singularity is included, the theories show a runaway behavior (involving moduli such as FI terms or equivalently dibaryonic operators), rather than stable non-supersymmetric minima. We comment on the implications of this gauge theory behavior for the infrared smoothing of the dual warped throat solutions with 3-form fluxes, describing duality cascades ending in such field th...
The Radiative Z2 Breaking Twin Higgs
Yu, Jiang-Hao
2016-01-01
In twin Higgs model, the Higgs boson mass is protected by a $Z_2$ symmetry. The $Z_2$ symmetry needs to be broken either explicitly or spontaneously to obtain misalignment between electroweak and new physics vacua. We propose a novel $Z_2$ breaking mechanism, in which the $Z_2$ is spontaneously broken by radiative corrections to the Higgs potential. Two twin Higgses with different vacua are needed, and vacuum misalignment is realized by opposite but comparable contributions from gauge and Yukawa interactions to the potential. Due to fully radiative symmetry breaking, the Higgs sector is completely determined by twin Higgs vacuum, Yukawa and gauge couplings. There are eight pseudo-Goldstone bosons: the Higgs boson, inert doublet Higgs, and three twin scalars. We show the 125 GeV Higgs mass and constraints from Higgs coupling measurements could be satisfied.
Mechanics of breaking coal by water jet
Energy Technology Data Exchange (ETDEWEB)
Chang, Z.; Xi, B.; Zhao, Y.; Zhao, L. [Taiyuan University of Technology, Taiyuan (China)
2008-09-15
It is presumed that the elastic modulus and compressive strength of inhomogeneous rock conform to the Weibull distribution. The methods of breaking inhomogeneous rock by water jet and the threshold pressure of the water jet were deduced using percolation theory. Continuous drilling in the inhomogeneous coal by water jet was numerically simulated by the finite element method and an experiment of breaking coal by water jet was carried out. The study indicated that under the pressure of water jets, the low strength cells in inhomogeneous rock are first destroyed and a crack is created. The effect of a water wedge occurring by the water jet entering the crack space produces a tensile stress concentration at the tip of a crack, so cracks expand rapidly and converge gradually. Eventually the rock is fragmented and a cracked pit forms. The length of a crack in coal caused by a water jet at 60 MPa is over 0.5 m. 8 refs., 6 figs.
Dynamics of Symmetry Breaking and Tachyonic Preheating
Felder, G; Greene, P B; Kofman, L A; Linde, Andrei D; Tkachev, Igor I; Felder, Gary; Garcia-Bellido, Juan; Greene, Patrick B.; Kofman, Lev; Linde, Andrei; Tkachev, Igor
2001-01-01
We reconsider the old problem of the dynamics of spontaneous symmetry breaking using 3d lattice simulations, and develop a theory of tachyonic preheating, which occurs due to the spinodal instability of the scalar field. Tachyonic preheating is so efficient that symmetry breaking typically completes within a single oscillation of the field distribution as it rolls towards the minimum of its effective potential. As an application of this theory we consider preheating in the hybrid inflation scenario, including SUSY-motivated F-term and D-term inflationary models. We show that preheating in hybrid inflation is typically tachyonic and the stage of oscillations of a homogeneous component of the scalar fields driving inflation ends after a single oscillation. Our results may also be relevant for the theory of the formation of disoriented chiral condensates in heavy ion collisions.
Four Generations: SUSY and SUSY Breaking
Godbole, Rohini M; Wingerter, Akin
2009-01-01
We revisit four generations within the context of supersymmetry. We compute the perturbativity limits for the fourth generation Yukawa couplings and show that if the masses of the fourth generation lie within reasonable limits of their present experimental lower bounds, it is possible to have perturbativity only up to scales around 1000 TeV. Such low scales are ideally suited to incorporate gauge mediated supersymmetry breaking, where the mediation scale can be as low as 10-20 TeV. The minimal messenger model, however, is highly constrained. While lack of electroweak symmetry breaking rules out a large part of the parameter space, a small region exists, where the fourth generation stau is tachyonic. General gauge mediation with its broader set of boundary conditions is better suited to accommodate the fourth generation.
A Fourth Chiral Generation And Susy Breaking
Wingerter, Akin
2011-01-01
We revisit four generations within the context of supersymmetry. We compute the perturbativity limits for the fourth generation Yukawa couplings and show that if the masses of the fourth generation lie within reasonable limits of their present experimental lower bounds, it is possible to have perturbativity only up to scales around 1000 TeV, i.e. the current experimental bounds and perturbative unification are mutually exclusive. Such low scales are ideally suited to incorporate gauge mediated supersymmetry breaking, where the mediation scale can be as low as 10-20 TeV. The minimal messenger model, however, is highly constrained. Lack of electroweak symmetry breaking rules out a large part of the parameter space, and in the remaining part, the fourth generation stau is tachyonic.
Electroweak symmetry breaking: Higgs/whatever
International Nuclear Information System (INIS)
In the first of these two lectures the Higgs mechanism is reviewed in its most general form, which does not necessarily require the existence of Higgs bosons. The general consequences of the hypothesis that electroweak symmetry breaking is due to the Higgs mechanism are deduced just from gauge invariance and unitarity. In the second lecture the general properties are illustrated with three specific models: the Weinberg-Salam model, its minimal supersymmetric extension, and technicolor. The second lecture concludes with a discussion of the experiment signals for strong WW scattering, whose presence or absence will allow us to determine whether the symmetry breaking sector lies above or below 1 TeV. 57 refs
Symmetry breaking in non conservative systems
Martínez-Pérez, N E
2016-01-01
We apply Noether's theorem to show how the invariances of conservative systems are broken for nonconservative systems, in the variational formulation of Galley. This formulation considers a conservative action, extended by the inclusion of a time reversed sector and a nonconservative generalized potential. We assume that this potential is invariant under the symmetries of the initial conservative system. The breaking occurs because the time reversed sector requires inverse symmetry transformations, under which the nonconservative potential is not invariant. The resulting violation of the conservation laws is consistent with the equations of motion. We generalize this formulation for fermionic and sypersymmetric systems. In the case of a supersymmetric oscillator, the effect of damping is that the bosonic and fermionic components become different frequencies. Considering that initially the nonconservative action is invariant under supersymmetry, and that the breaking is associated to an instability, this resul...
Cosmology of biased discrete symmetry breaking
Gelmini, Graciela B.; Gleiser, Marcelo; Kolb, Edward W.
1988-01-01
The cosmological consequences of spontaneous breaking of an approximate discrete symmetry are studied. The breaking leads to formation of proto-domains of false and true vacuum separated by domain walls of thickness determined by the mass scale of the model. The cosmological evolution of the walls is extremely sensitive to the magnitude of the biasing; several scenarios are possible, depending on the interplay between the surface tension on the walls and the volume pressure from the biasing. Walls may disappear almost immediately after they form, or may live long enough to dominate the energy density of the Universe and cause power-law inflation. Limits are obtained on the biasing that characterizes each possible scenario.
Lima, V; Lacroix, D; Blumenfeld, Y; Bourgeois, C; Chabot, M; Chomaz, Ph; Désesquelles, P; Duflot, V; Duprat, J; Fallot, M; Frascaria, N; Grévy, S; Guillemaud-Müller, D; Roussel-Chomaz, P; Savajols, H; Sorlin, O
2007-01-01
The break-up of 11Be was studied at 41AMeV using a secondary beam of 11Be from the GANIL facility on a 48Ti target by measuring correlations between the 10Be core, the emitted neutrons and gamma rays. The nuclear break-up leading to the emission of a neutron at large angle in the laboratory frame is identified with the towing mode through its characteristic n-fragment correlation. The experimental spectra are compared with a model where the time dependent Schrodinger equation (TDSE) is solved for the neutron initially in the 11 Be. A good agreement is found between experiment and theory for the shapes of neutron experimental energies and angular distributions. The spectroscopic factor of the 2s orbital is tentatively extracted to be 0.46+-0.15. The neutron emission from the 1p and 1d orbitals is also studied.
Isospin breaking in octet baryon mass splittings
Energy Technology Data Exchange (ETDEWEB)
Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics and Astronomy; Najjar, J. [Regensburg Univ. (Germany). Institut fuer Theoretische Physik; Nakamura, Y. [RIKEN Advanced Institute for Computational Science, Kobe, Hyogo (Japan); Pleiter, D. [Forschungszentrum Juelich (Germany). Juelich Supercomputer Centre; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Division; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Zanotti, J.M. [Adelaide Univ., SA (Australia). CSSM, School of Chemistry and Physics
2012-06-15
Using an SU(3) flavour symmetry breaking expansion in the quark mass, we determine the QCD component of the nucleon, Sigma and Xi mass splittings of the baryon octet due to up-down (and strange) quark mass differences in terms of the kaon mass splitting. Provided the average quark mass is kept constant, the expansion coefficients in our procedure can be determined from computationally cheaper simulations with mass degenerate sea quarks and partially quenched valence quarks. Both the linear and quadratic terms in the SU(3) flavour symmetry breaking expansion are considered; it is found that the quadratic terms only change the result by a few percent, indicating that the expansion is highly convergent.
Isospin breaking in octet baryon mass splittings
International Nuclear Information System (INIS)
Using an SU(3) flavour symmetry breaking expansion in the quark mass, we determine the QCD component of the nucleon, Sigma and Xi mass splittings of the baryon octet due to up-down (and strange) quark mass differences in terms of the kaon mass splitting. Provided the average quark mass is kept constant, the expansion coefficients in our procedure can be determined from computationally cheaper simulations with mass degenerate sea quarks and partially quenched valence quarks. Both the linear and quadratic terms in the SU(3) flavour symmetry breaking expansion are considered; it is found that the quadratic terms only change the result by a few percent, indicating that the expansion is highly convergent.
Collective neutrino oscillations and spontaneous symmetry breaking
Duan, Huaiyu
2015-08-01
Neutrino oscillations in a hot and dense astrophysical environment such as a core-collapse supernova pose a challenging, seven-dimensional flavor transport problem. To make the problem even more difficult (and interesting), neutrinos can experience collective oscillations through nonlinear refraction in the dense neutrino medium in this environment. Significant progress has been made in the last decade towards the understanding of collective neutrino oscillations in various simplified neutrino gas models with imposed symmetries and reduced dimensions. However, a series of recent studies seem to have "reset" this progress by showing that these models may not be compatible with collective neutrino oscillations because the latter can break the symmetries spontaneously if they are not imposed. We review some of the key concepts of collective neutrino oscillations by using a few simple toy models. We also elucidate the breaking of spatial and directional symmetries in these models because of collective oscillations.
Collective neutrino oscillations and spontaneous symmetry breaking
Duan, Huaiyu
2015-01-01
Neutrino oscillations in a hot and dense astrophysical environment such as a core-collapse supernova pose a challenging, seven-dimensional flavor transport problem. To make the problem even more difficult (and interesting), neutrinos can experience collective oscillations through nonlinear refraction in the dense neutrino medium in this environment. Significant progress has been made in the last decade towards the understanding of collective neutrino oscillations in various simplified neutrino gas models with imposed symmetries and reduced dimensions. However, a series of recent studies seem to have "reset" this progress by showing that these models may not be compatible with collective neutrino oscillations because the latter can break the symmetries spontaneously if they are not imposed. We review some of the key concepts of collective neutrino oscillations by using a few simple toy models. We also elucidate the breaking of spatial and directional symmetries in these models because of collective oscillation...
Spontaneous symmetry breaking in loop quantum gravity
Energy Technology Data Exchange (ETDEWEB)
Helesfai, G [Institute for Theoretical Physics, Eoetvoes University, Pazmany Peter setany 1/A, H-1117 Budapest (Hungary)], E-mail: heles@manna.elte.hu
2008-12-07
In this paper we investigate the question of how spontaneous symmetry breaking works in the framework of loop quantum gravity and compare it to the results obtained in the case of the Proca field, where we were able to quantize the theory in loop quantum gravity without introducing a Higgs field. We obtained that the Hamiltonian of the two systems is very similar, the only difference is an extra scalar field in the case of spontaneous symmetry breaking. This field can be identified as the field that carries the mass of the vector field. In the quantum regime this becomes a well-defined operator, which turns out to be a self-adjoint operator with continuous spectrum. To calculate the spectrum we used a new representation in the case of scalar fields, which in addition enabled us to rewrite the constraint equations to a finite system of linear partial differential equations. This made it possible to solve part of the constraints explicitly.
Large eddy simulation of breaking waves
DEFF Research Database (Denmark)
Christensen, Erik Damgaard; Deigaard, Rolf
2001-01-01
the steepening and the overturning of the wave. At a given instant, the model domain is extended to three dimensions, and the two-dimensional flow field develops spontaneously three-dimensional flow features with turbulent eddies. After a few wave periods, stationary (periodic) conditions are achieved......A numerical model is used to simulate wave breaking, the large scale water motions and turbulence induced by the breaking process. The model consists of a free surface model using the surface markers method combined with a three-dimensional model that solves the flow equations. The turbulence...... is described by large eddy simulation where the larger turbulent features are simulated by solving the flow equations, and the small scale turbulence that is not resolved by the flow model is represented by a sub-grid model. A simple Smagorinsky sub-grid model has been used for the present simulations...
Boost Breaking in the EFT of Inflation
Delacretaz, Luca V; Senatore, Leonardo
2015-01-01
If time-translations are spontaneously broken, so are boosts. This symmetry breaking pattern can be non-linearly realized by either just the Goldstone boson of time translations, or by four Goldstone bosons associated with time translations and boosts. In this paper we extend the Effective Field Theory of Multifield Inflation to consider the case in which the additional Goldstone bosons associated with boosts are light and coupled to the Goldstone boson of time translations. The symmetry breaking pattern forces a coupling to curvature so that the mass of the additional Goldstone bosons is predicted to be equal to $\\sqrt{2}H$ in the vast majority of the parameter space where they are light. This pattern therefore offers a natural way of generating self-interacting particles with Hubble mass during inflation. After constructing the general effective Lagrangian, we study how these particles mix and interact with the curvature fluctuations, generating potentially detectable non-Gaussian signals.
High Power Disk Loaded Guide Load
Energy Technology Data Exchange (ETDEWEB)
Farkas, Z.D.; /SLAC
2006-02-22
A method to design a matching section from a smooth guide to a disk-loaded guide, using a variation of broadband matching, [1, 2] is described. Using this method, we show how to design high power loads. The load consists of a disk-loaded coaxial guide operating in the TE{sub 01}-mode. We use this mode because it has no electric field terminating on a conductor, has no axial currents, and has no current at the cylinder-disk interface. A high power load design that has -35 dB reflection and a 200 MHz, -20 dB bandwidth, is presented. It is expected that it will carry the 600 MW output peak power of the pulse compression network. We use coaxial geometry and stainless steel material to increase the attenuation per cell.
Music and Video Gaming during Breaks
Liu, Shuyan; Schad, Daniel J.; Kuschpel, Maxim S.; Michael A Rapp; Heinz, Andreas
2016-01-01
Different systems for habitual versus goal-directed control are thought to underlie human decision-making. Working memory is known to shape these decision-making systems and their interplay, and is known to support goal-directed decision making even under stress. Here, we investigated if and how decision systems are differentially influenced by breaks filled with diverse everyday life activities known to modulate working memory performance. We used a within-subject design where young adult...
Wave breaking in tapered holey fibers
Institute of Scientific and Technical Information of China (English)
Shuguang Li; Lei Zhang; Bo Fu; Yi Zheng; Ying Han; Xingtao Zhao
2011-01-01
We numerically study the propagation of 1-ps laser pulse in three tapered holey fibers (THFs). The curvature indices of the concave, linear, and convex tapers are 2.0, 1.0, and 0.5, respectively. The central wavelength, located in the normal dispersion regime, is 800 nm. The nonlinear coefficient of the THFs increases from the initial 0.095 m-1· W-1 to the final 0.349 m-l·W-1. Wave breaking accompanied by oscillatory structures occurs near pulse edges, and sidelobes appear in the pulse spectrum. With the increase in propagation distance z, the pulse shape becomes broader and the pulse spectrum flattens. A concave THF is advantageous to the generation of wave breaking and enables easier achievement of super fiat spectra at short lengths.%@@ We numerically study the propagation of 1-ps laser pulse in three tapered holey fibers (THFs).The curvature indices of the concave, linear, and convex tapers are 2.0, 1.0, and 0.5, respectively.The central wavelength, located in the normal dispersion regime, is 800 nm.The nonlinear coefficient of the THFs increases from the initial 0.095 m-1.W-1 to the final 0.349 m-1.W-1.Wave breaking accompanied by oscillatory structures occurs near pulse edges, and sidelobes appear in the pulse spectrum.With the increase in propagation distance z, the pulse shape becomes broader and the pulse spectrum flattens.A concave THF is advantageous to the generation of wave breaking and enables easier achievement of super flat spectra at short lengths.
Soft branes in supersymmetry-breaking backgrounds
McGuirk, Paul; Shiu, Gary; Ye, Fang
2012-01-01
We revisit the analysis of effective field theories resulting from non-supersymmetric perturbations to supersymmetric flux compactifications of the type-IIB superstring with an eye towards those resulting from the backreaction of a small number of anti-D3-branes. Independently of the background, we show that the low-energy Lagrangian describing the fluctuations of a stack of probe D3-branes exhibits soft supersymmetry breaking, despite perturbations to marginal operators that were not fully c...
Breaking democracy with non renormalizable mass terms
Silva-Marcos, Joaquim I
2001-01-01
The exact democratic structure for the quark mass matrix, resulting from the action of the family symmetry group $A_{3L}\\times A_{3R}$, is broken by the vacuum expectation values of heavy singlet fields appearing in non renormalizable dimension 6 operators. Within this specific context of breaking of the family symmetry we formulate a very simple ansatz which leads to correct quark masses and mixings.
Flavour Violation in Anomaly Mediated Supersymmetry Breaking
Allanach, B. C.; Hiller, G; Jones, D. R. T.; Slavich, P.(LPTHE, UPMC Univ. Paris 06, Sorbonne Universités, 4 Place Jussieu, 75252, Paris, France)
2009-01-01
32 pages, 8 figures International audience We study squark flavour violation in the anomaly mediated supersymmetry broken (AMSB) minimal supersymmetric standard model. Analytical expressions for the three-generational squark mass matrices are derived. We show that the anomaly-induced soft breaking terms have a decreasing amount of squark flavour violation when running from the GUT to the weak scale. Taking into account inter-generational squark mixing, we work out non-trivial constraint...
Electroweak Symmetry Breaking Beyond the Standard Model
Bhattacharyya, Gautam
2012-01-01
In this talk, I shall address two key issues related to electroweak symmetry breaking. First, how fine-tuned different models are that trigger this phenomenon? Second, even if a light Higgs boson exists, does it have to be necessarily elementary? After a brief introduction, I shall first review the fine-tuning aspects of the MSSM, NMSSM, generalized NMSSM and GMSB scenarios. I shall then compare and contrast the little Higgs, composite Higgs and the Higgsless models. Finally, I shall summariz...
How does DNA break during chromosomal translocations?
Nambiar, Mridula; Raghavan, Sathees C.
2011-01-01
Chromosomal translocations are one of the most common types of genetic rearrangements and are molecular signatures for many types of cancers. They are considered as primary causes for cancers, especially lymphoma and leukemia. Although many translocations have been reported in the last four decades, the mechanism by which chromosomes break during a translocation remains largely unknown. In this review, we summarize recent advances made in understanding the molecular mechanism of chromosomal t...
Supersymmetry breaking made easy, viable, and generic
Murayama, Hitoshi
2007-01-01
The kind of supersymmetry that can be discovered at the LHC must be very much flavor-blind, which used to require very special intelligently designed models of supersymmetry breaking. This led to the pessimism for some in the community that it is not likely for the LHC to discover supersymmetry. I point out that this is not so, because a garden-variety supersymmetric theories actually can do this job.
Dynamic ice loads on conical structures
Institute of Scientific and Technical Information of China (English)
无
2011-01-01
Two series of model tests were performed to observe the dynamic ice loads on conical structures.The variable testing parameters include the water line diameter of the model cone and ice parameters.During small water line diameter tests,two-time breaking is found to be the typical failure of ice on steep conical structure,and also be controlled by other factors,such as ice speed and the cone angle.During big water line diameter tests,the ice sheet failed nonsimultaneously around the cone.Several independe...
The Beam Break-Up Numerical Simulator
International Nuclear Information System (INIS)
Beam Break-Up (BBU) is a severe constraint in accelerator design, limiting beam current and quality. The control of BBU has become the focus of much research in the design of the next generation collider, recirculating and linear induction accelerators and advanced accelerators. Determining the effect on BBU of modifications to cavities, the focusing elements or the beam is frequently beyond the ability of current analytic models. A computer code was written to address this problem. The Beam Break-Up Numerical Simulator (BBUNS) was designed to numerically solve for beam break-up (BBU) due to an arbitrary transverse wakefield. BBUNS was developed to be as user friendly as possible on the Cray computer series. The user is able to control all aspects of input and output by using a single command file. In addition, the wakefield is specified by the user and read in as a table. The program can model energy variations along and within the beam, focusing magnetic field profiles can be specified, and the graphical output can be tailored. In this note we discuss BBUNS, its structure and application. Included are detailed instructions, examples and a sample session of BBUNS. This program is available for distribution. 50 refs., 18 figs., 5 tabs
Dormancy Breaking in Ormosia arborea Seeds
Directory of Open Access Journals (Sweden)
Edilma Pereira Gonçalves
2011-01-01
Full Text Available Ormosia arborea is a tree species planted in urban areas and used to restore degraded areas. Its seeds are dormant and propagation is difficult. This study compares different dormancy breaking methods and physiological seed quality and seedling production. The seeds were germinated in sand in the laboratory of the Universidade Estadual de Santa Cruz, Ilhéus, Bahia, Brazil. The following dormancy breaking treatments were applied: control (intact seeds, 100°C water immersion; boiling water immersion followed by 24 hours of soaking; scarification with number 100 and number 50 sandpaper opposite from root emergence; sulfuric acid immersion for 1 hour, 50, 45, and 30 minutes. Seed immersion in 100°C and boiling water did not break the dormancy. The study species showed a greater vigor of seedling when its seeds were submitted to treatments associated with tegument rupturing by sandpaper or sulfuric acid. On the other hand, seed scarification with sulfuric acid for 1 hour, 50, 45, and 30 minutes or sandpaper favored seed germination and vigor.
The Beam Break-Up Numerical Simulator
Energy Technology Data Exchange (ETDEWEB)
Travish, G.A.
1989-11-01
Beam Break-Up (BBU) is a severe constraint in accelerator design, limiting beam current and quality. The control of BBU has become the focus of much research in the design of the next generation collider, recirculating and linear induction accelerators and advanced accelerators. Determining the effect on BBU of modifications to cavities, the focusing elements or the beam is frequently beyond the ability of current analytic models. A computer code was written to address this problem. The Beam Break-Up Numerical Simulator (BBUNS) was designed to numerically solve for beam break-up (BBU) due to an arbitrary transverse wakefield. BBUNS was developed to be as user friendly as possible on the Cray computer series. The user is able to control all aspects of input and output by using a single command file. In addition, the wakefield is specified by the user and read in as a table. The program can model energy variations along and within the beam, focusing magnetic field profiles can be specified, and the graphical output can be tailored. In this note we discuss BBUNS, its structure and application. Included are detailed instructions, examples and a sample session of BBUNS. This program is available for distribution. 50 refs., 18 figs., 5 tabs.
Kinematic dynamo, supersymmetry breaking, and chaos
Ovchinnikov, Igor V.; Enßlin, Torsten A.
2016-04-01
The kinematic dynamo (KD) describes the growth of magnetic fields generated by the flow of a conducting medium in the limit of vanishing backaction of the fields onto the flow. The KD is therefore an important model system for understanding astrophysical magnetism. Here, the mathematical correspondence between the KD and a specific stochastic differential equation (SDE) viewed from the perspective of the supersymmetric theory of stochastics (STS) is discussed. The STS is a novel, approximation-free framework to investigate SDEs. The correspondence reported here permits insights from the STS to be applied to the theory of KD and vice versa. It was previously known that the fast KD in the idealistic limit of no magnetic diffusion requires chaotic flows. The KD-STS correspondence shows that this is also true for the diffusive KD. From the STS perspective, the KD possesses a topological supersymmetry, and the dynamo effect can be viewed as its spontaneous breakdown. This supersymmetry breaking can be regarded as the stochastic generalization of the concept of dynamical chaos. As this supersymmetry breaking happens in both the diffusive and the nondiffusive cases, the necessity of the underlying SDE being chaotic is given in either case. The observed exponentially growing and oscillating KD modes prove physically that dynamical spectra of the STS evolution operator that break the topological supersymmetry exist with both real and complex ground state eigenvalues. Finally, we comment on the nonexistence of dynamos for scalar quantities.
Piecewise-smooth circle homeomorphisms with several break points
International Nuclear Information System (INIS)
We prove that the invariant probability measure of an ergodic piecewise-smooth circle homeomorphism with several break points and the product of the jumps at break points non-trivial is singular with respect to Lebesgue measure.
Healthy breaks: tasty tips for the under fives
Public Health Agency
2014-01-01
Today the Public Health Agency is launching a new resource pack designed to assist nursery schools and playgroups deliver a healthy breaks scheme.All nursery schools and playgroups in Northern Ireland will receive the pack - 'Healthy breaks for pre-school children' - which includes a poster and information leaflets for parents explaining why a healthy break is so important for pre-school children and some tips and ideas for healthy nutritious breaks.Judith Hanvey, Regional Food in Schools Co-...
French regulatory practice and reflections on the leak-before-break concept
International Nuclear Information System (INIS)
For nuclear units in the design phase, the vendor (FRAMATOME) and the utility (EDF) examine the possibility of applying the leak-before-break criterion to a certain number of circuits, particularly the primary circuit and various parts of the secondary circuit. EDF has not completed its reflection on the leak-before-break approach and consequently, French safety authorities have not been officially notified of any request for assessment of the acceptability of such an approach. Nevertheless, from a strict safety point of view, it is possible to determine minimal conditions required in the implementation of such a course of action. Firstly, removing pipe breaks from the design basis of the plant will significantly weaken the application of the defense in-depth concept. This must be counter-balanced by reinforced manufacturing non destructive examinations and a stringent in-service inspection. Secondly, the demonstration of the existence of leaks before breaks must be obtained with a high degree of certainty, which requires large investments in a certain number of fields. The exact methodology will be defined by the Vendor and the utility at a later stage. However, from our point of view, analysis should involve the following steps: Definition of a maximum size defect; analysis of evolution under normal loads; stability analysis, definition of the critical defect; Definition of the detectable defect. This paper develops each of these points, and specifies, for each discipline, the domains in which present knowledge must be expanded and deepened
Phenomenological approach to symmetry breaking pattern of democratic mass matrix
Harada, J
2002-01-01
We investigate the symmetry breaking pattern of the democratic mass matrix model, which leads to the small flavor mixing in quark sector and bi-large mixing in lepton sector. We present the symmetry breaking matrices in quark sector which are determined by alternative ways instead of conventional ansatz. These matrices might be useful for understanding the origin of democratic symmetry and its breaking.
A strict QCD inequality and mechanisms for chiral symmetry breaking
International Nuclear Information System (INIS)
A strict QCD inequality allows one to discuss mechanisms proposed for breaking the chiral symmetry in QCD. ''Order parameters'' are identified such that if sufficiently many gauge field configurations contribute to them, spontaneous chiral symmetry breaking follows. As an application the role of instantons is discussed in chiral symmetry breaking in QCD. (orig.)
24 CFR 982.315 - Family break-up.
2010-04-01
... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Family break-up. 982.315 Section... SECTION 8 TENANT BASED ASSISTANCE: HOUSING CHOICE VOUCHER PROGRAM Leasing a Unit § 982.315 Family break-up... assistance in the program if the family breaks up. The PHA administrative plan must state PHA policies on...
75 FR 80073 - Reasonable Break Time for Nursing Mothers
2010-12-21
... Hour Division RIN 1235-ZA00 Reasonable Break Time for Nursing Mothers AGENCY: Wage and Hour Division... Standards Act (FLSA) that requires employers to provide reasonable break time and a place for nursing... considers how best to help employers and employees understand the requirements of the break time for...
International Nuclear Information System (INIS)
The static method for the evaluation of the limit loads of a perfectly elasto-plastic structure is presented. Using the static theorem of Limit Analysis and the Finite Element Method, a lower bound for the colapso load can be obtained through a linear programming problem. This formulation if then applied to symmetrically loaded shells of revolution and some numerical results of limit loads in nozzles are also presented. (Author)
Shock imprint and rolling direction influence upon the breaking tenacity for 2P armor steel
Zichil, V.; Coseru, A.; Schnakovszky, C.; Herghelegiu, E.; Radu, C.
2016-08-01
The state of art in present literature shows that the breaking tenacity of a material is influenced by the integrity of the structure. Since armors used in aviation and to protect military vehicles are frequently impact loaded, through the contact between armor sheet and projectiles, or other foreign bodies, the authors have proposed to study the dependence between the breaking tenacity of 2P armor steel depending on the direction of the rolling of the armor plate, of the geometry (spherical imprint, pyramidal and linear imprint) and the depth of the deformation that results after impact. Tests were conducted upon CT (ASTM E- 399) specimen type, using the critical factor of stress intensity during the state of planar strain.
Vibrating-Rocking Motion of Caisson Breakwater Under Breaking Wave Impact
Institute of Scientific and Technical Information of China (English)
王元战; 郑斌
2001-01-01
The possible motions of a caisson breakwater under dynamic load excitation include vibrating, vibrating-sliding andvibrating-rocking motions. The models of vibrating motion and vibrating-sliding motion have been proposed in an earlypaper. In this paper, a model of vibrating-rocking motion of caisson breakwaters under breaking wave impact is presented, which can be used to simulate the histories of vibrating-rocking motion of caisson breakwaters. The effect of rocking motion on the displacement, rotation, sliding force and overturning moment of breakwaters is investigated. In casethe overturning moment exceeds the stability moment ofa caisson, the caisson may only rock. The caisson overturns only in case the rocking angle exceeds the critical angle. It is shown that the sliding force and overturning moment of break-waters can be reduced effectively due to the rocking motion. It is proposed that some rocking motion should be allowedin breakwater design.
Sparticle spectrum and constraints in anomaly mediated supersymmetry breaking models
Huitu, K; Pandita, P N
2002-01-01
We study in detail the particle spectrum in anomaly mediated supersymmetry breaking models in which supersymmetry breaking terms are induced by super-Weyl anomaly. We investigate the minimal anomaly mediated supersymmetry breaking models, gaugino assisted supersymmetry breaking models, as well as models with additional residual non-decoupling D-term contributions due to an extra U(1) gauge symmetry at high energy scale. We derive sum rules for the sparticle masses in these models which can help in differentiating between them. We also obtain the sparticle spectrum numerically, and compare and contrast the results so obtained for the different types of anomaly mediated supersymmetry breaking models.
Fuel breaks affect nonnative species abundance in Californian plant communities
Merriam, K.E.; Keeley, J.E.; Beyers, J.L.
2006-01-01
We evaluated the abundance of nonnative plants on fuel breaks and in adjacent untreated areas to determine if fuel treatments promote the invasion of nonnative plant species. Understanding the relationship between fuel treatments and nonnative plants is becoming increasingly important as federal and state agencies are currently implementing large fuel treatment programs throughout the United States to reduce the threat of wildland fire. Our study included 24 fuel breaks located across the State of California. We found that nonnative plant abundance was over 200% higher on fuel breaks than in adjacent wildland areas. Relative nonnative cover was greater on fuel breaks constructed by bulldozers (28%) than on fuel breaks constructed by other methods (7%). Canopy cover, litter cover, and duff depth also were significantly lower on fuel breaks constructed by bulldozers, and these fuel breaks had significantly more exposed bare ground than other types of fuel breaks. There was a significant decline in relative nonnative cover with increasing distance from the fuel break, particularly in areas that had experienced more numerous fires during the past 50 years, and in areas that had been grazed. These data suggest that fuel breaks could provide establishment sites for nonnative plants, and that nonnatives may invade surrounding areas, especially after disturbances such as fire or grazing. Fuel break construction and maintenance methods that leave some overstory canopy and minimize exposure of bare ground may be less likely to promote nonnative plants. ?? 2006 by the Ecological Society of America.
Spatial electric load forecasting
Willis, H Lee
2002-01-01
Spatial Electric Load Forecasting Consumer Demand for Power and ReliabilityCoincidence and Load BehaviorLoad Curve and End-Use ModelingWeather and Electric LoadWeather Design Criteria and Forecast NormalizationSpatial Load Growth BehaviorSpatial Forecast Accuracy and Error MeasuresTrending MethodsSimulation Method: Basic ConceptsA Detailed Look at the Simulation MethodBasics of Computerized SimulationAnalytical Building Blocks for Spatial SimulationAdvanced Elements of Computerized SimulationHybrid Trending-Simulation MethodsAdvanced
LARGE EDDY SIMLIATION WAVE BREAKING OVER MUDDY SEABED
Institute of Scientific and Technical Information of China (English)
HU Yi; NIU Xiao-jing; YU Xi-ping
2012-01-01
The Large Eddy Simulation (LES) of the wave breaking over a muddy seabed is carried out with a Coupled Level Set and Volume Of Fluid (CLSVOF) method to capture the interfaces.The effects of the mud on the wave breaking are studied.The existence of a mud layer beneath an otherwise rigid bottom is found to have a similar effect as an increase of the water depth.As compared with the case of a simple rigid bottom,the inception of the wave breaking is evidently delayed and the breaking intensity is mnch reduced.The dissipation of the wave energy is shown to have very different rates before,during and after the breaking.Before and after the breaking,the mud plays an important role.During the breaking,however,the turbulence as well as the entrainment of the air also dissipate a large amount of energy.
On inflation, cosmological constant, and SUSY breaking
Linde, Andrei
2016-01-01
We consider a broad class of inflationary models of two unconstrained chiral superfields, the stabilizer $S$ and the inflaton $\\Phi$, which can describe inflationary models with nearly arbitrary potentials. These models include, in particular, the recently introduced theories of cosmological attractors, which provide an excellent fit to the latest Planck data. We show that by adding to the superpotential of the fields $S$ and $\\Phi$ a small term depending on a nilpotent chiral superfield $P$ one can break SUSY and introduce a small cosmological constant without affecting main predictions of the original inflationary scenario.
Insight into Phenomena of Symmetry Breaking Bifurcation
Institute of Scientific and Technical Information of China (English)
FANG Tong; ZHANG Ying
2008-01-01
@@ We show that symmetry-breaking (SB) bifurcation is just a transition of different forms of symmetry, while still preserving system's symmetry. SB bifurcation always associates with a periodic saddle-node bifurcation, identifiable by a zero maximum of the top Lyapunov exponent of the system. In addition, we show a significant phase portrait of a newly born periodic saddle and its stable and unstable invariant manifolds, together with their neighbouring flow pattern of Poincaré mapping points just after the periodic saddle-node bifurcation, thus gaining an insight into the mechanism of SB bifurcation.
SU(3) flavour breaking and baryon structure
Energy Technology Data Exchange (ETDEWEB)
Cooke, A.N.; Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics and Astronomy; Nakamura, Y. [RIKEN Advanced Institute for Computational Science, Kobe, Hyogo (Japan); Pleiter, D. [Forschungszentrum Juelich GmbH (Germany). Juelich Supercomputing Centre (JSC); Regensburg Univ. (Germany). Institut fuer Theoretische Physik; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Div.; Shanahan, P.; Zanotti, J.M. [Adelaide Univ., SA (Australia). CSSM, School of Chemistry and Physics; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Stueben, H. [Hamburg Univ. (Germany). Regionales Rechenzentrum; Collaboration: QCDSF/UKQCD Collaboration
2013-11-15
We present results from the QCDSF/UKQCD collaboration for hyperon electromagnetic form factors and axial charges obtained from simulations using N{sub f}=2+1 flavours of O(a)-improved Wilson fermions. We also consider matrix elements relevant for hyperon semileptonic decays. We find flavour-breaking effects in hyperon magnetic moments which are consistent with experiment, while our results for the connected quark spin content indicates that quarks contribute more to the spin of the {Xi} baryon than they do to the proton.
Breaking of Cooper pairs in 108Pd
Rahmatinejad, A.; Kakavand, T.; Razavi, R.
2016-04-01
In this paper, breaking of Cooper pairs in 108Pd is investigated within the canonical ensemble framework and the BCS model. Our results show an evidence of two phase transitions, which are related to neutron and proton systems. Also, with consideration of pairing interaction, the role of neutron and proton systems in entropy, spin cutoff parameter and as a result in the moment of inertia are investigated. The results show minor role for the proton system at low temperatures and approximately equal roles for both neutron and proton systems after the critical temperature. Good agreement was observed between obtained results and the experimental data.
NASA Shared Services Center breaks ground
2006-01-01
NASA officials and elected leaders were on hand for the groundbreaking ceremony of the NASA Shared Services Center Feb. 24, 2006, on the grounds of Stennis Space Center. The NSSC provides agency centralized administrative processing, human resources, procurement and financial services. From left, Louisiana Economic Development Secretary Mike Olivier, Stennis Space Center Director Rick Gilbrech, Computer Sciences Corp. President Michael Laphen, NASA Deputy Administrator Shana Dale, Rep. Gene Taylor, Sen. Trent Lott, Mississippi Gov. Haley Barbour, NASA Administrator Mike Griffin and Shared Services Center Executive Director Arbuthnot use golden shovels to break ground at the site.
De Sitter uplift with Dynamical Susy Breaking
Retolaza, Ander; Uranga, Angel
2016-04-01
We propose the use of D-brane realizations of Dynamical Supersymmetry Breaking (DSB) gauge sectors as sources of uplift in compactifications with moduli stabilization onto de Sitter vacua. This construction is fairly different from the introduction of anti D-branes, yet allows for tunably small contributions to the vacuum energy via their embedding into warped throats. The idea is explicitly exemplified by the embedding of the 1-family SU(5) DSB model in a local warped throat with fluxes, which we discuss in detail in terms of orientifolds of dimer diagrams.
De Sitter Uplift with Dynamical Susy Breaking
Retolaza, Ander
2015-01-01
We propose the use of D-brane realizations of Dynamical Supersymmetry Breaking (DSB) gauge sectors as sources of uplift in compactifications with moduli stabilization onto de Sitter vacua. This construction is fairly different from the introduction of anti D-branes, yet allows for tunably small contributions to the vacuum energy via their embedding into warped throats. The idea is explicitly exemplified by the embedding of the 1-family $SU(5)$ DSB model in a local warped throat with fluxes, which we discuss in detail in terms of orientifolds of dimer diagrams.
Percolation picture of nucleus break-up
International Nuclear Information System (INIS)
The production of nuclear fragments in multifragmentation and spallation reactions is viewed as a percolation phenomenon. A model of nuclear percolation is proposed. The criteria for linkage of nucleons to a cluster are defined in real and momentum spaces. In addition, ''compactness'' conditions are imposed to the clusters in both spaces. This model behaves in many respects as a two-dimensional site percolation model, exhibiting a rather well defined percolation threshold at psub(c) approximately 0.6. The concentration p is related to the number of fast particles leaving the nuclear volume. We discuss possible experimental signatures of this new break-up mechanism
Implications of Local Chiral Symmetry Breaking
La, H S
2003-01-01
The spontaneous symmetry breaking of a local chiral symmetry to its diagonal vector symmetry naturally realizes a complete geometrical structure more general than that of Yang-Mills (YM) theory, rather similar to that of gravity. A good example is the Quantum Chromodynamics (QCD) with respect to the Chiral Color model. Also, a new anomaly-free particle content for a Chiral Color model is introduced: the Chiral Color can be realized without introducing whole new generations of quarks and leptons, but by simply enlarging each generation with new exotic fermions.
Electroweak symmetry breaking beyond the Standard Model
Indian Academy of Sciences (India)
Gautam Bhattacharyya
2012-10-01
In this paper, two key issues related to electroweak symmetry breaking are addressed. First, how ﬁne-tuned different models are that trigger this phenomenon? Second, even if a light Higgs boson exists, does it have to be necessarily elementary? After a brief introduction, the ﬁne-tuning aspects of the MSSM, NMSSM, generalized NMSSM and GMSB scenarios shall be reviewed, then the little Higgs, composite Higgs and the Higgsless models shall be compared. Finally, a broad overview will be given on where we stand at the end of 2011.
Extraordinary transmission caused by symmetry breaking
Hu, Dan; Liu, Ming; Zhang, Yan
2011-01-01
The terahertz transmission properties of H-shaped annular apertures arrays (AAAs) are investigated experimentally and numerically. It is found the only odd order resonances mode are observed in the symmetrical structures but both odd and even order resonances can be shown in the asymmetrical structures. Breaking the symmetry in H- shaped AAAs by gradual displacing from H-shaped to U-shaped AAAs allows an intensity modulation depth of 99% of the second order resonance. Simulation results verify the experimental conclusion well. This result provides a tremendous opportunities for terahertz wavelength tunable filters, sensing, and near-field imaging.
Rotation Breaking Induced by ELMs on EAST
DEFF Research Database (Denmark)
Xiong, H.; Xu, G.; Sun, Y.;
Spontaneous rotation has been observed in LHCD H-mode plasmas with type III ELMs (edge localized modes) on EAST, and it revealed that type III ELMs can induce the loss of both core and edge toroidal rotation. Here we work on the breaking mechanism during the ELMs. Several large tokamaks have...... of magnetic surface, thus generate NTV (neoclassical toroidal viscosity) torque that affects toroidal rotation. We adopt 1cm maximum edge magnetic surface displacement from experimental observation, and our calculation shows that the edge torque is about 0.35 N/m2, and the core very small. The expected...
Postmodernism and Consumer Psychology: Transformation or Break?
Directory of Open Access Journals (Sweden)
Manel Hamouda
2012-01-01
Full Text Available The research’s aim is to identify the postmodern consumer characteristics. Studied through its main conditions (Hyperreality, Fragmentation, Decentered subject, Reversal of production and consumption and Paradoxical juxtaposition of opposites, postmodernism seems to affect some psychological traits of the consumer (Materialism, social desirability, locus of control and social identity. We tried to generate a number of assumptions. The check of these assumptions could answer us whether these psychological characteristics have been radically influenced by postmodernism and in this case, the consumer would have undergone a break or the effect is partial and it is only a simple transformation within the consumer.
Spontaneous symmetry breaking in a classical particle
Sánchez, L A; Sanchez, Luis Alberto; Mahecha, Jorge
2003-01-01
Due to the fact that only matter fields have phase, frequently is believed that the gauge principle can induce gauge fields only in quantum systems. But this is not necessary. This paper, of pedagogical scope, presents a classical system constituted by a particle in a classical potential, which is used as a model to illustrate the gauge principle and the spontaneous symmetry breaking. Those concepts appear in the study of second order phase transitions. Ferroelectricity, ferromagnetism, superconductivity, plasmons in a free electron gas, and the mass of vector bosons in the gauge field Yang-Mills theories, are some of the phenomena in which these transitions occur.
Cascading Multicriticality in Nonrelativistic Spontaneous Symmetry Breaking
Griffin, Tom; Horava, Petr; Yan, Ziqi
2015-01-01
Without Lorentz invariance, spontaneous global symmetry breaking can lead to multicritical Nambu-Goldstone modes with a higher-order low-energy dispersion $\\omega\\sim k^n$ ($n=2,3,\\ldots$), whose naturalness is protected by polynomial shift symmetries. Here we investigate the role of infrared divergences and the nonrelativistic generalization of the Coleman-Hohenberg-Mermin-Wagner (CHMW) theorem. We find novel cascading phenomena with large hierarchies between the scales at which the value of $n$ changes, leading to an evasion of the "no-go" consequences of the relativistic CHMW theorem.
Breaking Barriers in Polymer Additive Manufacturing
Energy Technology Data Exchange (ETDEWEB)
Love, Lonnie J [ORNL; Duty, Chad E [ORNL; Post, Brian K [ORNL; Lind, Randall F [ORNL; Lloyd, Peter D [ORNL; Kunc, Vlastimil [ORNL; Peter, William H [ORNL; Blue, Craig A [ORNL
2015-01-01
Additive Manufacturing (AM) enables the creation of complex structures directly from a computer-aided design (CAD). There are limitations that prevent the technology from realizing its full potential. AM has been criticized for being slow and expensive with limited build size. Oak Ridge National Laboratory (ORNL) has developed a large scale AM system that improves upon each of these areas by more than an order of magnitude. The Big Area Additive Manufacturing (BAAM) system directly converts low cost pellets into a large, three-dimensional part at a rate exceeding 25 kg/h. By breaking these traditional barriers, it is possible for polymer AM to penetrate new manufacturing markets.
New Mechanisms For Transmission Of Supersymmetry Breaking
Ng, S P
2004-01-01
We considered new mechanisms for transmission of supersymmetry breaking and their phenomenological consequences. Specifically, we investigated the scalar mass corrections via five-dimensional supergravity loops and explored the possibility that supersymmetry is an accidental symmetry of Nature. We find that both these lead to phenomenologically viable scenarios. In the former, the negative slepton mass-squared masses arising from minimal anomaly mediation is cured. In the latter, which constitutes a paradigm shift, we find a more natural framework for low-energy supersymmetry than the conventional picture.
Modelling loading and break-up of RC structure due to internal explosion of fragmenting shells
Weerheijm, J.; Stolz, A.; Riedel, W.; Mediavilla, J.
2012-01-01
The Klotz Group (KG), an mtemational group of experts on explosion safety, investigates the debris throw hazard associated with the accidental detonation of ammunition in reinforced concrete (RC-) structures. Experiments are combined with engineering models but also with results of advanced computat
Modelling loading and break-up of RC structure due to internal explosion of fragmenting shells
Weerheijm, J.; Stolz, A.; Riedel, W.; Mediavilla Varas, J.
2012-01-01
The Klotz Group (KG), an international group of experts on explosion safety, investigates the debris throw hazard associated with the accidental detonation of ammunition in reinforced concrete (RC-) structures. Experiments are combined with engineering models but also with results of advanced comput
Modelling loading and break-up of RC structure due to internal explosion of fragmenting shells
Weerheijm, J.; Stolz, A; Riedel , W.; Mediavilla, J.
2012-01-01
The Klotz Group (KG), an mtemational group of experts on explosion safety, investigates the debris throw hazard associated with the accidental detonation of ammunition in reinforced concrete (RC-) structures. Experiments are combined with engineering models but also with results of advanced computational modeling, which is the topie of this paper. EMI and TNO are establishing a three step approach to analyze the explosion phenomena of single and multiple bare and cased charges in a RC structu...
Spontaneous spherical symmetry breaking in atomic confinement
Sveshnikov, K
2016-01-01
The effect of spontaneous breaking of initial SO(3) symmetry is shown to be possible for an H-like atom in the ground state, when it is confined in a spherical box under general boundary conditions of "not going out" through the box surface (i.e. third kind or Robin's ones), for a wide range of physically reasonable values of system parameters. The reason is that such boundary conditions could yield a large magnitude of electronic wavefunction in some sector of the box boundary, what in turn promotes atomic displacement from the box center towards this part of the boundary, and so the underlying SO(3) symmetry spontaneously breaks. The emerging Goldstone modes, coinciding with rotations around the box center, restore the symmetry by spreading the atom over a spherical shell localized at some distances from the box center. Atomic confinement inside the cavity proceeds dynamically -- due to the boundary condition the deformation of electronic wavefunction near the boundary works as a spring, that returns the at...
Hyperscaling violation and electroweak symmetry breaking
Energy Technology Data Exchange (ETDEWEB)
Elander, Daniel, E-mail: pelander@purdue.edu [Department of Physics, Purdue University, 525 Northwestern Avenue, West Lafayette, IN 47907-2036 (United States); Lawrance, Robert; Piai, Maurizio [Department of Physics, College of Science, Swansea University, Singleton Park, Swansea, Wales (United Kingdom)
2015-08-15
We consider a class of simplified models of dynamical electroweak symmetry breaking built in terms of their five-dimensional weakly-coupled gravity duals, in the spirit of bottom-up holography. The sigma-model consists of two abelian gauge bosons and one real, non-charged scalar field coupled to gravity in five dimensions. The scalar potential is a simple exponential function of the scalar field. The background metric resulting from solving the classical equations of motion exhibits hyperscaling violation, at least at asymptotically large values of the radial direction. We study the spectrum of scalar composite states of the putative dual field theory by fluctuating the sigma-model scalars and gravity, and discuss in which cases we find a parametrically light scalar state in the spectrum. We model the spontaneous breaking of the (weakly coupled) gauge symmetry to the diagonal subgroup by the choice of IR boundary conditions. We compute the mass spectrum of spin-1 states, and the precision electroweak parameter S as a function of the hyperscaling coefficient. We find a general bound on the mass of the lightest spin-1 resonance, by requiring that the indirect bounds on the precision parameters be satisfied, that implies that precision electroweak physics excludes the possibility of a techni-rho meson with mass lighter than several TeV.
Hyperscaling violation and electroweak symmetry breaking
International Nuclear Information System (INIS)
We consider a class of simplified models of dynamical electroweak symmetry breaking built in terms of their five-dimensional weakly-coupled gravity duals, in the spirit of bottom-up holography. The sigma-model consists of two abelian gauge bosons and one real, non-charged scalar field coupled to gravity in five dimensions. The scalar potential is a simple exponential function of the scalar field. The background metric resulting from solving the classical equations of motion exhibits hyperscaling violation, at least at asymptotically large values of the radial direction. We study the spectrum of scalar composite states of the putative dual field theory by fluctuating the sigma-model scalars and gravity, and discuss in which cases we find a parametrically light scalar state in the spectrum. We model the spontaneous breaking of the (weakly coupled) gauge symmetry to the diagonal subgroup by the choice of IR boundary conditions. We compute the mass spectrum of spin-1 states, and the precision electroweak parameter S as a function of the hyperscaling coefficient. We find a general bound on the mass of the lightest spin-1 resonance, by requiring that the indirect bounds on the precision parameters be satisfied, that implies that precision electroweak physics excludes the possibility of a techni-rho meson with mass lighter than several TeV
On chiral symmetry breaking, topology and confinement
Energy Technology Data Exchange (ETDEWEB)
Shuryak, Edward
2014-08-15
We start with the relation between the chiral symmetry breaking and gauge field topology. New lattice results further enhance the notion of Zero Mode Zone, a very narrow strip of states with quasizero Dirac eigenvalues. Then we move to the issue of “origin of mass” and Brown–Rho scaling: a number of empirical facts contradicts to the idea that masses of quarks and such hadrons as ρ,N decrease near T{sub c}. We argue that while at T=0 the main contribution to the effective quark mass is chirally odd m{sub χ/}, near T{sub c} it rotates to chirally-even component m{sub χ}, because “infinite clusters” of topological solitons gets split into finite ones. Recent progress in understanding of topology require introduction of nonzero holonomy 〈A{sub 0}〉≠0, which splits instantons into N{sub c} (anti)selfdual “instanton–dyons”. Qualitative progress, as well as first numerical studies of the dyon ensemble are reported. New connections between chiral symmetry breaking and confinement are recently understood, since instanton–dyons generate holonomy potential with a minimum at confining value, if the ensemble is dense enough.
Chip breaking system for automated machine tool
Arehart, Theodore A.; Carey, Donald O.
1987-01-01
The invention is a rotary selectively directional valve assembly for use in an automated turret lathe for directing a stream of high pressure liquid machining coolant to the interface of a machine tool and workpiece for breaking up ribbon-shaped chips during the formation thereof so as to inhibit scratching or other marring of the machined surfaces by these ribbon-shaped chips. The valve assembly is provided by a manifold arrangement having a plurality of circumferentially spaced apart ports each coupled to a machine tool. The manifold is rotatable with the turret when the turret is positioned for alignment of a machine tool in a machining relationship with the workpiece. The manifold is connected to a non-rotational header having a single passageway therethrough which conveys the high pressure coolant to only the port in the manifold which is in registry with the tool disposed in a working relationship with the workpiece. To position the machine tools the turret is rotated and one of the tools is placed in a material-removing relationship of the workpiece. The passageway in the header and one of the ports in the manifold arrangement are then automatically aligned to supply the machining coolant to the machine tool workpiece interface for breaking up of the chips as well as cooling the tool and workpiece during the machining operation.
Retinal breaks due to intravitreal ocriplasmin
Directory of Open Access Journals (Sweden)
Silva RA
2014-08-01
Full Text Available Ruwan A Silva, Darius M Moshfeghi, Theodore Leng Byers Eye Institute at Stanford, Stanford University School of Medicine, Palo Alto, CA, USA Abstract: Ocriplasmin represents a new treatment option for numerous vitreoretinopathies involving an abnormal vitreomacular interface. While the drug may circumvent the traditional risks of surgical treatment, pharmacologic vitreolysis is not devoid of risk itself. This report presents two cases, one of vitreomacular traction syndrome and the other of a full-thickness macular hole, both of which were treated with an intravitreal injection of ocriplasmin. Notably, in both cases, vitreomacular traction of the macula appears to have been alleviated; however, failure to completely relieve vitreoretinal traction from the peripheral retina generated retinal breaks with one patient eventually developing a macula-involving retinal detachment. Thus, even in instances of ‘successful’ pharmacologic treatment of vitreomacular traction, continued follow-up evaluation is essential. Keywords: posterior vitreous detachment, retinal detachment, vitreomacular traction, ocriplasmin, retinal break, macular hole, laser retinopexy
Spitzer View of Lyman Break Galaxies
Magdis, Georgios E
2007-01-01
Using a combination of deep MID-IR observations obtained by IRAC, MIPS and IRS on board Spitzer we investigate the MID-IR properties of Lyman Break Galaxies (LBGs) at z~3, establish a better understanding of their nature and attempt a complete characterisation of the population. With deep mid-infrared and optical observations of ~1000 LBGs covered by IRAC/MIPS and from the ground respectively, we extend the spectral energy distributions (SEDs) of the LBGs to mid-infrared. Spitzer data reveal for the first time that the mid-infrared properties of the population are inhomogeneous ranging from those with marginal IRAC detections to those with bright rest-frame near-infrared colors and those detected at 24mu MIPS band revealing the newly discovered population of the Infrared Luminous Lyman Break Galaxies (ILLBGs). To investigate this diversity, we examine the photometric properties of the population and we use stellar population synthesis models to probe the stellar content of these galaxies. We find that a fract...
Energy Technology Data Exchange (ETDEWEB)
Koponen, P. [VTT Energy, Espoo (Finland)
1998-08-01
Electricity cannot be stored in large quantities. That is why the electricity supply and consumption are always almost equal in large power supply systems. If this balance were disturbed beyond stability, the system or a part of it would collapse until a new stable equilibrium is reached. The balance between supply and consumption is mainly maintained by controlling the power production, but also the electricity consumption or, in other words, the load is controlled. Controlling the load of the power supply system is important, if easily controllable power production capacity is limited. Temporary shortage of capacity causes high peaks in the energy price in the electricity market. Load control either reduces the electricity consumption during peak consumption and peak price or moves electricity consumption to some other time. The project Optimisation of Load Control is a part of the EDISON research program for distribution automation. The following areas were studied: Optimization of space heating and ventilation, when electricity price is time variable, load control model in power purchase optimization, optimization of direct load control sequences, interaction between load control optimization and power purchase optimization, literature on load control, optimization methods and field tests and response models of direct load control and the effects of the electricity market deregulation on load control. An overview of the main results is given in this chapter
Institute of Scientific and Technical Information of China (English)
郑桂珍; 徐德伦
2004-01-01
More and more researches show that neither the critical downward acceleration nor the critical slope of water waves is a universal constant. On the contrary, they vary with particular wave conditions. This fact renders the models either for the probability of wave breaking B or for the whitecap coverage W based on these criteria difficult to apply. In this paper and the one which follows we seek to develop models for the prediction of both B and W based on the kinematical criterion. First, several joint probabilistic distribution functions (PDFs) of wave characteristics are derived, based on which the breaking properties B and W are estimated. The estimation is made on the assumption that a wave breaks if the horizontal velocity of water particles at its crest exceeds the local wave celerity, and whitecapping occurs in regions of fluid where water particles travel faster than the waves. The consequent B and W depend on wave spectral moments of orders 0 to 4.Then the JONSWAP spectrum is used to represent the fetch-limited sea waves in deep water, so as to relate the probability of wave breaking and the whitecap coverage with wind parameters. To this end, the time-averaging technique proposed by Glazman (1986) is applied to the estimation of the spectral moments involved, and furthermore, the theoretical models are compared with available observations collected from published literature. From the comparison, the averaging time scale is determined. The final models show that the probability of wave breaking as well as the whitecap coverage depends on the dimensionless fetch. The agreement between these models and the database is reasonable.
Breaking Wave on a Slender Cylinder
DEFF Research Database (Denmark)
Ramirez, Jorge Robert Rodriguez; Frigaard, Peter; Andersen, Thomas Lykke;
2012-01-01
CFD models are promising in predicting non-linear wave loads on fixed and floating offshore structures. The NS3 model is described in this paper and it has been validated by means of model test such as wave run-up on monopiles in regular waves. The goal for the use of the NS3 model is to make a d...
3D toroidal physics: testing the boundaries of symmetry breaking
Spong, Don
2014-10-01
Toroidal symmetry is an important concept for plasma confinement; it allows the existence of nested flux surface MHD equilibria and conserved invariants for particle motion. However, perfect symmetry is unachievable in realistic toroidal plasma devices. For example, tokamaks have toroidal ripple due to discrete field coils, optimized stellarators do not achieve exact quasi-symmetry, the plasma itself continually seeks lower energy states through helical 3D deformations, and reactors will likely have non-uniform distributions of ferritic steel near the plasma. Also, some level of designed-in 3D magnetic field structure is now anticipated for most concepts in order to lead to a stable, steady-state fusion reactor. Such planned 3D field structures can take many forms, ranging from tokamaks with weak 3D ELM-suppression fields to stellarators with more dominant 3D field structures. There is considerable interest in the development of unified physics models for the full range of 3D effects. Ultimately, the questions of how much symmetry breaking can be tolerated and how to optimize its design must be addressed for all fusion concepts. Fortunately, significant progress is underway in theory, computation and plasma diagnostics on many issues such as magnetic surface quality, plasma screening vs. amplification of 3D perturbations, 3D transport, influence on edge pedestal structures, MHD stability effects, modification of fast ion-driven instabilities, prediction of energetic particle heat loads on plasma-facing materials, effects of 3D fields on turbulence, and magnetic coil design. A closely coupled program of simulation, experimental validation, and design optimization is required to determine what forms and amplitudes of 3D shaping and symmetry breaking will be compatible with future fusion reactors. The development of models to address 3D physics and progress in these areas will be described. This work is supported both by the US Department of Energy under Contract DE
Investigation of PWM-controlled MOSFET with inductive load
Ljunggren, Tobias
2002-01-01
This report is the basis for a Bachelor of Science thesis in engineering done at Volvo Powertrain in Gothenburg. The problem consisted of investigating a circuit with a PWM-controlled MOSFET driving a DC-motor. The problem was to investigate what caused the circuit to break the transistor. Finally an improvement of the circuit is designed making the MOSFET withstand the stressful conditions exposed to. An overall description of the problems with switching an inductive load using a MOSFET as...
Symplectic Modeling of Beam Loading in Electromagnetic Cavities
Abell, Dan T; Webb, Stephen D
2016-01-01
Simulating beam loading in radiofrequency accelerating structures is critical for understanding higher-order mode effects on beam dynamics, such as beam break-up instability in energy recovery linacs. Full wave simulations of beam loading in radiofrequency structures are computationally expensive, while reduced models can ignore essential physics and can be difficult to generalize. We present a self-consistent algorithm derived from the least-action principle which can model an arbitrary number of cavity eigenmodes and with a generic beam distribution.
Energy Technology Data Exchange (ETDEWEB)
Valgas, Helio Moreira; Pinto, Roberto del Giudice R.; Franca, Carlos [Companhia Energetica de Minas Gerais (CEMIG), Belo Horizonte, MG (Brazil); Lambert-Torres, Germano; Silva, Alexandre P. Alves da; Pires, Robson Celso; Costa Junior, Roberto Affonso [Escola Federal de Engenharia de Itajuba, MG (Brazil)
1994-12-31
Accurate dynamic load models allow more precise calculations of power system controls and stability limits, which are critical mainly in the operation planning of power systems. This paper describes the development of a computer program (software) for static and dynamic load model studies using the measurement approach for the CEMIG system. Two dynamic load model structures are developed and tested. A procedure for applying a set of measured data from an on-line transient recording system to develop load models is described. (author) 6 refs., 17 figs.
Directory of Open Access Journals (Sweden)
Walt Wells
2008-01-01
Full Text Available Our objective in this paper is to solve a second order differential equation for a long, simply supported column member subjected to a lateral axial load using Heun's numerical method. We will use the solution to find the critical load at which the column member will fail due to buckling. We will calculate this load using Euler's derived analytical approach for an exact solution, as well as Euler's Numerical Method. We will then compare the three calculated values to see how much they deviate from one another. During the critical load calculation, it will be necessary to calculate the moment of inertia for the column member.
Concentrated loads on concrete
DEFF Research Database (Denmark)
Lorenzen, Karen Grøndahl; Nielsen, Mogens Peter
1997-01-01
This report deals with concentrated loads on concrete.A new upper bound solution in the axisymmetrical case of a point load in the center of the end face of a cylinder is developed.Based on previous work dealing with failure mechanisms and upper bound solutions, new approximate formulas are devel......This report deals with concentrated loads on concrete.A new upper bound solution in the axisymmetrical case of a point load in the center of the end face of a cylinder is developed.Based on previous work dealing with failure mechanisms and upper bound solutions, new approximate formulas...
Experimental characterization of materials subjected to combined loading conditions
Andrusca, L.; Goanta, V.; Barsanescu, P. D.; Savin, A.
2016-08-01
In real life experience, machine and structure elements are subjected to complex loading history. Combined loading testes facilitate the understanding of materials behavior subjected to multiaxial stress state. In this paper are presented experimental investigations used to evaluate the influence of an initial type of loading on material properties which will be subsequently tested through another load type. Initial tests are tension tests, by different elongations, and subsequent tests are torsion tests, until break. Circular cross section specimens will be used in these tests. Tension tests have been performed on a universal testing machine. Subsequently torsion tests have been conducted through an attachable device. It was found that the energy associated with plastic deformation obtained by subsequent torsional tests has the dominant influence on the material total plastic energy, although initial test was tension.
Energy Technology Data Exchange (ETDEWEB)
Torop, V.M.; Orynyak, I.V. [Institute for Problems of Strength, Kiev (Ukraine); Kutovoy, O.L. [Institute of Structure Integrity, Kiev (Ukraine)
1997-04-01
A software decision support system, STRENGTH, for application of leak before break analysis, is described. The background methodology and sample application are outlined. The program allows multioptional computation of loading parameters for different types of defects, and variable properties for metals and welded joints. Structural strength is assessed, and service life predictions are made. The program is used to analyze specific defects identified by nondestructive testing.
Statistical model on the surface elevation of waves with breaking
Institute of Scientific and Technical Information of China (English)
2008-01-01
In the surface wind drift layer with constant momentum flux, two sets of the consistent surface eleva- tion expressions with breaking and occurrence conditions for breaking are deduced from the first in- tegrals of the energy and vortex variations and the kinetic and mathematic breaking criterions, then the expression of the surface elevation with wave breaking is established by using the Heaviside function. On the basis of the form of the sea surface elevation with wave breaking and the understanding of small slope sea waves, a triple composite function of real sea waves is presented including the func- tions for the breaking, weak-nonlinear and basic waves. The expression of the triple composite func- tion and the normal distribution of basic waves are the expected theoretical model for surface elevation statistics.
Symmetry Breaking in MILP Formulations for Unit Commitment Problems
Lima, Ricardo M.
2015-12-11
This paper addresses the study of symmetry in Unit Commitment (UC) problems solved by Mixed Integer Linear Programming (MILP) formulations, and using Linear Programming based Branch & Bound MILP solvers. We propose three sets of symmetry breaking constraints for UC MILP formulations exhibiting symmetry, and its impact on three UC MILP models are studied. The case studies involve the solution of 24 instances by three widely used models in the literature, with and without symmetry breaking constraints. The results show that problems that could not be solved to optimality within hours can be solved with a relatively small computational burden if the symmetry breaking constraints are assumed. The proposed symmetry breaking constraints are also compared with the symmetry breaking methods included in two MILP solvers, and the symmetry breaking constraints derived in this work have a distinct advantage over the methods in the MILP solvers.
Magnetic rotation and chiral symmetry breaking
Indian Academy of Sciences (India)
Ashok Kumar Jain; Amita
2001-08-01
The deformed mean ﬁeld of nuclei exhibits various geometrical and dynamical symmetries which manifest themselves as various types of rotational and decay patterns. Most of the symmetry operations considered so far have been deﬁned for a situation wherein the angular momentum coincides with one of the principal axes and the principal axis cranking may be invoked. New possibilities arise with the observation of rotational features in weakly deformed nuclei and now interpreted as magnetic rotational bands. More than 120 MR bands have now been identiﬁed by ﬁltering the existing data. We present a brief overview of these bands. The total angular momentum vector in such bands is tilted away from the principal axes. Such a situation gives rise to several new possibilities including breaking of chiral symmetry as discussed recently by Frauendorf. We present the outcome of such symmetries and their possible experimental veriﬁcation. Some possible examples of chiral bands are presented.
Symmetry breaking: The standard model and superstrings
Energy Technology Data Exchange (ETDEWEB)
Gaillard, M.K.
1988-08-31
The outstanding unresolved issue of the highly successful standard model is the origin of electroweak symmetry breaking and of the mechanism that determines its scale, namely the vacuum expectation value (vev)v that is fixed by experiment at the value v = 4m//sub w//sup 2///g/sup 2/ = (..sqrt..2G/sub F/)/sup /minus/1/ approx. = 1/4 TeV. In this talk I will discuss aspects of two approaches to this problem. One approach is straightforward and down to earth: the search for experimental signatures, as discussed previously by Pierre Darriulat. This approach covers the energy scales accessible to future and present laboratory experiments: roughly (10/sup /minus/9/ /minus/ 10/sup 3/)GeV. The second approach involves theoretical speculations, such as technicolor and supersymmetry, that attempt to explain the TeV scale. 23 refs., 5 figs.
Gravitino condensation, supersymmetry breaking and inflation
Houston, N
2015-01-01
Motivated by dualistic considerations of the reality of quark condensation in quantum chromodynamics, and the connections of supergravity to the exotic physics of string and M-theory, in this thesis we investigate the dynamical breaking of local supersymmetry via gravitino condensation. We firstly demonstrate non-perturbative gravitino mass generation via this mechanism in flat spacetime, and from this derive the condensate mode wavefunction renormalisation. By then calculating the full canonically normalised one-loop effective potential for the condensate mode about a de Sitter background, we demonstrate that, contrary to claims in the literature, this process may both occur and function in a phenomenologically viable manner. In particular, we find that outside of certain unfortunate gauge choices, the stability of the condensate is intimately tied via gravitational degrees of freedom to the sign of the tree-level cosmological constant. Furthermore, we find that the energy density liberated may provide the n...
Thick brane solitons breaking $Z_2$ symmetry
Peyravi, Marzieh; Lobo, Francisco S N
2015-01-01
New soliton solutions for thick branes in 4 + 1 dimensions are considered in this article. In particular, brane models based on the sine-Gordon (SG), $\\varphi^{4}$ and $\\varphi^{6}$ scalar fields are investigated; in some cases $Z_{2}$ symmetry is broken. Besides, these soliton solutions are responsible for supporting and stabilizing the thick branes. In these models, the origin of the symmetry breaking resides in the fact that the modified scalar field potential may have non-degenerate vacuua and these non-degenerate vacuua determine the cosmological constant on both sides of the brane. At last, in order to explore the particle motion in the neighborhood of the brane, the geodesic equations along the fifth dimension are studied.
Supersymmetry Breaking, Gauge Mediation, and the LHC
Energy Technology Data Exchange (ETDEWEB)
Shih, David [Rutgers Univ., New Brunswick, NJ (United States)
2015-04-14
Gauge mediated SUSY breaking (GMSB) is a promising class of supersymmetric models that automatically satisfies the precision constraints. Prior work of Meade, Seiberg and Shih in 2008 established the full, model-independent parameter space of GMSB, which they called "General Gauge Mediation" (GGM). During the first half of 2010-2015, Shih and his collaborators thoroughly explored the parameter space of GGM and established many well-motivated benchmark models for use by the experimentalists at the LHC. Through their work, the current constraints on GGM from LEP, the Tevatron and the LHC were fully elucidated, together with the possible collider signatures of GMSB at the LHC. This ensured that the full discovery potential for GGM could be completely realized at the LHC.
A (critical) overview of electroweak symmetry breaking
International Nuclear Information System (INIS)
This presentation discusses the following points: The standard Higgs, big vs. little hierarchy; Electroweak Symmetry Breaking in supersymmetry and little hierarchy of Minimal Supersymmetric Standard Model (MSSM): Buried Higgs, Bigger quartic (D-terms, Next-to-Minimal Supersymmetric Standard Model (NMSSM), fat Higgs,..); Strong dynamics and related models: Technicolor, Monopole condensate, Warped extra dimensions, Realistic RS, Higgs-less, Composite Higgs, Little Higgs. In summary, we do not understand how Higgs is light and still no trace of new physics. In Supersymmetry (SUSY) it calls for extension of MSSM. In strong dynamics models: electroweak penguin (EWP) usually issue (Warped extra dimension - composite Higgs, Higgs-less, Little Higgs, Technicolor, monopole condensation,..). None of them is fully convincing but LHC should settle these
Medium effect on charge symmetry breaking
International Nuclear Information System (INIS)
We examine the nuclear medium effect on charge symmetry breaking (CSB) caused by isospin mixing of two neutral vector mesons interacting with nucleons in the nuclear medium. Isospin mixing is assumed to occur through the transition between isoscalar and isovector mesons. We use a quantum hadrodynamic nuclear model in the mean-field approximation for the meson fields involved. We find that (i) charge symmetry is gradually restored in nuclear matter in β equilibrium as the nucleon density increases; (ii) when the system departs from β equilibrium, CSB is much enhanced because the isospin mixing depends strongly on the nucleon isovector density; (iii) this leads to the symmetry energy coefficient of 32MeV, of which more than 50 percent arises from the mesonic mean fields; (iv) the Nolen-Schiffer anomaly regarding the masses of neighboring mirror nuclei can be resolved by considering these aspects of CSB in nuclear medium. copyright 1997 The American Physical Society
Supersymmetry Breaking, Gauge Mediation, and the LHC
International Nuclear Information System (INIS)
Gauge mediated SUSY breaking (GMSB) is a promising class of supersymmetric models that automatically satisfies the precision constraints. Prior work of Meade, Seiberg and Shih in 2008 established the full, model-independent parameter space of GMSB, which they called 'General Gauge Mediation' (GGM). During the first half of 2010-2015, Shih and his collaborators thoroughly explored the parameter space of GGM and established many well-motivated benchmark models for use by the experimentalists at the LHC. Through their work, the current constraints on GGM from LEP, the Tevatron and the LHC were fully elucidated, together with the possible collider signatures of GMSB at the LHC. This ensured that the full discovery potential for GGM could be completely realized at the LHC.
Symmetry Breaking And The Nilpotent Dirac Equation
Rowlands, Peter
2004-08-01
A multivariate 4-vector representation for space-time and a quaternion representation for mass and the electric, strong and weak charges leads to a nilpotent form of the Dirac equation, which packages the entire physical information available about a fermion state. The nilpotent state vector breaks the symmetry between the strong, electric and weak interactions, by associating their respective charges with vector, scalar and pseudoscalar operators, leading directly to the SU(3) × SU(2)L × U(1) symmetry, and to particle structures and mass-generating states. In addition, the nilpotent Dirac equation has just three solutions for spherically-symmetric distance-dependent potentials, and these correspond once again to those that would be expected for the three interactions: linear for the strong interaction; inverse linear for the electromagnetic; and a harmonic oscillator-type solution, which can be equated with the dipolar annihilation and creation mechanisms of the weak interaction.
Dirac Gauginos in Low Scale Supersymmetry Breaking
Goodsell, Mark D
2014-01-01
It has been claimed that Dirac gaugino masses are necessary for realistic models of low-scale supersymmetry breaking, and yet very little attention has been paid to the phenomenology of a light gravitino when gauginos have Dirac masses. We begin to address this deficit by investigating the couplings and phenomenology of the gravitino in the effective Lagrangian approach. We pay particular attention to the phenomenology of the scalar octets, where new decay channels open up. This leads us to propose a new simplified effective scenario including only light gluinos, sgluons and gravitinos, allowing the squarks to be heavy -- with the possible exception of the third generation. Finally, we comment on the application of our results to Fake Split Supersymmetry.
Dirac gauginos in low scale supersymmetry breaking
Energy Technology Data Exchange (ETDEWEB)
Goodsell, Mark D., E-mail: mark.goodsell@lpthe.jussieu.fr [Sorbonne Universités, UPMC Univ. Paris 06, UMR 7589, LPTHE, F-75005, Paris (France); CNRS, UMR 7589, LPTHE, F-75005, Paris (France); Tziveloglou, Pantelis, E-mail: pantelis.tziveloglou@vub.ac.be [Theoretische Natuurkunde and IIHE, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels (Belgium); International Solvay Institutes, Brussels (Belgium)
2014-12-15
It has been claimed that Dirac gaugino masses are necessary for realistic models of low-scale supersymmetry breaking, and yet very little attention has been paid to the phenomenology of a light gravitino when gauginos have Dirac masses. We begin to address this deficit by investigating the couplings and phenomenology of the gravitino in the effective Lagrangian approach. We pay particular attention to the phenomenology of the scalar octets, where new decay channels open up. This leads us to propose a new simplified effective scenario including only light gluinos, sgluons and gravitinos, allowing the squarks to be heavy – with the possible exception of the third generation. Finally, we comment on the application of our results to Fake Split Supersymmetry.
Generic Rigidity for Circle Diffeomorphisms with Breaks
Kocić, Saša
2016-06-01
We prove that {C^r}-smooth ({r > 2}) circle diffeomorphisms with a break, i.e., circle diffeomorphisms with a single singular point where the derivative has a jump discontinuity, are generically, i.e., for almost all irrational rotation numbers, not {C^{1+\\varepsilon}}-rigid, for any {\\varepsilon > 0}. This result complements our recent proof, joint with Khanin (Geom Funct Anal 24:2002-2028, 2014), that such maps are generically {C^1}-rigid. It stands in remarkable contrast to the result of Yoccoz (Ann Sci Ec Norm Sup 17:333-361, 1984) that {C^r}-smooth circle diffeomorphisms are generically {C^{r-1-κ}}-rigid, for any {κ > 0}.
Cosmic acceleration from Abelian symmetry breaking
International Nuclear Information System (INIS)
We discuss a consistent theory for a self-interacting vector field, breaking an Abelian symmetry in such a way to obtain an interesting behavior for its longitudinal polarization. In an appropriate decoupling limit, the dynamics of the longitudinal mode is controlled by Galileon interactions. The full theory away from the decoupling limit does not propagate ghost modes, and can be investigated in regimes where non-linearities become important. When coupled to gravity, this theory provides a candidate for dark energy, since it admits de Sitter cosmological solutions characterized by a technically natural value for the Hubble parameter. We also consider the homogeneous evolution when, besides the vector, additional matter in the form of perfect fluids is included. We find that the vector can have an important role in characterizing the universe expansion
Information Content of Spontaneous Symmetry Breaking
Gleiser, Marcelo
2012-01-01
We propose a measure of order in the context of nonequilibrium field theory and argue that this measure, which we call relative configurational entropy (RCE), may be used to quantify the emergence of coherent low-entropy configurations, such as time-dependent or time-independent topological and nontopological spatially-extended structures. As an illustration, we investigate the nonequilibrium dynamics of spontaneous symmetry-breaking in three spatial dimensions. In particular, we focus on a model where a real scalar field, prepared initially in a symmetric thermal state, is quenched to a broken-symmetric state. For a certain range of initial temperatures, spatially-localized, long-lived structures known as oscillons emerge in synchrony and remain until the field reaches equilibrium again. We show that the RCE correlates with the number-density of oscillons, thus offering a quantitative measure of the emergence of nonperturbative spatiotemporal patterns that can be generalized to a variety of physical systems.
Hadron physics and dynamical chiral symmetry breaking
Chang, Lei; Wilson, David J
2012-01-01
Physics is an experimental science; and a constructive feedback between theory and extant and forthcoming experiments is necessary if an understanding of nonperturbative QCD is to be achieved. The Dyson-Schwinger equations connect confinement with dynamical chiral symmetry breaking, both with the observable properties of hadrons, and hence can plausibly provide a means of elucidating the empirical content of strong QCD. We illustrate these points via comments on: in-hadron condensates; dressed-quark anomalous chromo- and electro-magnetic moments; the self-limiting magnitudes of such moments and pion-loop contributions to the gap equation; deep inelastic scattering; the spectra of mesons and baryons; the critical role played by hadron-hadron interactions in producing these spectra; and nucleon elastic and transition form factors.
Breaking a Dark Degeneracy with Gravitational Waves
Lombriser, Lucas
2015-01-01
We identify a scalar-tensor model embedded in the Horndeski action whose cosmological background and linear scalar fluctuations are degenerate with the concordance cosmology. The model admits a self-accelerated background expansion at late times that is stable against perturbations with a sound speed attributed to the new field that is equal to the speed of light. While degenerate in scalar fluctuations, self acceleration of the model implies a present cosmological tensor mode propagation at 5% less efficient than in general relativity. These discrepancies will be testable with future measurements of gravitational waves emitted by events at cosmological distances. Hence, they can be used to break the dark degeneracy in our current observations between two fundamentally different explanations of cosmic acceleration - a cosmological constant and a scalar-tensor modification of gravity.
Black Holes and Abelian Symmetry Breaking
Chagoya, Javier; Tasinato, Gianmassimo
2016-01-01
Black hole configurations offer insights on the non-linear aspects of gravitational theories, and can suggest testable predictions for modifications of General Relativity. In this work, we examine exact black hole configurations in vector-tensor theories, originally proposed to explain dark energy by breaking the Abelian symmetry with a non-minimal coupling of the vector to gravity. We are able to evade the no-go theorems by Bekenstein on the existence of regular black holes in vector-tensor theories with Proca mass terms, and exhibit regular black hole solutions with a profile for the longitudinal vector polarization, characterised by an additional charge. We analytically find the most general static, spherically symmetric black hole solutions with and without a cosmological constant, and study in some detail their features, such as how the geometry depends on the vector charges. We also include angular momentum, and find solutions describing slowly-rotating black holes. Finally, we extend some of these solu...
Applicability of the leak before break concept
International Nuclear Information System (INIS)
Within the framework of the IAEA Extrabudgetary Programme on the Safety of WWER-440 Model 230 NPPs, a list of safety issues requiring broad studies of general interest have been agreed upon by an Advisory Group which met in Vienna in September 1990. The information on the status of the issues, and on amount of work already completed and under way in various countries, needs to be compiled. Moreover, an evaluation of what further work is required to resolve each of the issues is also necessary. In view of this, the IAEA has started the preparation of a series of status reports on the various issues. This report on the generic safety issue ''Applicability of the Leak Before Break Concept'' presents a comprehensive survey of technical information available in the field and identifies those which require further investigation. 50 refs, 15 figs, 2 tabs
Self-breaking retarded acid emulsion
Energy Technology Data Exchange (ETDEWEB)
Scherubel, G.A.
1979-02-20
A subterranean formation is acidized with an acid-in-oil emulsion consisting of an aqueous acidizing solution, an oil, an alkyl C/sub 8/ to C/sub 18/ primary fatty amine, and at least one diethanolamide of at least one C/sub 8/ to C/sub 18/ fatty acid. The present invention is an improved acid-in-oil acidizing emulsion, and acidizing method such as an emulsion, the emulsion being of the type containing an effective amount of at least one C/sub 8/ to C/sub 18/ primary amine as a cationic surfactant to increase the normal reaction. The diethanolamine is a nonionic surfactant which causes the emulsion to break as the acidizing capacity of the emulsion becomes substantially depleted, i.e., spent, on the formation. 41 claims.
Time-symmetry breaking in turbulence
Jucha, Jennifer; Pumir, Alain; Bodenschatz, Eberhard
2014-01-01
In three-dimensional turbulent flows, the flux of energy from large to small scales breaks time symmetry. We show here that this irreversibility can be quantified by following the relative motion of several Lagrangian tracers. We find by analytical calculation, numerical analysis and experimental observation that the existence of the energy flux implies that, at short times, two particles separate temporally slower forwards than backwards, and the difference between forward and backward dispersion grows as $t^3$. We also find the geometric deformation of material volumes, surrogated by four points spanning an initially regular tetrahedron, to show sensitivity to the time-reversal with an effect growing linearly in $t$. We associate this with the structure of the strain rate in the flow.
Unit roots, nonlinearities and structural breaks
DEFF Research Database (Denmark)
Haldrup, Niels; Kruse, Robinson; Teräsvirta, Timo;
One of the most influential research fields in econometrics over the past decades concerns unit root testing in economic time series. In macro-economics much of the interest in the area originate from the fact that when unit roots are present, then shocks to the time series processes have a...... persistent effect with resulting policy implications. From a statistical perspective on the other hand, the presence of unit roots has dramatic implications for econometric model building, estimation, and inference in order to avoid the so-called spurious regression problem. The present paper provides a...... selective review of contributions to the field of unit root testing over the past three decades. We discuss the nature of stochastic and deterministic trend processes, including break processes, that are likely to affect unit root inference. A range of the most popular unit root tests are presented and...
Higgsless approach to electroweak symmetry breaking
Grojean, Christophe
2007-01-01
Higgsless models are an attempt to achieve a breaking of the electroweak symmetry via boundary conditions at the end-points of a fifth dimension compactified on an interval, as an alternative to the usual Higgs mechanism. There is no physical Higgs scalar in the spectrum and the perturbative unitarity violation scale is delayed via the exchange of massive spin-1 KK resonances. The correct mass spectrum is reproduced in a model in warped space, which inherits a custodial symmetry from a left–right gauge symmetry in the bulk. Phenomenological challenges as well as collider signatures are presented. From the AdS/CFT perspective, this model appears as a weakly coupled dual to walking technicolour models.
Sandwich-type gated mechanical break junctions
International Nuclear Information System (INIS)
We introduce a new device architecture for the independent mechanical and electrostatic tuning of nanoscale charge transport. In contrast to previous gated mechanical break junctions with suspended source-drain electrodes, the devices presented here prevent an electromechanical tuning of the electrode gap by the gate. This significant improvement originates from a direct deposition of the source and the drain electrodes on the gate dielectric. The plasma-enhanced native oxide on the aluminum gate electrode enables measurements at gate voltages up to 1.8 V at cryogenic temperatures. Throughout the bending-controlled tuning of the source-drain distance, the electrical continuity of the gate electrode is maintained. A nanoscale island in the Coulomb blockade regime serves as a first experimental test system for the devices, in which the mechanical and electrical control of charge transport is demonstrated.
Dynamical Breaking of Generalized Yang-Mills Theory
Institute of Scientific and Technical Information of China (English)
WANGDian-Fu; SONGHe-Shan
2004-01-01
The dynamical breaking of a generalized Yang-Mills theory is discussed. It is shown, in terms of the Nambu Jona-Lasinio mechanism, that the gauge symmetry breaking can be realized dynamically in the generalized Yang-Mills theory. The combination of the generalized Yang-Mills theory and the NJL mechanism provides a way to overcome the difficulties related to the Higgs field and the Higgs mechanism in the usual spontaneous symmetry breaking theory.
Dynamical Breaking of Generalized Yang-Mills Theory
Institute of Scientific and Technical Information of China (English)
WANG Dian-Fu; SONG He-Shah
2004-01-01
The dynamical breaking of a generalized Yang-Mills theory is discussed. It is shown, in terms of the Nambu-Jona-Lasinio mechanism, that the gauge symmetry breaking can be realized dynamically in the generalized Yang-Mills theory. The combination of the generalized Yang-Mills theory and the NJL mechanism provides a way to overcome the difficulties related to the Higgs field and the Higgs mechanism in the usual spontaneous symmetry breaking theory.
Three-Dimensional Simulations of Deep-Water Breaking Waves
Brucker, Kyle A; Dommermuth, Douglas G; Adams, Paul
2014-01-01
The formulation of a canonical deep-water breaking wave problem is introduced, and the results of a set of three-dimensional numerical simulations for deep-water breaking waves are presented. In this paper fully nonlinear progressive waves are generated by applying a normal stress to the free surface. Precise control of the forcing allows for a systematic study of four types of deep-water breaking waves, characterized herein as weak plunging, plunging, strong plunging, and very strong plunging.
Supersymmetric Unification with Radiative Breaking of R-parity
Romão, J C; Valle, José W F
1997-01-01
We show how R-parity can break spontaneously as a result of radiative corrections in unified N=1 supergravity models. We illustrate this with a concrete rank-four unified model, where the spontaneous breaking of R-parity is accompanied by the existence of a physical majoron. We determine the resulting supersymmetric particle mass spectrum and show that R-parity-breaking signals may be detectable at LEP200.
Distributed Decision Making in Combined Vehicle Routing and Break Scheduling
Meyer, Christoph Manuel; Kopfer, Herbert; Kok, Adrianus Leendert; Schutten, Marco
2009-01-01
The problem of combined vehicle routing and break scheduling comprises three subproblems: clustering of customer requests, routing of vehicles, and break scheduling. In practice, these subproblems are usually solved in the interaction between planners and drivers. We consider the case that the planner performs the clustering and the drivers perform the routing and break scheduling. To analyze this problem, we embed it into the framework of distributed decision making proposed by Schneeweiss (...
Breaking Gaussian incompatibility on continuous variable quantum systems
International Nuclear Information System (INIS)
We characterise Gaussian quantum channels that are Gaussian incompatibility breaking, that is, transform every set of Gaussian measurements into a set obtainable from a joint Gaussian observable via Gaussian postprocessing. Such channels represent local noise which renders measurements useless for Gaussian EPR-steering, providing the appropriate generalisation of entanglement breaking channels for this scenario. Understanding the structure of Gaussian incompatibility breaking channels contributes to the resource theory of noisy continuous variable quantum information protocols
Breaking Gaussian incompatibility on continuous variable quantum systems
Energy Technology Data Exchange (ETDEWEB)
Heinosaari, Teiko, E-mail: teiko.heinosaari@utu.fi [Turku Centre for Quantum Physics, Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Kiukas, Jukka, E-mail: jukka.kiukas@aber.ac.uk [Department of Mathematics, Aberystwyth University, Penglais, Aberystwyth, SY23 3BZ (United Kingdom); Schultz, Jussi, E-mail: jussi.schultz@gmail.com [Turku Centre for Quantum Physics, Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy)
2015-08-15
We characterise Gaussian quantum channels that are Gaussian incompatibility breaking, that is, transform every set of Gaussian measurements into a set obtainable from a joint Gaussian observable via Gaussian postprocessing. Such channels represent local noise which renders measurements useless for Gaussian EPR-steering, providing the appropriate generalisation of entanglement breaking channels for this scenario. Understanding the structure of Gaussian incompatibility breaking channels contributes to the resource theory of noisy continuous variable quantum information protocols.
Bayesian Analysis of Dynamic Multivariate Models with Multiple Structural Breaks
Sugita, Katsuhiro
2006-01-01
This paper considers a vector autoregressive model or a vector error correction model with multiple structural breaks in any subset of parameters, using a Bayesian approach with Markov chain Monte Carlo simulation technique. The number of structural breaks is determined as a sort of model selection by the posterior odds. For a cointegrated model, cointegrating rank is also allowed to change with breaks. Bayesian approach by Strachan (Journal of Business and Economic Statistics 21 (2003) 185) ...
Simulation of dike-break processes in the Yellow River
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
Although dike-break and dam-break processes have similar unsteady and discontinuous hydrodynamic characteristics, there are significant differences. In general, dam-break simulations focus on the flood discharge, whereas dike-break simulations are required to provide detailed information on the hydraulic and breach evolution processes, such as pit-scour and breach-expansion. In order to overcome the difficulties inherent in applying existing dam-break models to dike-breaks, this paper presents an integrated model that combines the shallow water, sediment transport, riverbed deformation and breach-expansion equations. A Godunov-type finite volume method is used for the flow simulation, based on a fixed quadtree grid system. The hydrodynamic aspects of the model are validated for an idealized rectangular dam break. A representative reach in the Yellow River is selected at a location where there is a significant risk of a dike-break, and full-scale topographic and hydrologic data are available. Typical dike-break processes are successfully simulated, with predicted hydraulic characteristics and terrain changes qualitatively in agreement with laboratory data. The modeling study is of practical importance for implementation of engineering countermeasures in the Yellow River, such as breach blocking and head wrapping.
Breaking of modulated wave trains: energy and spectra evolution
De Vita, Francesco; Verzicco, Roberto; Iafrati, Alessandro
2016-04-01
The breaking of free surface waves plays an important role on the gas, heat, momentum and energy exchanges taking place across the air-sea interface. The breaking is also responsible for the dissipation of a large fraction of the wave energy, and it represents the most important dissipation term in wave forecasting approaches. In spite of its relevance, there are many aspects of the phenomenon which are still obscure. For the practical applications the dissipated energy fraction and the changes operated to the pre-breaking spectrum are the most interesting aspects. The progress in the understanding of the breaking was hindered by some inherent technical difficulties featuring its experimental investigation. Even laboratory experiments do not help substantially as most of them exploit the superposition of linear waves and the dispersive focusing to induce breaking and only few studies uses the modulational instability. The two breaking processes display substantial differences. In the dispersive focusing case the breaking occur as a single event and all the energy is dissipated within few wave periods after the onset. In the modulational instability case, the breaking happens in several events, each one lasting short fraction of the wave period Tp, with a recurrence period of about 2 Tp. Furthermore, the results available in litterature display a large scatter in the energy dissipation of each breaking event. In order to achieve a better understanding of the phenomenon the breaking generated by modulational instability is here investigated numerically by the two-fluids approach using the open source Gerris code which solves the Navier-Stokes equations with a Volume of Fluid (VOF) technique to describe the interface dynamics. The solution is initialized as a fundamental wave component with two sideband disturbances and it is left to evolve in a computational domain with periodic boundary conditions. It is shown that several breaking events occur before the breaking
Theoretical and Experimental Study of Breaking Wave on Sloping Bottoms
Institute of Scientific and Technical Information of China (English)
YANG Kuei-Sen; CHEN Yang-Yih; LI Meng-Syue; HSU Hung-Chu
2013-01-01
This paper studies the continuous evolution of breaking wave for the surface water waves propagating on a sloping beach. A Lagrangian asymptotic solution is derived. According to the solution coupled with the wave breaking criteria and the equations of water particles motion, the wave deformation and the continuous wave breaking processes for the progressive water waves propagating on a sloping bottom can be derived. A series of experiments are also conducted to compare with the theoretical solution. The results show that the present solution can reasonably describe the plunging or spilling wave breaking phenomenon.
Practical applications of the R6 leak-before-break procedure
Energy Technology Data Exchange (ETDEWEB)
Bouchard, P.J.
1997-04-01
A forthcoming revision to the R6 Leak-before-Break Assessment Procedure is briefly described. Practical application of the LbB concepts to safety-critical nuclear plant is illustrated by examples covering both low temperature and high temperature (>450{degrees}C) operating regimes. The examples highlight a number of issues which can make the development of a satisfactory LbB case problematic: for example, coping with highly loaded components, methodology assumptions and the definition of margins, the effect of crack closure owing to weld residual stresses, complex thermal stress fields or primary bending fields, the treatment of locally high stresses at crack intersections with free surfaces, the choice of local limit load solution when predicting ligament breakthrough, and the scope of calculations required to support even a simplified LbB case for high temperature steam pipe-work systems.
Practical applications of the R6 leak-before-break procedure
International Nuclear Information System (INIS)
A forthcoming revision to the R6 Leak-before-Break Assessment Procedure is briefly described. Practical application of the LbB concepts to safety-critical nuclear plant is illustrated by examples covering both low temperature and high temperature (>450 degrees C) operating regimes. The examples highlight a number of issues which can make the development of a satisfactory LbB case problematic: for example, coping with highly loaded components, methodology assumptions and the definition of margins, the effect of crack closure owing to weld residual stresses, complex thermal stress fields or primary bending fields, the treatment of locally high stresses at crack intersections with free surfaces, the choice of local limit load solution when predicting ligament breakthrough, and the scope of calculations required to support even a simplified LbB case for high temperature steam pipe-work systems
Energy Technology Data Exchange (ETDEWEB)
Frandsen, S.; Tarp Johansen, N.J.; Joergensen, H. [Forskningscenter Risoe, Roskilde (Denmark); Gravesen, H.; Soerensen, S.L. [Carl Bro, Glostrup (Denmark); Pedersen, J. [Elsam Engineering, Fredericia (Denmark); Zorn, R.; Hvidberg Knudsen, M. [DHI Water and Environment, Hoersholm (Denmark); Voelund, P. [Energi E2, Koebenhavn (Denmark)
2003-09-01
The project onbectives have been: To improve and consequently opimise the basis for design of offshore wind turbines. This is done through 1) mapping the wind, wave ice and current as well as correlations of these, and 2) by clarifyring how these external conditions transform into loads. A comprehensive effort has been made to get a thorough understanding of the uncertainties that govern the reliability of wind turbines with respect to wind and wave loading. One of the conclusions is that the reliability of wind turbines is generally lower, than the average reliability of building structures that are subject not only to environmental loads, which are very uncertain, but also imposed loads and self weight, which are less uncertain than the environmental loads. The implication is that, at the moment lower load partial safety factors for onshore wind turbines cannot be recommended. For the combination of wind and wave design loads the problem is twofold: 1). A very conservative design will be generated by simply adding the individual wind and wave design loads disregarding the independence of the short-term fluctuations of wind and wave loads. 2). Characteristic values and partial safety factors for wind and wave loads are not defined similarly. This implies that the reliability levels of turbine support structures subject to purely aerodynamic loads and subject to purely hydrodynamic loads are not identical. For the problem of combining aerodynamic design loads and hydrodynamic design loads two results have been obtained in the project: 1). By simple means a site specific wave load safety factor rendering the same safety level for hydrodynamic loads as for aerodynamic loads is derived, and next, by direct square summation of extreme fluctuations, the wind and wave load safety factors are weighted. 2). Under the assumptions that a deep water site is considered and that the wave loading is a fifty-fifty mix of drag and inertia the same wind and wave load safety factor
Breaking cover: neural responses to slow and fast camouflage-breaking motion
Yin, Jiapeng; Gong, Hongliang; An, Xu; Chen, Zheyuan; Lu, Yiliang; Andolina, Ian M.; McLoughlin, Niall; Wang, Wei
2015-01-01
Primates need to detect and recognize camouflaged animals in natural environments. Camouflage-breaking movements are often the only visual cue available to accomplish this. Specifically, sudden movements are often detected before full recognition of the camouflaged animal is made, suggesting that initial processing of motion precedes the recognition of motion-defined contours or shapes. What are the neuronal mechanisms underlying this initial processing of camouflaged motion in the primate vi...
Manville, V.; Lube, G.; Cronin, S. J.; Doyle, E. E.; Cole, S. E.; Procter, J.; Carrivick, J.; Graettinger, A. H.; Massey, C.; Jongens, R.; Watson, J.; Halstead, J.; Keys, H. J.; Lawrence, C.
2010-12-01
Break-out floods from natural or artificial impoundments are significant hazards in many environments and regions around the world, resulting in loss of life, damage to infrastructure, and dramatic geomorphic changes due to the very high rate of energy expenditure associated with high flow velocities and depths in newly created or underfit pre-existing channels. At Mt. Ruapehu, New Zealand, a forecast break-out flood from a summit Crater Lake enabled characterisation of the evolution and impact of a discrete floodwave through: (i) multi-parameter measurement of time-series hydraulic parameters at key locations along the channel by automatic equipment and human observers; and (ii) pre- and post-event high resolution topographic surveys and vertical aerial and oblique imagery of the flowpath. Failure of the tephra dam released c. 1.0 Mm3 of warm, highly mineralised water into the steep gorge of the upper Whangaehu River in flood anastomosed into multiple distributary channels, and the single-thread meandering river valley further downstream. Overall, patterns of erosion and deposition were a complex function of channel gradient, width and expansion ratio. Stage, discharge, sediment-load, geochemical, and frontal and flow velocity data show that the flood wave propagated as a number of compositionally distinct but overlapping kinematic waveforms. A complex series of interactions with the flowpath produced spatially and temporarily varying sediment loads that affected its density, viscosity, mobility, peak discharge and absolute volume. Peak volumetric bulking factor (3.6) and sediment concentrations (63 vol.%) were achieved early, and then maintained at almost constant values for c. 50 km, suggesting that feedbacks between the evolving flood and the flowpath stabilised key flow parameters at the rheological transition between hyperconcentrated and debris flow behaviour. This maximised sediment transport capacity, despite downstream changes in channel geometry that
One-Dimensional Horizontal Boussinesq Model Enhanced for Non-Breaking and Breaking Waves
Institute of Scientific and Technical Information of China (English)
DONG Guo-hai; MA Xiao-zhou; TENG Bin
2008-01-01
Based on a set of fully nonlinear Boussinesq equations up to the order of O(μ2, ε3μ2) (where ε is the ratio of wave amplitude to water depth and μ is the ratio of water depth to wave length) a numerical wave model is formulated. The model's linear dispersion is acceptably accurate to μ≌1.0, which is confirmed by comparisons between the simulated and measured time series of the regular waves propagating on a submerged bar. The moving shoreline is treated numerically by replacing the solid beach with a permeable beach. Run-up of nonbreaking waves is verified against the analytical solution for nonlinear shallow water waves. The inclusion of wave breaking is fulfilled by introducing an eddy term in the momentum equation to serve as the breaking wave force term to dissipate wave energy in the surf zone. The model is applied to cross-shore motions of regular waves including various types of breaking on plane sloping beaches. Comparisons of the model test results comprising spatial distribution of wave height and mean water level with experimental data are presented.
A Microscopic View of Oil Slick Break-Up and Emulsion Formation in Breaking Waves
Law, J.; Shahrokhi, H.; Shaw, J. M.
1996-11-01
The hydrodynamic behaviour of oil spills in breaking waves determines the appropriateness and effectiveness of remedial measures during clean-up operations. Oil slicks either disperse as fine drops or form water in oil emulsions when exposed to breaking waves. However, there is little agreement with respect to the controlling variables or mechanisms for emulsification or dispersion and predictions are unreliable. For example, predicted energy dissipation rates in breaking waves are too low to account for the drop sizes encountered experimentally[1]. In this paper, we assess the impact of hydrodynamics and physical properties on the formation of dispersions or emulsions. The maximum stable drop size for dispersions arising from oil slicks and water in oil emulsions are shown to be controlled by Raleigh-Taylor instability or the prevalent local shear stress. Data from four experimental studies[2-5], with a broad range of physical properties were fitted quantitatively. As high shear events are intermittent, stable water in oil emulsions can be formed by dispersion inversion near the water air interface or by water entrained by gas bubbles passing through oil slicks. 1) Li & Garrett, 19th AMOP, Calgary AB, 1, 185-198 (1996). 2) Lin et al., Report CG-D-54-78, U.S. Coast Guard, Washington D.C. (1978). 3) Buist, MASc Thesis, University of Toronto (1979). 4) Wallace et al., 9th AMOP, Edmonton AB, 2, 421-429, June 10-12 (1986). 5) Ross Environmental Research Ltd., Ottawa ON, Report EE-96, (1987).
Relationship between Age and the Ability to Break Scored Tablets
Notenboom, Kim; Vromans, Herman; Schipper, Maarten; Leufkens, Hubert G. M.; Bouvy, Marcel L.
2016-01-01
Background: Practical problems with the use of medicines, such as difficulties with breaking tablets, are an often overlooked cause for non-adherence. Tablets frequently break in uneven parts and loss of product can occur due to crumbling and powdering. Health characteristics, such as the presence of peripheral neuropathy, decreased grip strength and manual dexterity, can affect a patient's ability to break tablets. As these impairments are associated with aging and age-related diseases, such as Parkinson's disease and arthritis, difficulties with breaking tablets could be more prevalent among older adults. The objective of this study was to investigate the relationship between age and the ability to break scored tablets. Methods: A comparative study design was chosen. Thirty-six older adults and 36 young adults were systematically observed with breaking scored tablets. Twelve different tablets were included. All participants were asked to break each tablet by three techniques: in between the fingers with the use of nails, in between the fingers without the use of nails and pushing the tablet downward with one finger on a solid surface. It was established whether a tablet was broken or not, and if broken, whether the tablet was broken accurately or not. Results: The older adults experienced more difficulties to break tablets compared to the young adults. On average, the older persons broke 38.1% of the tablets, of which 71.0% was broken accurately. The young adults broke 78.2% of the tablets, of which 77.4% was broken accurately. Further analysis by mixed effects logistic regression revealed that age was associated with the ability to break tablets, but not with the accuracy of breaking. Conclusions: Breaking scored tablets by hand is less successful in an elderly population compared to a group of young adults. Health care providers should be aware that tablet breaking is not appropriate for all patients and for all drugs. In case tablet breaking is unavoidable, a
Skills Associated with Line Breaks in Elite Rugby Union
Directory of Open Access Journals (Sweden)
Steve den Hollander, James Brown, Michael Lambert, Paul Treu, Sharief Hendricks
2016-09-01
Full Text Available The ability of the attacking team to break through the defensive line is a key indicator of success as it creates opportunities to score tries. The aim of this study was to analyse line breaks and identify the associated skills and playing characteristics. The 2013 Super Rugby season (125 games was analysed, in which 362 line breaks were identified and coded using variables that assessed team patterns and non-contact attacking skills in the phases preceding the line break. There was an average of 3 line breaks per game, with 39% of line breaks resulting in a try. Line breaks occurred when the ball-carrier was running fast [61%, x2(4 = 25.784, p = 0.000, Cramer’s v = 0.1922, weak]. At a moderate distance, short lateral passes (19% and skip passes (15% attributed to the highest percentage of line breaks [x2(26 = 50.899, p = 0.036, Cramer’s v = 0.2484, moderate]. Faster defensive line speeds resulted in more line breaks [x2(12 = 61.703, p < 0.001, Cramer’s v = 0.3026, moderate]. Line breaks are associated with overall team success and try scoring opportunities. Awareness of the defenders line speed and depth, fast running speed when receiving the ball and quick passing between attackers to the outside backs creates line break opportunities. During training, coaches should emphasise the movement speed of the ball between attackers and manipulate the speed and distance of the defenders.
Detecting multiple breaks in geodetic time series using indicator saturation.
Jackson, Luke; Pretis, Felix
2016-04-01
Identifying the timing and magnitude of breaks in geodetic time series has been the source of much discussion. Instruments recording different geophysical phenomena may record long term trends, quasi-periodic signals at a variety of time scales from days to decades, and sudden breaks due to natural or anthropogenic causes, ranging from instrument replacement to earthquakes. Records can not always be relied upon to be continuous in time, yet one may desire to accurately bridge gaps without performing interpolation. We apply the novel Indicator Saturation (IS) method to identify breaks in a synthetic GPS time series used for the Detection of Offsets in GPS Experiments (DOGEX). The IS approach differs from alternative break detection methods by considering every point in the time series as a break, until it is demonstrated statistically that it is not. Saturating a model with a full set of break functions and removing all but significant ones, formulates the detection of breaks as a problem of model selection. This allows multiple breaks of different forms (from impulses, to shifts in the mean, and changing trends) without requiring a minimum break-length to be detected, while simultaneously modelling any underlying variation driven by additional covariates. To address selection bias in the coefficients, we demonstrate the bias-corrected estimates of break coefficients when using step-shifts in the mean of the modelled time-series. The regimes of the time-varying mean of the time-series (the `coefficient path' of the intercept determined by the detected breaks) can be used to conduct hypothesis tests on whether subsequent shifts offset each other - for example whether a measurement change induces a temporary bias rather than a permanent one. We explore this non-classical analysis method to see if it can bring about the sub millimetre errors in long term rates of land motion currently required by the GPS community.
International Nuclear Information System (INIS)
In order to evaluate the possible release of radioactivity in extreme events, some postulated accidents are analysed and studied during the design stage of Steam Generator (SG). Among the various accidents postulated, the most important are Feed Water Line Break (FWLB) and Main Steam Line Break (MSLB). This report concerns with dynamic structural analysis of SG internals following FWLB/MSLB. The pressure/drag-force time histories considered were corresponding to the conditions leading to the accident of maximum potential. The SG internals were analysed using two approaches of structural dynamics. In first approach simplified DLF method was adopted. This method yields an upper bound values of stresses and deflection. In the second approach time history analysis by Mode Superposition Technique was adopted. This approach gives more realistic results. The structure was qualified as per ASME B and PV Code SecIII NB. It was concluded that in all the components except perforated flow distribution plate, the stress values based on elastic analysis are within the limits specified by ASME Code. In case of perforated flow distribution plate during the MSLB transient the stress values based on elastic analysis are higher than the ASME Code limits. Therefore, its limit load analysis had to be done. Finally, the collapse pressure evaluated using limit load analysis was shown to be within the limits of ASME B and PV Code SecIII Nb. (author). 31 refs., 94 figs., 16 tabs
Load Balancing Scientific Applications
Energy Technology Data Exchange (ETDEWEB)
Pearce, Olga Tkachyshyn [Texas A & M Univ., College Station, TX (United States)
2014-12-01
The largest supercomputers have millions of independent processors, and concurrency levels are rapidly increasing. For ideal efficiency, developers of the simulations that run on these machines must ensure that computational work is evenly balanced among processors. Assigning work evenly is challenging because many large modern parallel codes simulate behavior of physical systems that evolve over time, and their workloads change over time. Furthermore, the cost of imbalanced load increases with scale because most large-scale scientific simulations today use a Single Program Multiple Data (SPMD) parallel programming model, and an increasing number of processors will wait for the slowest one at the synchronization points. To address load imbalance, many large-scale parallel applications use dynamic load balance algorithms to redistribute work evenly. The research objective of this dissertation is to develop methods to decide when and how to load balance the application, and to balance it effectively and affordably. We measure and evaluate the computational load of the application, and develop strategies to decide when and how to correct the imbalance. Depending on the simulation, a fast, local load balance algorithm may be suitable, or a more sophisticated and expensive algorithm may be required. We developed a model for comparison of load balance algorithms for a specific state of the simulation that enables the selection of a balancing algorithm that will minimize overall runtime.
Shear stresses and mean flow in shoaling and breaking waves
Stive, M.J.F.; De Vriend, H.J.
1994-01-01
We investigate the vertical, wave averaged distributions of shear stresses and Eulerian flow in normally incident, shoaling and breaking waves. It is found that shear stresses are solely due to wave amplitude variations, which can be caused by shoaling, boundary layer dissipation and/or breaking wav
Experimental Study on Coal-Breaking Pressure for Compressed Air
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
Based on lab model experiments and through the limit analysis, the theoretical formula of calculauoncoal-breaking pressure with compressed air was derived. The experimental result shows that blasting pressure mustexceed 84.0 MPa to break coal with compressive strength of 13.2 MPa. The research provides an important theoretical basis for the design of airshooting mining and industrial tests.
46 CFR 176.704 - Breaking of safety valve seals.
2010-10-01
... 46 Shipping 7 2010-10-01 2010-10-01 false Breaking of safety valve seals. 176.704 Section 176.704... TONS) INSPECTION AND CERTIFICATION Repairs and Alterations § 176.704 Breaking of safety valve seals... the seal on a boiler safety valve on a vessel is broken....
46 CFR 115.704 - Breaking of safety valve seals.
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Breaking of safety valve seals. 115.704 Section 115.704... CERTIFICATION Repairs and Alterations § 115.704 Breaking of safety valve seals. The owner, managing operator, or master shall notify the cognizant OCMI as soon as practicable after the seal on a boiler safety valve...
Mediation of Supersymmetry Breaking via Anti-Generation Fields
Ito, M
2000-01-01
In the context of the weakly coupled heterotic string, we propose a new model of mediating supersymmetry breaking. The breakdown of supersymmetry in the hidden sector is transmitted to anti-generation fields via gravitational interactions. Subsequent transmission of the breaking to the MSSM sector occurs via gauge interactions. It is shown that the mass spectra of superparticles are phenomenologically viable.
"Old Dead Guys": Using Activity Breaks to Teach History
Holles, Joseph H.
2009-01-01
The people and history of chemical engineering surround us: Gibbs free energy, Arrhenius Equation, and Reynolds number. Since these seminal figures appear in almost every classroom lecture, they provide an opportunity for a historically focused activity break. Each activity break provides the students with an image of the historical figure along…
Spontaneous Breaking of Spatial and Spin Symmetry in Spinor Condensates
DEFF Research Database (Denmark)
Scherer, M.; Lücke, B.; Gebreyesus, G.;
2010-01-01
Parametric amplification of quantum fluctuations constitutes a fundamental mechanism for spontaneous symmetry breaking. In our experiments, a spinor condensate acts as a parametric amplifier of spin modes, resulting in a twofold spontaneous breaking of spatial and spin symmetry in the amplified...
Break-Dance: An Unusual Cause of Hammer Syndrome
International Nuclear Information System (INIS)
We report the case of a young break-dancer presenting with hammer syndrome. This syndrome has been correlated with many professional and recreational activities but this is, to our knowledge, the first description of hammer syndrome caused by break-dancing. The etiology, diagnosis and treatment modalities of this rare syndrome are considered
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 t...
Mechanisms of supersymmetry breaking in the minimal supersymmetric standard model
Indian Academy of Sciences (India)
Probir Roy
2003-02-01
We provide a bird’s eyeview of current ideas on supersymmetry breaking mechanisms in the MSSM. The essentials of gauge, gravity, anomaly and gaugino/higgsino mediation mechanisms are covered brieﬂy and the phenomenology of the associated models is touched upon. A few statement are also made on braneworld supersymmetry breaking.
Young Children's Interpretations of Page Breaks in Contemporary Picture Storybooks
Sipe, Lawrence R.; Brightman, Anne E.
2009-01-01
This article reports on a study of the responses of a second-grade class to the page breaks in contemporary picturebooks. In a picturebook, the text and accompanying illustrations are divided into a series of facing pages called openings, and the divisions between the openings are called page breaks or turns. Unlike a novel, in which the page…
General Analysis of U-Spin Breaking in B Decays
Jung, Martin; Mannel, Thomas
2009-01-01
We analyse the breaking of U-spin on a group theoretical basis. Due to the simple behaviour of the weak effective hamiltonian under U-spin and the unique structure of the breaking terms such a group theoretical analysis leads to a manageable number of parameters. Several applications are discussed, including the decays B -> J/psi K and B -> D K.
General analysis of U-spin breaking in B decays
International Nuclear Information System (INIS)
We analyze the breaking of U-spin on a group theoretical basis. Because of the simple behavior of the weak effective Hamiltonian under U-spin and the unique structure of the breaking terms such a group theoretical analysis leads to a manageable number of parameters. Several applications are discussed, including the decays B→J/ψK and B→DK.
Salam-Weinberg symmetry breaking with superheavy Higgs particles
International Nuclear Information System (INIS)
We discuss here the possibility of the breaking of the Salam-Weinberg symmetry by Higgs particles which are superheavy. The symmetry-breaking is associated with a nonzero vacuum expectation value of fermion condensates. This mechanism, if operative in nature, will imply the absence of Higgs particles at the weak scale. (author)
ANALYSIS OF MEN'S AND WOMEN'S BASKETBALL FAST-BREAKS
Directory of Open Access Journals (Sweden)
Ignacio Refoyo
2009-01-01
opposition. For men, some dependence relationships were found between the fast break result and the following variables: duration, completion area, and opposition to its completion. For women, the results revealed a weak association between the fast break result and the opposition to its completion.
DNA breaks early in replication in B cell cancers
Research by scientists at the NCI has identified a new class of DNA sites in cells that break early in the replication process. They found that these break sites correlate with damage often seen in B cell cancers, such as diffuse large B cell lymphoma.
Breaking temporal symmetries for emission and absorption
Hadad, Yakir; Soric, Jason C.; Alu, Andrea
2016-01-01
Time-reversal symmetries impose stringent constraints on emission and absorption. Antennas, from radiofrequencies to optics, are bound to transmit and receive signals equally well from the same direction, making a directive antenna prone to receive echoes and reflections. Similarly, in thermodynamics Kirchhoff’s law dictates that the absorptivity and emissivity are bound to be equal in reciprocal systems at equilibrium, e(ω,θ)=a(ω,θ), with important consequences for thermal management and energy applications. This bound requires that a good absorber emits a portion of the absorbed energy back to the source, limiting its overall efficiency. Recent works have shown that weak time modulation or mechanical motion in suitably designed structures may largely break reciprocity and time-reversal symmetry. Here we show theoretically and experimentally that a spatiotemporally modulated device can be designed to have drastically different emission and absorption properties. The proposed concept may provide significant advances for compact and efficient radiofrequency communication systems, as well as for energy harvesting and thermal management when translated to infrared frequencies. PMID:26984502
Charge symmetry breaking in $\\Lambda$ hypernuclei revisited
Gal, Avraham
2015-01-01
The large charge symmetry breaking (CSB) implied by the $\\Lambda$ binding energy difference $\\Delta B^{4}_{\\Lambda}(0^+_{\\rm g.s.})\\equiv B_{\\Lambda}(_{\\Lambda}^4$He)$-$$B_{\\Lambda}(_{\\Lambda}^4$H) = 0.35$\\pm$0.06 MeV of the $A=4$ mirror hypernuclei ground states, determined from emulsion studies, has defied theoretical attempts to reproduce it in terms of CSB in hyperon masses and in hyperon-nucleon interactions, including one pion exchange arising from $\\Lambda-\\Sigma^0$ mixing. Using a schematic strong-interaction $\\Lambda N\\leftrightarrow\\Sigma N$ coupling model developed by Akaishi and collaborators for $s$-shell $\\Lambda$ hypernuclei, we revisit the evaluation of CSB in the $A=4$ $\\Lambda$ hypernuclei and extend it to $p$-shell mirror $\\Lambda$ hypernuclei. The model yields values of $\\Delta B^{4}_{\\Lambda} (0^+_{\\rm g.s.})\\sim 0.25$ MeV. Smaller size and mostly negative $p$-shell binding energy differences are calculated for the $A=7-10$ mirror hypernuclei, in rough agreement with the few available dat...
Generalized geometry and partial supersymmetry breaking
Energy Technology Data Exchange (ETDEWEB)
Triendl, Hagen Mathias
2010-08-15
This thesis consists of two parts. In the first part we use the formalism of (exceptional) generalized geometry to derive the scalar field space of SU(2) x SU(2)-structure compactifications. We show that in contrast to SU(3) x SU(3) structures, there is no dynamical SU(2) x SU(2) structure interpolating between an SU(2) structure and an identity structure. Furthermore, we derive the scalar manifold of the low-energy effective action for consistent Kaluza-Klein truncations as expected from N = 4 supergravity. In the second part we then determine the general conditions for the existence of stable Minkowski and AdS N = 1 vacua in spontaneously broken gauged N = 2 supergravities and construct the general solution under the assumption that two appropriate commuting isometries exist in the hypermultiplet sector. Furthermore, we derive the low-energy effective action below the scale of partial supersymmetry breaking and show that it satisfies the constraints of N = 1 supergravity. We then apply the discussion to special quaternionic-Kaehler geometries which appear in the low-energy limit of SU(3) x SU(3)-structure compactifications and construct Killing vectors with the right properties. Finally we discuss the string theory realizations for these solutions. (orig.)
LHC Report: a break from luminosity production
Jan Uythoven for the LHC team
2016-01-01
The LHC has been in great shape over the last few months, delivering over 20 fb-1 of integrated luminosity before the ICHEP conference in Chicago at the beginning of August. This is not much below the 25 fb-1 target for the whole of 2016. With this success in mind, a break in luminosity production was taken for six days, starting on 26 July 2016, for a machine development period. This year, 20 days of the LHC schedule are devoted to machine development with the aim of carrying out detailed studies of the accelerator. The 20 days are divided over five different periods, called MD blocks. They can be seen as an investment in the future, so the machine can produce collisions more efficiently in the months and years to come. A detailed programme is worked out for each MD block, whereby different specialist teams are assigned periods of four to twelve hours, depending on the topic, to perform their previously approved tests. The MD program continues 24 hours per day, as in normal physics operation. One...
Black holes and Abelian symmetry breaking
Chagoya, Javier; Niz, Gustavo; Tasinato, Gianmassimo
2016-09-01
Black hole configurations offer insights on the nonlinear aspects of gravitational theories, and can suggest testable predictions for modifications of General Relativity. In this work, we examine exact black hole configurations in vector–tensor theories, originally proposed to explain dark energy by breaking the Abelian symmetry with a non-minimal coupling of the vector to gravity. We are able to evade the no-go theorems by Bekenstein on the existence of regular black holes in vector–tensor theories with Proca mass terms, and exhibit regular black hole solutions with a profile for the longitudinal vector polarisation, characterised by an additional charge. We analytically find the most general static, spherically symmetric black hole solutions with and without a cosmological constant, and study in some detail their features, such as how the geometry depends on the vector charges. We also include angular momentum, and find solutions describing slowly-rotating black holes. Finally, we extend some of these solutions to higher dimensions.
Isospin symmetry breaking in sd shell nuclei
International Nuclear Information System (INIS)
In the thesis, we develop a microscopic approach to describe the isospin-symmetry breaking effects in sd-shell nuclei. The work is performed within the nuclear shell model. A realistic isospin-conserving Hamiltonian is perfected by a charge-dependent part consisting of the Coulomb interaction and Yukawa-type meson exchange potentials to model charge-dependent forces of nuclear origin. The extended database of the experimental isobaric mass multiplet equation coefficients was compiled during the thesis work and has been used in a fit of the Hamiltonian parameters. The constructed Hamiltonian provides an accurate theoretical description of the isospin mixing nuclear states. A specific behaviour of the IMME (Isobaric Multiplet Mass Equation) coefficients have been revealed. We present two important applications: (i) calculations of isospin-forbidden proton emission amplitudes, which is often of interest for nuclear astrophysics, and (ii) calculation on corrections to nuclear Fermi beta decay, which is crucial for the tests of fundamental symmetries of the weak interaction. (author)
Chiral symmetry breaking in QCD Lite
Engel, Georg P; Lottini, Stefano; Sommer, Rainer
2014-01-01
A distinctive feature of the presence of spontaneous chiral symmetry breaking in QCD is the condensation of low modes of the Dirac operator near the origin. The rate of condensation must be equal to the slope of (Mpi^2 Fpi^2)/2 with respect to the quark mass m in the chiral limit, where Mpi and Fpi are the mass and the decay constant of the Nambu-Goldstone bosons. We compute the spectral density of the (Hermitian) Dirac operator, the quark mass, the pseudoscalar meson mass and decay constant by numerical simulations of lattice QCD with two light degenerate Wilson quarks. We use CLS lattices at three values of the lattice spacing in the range 0.05-0.08 fm, and for several quark masses corresponding to pseudoscalar mesons masses down to 190 MeV. Thanks to this coverage of parameters space, we can extrapolate all quantities to the chiral and continuum limits with confidence. The results show that the low quark modes do condense in the continuum as expected by the Banks-Casher mechanism, and the rate of condensat...
Breaking of electroweak symmetry: origin and effects
International Nuclear Information System (INIS)
The Higgs boson appears as the corner stone of high energy physics, it might be the cause of the excess of matter that led to the formation of the structures of the universe and it seems that it drives the breaking of the electroweak symmetry. Moreover, when the stability at low energies of the Higgs boson is assured by an extra space dimension, it appears that this extra dimension can explain most issues in the flavor physics that are not understood by the standard model. The first chapter presents the main tools of effective field theories, the role of experimental data in the construction of theories valid beyond the standard model is discussed. The second chapter focuses on the electroweak baryogenesis that allows the testing of new physics via the electroweak phase transition. We detail the calculation of a Higgs potential at finite temperature. We follow the dynamics of the phase transition including nucleation an supercooling. Finally we investigate the prospects of gravity wave detection to see the effects of a strong electroweak phase transition. The 2 last chapters are dedicated to the physics of extra-dimension. The properties of the dynamics of scalar, vector fields with a 1/2 spin plunged in a 5 d. Anti de Sitter geometry are reviewed. We present a model of lepton masses and mixings based on the A4 non-Abelian discrete symmetry. It is shown that this model does not contradict the tests of electroweak precision. (A.C.)
Breaking temporal symmetries for emission and absorption.
Hadad, Yakir; Soric, Jason C; Alu, Andrea
2016-03-29
Time-reversal symmetries impose stringent constraints on emission and absorption. Antennas, from radiofrequencies to optics, are bound to transmit and receive signals equally well from the same direction, making a directive antenna prone to receive echoes and reflections. Similarly, in thermodynamics Kirchhoff's law dictates that the absorptivity and emissivity are bound to be equal in reciprocal systems at equilibrium, e(ω, θ)=a(ω, θ), with important consequences for thermal management and energy applications. This bound requires that a good absorber emits a portion of the absorbed energy back to the source, limiting its overall efficiency. Recent works have shown that weak time modulation or mechanical motion in suitably designed structures may largely break reciprocity and time-reversal symmetry. Here we show theoretically and experimentally that a spatiotemporally modulated device can be designed to have drastically different emission and absorption properties. The proposed concept may provide significant advances for compact and efficient radiofrequency communication systems, as well as for energy harvesting and thermal management when translated to infrared frequencies. PMID:26984502
Warped electroweak breaking without custodial symmetry
Cabrer, Joan A.; von Gersdorff, Gero; Quirós, Mariano
2011-03-01
We propose an alternative to the introduction of an extra gauge (custodial) symmetry to suppress the contribution of KK modes to the T parameter in warped theories of electroweak breaking. The mechanism is based on a general class of warped 5D metrics and a Higgs propagating in the bulk. The metrics are nearly AdS in the UV region but depart from AdS in the IR region, towards where KK fluctuations are mainly localized, and have a singularity outside the slice between the UV and IR branes. This gravitational background is generated by a bulk stabilizing scalar field which triggers a natural solution to the hierarchy problem. Depending on the model parameters, gauge-boson KK modes can be consistent with present bounds on EWPT for mKK≳1 TeV at 95% CL. The model contains a light Higgs mode which unitarizes the four-dimensional theory. The reduction in the precision observables can be traced back to a large wave function renormalization for this mode.
Warped Electroweak Breaking Without Custodial Symmetry
Cabrer, Joan A; Quiros, Mariano
2010-01-01
We propose an alternative to the introduction of an extra gauge (custodial) symmetry to suppress the contribution of KK modes to the T parameter in warped theories of electroweak breaking. The mechanism is based on a general class of warped 5D metrics and a Higgs propagating in the bulk. The metrics are nearly AdS in the UV region but depart from AdS in the IR region, towards where KK fluctuations are mainly localized, and have a singularity outside the slice between the UV and IR branes. This gravitational background is generated by a bulk stabilizing scalar field which triggers a natural solution to the hierarchy problem. Depending on the model parameters, gauge-boson KK modes can be consistent with present bounds on EWPT for m > 1 TeV at 95% CL. The model contains a light Higgs mode which unitarizes the four-dimensional theory. The reduction in the precision observables can be traced back to a large wave function renormalization for this mode.
Breaking temporal symmetries for emission and absorption
Hadad, Yakir; Soric, Jason C.; Alu, Andrea
2016-03-01
Time-reversal symmetries impose stringent constraints on emission and absorption. Antennas, from radiofrequencies to optics, are bound to transmit and receive signals equally well from the same direction, making a directive antenna prone to receive echoes and reflections. Similarly, in thermodynamics Kirchhoff's law dictates that the absorptivity and emissivity are bound to be equal in reciprocal systems at equilibrium, e(ω,θ)=a(ω,θ), with important consequences for thermal management and energy applications. This bound requires that a good absorber emits a portion of the absorbed energy back to the source, limiting its overall efficiency. Recent works have shown that weak time modulation or mechanical motion in suitably designed structures may largely break reciprocity and time-reversal symmetry. Here we show theoretically and experimentally that a spatiotemporally modulated device can be designed to have drastically different emission and absorption properties. The proposed concept may provide significant advances for compact and efficient radiofrequency communication systems, as well as for energy harvesting and thermal management when translated to infrared frequencies.
Self-breaking retarded acid emulsion
Energy Technology Data Exchange (ETDEWEB)
Scherubel, G.A.
1980-10-07
An acid-in-oil acidizing emulsion, and acidizing method use an emulsion of the type containing an effective amount of at least one C8 to C18 primary amine as a cationic surfactant to increase the normal reaction time of the acid with an acid soluble formation. The composition and method aspects are both affected by the inclusion in the emulsion of an effective amount of a nonionic surfactant. Specifically, the emulsion resides in a composition for acidizing a subterranean formation, the composition being of the acidizing solution-in-oil emulsion type containing an effective amount of an alkyl C8 to C18 primary amine to reduce the normal reaction rate of the emulsion, and an effective amount of at least one diethanolamide of at least one C8 to C18 fatty acid so that the emulsion substantially completely breaks when the acidizing capacity of the emulsion becomes substantially spent as a result of reaction with such a formation. 19 claims.
Golden Probe of Electroweak Symmetry Breaking
Chen, Yi; Spiropulu, Maria; Stolarski, Daniel; Vega-Morales, Roberto
2016-01-01
The ratio of the Higgs couplings to $WW$ and $ZZ$ pairs, $\\lambda_{WZ}$, is a fundamental parameter in electroweak symmetry breaking as well as a measure of the (approximate) custodial symmetry possessed by the gauge boson mass matrix. We show that Higgs decays to four leptons are sensitive, via tree level/1-loop interference effects, to both the magnitude and, in particular, overall sign of $\\lambda_{WZ}$. Determining this sign requires interference effects, as it is nearly impossible to measure with rate information. Furthermore, simply determining the sign effectively establishes the custodial representation of the Higgs boson. We find that $h\\to4\\ell$ ($4\\ell \\equiv 2e2\\mu, 4e, 4\\mu$) decays have excellent prospects of directly establishing the overall sign at a high luminosity 13 TeV LHC. We also examine the ultimate LHC sensitivity in $h\\to4\\ell$ to the magnitude of $\\lambda_{WZ}$. Our results are independent of other measurements of the Higgs boson couplings and, in particular, largely free of assumpti...
Spontaneous Planar Chiral Symmetry Breaking in Cells
Hadidjojo, Jeremy; Lubensky, David
Recent progress in animal development has highlighted the central role played by planar cell polarity (PCP) in epithelial tissue morphogenesis. Through PCP, cells have the ability to collectively polarize in the plane of the epithelium by localizing morphogenetic proteins along a certain axis. This allows direction-dependent modulation of tissue mechanical properties that can translate into the formation of complex, non-rotationally invariant shapes. Recent experimental observations[1] show that cells, in addition to being planar-polarized, can also spontaneously develop planar chirality, perhaps in the effort of making yet more complex shapes that are reflection non-invariant. In this talk we will present our work in characterizing general mechanisms that can lead to spontaneous chiral symmetry breaking in cells. We decompose interfacial concentration of polarity proteins in a hexagonal cell packing into irreducible representations. We find that in the case of polar concentration distributions, a chiral state can only be reached from a secondary instability after the cells are polarized. However in the case of nematic distributions, we show that a finite-amplitude (subcritical, or ``first-order'') nematic transition can send the system from disorder directly to a chiral state. In addition, we find that perturbing the system by stretching the hexagonal packing enables direct (supercritical, or ``second-order'') chiral transition in the nematic case. Finally, we do a Landau expansion to study competition between stretch-induced chirality and the tendency towards a non-chiral state in packings that have retained the full 6-fold symmetry.
Generalized Geometry and Partial Supersymmetry Breaking
Triendl, Hagen
2010-01-01
This review article consists of two parts. In the first part we use the formalism of (exceptional) generalized geometry to derive the scalar field space of SU(2)xSU(2)-structure compactifications. We show that in contrast to SU(3)xSU(3) structures, there is no dynamical SU(2)xSU(2) structure interpolating between an SU(2) structure and an identity structure. Furthermore, we derive the scalar manifold of the low-energy effective action for consistent Kaluza-Klein truncations as expected from N=4 supergravity. In the second part we then determine the general conditions for the existence of stable Minkowski and AdS N=1 vacua in spontaneously broken gauged N=2 supergravities and construct the general solution under the assumption that two appropriate commuting isometries exist in the hypermultiplet sector. Furthermore, we derive the low-energy effective action below the scale of partial supersymmetry breaking and show that it satisfies the constraints of N=1 supergravity. We then apply the discussion to special q...
Is Electroweak Symmetry Breaking Still Natural in the MSSM?
Dutta, Bhaskar
2016-01-01
The absence of any signal of supersymmetry (SUSY) at the LHC has raised the SUSY particle mass scale compared to $Z$ boson mass $M_Z$. We investigate the naturalness of the electroweak symmetry breaking after considering radiative symmetry breaking along with 125 GeV Higgs mass. We find that the important quantity to measure the naturalness of the hierarchy between the SUSY scale and $M_Z$ is the separation between the radiative symmetry breaking scale, i.e., where $m_{H_u}^2+\\mu^2$ turns negative for large $\\tan\\beta$ case ($\\mu$ is the Higgsino mass and $m_{H_u}$ is the SUSY breaking up-type Higgs boson mass) and the average stop mass. Using this measure, one can show that the electroweak symmetry breaking can be natural even if $\\mu$ is large contrary to the prevailing claim that $\\mu$ is needed to be small to maintain the naturalness.
A synopsis of experimental activities on small-break LOCA
International Nuclear Information System (INIS)
Through reactor safety studies like WASH 1400 or the ''Deutsche Risiko-Studie'' the attention has turned from large break loss of coolant accidents to small breaks because of the high contribution of this type of accidents to core meltdown. But only after the TMI-2 accident were also the main activities in the experimental fields shifted world-wide to the small break LOCAs. Since TMI numerous research programs have either been finished or are underway. This review paper presents: a classification of the various types of transients according to break size; a discussion of major physical phenomena associated with a small break LOCA, and a description of a few selected research programs and the most important results achieved. (author)
Detecting structural breaks in time series via genetic algorithms
DEFF Research Database (Denmark)
Doerr, Benjamin; Fischer, Paul; Hilbert, Astrid;
2016-01-01
Detecting structural breaks is an essential task for the statistical analysis of time series, for example, for fitting parametric models to it. In short, structural breaks are points in time at which the behaviour of the time series substantially changes. Typically, no solid background knowledge...... of the time series under consideration is available. Therefore, a black-box optimization approach is our method of choice for detecting structural breaks. We describe a genetic algorithm framework which easily adapts to a large number of statistical settings. To evaluate the usefulness of different crossover...... operator alone. Moreover, we present a specific fitness function which exploits the sparse structure of the break points and which can be evaluated particularly efficiently. The experiments on artificial and real-world time series show that the resulting algorithm detects break points with high precision...
Wave Loading on Bodies in the Free Surface Using Smoothed Particle Hydrodynamics (SPH)
Omidvar, Pourya
2010-01-01
This thesis investigates wave loading on bodies in the free surface using smoothed particle hydrodynamics (SPH). This includes wave loading on fixed bodies, waves generated by heaving bodies in still water and the heave response of a body in waves, representing a wave energy device. SPH is a flexible Lagrangian technique for CFD simulations, which in principle applies to steep and breaking waves without special treatment allowing us to simulate highly nonlinear and potentially violent flows e...
Goose`s eggshell strength at compressive loading
Directory of Open Access Journals (Sweden)
Šárka Nedomová
2014-02-01
Full Text Available The paper deals with the study of the goose eggs behaviour under compressive loading between two plates using testing device TIRATEST. The influences of the loading orientation as well as the effect of compressive velocity are studied. 226 eggs from Landes geese were chosen for the experiment. Eggs have been loaded between their poles and in the equator plane. Five different compressive velocities (0.0167, 0.167, 0.334, 1.67 and 5 mm.s-1 were used. The increase in rupture force with loading rate was observed for loading in all direction (along main axes. Dependence of the rupture force on loading rate was quantifies and described. The highest rupture force was obtained when the eggs were loaded along their axes of symmetry (X-axis. Compression in the equator plane (along the Z-axis required the least compressive force to break the eggshells. The eggshell strength was described by the rupture force, specific rupture deformation and by the absorbed energy. The rupture force is highly dependent on compression speeds. The dependence of the rupture force on the compression velocity can be described by a power function. The same is valid for the rate dependence of the energy absorbed by the egg up to the fracture. The rate sensitivity of the Goose's eggshells strength is significantly higher than that reported for the hen's eggs
National Aeronautics and Space Administration — We provide MATLAB binary files (.mat) and comma separated values files of data collected from a pilot study of a plug load management system that allows for the...
Lumbriculus variegatus loading study
U.S. Environmental Protection Agency — Results from sediment bioaccumulation tests with Lumbriculus variegatus with evaluating the effects of organism loading density This dataset is associated with the...
Kirschner, Paul A.; Kirschner, Femke; Paas, Fred
2010-01-01
Kirschner, P. A., Kirschner, F. C., & Paas, F. (2009). Cognitive load theory. In E. M. Anderman & L. H. Anderman (Eds.). Psychology of classroom learning: An encyclopedia, Volume 1, a-j (pp. 205-209). Detroit, MI: Macmillan Reference.
U.S. Environmental Protection Agency — LSPC is the Loading Simulation Program in C++, a watershed modeling system that includes streamlined Hydrologic Simulation Program Fortran (HSPF) algorithms for...
Federal Laboratory Consortium — FUNCTION: Provides the capability to perform large-scale structural loads testing on spacecraft and other structures. Results from these tests can be used to verify...
Energy Technology Data Exchange (ETDEWEB)
Woof, M.
1998-06-01
An electric skid steer loader has been developed in the UK by Hay Royds, offering an innovative approach to underground loading. Its compact design makes it ideal for loading thin coal piled at the face to conveyors in restricted headroom conditions. The loader is in operation at Hay Royd`s colliery near Huddersfield in Yorkshire and at Rashiehill mine near Edinburgh. The article describes the design and operation of the skid steer loader. 1 photo.
A lead-before-break strategy for primary heat transport piping of 500 MWe Indian PHWR
Energy Technology Data Exchange (ETDEWEB)
Chattopadhyay, J.; Dutta, B.K.; Kushwaha, H.S. [Bhabha Atomic Research Centre, Bombay (India)] [and others
1997-04-01
Leak-Before-Break (LBB) is being used to design the primary heat transport piping system of 500 MWe Indian Pressurized Heavy Water Reactors (IPHWR). The work is categorized in three directions to demonstrate three levels of safety against sudden catastrophic break. Level 1 is inherent in the design procedure of piping system as per ASME Sec.III with a well defined factor of safety. Level 2 consists of fatigue crack growth study of a postulated part-through flaw at the inside surface of pipes. Level 3 is stability analysis of a postulated leakage size flaw under the maximum credible loading condition. Developmental work related to demonstration of level 2 and level 3 confidence is described in this paper. In a case study on fatigue crack growth on PHT straight pipes for level 2, negligible crack growth is predicted for the life of the reactor. For level 3 analysis, the R6 method has been adopted. A database to evaluate SIF of elbows with throughwall flaws under combined internal pressure and bending moment has been generated to provide one of the inputs for R6 method. The methodology of safety assessment of elbow using R6 method has been demonstrated for a typical pump discharge elbow. In this analysis, limit load of the cracked elbow has been determined by carrying out elasto-plastic finite element analysis. The limit load results compared well with those given by Miller. However, it requires further study to give a general form of limit load solution. On the experimental front, a set of small diameter pipe fracture experiments have been carried out at room temperature and 300{degrees}C. Two important observations of the experiments are - appreciable drop in maximum load at 300{degrees}C in case of SS pipes and out-of-plane crack growth in case of CS pipes. Experimental load deflection curves are finally compared with five J-estimation schemes predictions. A material database of PHT piping materials is also being generated for use in LBB analysis.
A lead-before-break strategy for primary heat transport piping of 500 MWe Indian PHWR
International Nuclear Information System (INIS)
Leak-Before-Break (LBB) is being used to design the primary heat transport piping system of 500 MWe Indian Pressurized Heavy Water Reactors (IPHWR). The work is categorized in three directions to demonstrate three levels of safety against sudden catastrophic break. Level 1 is inherent in the design procedure of piping system as per ASME Sec.III with a well defined factor of safety. Level 2 consists of fatigue crack growth study of a postulated part-through flaw at the inside surface of pipes. Level 3 is stability analysis of a postulated leakage size flaw under the maximum credible loading condition. Developmental work related to demonstration of level 2 and level 3 confidence is described in this paper. In a case study on fatigue crack growth on PHT straight pipes for level 2, negligible crack growth is predicted for the life of the reactor. For level 3 analysis, the R6 method has been adopted. A database to evaluate SIF of elbows with throughwall flaws under combined internal pressure and bending moment has been generated to provide one of the inputs for R6 method. The methodology of safety assessment of elbow using R6 method has been demonstrated for a typical pump discharge elbow. In this analysis, limit load of the cracked elbow has been determined by carrying out elasto-plastic finite element analysis. The limit load results compared well with those given by Miller. However, it requires further study to give a general form of limit load solution. On the experimental front, a set of small diameter pipe fracture experiments have been carried out at room temperature and 300 degrees C. Two important observations of the experiments are - appreciable drop in maximum load at 300 degrees C in case of SS pipes and out-of-plane crack growth in case of CS pipes. Experimental load deflection curves are finally compared with five J-estimation schemes predictions. A material database of PHT piping materials is also being generated for use in LBB analysis
Breaking Bad News to Togolese Patients.
Kpanake, Lonzozou; Sorum, Paul Clay; Mullet, Etienne
2016-11-01
The aim of this study was to map Togolese people's positions regarding the breaking of bad news to elderly patients. Two hundred eleven participants who had in the past received bad medical news were presented with 72 vignettes depicting communication of bad news to elderly female patients and asked to indicate the acceptability of the physician's conduct in each case. The vignettes were all combinations of five factors: (a) the severity of the disease, (b) the patient's wishes about disclosure, (c) the level of social support during hospitalization, (d) the patient's psychological robustness, and (e) the physician's decision about how to communicate the bad news. Five qualitatively different positions were found. Two percent of the participants preferred that the physician always tell the full truth to both the patient and her relatives, 8% preferred that the truth be told depending on the physician's perception of the situation, 15% preferred that the physician tell the truth but understood that in some cases nondisclosure to the patient was not inappropriate, 33% preferred that the physician tell the full truth to the relatives but not as much information to the patient, and 42% preferred that the physician tell the full truth to the relatives only. These findings present a challenge to European physicians taking care of African patients living in Europe or working in African hospitals, and to African physicians trained in Europe and now working in their home countries. If these physicians respect the imperative of always telling the truth directly to their patients, their behavior may trigger anger and considerable misunderstanding among African patients and their families.
Numerical simulation of hydrodynamic wave loading by a compressible two-phase flow method
Wemmenhove, Rik; Luppes, Roelf; Veldman, Arthur; Bunnik, Tim
2015-01-01
Hydrodynamic wave loading on and in offshore structures is studied by carrying out numerical simulations. Particular attention is paid to complex hydrodynamic phenomena such as wave breaking and air entrapment. The applied CFD method, ComFLOW, solves the Navier–Stokes equations with an improved Volu
Interface debond crack growth in tension–tension cyclic loading of single fiber polymer composites
DEFF Research Database (Denmark)
Pupurs, Andrejs; Goutianos, Stergios; Brøndsted, Povl;
2013-01-01
Fiber/matrix interface debond crack growth from a fiber break is defined as one of the key mechanisms of fatigue damage in unidirectional composites. Considering debond as an interface crack its growth in cyclic loading is analyzed utilizing a power law, where the debond growth rate is a power fu...
Modeling of the eddy viscosity by breaking waves
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
Breaking wave induced nearsurface turbulence has important consequences for many physical and biochemical processes including water column and nutrients mixing, heat and gases exchange across air-sea interface. The energy loss from wave breaking and the bubble plume penetration depth are estimated. As a consequence, the vertical distribution of the turbulent kinetic energy (TKE), the TKE dissipation rate and the eddy viscosity induced by wave breaking are also provided. It is indicated that model results are found to be consistent with the observational evidence that most TKE generated by wave breaking is lost within a depth of a few meters near the sea surface. High turbulence level with intensities of eddy viscosity induced by breaking is nearly four orders larger than υwl(=κu *wz), the value predicted for the wall layer scaling close to the surface, where u *w is the friction velocity in water, κ with 0.4 is the von Kármán constant, and z is the water depth, and the strength of the eddy viscosity depends both on wind speed and sea state, and decays rapidly through the depth. This leads to the conclusion that the breaking wave induced vertical mixing is mainly limited to the near surface layer, well above the classical values expected from the similarity theory. Deeper down, however, the effects of wave breaking on the vertical mixing become less important.
Probabilistic assessment of leak-before-break
International Nuclear Information System (INIS)
A summary of results illustrating what might be derived from a probabilistic risk assessment (PRA) study follows. The failure probabilities for larger sizes of nuclear piping are considered to be in the range of 10-4 to 10-6 per reactor-year (exclusive of intergranular stress corrosion cracking (IGSCC). Smaller pipe sizes, of lesser safety significance, have much higher failure rates. In BWRs, IGSCC can cause failure rates much higher than 10-4 in piping 4 to 10 in. in size. Suggested failure mechanisms apply in most instances, exclusive of IGSCC. Catastrophic failures would appear more likely from operator error or design and construction errors (water hammer, improper handling of dynamic loads, and undetected fabrication defects) rather than conventional flaw initiation and growth by fatigue
Dark Matter and Dark Energy from Gravitational Symmetry Breaking
Fuzfa, A
2010-01-01
We build a mechanism of gravitational symmetry breaking (GSB) of a global U(1) symmetry based on the relaxation of the equivalence principle due to the mass variation of pseudo Nambu-Goldstone dark matter (DM) particles. This GSB process is described by the modified cosmological convergence mechanism of the Abnormally Weighting Energy (AWE) Hypothesis previously introduced by the authors. Several remarkable constraints from the Hubble diagram of far-away supernovae are derived, notably on the explicit and gravitational symmetry breaking energy scales of the model. We then briefly present some consequences on neutrino masses when this mechanism is applied to the particular case of the breaking of lepton number symmetry.
Vacuum condensates as a mechanism of spontaneous supersymmetry breaking
Capolupo, Antonio
2015-01-01
A possible mechanism for the spontaneous breaking of SUSY, based on the presence of vacuum condensates, is reviewed. Such a mechanism could occur in many physical examples, both at the fundamental and emergent level, and would be formally analogous to spontaneous SUSY breaking at finite temperature in the TFD formalism, in which case it can be applied as well. A possible experimental setup for detecting such a breaking through measurement of the Anandan-Aharonov invariants associated with vacuum condensates in an optical lattice model is proposed.
Vacuum Condensates as a Mechanism of Spontaneous Supersymmetry Breaking
Directory of Open Access Journals (Sweden)
Antonio Capolupo
2015-01-01
Full Text Available A possible mechanism for the spontaneous breaking of SUSY, based on the presence of vacuum condensates, is reviewed. Such a mechanism could occur in many physical examples, at both the fundamental and emergent levels, and would be formally analogous to spontaneous SUSY breaking at finite temperature in the TFD formalism, in which case it can be applied as well. A possible experimental setup for detecting such a breaking through measurement of the Anandan-Aharonov invariants associated with vacuum condensates in an optical lattice model is proposed.
Spontaneous symmetry breaking, self-trapping, and Josephson oscillations
2013-01-01
This volume collects a a number of contributions on spontaneous symmetry breaking. Current studies in this general field are going ahead at a full speed. The book present review chapters which give an overview on the major break throughs of recent years. It covers a number of different physical settings which are introduced when a nonlinearity is added to the underlying symmetric problems and its strength exceeds a certain critical value. The corresponding loss of symmetry, called spontaneous symmetry breaking, alias self-trapping into asymmetric states is extensively discussed in this book.
An automatic system for elaboration of chip breaking diagrams
DEFF Research Database (Denmark)
Andreasen, Jan Lasson; De Chiffre, Leonardo
1998-01-01
A laboratory system for fully automatic elaboration of chip breaking diagrams has been developed and tested. The system is based on automatic chip breaking detection by frequency analysis of cutting forces in connection with programming of a CNC-lathe to scan different feeds, speeds and cutting...... depths. An evaluation of the system based on a total of 1671 experiments has shown that unfavourable snarled chips can be detected with 98% certainty which indeed makes the system a valuable tool in chip breakability tests. Using the system, chip breaking diagrams can be elaborated with a previously...
Active and break spells of the Indian summer monsoon
Indian Academy of Sciences (India)
M Rajeevan; Sulochana Gadgil; Jyoti Bhate
2010-06-01
In this paper, we suggest criteria for the identification of active and break events of the Indian summer monsoon on the basis of recently derived high resolution daily gridded rainfall dataset over India (1951–2007). Active and break events are defined as periods during the peak monsoon months of July and August, in which the normalized anomaly of the rainfall over a critical area, called the monsoon core zone exceeds 1 or is less than −1.0 respectively, provided the criterion is satisfied for at least three consecutive days. We elucidate the major features of these events. We consider very briefly the relationship of the intraseasonal fluctuations between these events and the interannual variation of the summer monsoon rainfall. We find that breaks tend to have a longer life-span than active spells. While, almost 80% of the active spells lasted 3–4 days, only 40% of the break spells were of such short duration. A small fraction (9%) of active spells and 32% of break spells lasted for a week or longer. While active events occurred almost every year, not a single break occurred in 26% of the years considered. On an average, there are 7 days of active and break events from July through August. There are no significant trends in either the days of active or break events. We have shown that there is a major difference between weak spells and long intense breaks. While weak spells are characterized by weak moist convective regimes, long intense break events have a heat trough type circulation which is similar to the circulation over the Indian subcontinent before the onset of the monsoon. The space-time evolution of the rainfall composite patterns suggests that the revival from breaks occurs primarily from northward propagations of the convective cloud zone. There are important differences between the spatial patterns of the active/break spells and those characteristic of interannual variation, particularly those associated with the link to ENSO. Hence, the
Direct gauge mediation of uplifted metastable supersymmetry breaking in supergravity
International Nuclear Information System (INIS)
We propose a direct gauge mediation model based on an uplifted metastable supersymmetry (SUSY) breaking coupled to supergravity. A constant superpotential plays an essential role to fix the moduli as well as breaking SUSY and R symmetry and the cancellation of the cosmological constant. Gaugino masses are generated at leading order of SUSY breaking scale, and comparable to the sfermion masses as in the ordinary gauge mediation. The Landau pole problem for QCD coupling can be easily solved since more than half of messengers become superheavy, which are heavier than the grand unified theory (GUT) scale.
Breaking of Waves over a Steep Bottom Slope
DEFF Research Database (Denmark)
Jensen, Morten S.
The thesis deals with the wave breaking process of waves propagating over a steep submerged bottom slope. The amount of energy dissipated in the wave breaking process is focused upon. An extensive number of experimental tests (>400) using regular and irregular waves breaking over a simulated reef...... in the hydraulic laboratory are performed. Based on the experimental tests several formulae developed. Formulae are capable of predicting the transmitted wave height and wave energy flux, respectively. Futhermore, a numerical wave model based on the extended Mild-Slope equation has been developed. The model...
International Nuclear Information System (INIS)
The Executive Director for Operations (EDO) in establishing the Piping Review Committee concurred in its overall scope that included an evaluation of the potential for pipe breaks. The Pipe Break Task Group has responded to this directive. This report summarizes a review of regulatory documents and contains the Task Group's recommendations for application of the leak-before-break (LBB) approach to the NRC licensing process. The LBB approach means the application of fracture mechanics technology to demonstrate that high energy fluid piping is very unlikely to experience double-ended ruptures or their equivalent as longitudinal or diagonal splits. The Task Group's reommendations and discussion are founded on current and ongoing NRC staff actions as presented in Section 3.0 of this report. Additional more detailed comments and discussion are presented in Section 5.0 and in Appendices A and B. The obvious issues are the reexamination of the large pipe break criteria and the implications of any changes in the criteria as they influence items such as jet loads and pipe whip. The issues have been considered and the Task Group makes the following recommendations
DEFF Research Database (Denmark)
Hoffmeyer, Preben; Sørensen, John Dalsgaard
2007-01-01
mechanosorptive effect was demonstrated both in terms of increased creep and shortening of time to failure. The test results were employed for the calibration of four existing duration of load models. The effect of long-term loading was expressed as the stress level SL50 to cause failure after 50 years of loading...... were formed. Four groups were subjected to short-term strength tests, and four groups were subjected to long-term tests. Creep and time to failure were moni-tored. Time to failure as a function of stress level was established and the reliability of stress level assessment was discussed. A significant....... SL50 was found to be of the order 0.60 for MC = 11 %, 0.50 for MC = 20 % and 0.44 MC varying be-tween 11 % and 20 %. The test results revealed no evidence of a threshold stress level. A reliability based cali-bration of load-duration factors was performed using probabilistic models of loads...
TE(01) High Power Disk Loaded Guide Load
Farkas, Zoltan D
2005-01-01
A method to design a matching section from a smooth guide to a disk loaded guide, using a variation of broadband matching* is described. Using this method, we show how to design high power loads, filters and attenuators. The load consists of a disk loaded coaxial guide, operating in the T01
Schubert, Ingo; Schubert, Veit; Fuchs, Jörg
2011-01-01
“Break-induced replication” (BIR) is considered as one way to repair DNA double-strand breaks (DSBs). BIR is defined as replication of the proximal break-ends up to the end of the broken chromosome using an undamaged (homologous) double-stranded template and mimicking a non-reciprocal translocation. This phenomenon was detected by genetic experiments in yeast. BIR is assumed to occur also in mammals, but experimental evidence is not yet at hand. We have studied chromosomes of the field bean, ...
Ingo eSchubert; Veit eSchubert; Jörg eFuchs
2011-01-01
‘Break-induced replication’ (BIR) is considered as one way to repair DNA double-strand breaks (DSBs). BIR is defined as replication of the proximal break-ends up to the end of the broken chromosome using an undamaged homologous double-stranded template and mimicking a non-reciprocal translocation. This phenomenon was detected by genetic experiments in yeast. BIR is assumed to occur also in mammals, but experimental evidence is not yet at hand. We have studied chromosomes of the field bean, V...
Rodríguez Rodríguez, Javier; Martínez Bazán, Carlos; Montañés García, José Luis
2003-01-01
A new method has been developed to measure experimentally the break-up properties of bubbles. The technique is based on the application of a particle tracking velocimetry algorithm to high-speed video images not only to measure the velocity of the bubbles, but also to detect the break-up events. Thus the algorithm is able to associate every broken bubble with the daughter bubbles formed upon their corresponding break-up. Moreover, the lifetime, as well as the number and size of fragments resu...
DEFF Research Database (Denmark)
Raun Gottfredsen, F.
In this thesis results from experiments on mortar joints and masonry as well as methods of calculation of strength and deformation of laterally loaded masonry are presented. The strength and deformation capacity of mortar joints have been determined from experiments involving a constant compressive...... stress and increasing shear. The results show a transition to pure friction as the cohesion is gradually destroyed. An interface model of a mortar joint that can take into account this aspect has been developed. Laterally loaded masonry panels have also been tested and it is found to be characteristic...
DEFF Research Database (Denmark)
Burcharth, H. F.; Frigaard, Peter
1989-01-01
Wave loads may be defined as time varying forces on a body resulting from the wave induced flow fields which surrounds the body in whole or in part. Such unsteady fluid forces are the net result of pressure and shear forces integrated over the instantaneous wetted area.......Wave loads may be defined as time varying forces on a body resulting from the wave induced flow fields which surrounds the body in whole or in part. Such unsteady fluid forces are the net result of pressure and shear forces integrated over the instantaneous wetted area....
Stellar Mass Function of Lyman Break Galaxies: Theoretical Perspective
Institute of Scientific and Technical Information of China (English)
LIU Xiao-Liang; HUANG Yong-Qing; LIU Nian-Hua; LAI Zhen-Quan; SHU Cheng-Gang
2006-01-01
@@ Adopting the observational distributions of star formation rates and half-light radii of Lyman break galaxies (LBGs) in the rest frame UV, we investigate empirically the predicted stellar mass function for LBGs.
CFD modelling approach for dam break flow studies
Directory of Open Access Journals (Sweden)
C. Biscarini
2010-04-01
Full Text Available This paper presents numerical simulations of free surface flows induced by a dam break comparing the shallow water approach to fully three-dimensional simulations. The latter are based on the solution of the complete set of Reynolds-Averaged Navier-Stokes (RANS equations coupled to the Volume of Fluid (VOF method.
The methods assessment and comparison are carried out on a dam break over a flat bed without friction, a dam break over a triangular bottom sill and a dam break flow over a 90° bend. Experimental and numerical literature data are compared to present results.
The results demonstrate that the shallow water approach, even if able to sufficiently reproduce the main aspects of the fluid flows, loses some three-dimensional phenomena, due to the incorrect shallow water idealization that neglects the three-dimensional aspects related to the gravity force.
Parking Areas at Cedar Breaks National Monument, Utah (prkareas)
National Park Service, Department of the Interior — This polygon dataset locates the parking areas within Cedar Breaks National Monument. The parking areas were digitized from the 2002 Color aerial photographs and...
Transportation Signs at Cedar Breaks National Monument, Utah (trspsign)
National Park Service, Department of the Interior — This coverage contains the starting point for the collection of transportation signs at Cedar Breaks National Monument. There are over 400 signs (transportation and...
Footprints of Buildings at Cedar Breaks National Monument, Utah (footprints)
National Park Service, Department of the Interior — This is an Arc/INFO coverage consisting of 10 polygons representing the buildings' footprints at Cedar Breaks National Monument, Utah. The footprints were collected...
Designated Overlook Areas at Cedar Breaks National Monument, Utah (ovrareas)
National Park Service, Department of the Interior — This coverage contains three polygons that represent areas of designated overlooks at Cedar Breaks National Monument. Note: Point Supreme needs an FMSS number - it...
Service Areas at Cedar Breaks National Monument, Utah (srvcarea)
National Park Service, Department of the Interior — This coverage contains service areas at Cedar Breaks National Monument. The service areas were collected by a Trimble GeoXT GPS unit and post processed for...
Utilities at Cedar Breaks National Monument, Utah (utilpnt)
National Park Service, Department of the Interior — This feature class represents various types of utilities, including water- and power-related utilities, at Cedar Breaks National Monument, Utah. The utilities were...
Finite amplitude gravity waves: Harmonics, advective steepening, breaking and saturation
Weinstock, J.
1985-01-01
A simple theory is presented which determines details of the breaking and saturation of a gravity wave as it propagates upward in the atmosphere. Breaking and saturation are here due to nonlinear advection analogous to the breaching of a surface wave and to the breaking of a planetary wave. Much simplification is obtained by the assumption that in a wave packet consisting of a primary wave and its harmonics, the primary wave remains dominant. This assumption, referred to a quasi-monochromatic approximation, is suggested by observations. Determined by this approximate theory are: a detailed picture of the waveform as it steepens and breaks; harmonics of the wave; the turbulence generation; and an underlying relationship between superadiabatic lapse rate and saturation by wave-wave interactions.
Dynamical R-parity Breaking at the LHC
Chen, Shao-Long; Mohapatra, Rabindra N; Zhang, Yue
2010-01-01
In a class of extensions of the minimal supersymmetric standard model with (B-L)/left-right symmetry that explains the neutrino masses, breaking R-parity symmetry is an essential and dynamical requirement for successful gauge symmetry breaking. Two consequences of these models are: (i) a new kind of R-parity breaking interaction that protects proton stability but adds new contributions to neutrinoless double beta decay and (ii) an upper bound on the extra gauge and parity symmetry breaking scale which is within the large hadron collider (LHC) energy range. We point out that an important prediction of such theories is a potentially large mixing between the right-handed charged lepton ($e^c$) and the superpartner of the right-handed gauge boson ($\\widetilde W_R^+$), which leads to a brand new class of R-parity violating interactions of type $\\widetilde{\\mu^c}^\\dagger\
Catalysis of Dynamical Chiral Symmetry Breaking by Chiral Chemical Potential
Braguta, V V
2016-01-01
In this paper we study the properties of media with chiral imbalance parameterized by chiral chemical potential. It is shown that depending on the strength of interaction between constituents in the media the chiral chemical potential either creates or enhances dynamical chiral symmetry breaking. Thus the chiral chemical potential plays a role of the catalyst of dynamical chiral symmetry breaking. Physically this effect results from the appearance of the Fermi surface and additional fermion states on this surface which take part in dynamical chiral symmetry breaking. An interesting conclusion which can be drawn is that at sufficiently small temperature chiral plasma is unstable with respect to condensation of Cooper pairs and dynamical chiral symmetry breaking even for vanishingly small interactions between constituents.
Approximate equations at breaking for nearshore wave transformation coefficients
Digital Repository Service at National Institute of Oceanography (India)
Chandramohan, P.; Nayak, B.U.; SanilKumar, V.
Based on small amplitude wave theory approximate equations are evaluated for determining the coefficients of shoaling, refraction, bottom friction, bottom percolation and viscous dissipation at breaking. The results obtainEd. by these equations...
On structural physical approximations and entanglement breaking maps
Augusiak, Remigiusz; Czekaj, Łukasz; Lewenstein, Maciej
2010-01-01
Very recently a conjecture saying that the so-called structural physical approximations to optimal positive maps (optimal entanglement witnesses) give entanglement breaking (EB) maps (separable states) has been posed [J. K. Korbicz et al., Phys. Rev. A 78, 062105 (2008)]. The main purpose of this contribution is to explore this subject. First, we extend the set of witnesses obeying the conjecture. Then, we ask if structural physical approximations constructed from other than the depolarizing channel maps also lead to some EB maps. We formulate and prove a weaker conjecture stating that for any positive map there exists an entanglement breaking map such that SPA constructed from it is entanglement breaking. Finally, we ask similar questions in the case of continuous variable systems. We provide a simple way of contraction of SPA, and prove that in the case of the transposition map it gives entanglement breaking channel.
Isospin breaking in the pion-nucleon scattering lengths
Hoferichter, Martin; Meißner, Ulf-G
2009-01-01
We analyze isospin breaking through quark mass differences and virtual photons in the pion-nucleon scattering lengths in all physical channels in the framework of covariant baryon chiral perturbation theory.
Electroweak symmetry breaking in light of LHC results
Energy Technology Data Exchange (ETDEWEB)
Ellis, John [Physics Department, King' s College London (United Kingdom); Theory Division, CERN (Switzerland)
2012-07-01
The prospects for various proposed models of electroweak symmetry breaking are assessed in light of LHC results, and key experimental tests are discussed. Models discussed include the Standard Model, its supersymmetric extensions, and composite models with relatively light scalar bosons.
Springs at Cedar Breaks National Monument, Utah (allsprgs)
National Park Service, Department of the Interior — This is an Arc/Info coverage consisting of 151 points representing spring locations in and surrounding Cedar Breaks National Monument, Utah. This data originates...
Precursors and electron-positron pair loading from erupting fireballs
Ramirez-Ruiz, E; Lazzati, D; Ramirez-Ruiz, Enrico; Fadyen, Andrew I. Mac; Lazzati, Davide
2002-01-01
Recent observations suggest that long-duration gamma-ray bursts and their afterglows are produced by highly relativistic jets emitted in core-collapse explosions. As the jet makes its way out of the stellar mantle, a bow shock runs ahead and a strong thermal precursor is produced as the shock breaks out. Such erupting fireballs produce a very bright gamma-ray precursor as they interact with the thermal break-out emission. The prompt gamma-ray emission propagates ahead of the fireball before it becomes optically thin, leading to electron-positron pair loading and radiative acceleration of the external medium. The detection of such precursors would offer the possibility of diagnosing not only the radius of the stellar progenitor and the initial Lorentz factor of the collimated fireball, but also the density of the external environment.
Automatic first-break picking using the instantaneous traveltime attribute
Saragiotis, Christos
2012-01-01
Picking the first breaks is an important step in seismic processing. The large volume of the seismic data calls for automatic and objective picking. We introduce a new automatic first-break picker, which uses specifically designed time windows and an iterative procedure based on the instantaneous traveltime attribute. The method is fast as it only uses a few FFT\\'s per trace. We demonstrate the effectiveness of this automatic method by applying it on real test data.
Numerical Detection of Ergodicity Breaking in a Glass Model
Sasaki, Munetaka; Hukushima, Koji
2016-07-01
We present a numerical method of directly detecting ergodicity breaking in glassy systems. To examine the validity of the proposed method, we applied it to the Biroli-Mézard glass model on a regular random graph. The obtained results clearly indicate that the model exhibits a dynamical transition with ergodicity breaking at an occupation density, that is consistent with the prediction obtained by the cavity method. The present method is applicable to glassy systems in finite dimensions.
Concepts of electroweak symmetry breaking and Higgs physics
Energy Technology Data Exchange (ETDEWEB)
Gomez-Bock, M. [Benemerita Univ., Puebla (Mexico). Inst. de Fisica; Mondragon, M. [Universidad Nacional Autonoma de Mexico, Mexico City (Mexico). Inst. de Fisica; Muehlleitner, M. [Laboratoire d' Annecy-Le-Vieux de Physique Theorique, 74 (France)]|[CERN - European Organization for Nuclear Research, Geneva (Switzerland). Theory Div.; Spira, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Zerwas, P.M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)]|[RWTH Aachen (Germany). Inst. Theor. Physik E]|[Univ. Paris- Sud, Orsay (France). Laboratoire de Physique Theorique
2007-12-15
We present an introduction to the basic concepts of electroweak symmetry breaking and Higgs physics within the Standard Model and its supersymmetric extensions. A brief overview will also be given on alternative mechanisms of electroweak symmetry breaking. In addition to the theoretical basis, the present experimental status of Higgs physics and prospects at the Tevatron, the LHC and e{sup +}e{sup -} linear colliders are discussed. (orig.)
11Li structural information from inclusive break-up measurements
Directory of Open Access Journals (Sweden)
Fernández-García J. P.
2015-01-01
Full Text Available Structure information of 11Li halo nucleus has been obtained from the inclusive break-up measurements of the 11Li+208Pb reactions at energies around the Coulomb barrier (Elab = 24.3 and 29.8 MeV. The effective break-up energy and the slope of B(E1 distribution close to the threshold have been extracted from the experimental data.
Lorentz symmetry breaking effects on relativistic EPR correlations
Energy Technology Data Exchange (ETDEWEB)
Belich, H. [Universidade Federal do Espirito Santo, Departamento de Fisica e Quimica, Vitoria, ES (Brazil); Furtado, C.; Bakke, K. [Universidade Federal da Paraiba, Departamento de Fisica, Caixa Postal 5008, Joao Pessoa, PB (Brazil)
2015-09-15
Lorentz symmetry breaking effects on relativistic EPR (Einstein-Podolsky-Rosen) correlations are discussed. From the modified Maxwell theory coupled to gravity, we establish a possible scenario of the Lorentz symmetry violation and write an effective metric for the Minkowski spacetime. Then we obtain the Wigner rotation angle via the Fermi-Walker transport of spinors and consider the WKB (Wentzel-Kramers-Brillouin) approximation in order to study the influence of Lorentz symmetry breaking effects on the relativistic EPR correlations. (orig.)
Impact of symmetry breaking in networks of globally coupled oscillators
Premalatha, K.; Chandrasekar, V. K.; Senthilvelan, M.; Lakshmanan, M.
2015-01-01
We analyze the consequences of symmetry breaking in the coupling in a network of globally coupled identical Stuart-Landau oscillators. We observe that symmetry breaking leads to increased disorderliness in the dynamical behavior of oscillatory states and consequently results in a rich variety of dynamical states. Depending on the strength of the nonisochronicity parameter, we find various dynamical states such as amplitude chimera, amplitude cluster, frequency chimera and frequency cluster st...
Majorana Fermions, Supersymmetry Breaking, and Born-Infeld Theory
Ferrara, Sergio; Yeranyan, Armen
2015-01-01
This review is devoted to highlight some aspects of the relevance of Majorana fermions in rigid supersymmetry breaking in four spacetime dimensions. After introducing some basic facts on spinors, and on their symmetries and reality properties, we consider Goldstino actions describing partial breaking of rigid supersymmetry, then focussing on Born-Infeld non-linear theory, its duality symmetry, and its supersymmetric extensions, also including multi-field generalizations exhibiting doubly self-duality.
Concepts of electroweak symmetry breaking and Higgs physics
International Nuclear Information System (INIS)
We present an introduction to the basic concepts of electroweak symmetry breaking and Higgs physics within the Standard Model and its supersymmetric extensions. A brief overview will also be given on alternative mechanisms of electroweak symmetry breaking. In addition to the theoretical basis, the present experimental status of Higgs physics and prospects at the Tevatron, the LHC and e+e- linear colliders are discussed. (orig.)
Jet spectral breaks in black hole X-ray binaries
Russell, D M; Casella, P; Cantrell, A G; Chatterjee, R; Fender, R P; Gallo, E; Gandhi, P; Homan, J; Maitra, D; Miller-Jones, J C A; O'Brien, K; Shahbaz, T
2012-01-01
In X-ray binaries, compact jets are known to commonly radiate at radio to infrared frequencies, whereas at optical to gamma-ray energies, the contribution of the jet is debated. The total luminosity, and hence power of the jet is critically dependent on the position of the break in its spectrum, between optically thick (self-absorbed) and optically thin synchrotron emission. This break, or turnover, has been reported in just one black hole X-ray binary (BHXB) thus far, GX 339-4, and inferred via spectral fitting in two others, A0620-00 and Cyg X-1. Here, we collect a wealth of multiwavelength data from the outbursts of BHXBs during hard X-ray states, in order to search for jet breaks as yet unidentified in their spectral energy distributions. In particular, we report the direct detection of the jet break in the spectrum of V404 Cyg during its 1989 outburst, at nu_b = (1.8 +- 0.3) x 10^14 Hz (1.7 +- 0.2 microns). We increase the number of BHXBs with measured jet breaks from three to eight. Jet breaks are found...
Assessment procedures and analytical tools for leak-before-break applications
International Nuclear Information System (INIS)
Leak-before-break assessment as part of power plant pipeline strength analysis uses either the yield stress criterion or fracture-mechanical methods by the FAD concept. In thelatter case, fracture-mechanical and strength data of the material are required as well as analytical equations for calculating the stress intensity factor Kl and the plastic limiting load Lr. The application of verified and generally valid Kl and Ll solutions is of vast importance. The contribution compares selected advanced stress intensity factor solutions for cylinder with surface cracks and through cracks. Apart from the limits of application of solutions for the geometry and load parameters, also their accuracy is assessed. For this, a method for estimating numeric errors of Kl solutions is presented and is applied to a series of solutions. Equations are presented for the plastic limiting load resp. the parameter Lr. The application of the calculation methods is demonstrated for a pipeline using the current version of the failure assessment programme VERB. (orig.)
Symmetry-Break in Voronoi Tessellations
Directory of Open Access Journals (Sweden)
Valerio Lucarini
2009-08-01
Full Text Available We analyse in a common framework the properties of the Voronoi tessellations resulting from regular 2D and 3D crystals and those of tessellations generated by Poisson distributions of points, thus joining on symmetry breaking processes and the approach to uniform random distributions of seeds. We perturb crystalline structures in 2D and 3D with a spatial Gaussian noise whose adimensional strength is α and analyse the statistical properties of the cells of the resulting Voronoi tessellations using an ensemble approach. In 2D we consider triangular, square and hexagonal regular lattices, resulting into hexagonal, square and triangular tessellations, respectively. In 3D we consider the simple cubic (SC, body-centred cubic (BCC, and face-centred cubic (FCC crystals, whose corresponding Voronoi cells are the cube, the truncated octahedron, and the rhombic dodecahedron, respectively. In 2D, for all values α>0, hexagons constitute the most common class of cells. Noise destroys the triangular and square tessellations, which are structurally unstable, as their topological properties are discontinuous in α=0. On the contrary, the honeycomb hexagonal tessellation is topologically stable and, experimentally, all Voronoi cells are hexagonal for small but finite noise with α<0.12. Basically, the same happens in the 3D case, where only the tessellation of the BCC crystal is topologically stable even against noise of small but finite intensity. In both 2D and 3D cases, already for a moderate amount of Gaussian noise (α>0.5, memory of the specific initial unperturbed state is lost, because the statistical properties of the three perturbed regular tessellations are indistinguishable. When α>2, results converge to those of Poisson-Voronoi tessellations. In 2D, while the isoperimetric ratio increases with noise for the perturbed hexagonal tessellation, for the perturbed triangular and square tessellations it is optimised for specific value of noise intensity
Load research and load estimation in electricity distribution
Energy Technology Data Exchange (ETDEWEB)
Seppaelae, A. [VTT Energy, Espoo (Finland). Energy Systems
1996-12-31
The topics introduced in this thesis are: the Finnish load research project, a simple form customer class load model, analysis of the origins of customers load distribution, a method for the estimation of the confidence interval of customer loads and Distribution Load Estimation (DLE) which utilises both the load models and measurements from distribution networks. The Finnish load research project started in 1983. The project was initially coordinated by the Association of Finnish Electric Utilities and 40 utilities joined the project. Now there are over 1000 customer hourly load recordings in a database. A simple form customer class load model is introduced. The model is designed to be practical for most utility applications and has been used by the Finnish utilities for several years. The only variable of the model is the customers annual energy consumption. The model gives the customers average hourly load and standard deviation for a selected month, day and hour. The statistical distribution of customer loads is studied and a model for customer electric load variation is developed. The model results in a lognormal distribution as an extreme case. Using the `simple form load model`, a method for estimating confidence intervals (confidence limits) of customer hourly load is developed. The two methods selected for final analysis are based on normal and lognormal distribution estimated in a simplified manner. The estimation of several cumulated customer class loads is also analysed. Customer class load estimation which combines the information from load models and distribution network load measurements is developed. This method, called Distribution Load Estimation (DLE), utilises information already available in the utilities databases and is thus easy to apply
DEFF Research Database (Denmark)
Chen, Peiyuan; Chen, Zhe; Bak-Jensen, Birgitte
2008-01-01
This paper reviews the development of the probabilistic load flow (PLF) techniques. Applications of the PLF techniques in different areas of power system steady-state analysis are also discussed. The purpose of the review is to identify different available PLF techniques and their corresponding...
International Nuclear Information System (INIS)
The mechanism of a ferrite-loaded rf cavity is explained from the point of view of its operation. Then, an analysis of the automatic cavity-tuning system is presented using the transfer function; and a systematic analysis of a beam-feedback system using transfer functions is also presented. (author)
Directory of Open Access Journals (Sweden)
Guodong Li
2016-01-01
Full Text Available The load bearing capacity and deformation response of granular spoils under uniaxial compression are numerically and experimentally investigated, aiming to shed light on the performance of back filled waste spoils while controlling ground subsidence after coal extraction. In numerical study, the particles are assembled in PFC commercial code in light of the digitized real shape of spoils with image technique, which is proved to be consistent with the physical test. The results from numerical and laboratory experiments showed that the complete compressive process of spoils tended to have spatial and temporal characteristics. The load-strain curves of investigated specimens could be divided into three stages (stage I, rearranging stage; stage II, breaking stage; stage III, consolidating stage and three zones (I, rearranging zone; II, interlocking zone; III, consolidated zone from outside to inside. During stage I, the load increasing rate of smaller spoils is relatively low, but it increases faster than larger ones in stages II and III. In addition, spoils with Talbot’s gradation are greater than single gradations. The magnitude of the density in consolidated zone is maximum, indicating that it is the main part holding the overlying strata weight.
Loading rate effects on the fracture of Ni/Au nano-coated acrylic particles
Directory of Open Access Journals (Sweden)
Z. L. Zhang
2012-03-01
Full Text Available Mechanical failure of monodisperse Ni/Au coated acrylic particles has been investigated by individual compression tests using nanoindentation-based technique equipped with a flat diamond punch. We have found that both fracture property and morphology of particles depend on the compression loading rate. The breaking strain of the metal coating decreases with increasing loading rate, while the breaking stress increases. Two obvious fracture patterns with cracking in meridian or latitude direction are identified according to the loading rate, and attributed respectively to tension- or bendingdominated deformation of the coating. The findings reported here give a significant guiding to the manufacture design of metal coated polymer particles for Anisotropic Conductive Adhesive (ACA packaging.
Risk Analysis of Breakwater Caisson Under Wave Attack Using Load Surface Approximation
Institute of Scientific and Technical Information of China (English)
Dong Hyawn KIM
2014-01-01
A new load surface based approach to the reliability analysis of caisson-type breakwater is proposed. Uncertainties of the horizontal and vertical wave loads acting on breakwater are considered by using the so-called load surfaces, which can be estimated as functions of wave height, water level, and so on. Then, the first-order reliability method (FORM) can be applied to determine the probability of failure under the wave action. In this way, the reliability analysis of breakwaters with uncertainties both in wave height and in water level is possible. Moreover, the uncertainty in wave breaking can be taken into account by considering a random variable for wave height ratio which relates the significant wave height to the maximum wave height. The proposed approach is applied numerically to the reliability analysis of caisson breakwater under wave attack that may undergo partial or full wave breaking.
A second order volume of fluid (VOF) scheme for numerical simulation of 2-D breaking waves
Institute of Scientific and Technical Information of China (English)
ZONG Zhi; DONG Guo-hai
2007-01-01
Among all environmental forces acting on ocean structures and marine vessels, those resulting from wave impacts are likely to yield the highest loads. Being highly nonlinear, transient and complex, a theoretical analysis of their impact would be impossible without numerical simulations. In this paper,a pressure-split two-stage numerical algorithm is proposed based on Volume Of Fluid (VOF) methodology.The algorithm is characterized by introduction of two pressures at each half and full cycle time step, and thus it is a second-order accurate algorithm in time. A simplified second-order Godunov-type solver is used for the continuity equations. The method is applied to simulation of breaking waves in a 2-D water tank, and a qualitative comparison with experimental photo observations is made. Quite consistent results are observed between simulations and experiments. Commercially available software and Boundary Integral Method (BIM) have also been used to simulate the same problem. The results from present code and BIM are in good agreement with respect to breaking location and timing, while the results obtained from the commercial software which is only first-order accurate in time has clearly showed a temporal and spatial lag, verifying the need to use a higher order numerical scheme.
Leak-before-break due to fatigue cracks in the cold leg piping system
International Nuclear Information System (INIS)
This review paper presents the results of a deterministic assessment of the margin of safety against a large break in the cold leg piping system of pressurized water reactors. The paper focuses on the computation of leak rates resulting from fatigue cracks that penetrate the full wall thickness. Results are presented that illustrate the sensitivity of the leak rate to stress level, crack shape and crack orientation. Further, the leak rates for specific conditions are contrasted to detection levels, shutdown criteria, make-up capacity and the leak rate associated with final failure of the piping system. The results of these computations indicate that, in general, leaks far in excess of the present detection sensitivities would result at crack sizes well below the critical crack sizes for the upset loadings on the cold leg piping system
Numerical Simulation of Independent Advance of Ore Breaking in the Non-pillar Sublevel Caving Method
Institute of Scientific and Technical Information of China (English)
ZHOU Chuan-bo; YAO Ying-kang; GUO Liao-wu; YIN Xiao-peng; FAN Xiao-feng; SHANG Ying
2007-01-01
The mechanism of stress generation and propagation by detonation loading in five separate independent advance of ore breaking patterns is discussed in the paper. An elastic numerical model was developed using ANSYS/LS-DYNA 3D Nonlinear Dynamic Finite Element Software. In this package ANSYS is the preprocessor and LS-DYNA is the postprocessor. Numerical models in the paper to actual were 1:10 and the element mesh was dissected in scanning mode utilizing the symmetry characteristics of the numerical model. Five different advance rates were studied. Parameters, such as the time required to maximum stress, the action time of the available stress, the maximum velocity of the nodes, the stress penetration time, the magnitude of the stress peak and the time duration for high stress were numerically simulated. The 2.2 m advance appeared optimum from an analysis of the simulation results. The results from numerical simulation have been validated by tests with physical models.
Directory of Open Access Journals (Sweden)
Petrus H.A.J.M van Gelder
2013-05-01
Full Text Available The dam-break induced loads and their effects on buildings are of vital importance for assessing the vulnerability of buildings in flood-prone areas. A comprehensive methodology, for risk assessment of buildings subject to flooding, is nevertheless still missing. This research aims to take a step forward by following previous research. To this aim, (1 five statistical procedures including: simple correlation analysis, multiple linear regression model, stepwise multiple linear regression model, principal component analysis and cluster analysis are used to study relationship between mean normalized force on structure and other related variables; (2 a new and efficient variable that can take into account both the shape of the structure and flow conditions is proposed; (3 a new and practical formula for predicting the mean normalized force is suggested for different types of obstacles, which is missing in the previous research.
Assessment of In-Core Damage for Feeder Stagnation Break in CANDU
Energy Technology Data Exchange (ETDEWEB)
Jung, Jong Yeob; Park, Joo Hwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2010-05-15
A feeder break is a single channel accident while the other channels remain intact in the CANDU core. For some ranges of feeder break size, a flow in the channel can become stagnate due to a force balance between the upstream and the downstream ends. In the extreme, this can lead to a rapid fuel heat up and fuel damage, and the failure of a fuel channel. This break scenario is called a feeder stagnation break. Following the feeder stagnation break, the fuel and pressure tube in the affected channel heat up quickly. The channel fails due to overheating and the channel contents begin to discharge into the moderator. The discharge is composed of steam, some hydrogen produced by possible metal-water reaction, and solid fuel elements of fuel fragments with molten material. The severity of the transient is primarily determined by the amount of molten material discharged into the moderator, and by the interaction between the molten material and the moderator, which determines the rate of energy release. After a channel rupture (pressure tube and calandria tube) some SOR (Shut-Off Rod) guide tubes, which are located in the vicinity of the break in the core, may be damaged. If the damage to the guide tube is substantial, some SORs may not be able to descend into the moderator, and therefore, not contribute to the shut down of the reactor. The increase in system reactivity, due to factors such as poison dilution from discharging coolant and void formation, may challenge the reactivity worth of the available undamaged SORs. Therefore, an analysis of the reactivity worth of the partially impaired SDS 1 (Shut-Down System 1) is required to determine that it can compensate for the increase in reactivity and shut down the reactor. In this study, the hydrodynamic transient, due to the dispersed molten material and the discharged steam, was calculated following the feeder stagnation break. The timing of the channel failure and the mass of the molten material were provided from the
Energy Technology Data Exchange (ETDEWEB)
Woof, M.
2001-02-01
By analysing several trucks and LHDs, this paper gives the trend for upgrading. For trucks, most firms have looked closely at fire prevention and suppression, by such methods as separation of electrical and hydraulic systems, better shielding and firewalls around hot areas and fire damping equipment for emergencies. LHDs have to meet the same criteria when it comes to tunnel dimensions, carriers and ramp gradients. In addition, the design requirements of a load and carry machine can be very different from those of an LHD used safely for truck loading. It also points out that computer control of LHDs provides one solution to both safety and productivity issues, as productivity can be optimised, while miners do not have to enter dangerous working areas. 6 photos.
A French guideline for defect assessment at elevated temperature and leak before break analysis
Energy Technology Data Exchange (ETDEWEB)
Drubay, B.; Chapuliot, St.; Lacire, M.H.; Marie, St. [CEA Saclay, Lab. d' Ingegrite des Structures et Normalisation, LISN, 91 - Gif sur Yvette (France); Deschanels, H. [FRAMATOME/Novatome, 69 - Lyon (France); Cambefort, P. [Electricite de France (EDF/SEPTEN), 69 - Lyon (France)
2001-07-01
A large program is performed in France in order to develop, for the design and operating FBR (fast breeder reactor) plants, defect assessment procedures and Leak-Before-Break methods (L.B.B.). The main objective of this A16 guide is to propose analytical solutions at elevated temperature coherent with those proposed at low temperature by the RSE-M. The main items developed in this A16 guide for laboratory specimen, plates, pipes and elbows are the following: evaluation of ductile crack initiation and crack propagation based on the J parameter and material characteristics as J{sub R}-{delta}a curve or J{sub i}/G{sub fr}. Algorithms to evaluate the maximum endurable load under increasing load for through wall cracks or surface cracks are also proposed; determination of fatigue or creep-fatigue crack initiation based on the {sigma} approach calculating stress and strain at a characteristic distance d from the crack tip; evaluation of fatigue crack growth based on da/dN-{delta}K{sub eff} relationship with a {delta}K{sub eff} derived from a simplified estimation of {delta}J for the cyclic load; evaluation of creep-fatigue crack growth adding the fatigue crack growth and the creep crack growth during the hold time derived from a simplified evaluation of C{sup *}; Leak-Before-Break procedure. The fracture mechanic parameters determined in the A16 guide (K{sub 1}, J, C{sup *}) are derived from handbooks and formula in accordance with those proposed in the RSE-M document for in service inspection. Those are: the K{sub I} handbook for a large panel of surface and through-wall defect in plates, pipes and elbows; elastic stress and reference stress formula; analytical Js and Cs{sup *} formulations for mechanical and through thickness thermal load. The main part of the formula and assessment methodologies proposed in the A16 guide are included in a software, called MJSAM, developed under the MS Windows environment in support of the document. This allows a simple application of
Improving Short Wave Breaking Behavior In Surfbeat Models
Roelvink, J.; Daly, C.; Vandongeren, A. R.; van Thiel de Vries, J.; McCall, R.
2009-12-01
In present surfzone modeling three approaches are widely applied: short-wave resolving models, ‘surfbeat’ models, which resolve wave energy modulations on the time-scale of wave groups and their associated infragravity waves, and wave averaged models. In all three approaches, wave breaking is a process that is highly schematized and governed by several empirical coefficients. In this presentation we will focus on the breaking process in ‘surfbeat’ models, such as XBeach (Roelvink et al, 2009). These models need to describe the short wave dissipation by breaking as a function of the slowly-varying short wave energy or wave height. The model usually applied is that by Roelvink (1993), which combines a probability that waves are breaking as function of wave heigth over water depth ratio H/h with a bore-type dissipation formulation similar to that by Battjes and Janssen (1978). A drawback of such a formulation is that there is no ‘memory’ in the breaking process, and the amount of breaking instantly varies with the water depth (though the wave height itself does have a memory). For cases with bichromatic waves, or for long-period swell, this does not reflect reality enough: waves that start breaking do not instantly stop breaking once the water depth increases, but continue until some lower threshold is reached. This concept was captured in Dally’s (1992) wave-by-wave approach, where individual waves are tracked in a probabilistic setting. We have now implemented a similar formulation in XBeach, where the property that waves are breaking is tracked; it is switched on when H/h exceeds a first criterion; this property is propagated using an advection equation and when H/h gets below a second criterion breaking is switched off. This formulation can do two things the previous one can’t: maintain groupiness inside the surf zone and have a maximum of wave breaking in the trough after a steep bar, as was observed for instance in Arcilla et al’s (1994) test 1
Ryall, T. G.; Moses, R. W.; Hopkins, M. A.; Henderson, D.; Zimcik, D. G.; Nitzsche, F.
2004-01-01
High performance aircraft are, by their very nature, often required to undergo maneuvers involving high angles of attack. Under these conditions unsteady vortices emanating from the wing and the fuselage will impinge on the twin fins (required for directional stability) causing excessive buffet loads, in some circumstances, to be applied to the aircraft. These loads result in oscillatory stresses, which may cause significant amounts of fatigue damage. Active control is a possible solution to this important problem. A full-scale test was carried out on an F/A-18 fuselage and fins using piezoceramic actuators to control the vibrations. Buffet loads were simulated using very powerful electromagnetic shakers. The first phase of this test was concerned with the open loop system identification whereas the second stage involved implementing linear time invariant control laws. This paper looks at some of the problems encountered as well as the corresponding solutions and some results. It is expected that flight trials of a similar control system to alleviate buffet will occur as early as 2001.
Heavy ion induced double strand breaks in bacteria and bacteriophages
Micke, U.; Schäfer, M.; Anton, A.; Horneck, G.; Bücker, H.
DNA damage induced by heavy ions in bacterial cells and bacteriophages such as Bacillus subtilis, E. coli and Bacteriophage Tl were investigated by analyzing the double strand breaks in the chromosomal DNA. This kind of lesion is considered as one of the main reasons for lethal events. To analyze double strand breaks in long molecules of DNA - up to some Mbp in length - the technique of pulse field agarose gel electrophoresis has been used. This allows the detection of one double strand break per genome. Cell lysis and DNA isolation were performed in small agarose blocks directly. This procedure secured minimum DNA destruction by shearing forces. After running a gel, the DNA was stained with ethidium bromide. The light intensity of ethidium bromide fluorescence for both the outcoming (running) DNA and the remaining intact DNA were measured by scanning. The mean number of double strand breaks was calculated by determining the quotient of these intensities. Strand break induction after heavy ion and X-ray irradiation was compared.
Effect of loading on stable tearing of wide plates
International Nuclear Information System (INIS)
A series of wide plate tests using a 0.36% carbon steel have been carried out in the AEA Structural Features Test Facility to determine the stable tearing behaviour of cracks under different loading conditions, typical of pressurized components. The majority of the plates were edge cracked. They were tested in pure in-plane bending, pure ligament tension, nominal tension and cyclic tensile loading. These tests can be compared with large centre cracked wide plates, described in a companion paper at this conference. Small scale fracture toughness tests were also made of the same material. It was found that Failure Assessment Diagrams (FADs) could be used to plot out the results and showed that the assessment line gave a good failure prediction or was conservative. The very conservative evaluation of a plate in bending cannot currently be explained. Where there was combined fatigue and tearing, linearly adding crack growth due to the different processes well predicted the results. For a surface breaking defect, initiation is well predicted from using a local limit load in the FAD, but as loads increase towards net section yield, the global limit load is more appropriate. 4 figs., 1 tab
Mechanical Behaviors of Silt Rock Subjected to Coupling Static and Impact Loads
Institute of Scientific and Technical Information of China (English)
ZHOU Zilong; LI Xibing; HONG Liang; MA Chunde
2006-01-01
Experiments of silt rock subjected to coupling loads were carried out on tailormade equipment.With a constant dynamic load,the behaviors of eight sets of siltite specimens were investigated with different axial static loads.The experimental results show that the modulus of the specimens under coupling loads increases at first and then decreases with the increase of axial static pressure.The failure model of the specimens also varies.Keeping the dynamic load constant,when the axial static pressure is Iow,the specimen breaks in two simply.With the increase of axial static pressure,the cone-shaped fragment appeares.When the axial static pressure reaches 90% of the static strength of rock,the specimen smashes into amount of small fragments.
NSGIC GIS Inventory (aka Ramona) — This Break Lines dataset, was produced all or in part from LIDAR information as of 2000. It is described as 'Break line shape files by township for Rock County,...
Application of break preclusion concept in German nuclear power plants
Energy Technology Data Exchange (ETDEWEB)
Roos, E. [Energie-Versorgung Schwaben AG, Stuttgart (Germany); Maier, V. [Bayernwerk AG, Muenchen (Germany); Nagel, G. [PraussenElektra AG, Hannover (Germany)] [and others
1997-04-01
The break preclusion concept is based on {open_quotes}KTA rules{close_quotes}, {open_quotes}RSK guidelines{close_quotes} and {open_quotes}Rahmenspeziflkation Basissicherheit{close_quotes}. These fundamental rules containing for example requirements on material, design, calculation, manufacturing and testing procedures are explained and the technical realisation is shown by means of examples. The proof of the quality of these piping systems can be executed by means of fracture mechanics calculations by showing that in every case the leakage monitoring system already detect cracks which are clearly smaller than the critical crack. Thus the leak before break behavior and the break preclusion concept is implicitly affirmed. In order to further diminish conservativities in the fracture mechanics procedures, specific research projects are executed which are explained in this contribution.
Radiatively induced breaking of conformal symmetry in a superpotential
Arbuzov, A. B.; Cirilo-Lombardo, D. J.
2016-07-01
Radiatively induced symmetry breaking is considered for a toy model with one scalar and one fermion field unified in a superfield. It is shown that the classical quartic self-interaction of the superfield possesses a quantum infrared singularity. Application of the Coleman-Weinberg mechanism for effective potential leads to the appearance of condensates and masses for both scalar and fermion components. That induces a spontaneous breaking of the initial classical symmetries: the supersymmetry and the conformal one. The energy scales for the scalar and fermion condensates appear to be of the same order, while the renormalization scale is many orders of magnitude higher. A possibility to relate the considered toy model to conformal symmetry breaking in the Standard Model is discussed.
Radiatively Induced Breaking of Conformal Symmetry in a Superpotential
Arbuzov, A B
2015-01-01
Radiatively induced symmetry breaking is considered for a toy model with one scalar and one fermion field unified in a superfield. It is shown that the classical quartic self-interaction of the superfield possesses a quantum infrared singularity. Application of the Coleman-Weinberg mechanism for effective potential leads to the appearance of condensates and masses for both scalar and fermion components. That induces a spontaneous breaking of the initial classical symmetries: the supersymmetry and the conformal one. The energy scales for the scalar and fermion condensates appear to be of the same order, while the renormalization scale is many orders of magnitude higher. A possibility to relate the considered toy model to conformal symmetry breaking in the Standard Model is discussed.
Structural breaks in finance growth nexus: the study of Indonesia
Directory of Open Access Journals (Sweden)
Bidisha Mukhopadhyay
2011-01-01
Full Text Available This paper empirically investigates the finance-growth nexus for an annual data set of Indonesia during the last two decades. The purpose is to examine the causal relationship between financial development and economic growth in Indonesia and also to test the structural breaks in the finance-growth relationship to investigate the change in policy regimes. To examine the causal relationship between financial development and economic growth, the newly proposed ARDL bound testing approach by Pesaran et al. (1996 has been applied .The estimated results support the view of Lucas (1988 that finance doesn’t matter for economic growth. Structural break is identified in the year 1997 in Indonesia with the estimated finance-growth relationship. The stability of the estimated relationship is examined with break-point Chow tests (F tests.
Break-even Analyses for Random Production and Demand Processes
Institute of Scientific and Technical Information of China (English)
Marcus Schweitzer
2002-01-01
Break-even analyses are often used as controlling instruments. Typically, they are applied to support decision processes or to gain information for the control of profits and sales. Firstly, the study gives an overview of the basic accounting systems. Secondly, the study shows possible ways of performing break-even analyses for a single-stage, make-to-order production in the case of random production and demand structures. To model these structures, queueing systems are employed. As a general result, we see that break-even analyses must always be performed taking into account an existing planning system. Under practical aspects, GI/G/1 systems turn out to map complex real situations realistically. From the examples given it can be concluded that one achieves different results compared with using a deterministic model even in the case of a simple, random effects approach. In particular, it is shown that stochastic modelling in general is helpful in avoiding incorrect decisions.
Supersymmetry Breaking due to Moduli Stabilization in String Theory
Linde, Andrei; Olive, Keith A
2011-01-01
We consider the phenomenological consequences of fixing compactification moduli. In the simplest KKLT constructions, stabilization of internal dimensions is rather soft: weak scale masses for moduli are generated, and are of order m_\\sigma ~ m_{3/2}. As a consequence one obtains a pattern of soft supersymmetry breaking masses found in gravity and/or anomaly mediated supersymmetry breaking (AMSB) models. These models may lead to destabilization of internal dimensions in the early universe, unless the Hubble constant during inflation is very small. Fortunately, strong stabilization of compactified dimensions can be achieved by a proper choice of the superpotential (e.g in the KL model with a racetrack superpotential). This allows for a solution of the cosmological moduli problem and for a successful implementation of inflation in supergravity. We show that strong moduli stabilization leads a very distinct pattern of soft supersymmetry breaking masses. In general, we find that soft scalar masses remain of order ...
Break-up stage restoration in multifragmentation reactions
Energy Technology Data Exchange (ETDEWEB)
Raduta, Ad.R. [Institut de Physique Nucleaire, IN2P3-CNRS, F-91406 Orsay cedex (France)]|[NIPNE, Bucharest-Magurele, POB-MG 6 (Romania); Bonnet, E.; Borderie, B.; Le Neindre, N.; Rivet, M.F. [Institut de Physique Nucleaire, IN2P3-CNRS, F-91406 Orsay cedex (France); Piantelli, S. [Dip. di Fisica e Sezione INFN, Universita di Firenze, I-50019 Sesto Fiorentino, Fi (Italy)
2007-02-15
In the case of Xe+Sn at 32 MeV/nucleon multifragmentation reaction break-up fragments are built-up from the experimentally detected ones using evaluations of light particle evaporation multiplicities which thus settle fragment internal excitation. Freeze-out characteristics are extracted from experimental kinetic energy spectra under the assumption of full decoupling between fragment formation and energy dissipated in different degrees of freedom. Thermal kinetic energy is determined uniquely while for freeze-out volume - collective energy a multiple solution is obtained. Coherence between the solutions of the break-up restoration algorithm and the predictions of a multifragmentation model with identical definition of primary fragments is regarded as a way to select the true value. The broad kinetic energy spectrum of {sup 3}He is consistent with break-up genesis of this isotope. (authors)
Matter Representations and Gauge Symmetry Breaking via Compactified Space
Hatanaka, H
1999-01-01
We study dynamical gauge symmetry breaking via compactified space in the framework of SU($N$) gauge theory on $M^{d-1}\\times S^1$ ($d=4,5,6$) space-time. Especially, we study in detail the gauge symmetry breaking in SU(2) and SU(3) gauge theories when the models contain both fundamental and adjoint matters. As the result, we find that any pattern of gauge symmetry breaking is realized by selecting appropriate set of numbers $(\\Nf,\\Nad)$ in these cases. It is achieved without tuning boundary conditions of matter fields. As the by-product, in some cases we get effective potential which has no curvature at the minimum thus leading to massless Higgs scalars, irrespectively of the size of compactified space.
Experimental Study of Wave Breaking on Gentle Slope
Institute of Scientific and Technical Information of China (English)
2000-01-01
－An experimental study of regular wave and irregular wave breaking is performed on a gentle slope of 1:200. In the experiment, asymmetry of wave profile is analyzed to determine its effect on wave breaker indices and to explain the difference between Goda and Nelson about the breaker indices of regular waves on very mild slopes. The study shows that the breaker index of irregular waves is under less influence of bottom slope i, relative water depth d/ L0 and the asymmetry of wave profile than that of regular waves. The breaker index of regular waves from Goda may be used in the case of irregular waves, while the coefficient A should be 0.15. The ratio of irregular wavelength to the length calculated by linear wave theory is 0.74. Analysis is also made on the waveheight damping coefficient of regular waves after breaking and on the breaking probability of large irregular waves.
On the Quantum Origin of SUSY-Breaking Vacua
Farakos, Fotis
2014-01-01
We study the effect of radiative corrections on the vacuum structure of a class of 4-D, ${\\cal N}=1$ supersymmetric theories. Motivated by recent supersymmetry breaking techniques which employ higher dimensional operators, we investigate the possibility that these operators are generated radiatively. The result is affirmative. Our interest lies within renormalizable models with no tree-level supersymmetry breaking. We then integrate out the massive fluctuations, and probe the existence of new supersymmetry-breaking vacua. More specifically, we consider models of massive $U(1)$ vector multiplets, coupled to massive, and massless, complex linear multiplets and calculate the low energy effective theory for the latter ones. The resulting auxiliary field potential is deformed due to finite contributions from specific superspace higher derivatives. However, we find that there exist even higher order corrections which interfere with the leading order result, thus rendering the truncation to leading terms unreliable....
Non-minimal scalar multiplets, supersymmetry breaking and dualities
Farakos, Fotis; Kočí, Pavel; von Unge, Rikard
2015-01-01
We study supersymmetry breaking in theories with non-minimal multiplets (such as the complex linear or CNM multiplets), by using superspace higher derivative terms which give rise to new supersymmetry breaking vacuum solutions on top of the standard supersymmetric vacuum. We illustrate the decoupling of the additional massive sectors inside the complex linear and the CNM multiplets and show that only the Goldstino sector is left in the low energy limit. We also discuss the duality between non-minimal scalar multiplets and chiral multiplets in the presence of superspace higher derivatives. From the superspace Noether procedure we calculate the supercurrents, and we show that in the supersymmetry breaking vacuum the chiral superfield X which enters the Ferrara-Zumino supercurrent conservation equation does indeed flow in the IR to the chiral constrained Goldstino superfield. We also provide a universal description of the Goldstino sector in terms of the Samuel-Wess superfield.
Massive photons from Super and Lorentz symmetry breaking
Bonetti, Luca; Helayël-Neto, José A; Spallicci, Alessandro D A M
2016-01-01
In the context of Standard Model Extensions (SMEs), we analyse four general classes of Super Symmetry (SuSy) and Lorentz Symmetry (LoSy) breaking, leading to {observable} imprints at our energy scales. The photon dispersion relations show a non-Maxwellian behaviour for the CPT (Charge-Parity-Time reversal symmetry) odd and even sectors. The group velocities exhibit also a directional dependence with respect to the breaking background vector (odd CPT) or tensor (even CPT). In the former sector, the group velocity may decay following an inverse squared frequency behaviour. Thus, we extract a massive and gauge invariant Carroll-Field-Jackiw photon term in the Lagrangian and show that the mass is proportional to the breaking vector. The latter is estimated by ground measurements and leads to a photon mass upper limit of $10^{-19}$ eV or $2 \\times 10^{-55}$ kg and thereby to a potentially measurable delay at low radio frequencies.
Spontaneous symmetry breaking in 5D conformally invariant gravity
Moon, Taeyoon
2016-01-01
We explore the possibility of the spontaneous symmetry breaking in 5D conformally invariant gravity, whose action consists of a scalar field nonminimally coupled to the curvature with its potential. Performing dimensional reduction via ADM decomposition, we find that the model allows an exact solution giving rise to the 4D Minkowski vacuum. Exploiting the conformal invariance with Gaussian warp factor, we show that it also admits a solution which implement the spontaneous breaking of conformal symmetry. We investigate its stability by performing the tensor perturbation and find the resulting system is described by the conformal quantum mechanics. Possible applications to the spontaneous symmetry breaking of time-translational symmetry along the dynamical fifth direction and the brane-world scenario are discussed.
Lorentz symmetry breaking as a quantum field theory regulator
Visser, Matt
2009-01-01
Perturbative expansions of relativistic quantum field theories typically contain ultraviolet divergences requiring regularization and renormalization. Many different regularization techniques have been developed over the years, but most regularizations require severe mutilation of the logical foundations of the theory. In contrast, breaking Lorentz invariance, while it is certainly a radical step, at least does not damage the logical foundations of the theory. We shall explore the features of a Lorentz symmetry breaking regulator in a simple polynomial scalar field theory, and discuss its implications. We shall quantify just "how much" Lorentz symmetry breaking is required to fully regulate the theory and render it finite. This scalar field theory provides a simple way of understanding many of the key features of Horava's recent article [arXiv:0901.3775 [hep-th
Breaking strain of neutron star crust and gravitational waves.
Horowitz, C J; Kadau, Kai
2009-05-15
Mountains on rapidly rotating neutron stars efficiently radiate gravitational waves. The maximum possible size of these mountains depends on the breaking strain of the neutron star crust. With multimillion ion molecular dynamics simulations of Coulomb solids representing the crust, we show that the breaking strain of pure single crystals is very large and that impurities, defects, and grain boundaries only modestly reduce the breaking strain to around 0.1. Because of the collective behavior of the ions during failure found in our simulations, the neutron star crust is likely very strong and can support mountains large enough so that their gravitational wave radiation could limit the spin periods of some stars and might be detectable in large-scale interferometers. Furthermore, our microscopic modeling of neutron star crust material can help analyze mechanisms relevant in magnetar giant flares and microflares.
Weak ergodicity breaking induced by global memory effects
Budini, Adrián A.
2016-08-01
We study the phenomenon of weak ergodicity breaking for a class of globally correlated random walk dynamics defined over a finite set of states. The persistence in a given state or the transition to another one depends on the whole previous temporal history of the system. A set of waiting time distributions, associated to each state, sets the random times between consecutive steps. Their mean value is finite for all states. The probability density of time-averaged observables is obtained for different memory mechanisms. This statistical object explicitly shows departures between time and ensemble averages. While the residence time in each state may have a divergent mean value, we demonstrate that this condition is in general not necessary for breaking ergodicity. Hence, we conclude that global memory effects are an alternative mechanism able to induce ergodicity breaking without involving power-law statistics. Analytical and numerical calculations support these results.
Commercial breaks vs. product placement: what works for young consumers?
Directory of Open Access Journals (Sweden)
Ovidiu Mircea ŢIEREAN
2015-06-01
Full Text Available The article presents the results of a quantitative marketing research conducted on young consumers from Braşov County regarding their perceptions about commercial breaks and product placement during the most important reality shows. The purpose of this research is to determine to what extent young consumers watch the evening shows and to what extent they remember the brands advertised during commercial breaks and product placement within the shows. For young consumers, the evening shows are time spent with family and friends. A large majority do not watch the commercial breaks and they mostly remember brands that also practice product placement during the shows. There is a direct corelation between numbers of shows watched and the percentage of consumers who remember the main sponsors for evening shows.
Comparing Measured Fluorocarbon Leader Breaking Strength with Manufacturer Claims
Haight, Christine; McQueeney, Kathleen; Courtney, Ya'el
2012-01-01
The experiment reported in this article addresses manufacturer claims of fluorocarbon leader material strength versus experimental tests of leaders strength. Breaking strength of fishing line is the most common specification when marketing fishing line. In this study, eight leaders rated near 15 pounds by their manufacturers were tested. Each leader was tested with a knot in the line and without a knot in the line. The strongest leader tested without a knot was Cabela's Seaguar fluorocarbon and the weakest leader tested without a knot was Cabela's Premier leader. The highest strength of leaders with a knot was the Ande Monofilament Fluorocarbon and the lowest breaking strength of leaders with a knot was the Seaguar Grand Max Fluorocarbon. Few published studies actually test the breaking strength of a leader to determine the accuracy of manufacturers' claims. Tensile strengths are also reported.
The International Mass Loading Service
Petrov, Leonid
2015-01-01
The International Mass Loading Service computes four loadings: a) atmospheric pressure loading; b) land water storage loading; c) oceanic tidal loading; and d) non-tidal oceanic loading. The service provides to users the mass loading time series in three forms: 1) pre-computed time series for a list of 849 space geodesy stations; 2) pre-computed time series on the global 1deg x 1deg grid; and 3) on-demand Internet service for a list of stations and a time range specified by the user. The loading displacements are provided for the time period from 1979.01.01 through present, updated on an hourly basis, and have latencies 8-20 hours.
Nutrient and Coliform Loading (NCL)
National Oceanic and Atmospheric Administration, Department of Commerce — This is a database of available fecal coliform bacteria, fecal streptococci bacteria, and nutrient loading data. Loading for contaminants other than fecal coliform...
Defining Nitrogen Kinetics for Air Break in Prebreathe
Conkin, Johnny
2009-01-01
Actual tissue nitrogen (N2) kinetics are complex; the uptake and elimination is often approximated with a single half-time compartment in statistical descriptions of denitrogenation [prebreathe (PB)] protocols. Air breaks during PB complicate N2 kinetics. A comparison of symmetrical versus asymmetrical N2 kinetics was performed using the time to onset of hypobaric decompression sickness (DCS) as a surrogate for actual venous N2 tension. Published results of 12 tests involving 179 hypobaric exposures in altitude chambers after PB, with and without air breaks, provide the complex protocols from which to model N2 kinetics. DCS survival time for combined control and air breaks were described with an accelerated log logistic model where N2 uptake and elimination before, during, and after the air break was computed with a simple exponential function or a function that changed half-time depending on ambient N2 partial pressure. P1N2-P2 = delta P defined DCS dose for each altitude exposure, where P2 was the test altitude and P1N2 was computed N2 pressure at the beginning of the altitude exposure. The log likelihood (LL) without DCS dose (null model) was -155.6, and improved (best-fit) to -97.2 when dose was defined with a 240 min half-time for both N2 elimination and uptake during the PB. The description of DCS survival time was less precise with asymmetrical N2 kinetics, for example, LL was -98.9 with 240 min half-time elimination and 120 min half-time uptake. The statistical regression described survival time mechanistically linked to symmetrical N2 kinetics during PBs that also included air breaks. The results are data-specific, and additional data may change the conclusion. The regression is useful to compute additional PB time to compensate for an air break in PB within the narrow range of tested conditions.
PROBABILISTIC MODELING OF EXPLOSIVE LOADING
Mkrtychev Oleg Vartanovich; Dorozhinskiy Vladimir Bogdanovich
2012-01-01
According to existing design standards, explosive loading represents a special type of loading. Explosive loading is, in most cases, local in nature, although it can exceed the loads for which buildings are designed by a dozen of times. The analysis of terrorist attacks with explosives employed demonstrates that charges have a great power and, consequently, a substantial shock wave pressure. Blast effects are predictable with a certain probability. Therefore, we cannot discuss ...
Demand Response Load Following of Source and Load Systems
DEFF Research Database (Denmark)
Hu, Jianqiang; Cao, Jinde; Yong, Taiyou;
2016-01-01
This paper presents a demand response load following strategy for an interconnected source and load system, in which we utilize traditional units and population of cooling thermostatically controlled loads (TCLs) to follow the mismatched power caused by the load activities and the renewable power...... injection in real time. In the demand side of power systems, these TCLs are often affiliated to a bus load agent and can be aggregated to multiple TCL aggregators. Firstly, aggregate evaluation of the TCL aggregator is carried out based on a bilinear aggregate model so as to derive the available regulation...
Taking a Break. Some Thoughts about Media Consumption
Mira Moshe
2015-01-01
This article examines the structural characteristics of media consumption as a routine break from habitual activity. While acknowledging the existence and importance of “taking a breather” in everyday life, one may ask if and when it is possible to characterize taking a break in today’s media field. The “media break” refers to communications consumption that is not directed at finding out what is occurring in the outside world, correlating between parts of the social and/or political syste...
SU(3) flavour symmetry breaking and charmed states
Energy Technology Data Exchange (ETDEWEB)
Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics and Astronomy; Najjar, J. [Regensburg Univ. (Germany). Institut fuer Theoretische Physik; Nakamura, Y. [RIKEN Advanced Institute for Computational Science, Hyogo (Japan); Perlt, H.; Schiller, A. [Leipzig Univ. (Germany). Inst. fuer Theoretische Physik; Pleiter, D. [Forschungszentrum Juelich GmbH (Germany). Juelich Supercomputing Centre (JSC); Regensburg Univ. (Germany). Institut fuer Theoretische Physik; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Div.; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Stueben, H. [Hamburg Univ. (Germany). Regionales Rechenzentrum; Zanotti, J.M. [Adelaide Univ. (Australia). CSSM, School of Chemistry and Physics; Collaboration: QCDSF-UKQCD Collaborations
2013-11-15
By extending the SU(3) flavour symmetry breaking expansion from up, down and strange sea quark masses to partially quenched valence quark masses we propose a method to determine charmed quark hadron masses including possible QCD isospin breaking effects. Initial results for some open charmed pseudoscalar meson states and singly and doubly charmed baryon states are encouraging and demonstrate the potential of the procedure. Essential for the method is the determination of the scale using singlet quantities, and to this end we also give here a preliminary estimation of the recently introduced Wilson flow scales.
Energy dissipation through wind-generated breaking waves
Institute of Scientific and Technical Information of China (English)
ZHANG Shuwen; CAO Ruixue; XIE Lingling
2012-01-01
Wave breaking is an important process that controls turbulence properties and fluxes of heat and mass in the upper oceanic layer.A model is described for energy dissipation per unit area at the ocean surface attributed to wind-generated breaking waves,in terms of ratio of energy dissipation to energy input,windgenerated wave spectrum,and wave growth rate.Also advanced is a vertical distribution model of turbulent kinetic energy,based on an exponential distribution method.The result shows that energy dissipation rate depends heavily on wind speed and sea state.Our results agree well with predictions of previous works.
EXPERIMENTAL STUDY OF ROCK BREAKING EFFECT OF STEEL PARTICLES
Institute of Scientific and Technical Information of China (English)
CUI Meng; ZHAI Ying-hu; JI Guo-dong
2011-01-01
Particle impact drilling is an efficient drilling technology for deep-well hard formation, With this technology, the rock is cut mainly by high-speed spherical particle impact under hydraulic action. In this article, the influence of jet flow factors, hydraulic factors and abrasive factors on rock breaking is studied through indoor experiments of impact by steel particles. The results indicate that the particle water jet has an optimal standoff distance and particle concentration; the rock breaking effect declines with the increase of the confining pressure and the decrease of the pump pressure and particle diameter. This study will provide some food of thought for the development of particle impact drilling technology.
New Mechanism of Flavor Symmetry Breaking from Supersymmetric Strong Dynamics
Carone, C D; Moroi, T; Carone, Christopher D.; Hall, Lawrence J.; Moroi, Takeo
1997-01-01
We present a class of supersymmetric models in which flavor symmetries are broken dynamically, by a set of composite flavon fields. The strong dynamics that is responsible for confinement in the flavor sector also drives flavor symmetry breaking vacuum expectation values, as a consequence of a quantum-deformed moduli space. Yukawa couplings result as a power series in the ratio of the confinement to Planck scale, and the fermion mass hierarchy depends on the differing number of preons in different flavor symmetry-breaking operators. We present viable non-Abelian and Abelian flavor models that incorporate this mechanism.
Margins in high temperature leak-before-break assessments
Energy Technology Data Exchange (ETDEWEB)
Budden, P.J.; Hooton, D.G.
1997-04-01
Developments in the defect assessment procedure R6 to include high-temperature mechanisms in Leak-before-Break arguments are described. In particular, the effect of creep on the time available to detect a leak and on the crack opening area, and hence leak rate, is discussed. The competing influence of these two effects is emphasized by an example. The application to Leak-before-Break of the time-dependent failure assessment diagram approach for high temperature defect assessment is then outlined. The approach is shown to be of use in assessing the erosion of margins by creep.
BREAKING A FEISTEL-TYPE BLOCK CIPHER BY BACTERIA ENGINEERING
Directory of Open Access Journals (Sweden)
Abbas Khosravani
2012-02-01
Full Text Available In this paper we propose a theoretical method for breaking a block cipher based on a Feistel structurewhich is a variant of DES (S-DES using one pair of (plaintext, ciphertext. Our scheme utilizes bacterialcomputing for the first time in cryptanalysis. For this reason, we design and simulate an engineered generegulatory network to break S-DES which possesses a superior performance than the other methodsbased on DNA computing because it utilizes the power of massive parallelism of DNA molecules as wellas capability of cellular division of bacterial cells which gives our proposed S-DES cracker system theflavour of massive parallel processing.
Numerical Simulation of Sediment Transport due to Plunging Breaking Waves
DEFF Research Database (Denmark)
Pedersen, Claus
A numerical model simulating the sediment transport due to plunging breaking waves has been developed. The model is two-dimensional, assuming conditions in the long-shore direction invariable. A plunging breaker is simulated by superimposing a non-breaking wave with a jet. Based on the description...... of the sediment transport rates, a simple model describing the morphological changes has been applied to simulate the evolution of a plunge point generated vorticity included, the bottom topography from the experiments by Dette & Uliczka was not in equilibrium according to the model....
Singularity and Breaking of the Third Order Stokes Waves
Institute of Scientific and Technical Information of China (English)
孙孚; 高山; 王伟; 钱成春
2003-01-01
In this paper, the fact is revealed that the surface elevation of the third order Stokes waves in implicit form could have no solution or have simultaneously a trivial one and a singular one on certain conditions. Based on this fact, the relative breaking width, a more reasonable quantity in agreement with the definition of whitecapping coverage rate, is obtained directly from the assumption that no solution means breaking. The implications of the singular solution existing in the third order stokes waves are also discussed briefly.
Quantum phase transitions about parity breaking in matrix product systems
Institute of Scientific and Technical Information of China (English)
ZHU Jing-Min
2011-01-01
According to our scheme to construct quantum phase transitions (QPTs) in spin chain systems with matrix product ground states, we first successfully combine matrix product state (MPS) QPTs with spontaneous symmetry breaking. For a concrete model, we take into account a kind of MPS QPTs accompanied by spontaneous parity breaking, though for either side of the critical point the GS is typically unique, and show that the kind of MPS QPTs occur only in the thermodynamic limit and are accompanied by the appearance of singularities, diverging correlation length, vanishing energy gap and the entanglement entropy of a half-infinite chain not only staying finite but also whose first derivative discontinuous.
Large Eddy Simulation for Wave Breaking in the Surf Zone
Institute of Scientific and Technical Information of China (English)
白玉川; 蒋昌波; 沈焕庭
2001-01-01
In this paper, the large eddy simulation method is used combined with the marker and cell method to study the wave propagation or shoaling and breaking process. As wave propagates into shallow water, the shoaling leads to the increase of wave height, and then at a certain position, the wave will be breaking. The breaking wave is a powerful agent for generating turbulence, which plays an important role in most of the fluid dynamic processes throughout the sarf zone, such as transformation of wave energy, generation of near-shore current and diffusion of materials. So a proper numerical model for describing the turbulence effect is needed. In this paper, a revised Smagorinsky subgrid-scale model is used to describe the turbulence effect. The present study reveals that the coefficient of the Smagorinsky model for wave propagation or breaking simulation may be taken as a varying function of the water depth and distance away from the wave breaking point. The large eddy simulation model presented in this paper has been used to study the propagation of the solitary wave in constant water depth and the shoaling of the non-breaking solitary wave on a beach. The model is based on large eddy simulation, and to track free-surface movements, the Tokyo University Modified Marker and Cell (TUMMAC) method is employed. In order to ensure the accuracy of each component of this wave mathematical model,several steps have been taken to verify calculated solutions with either analytical solutions or experimental data. For non-breaking waves, very accurate results are obtained for a solitary wave propagating over a constant depth and on a beach. Application of the model to cnoidal wave breaking in the surf zone shows that the model results are in good agreement with analytical solution and experimental data. From the present model results, it can be seen that the turbulent eddy viscosity increases from the bottom to the water surface in surf zone. In the eddy viscosity curve, there is a
Effect of symmetry breaking on transition strength distributions
International Nuclear Information System (INIS)
The quantum numbers of over 100 states in 30P have been determined from the ground state to 8 MeV. Previous measurements had provided complete spectroscopy in 26Al. For these N=Z=odd nuclei, states of isospin T=0 and T=1 coexist at all energies. These spectra provide a unique opportunity to test the effect of symmetry breaking (of the approximate symmetry isospin) on the level statistics and on the transition strength distributions. The level statistics are strongly affected by the small symmetry breaking and the transition strength distributions differ from the Porter-Thomas distribution
Slamming of a breaking wave on a wall
Shu, Jian-Jun
2014-01-01
This paper is intended to study impact forces of breaking waves on a rigid wall based on a nonlinear potential-flow theory. This is a model problem for some technologically important design issues such as the impact of breaking waves on ships, coastal and offshore structures. We are interested in the short-time successive triggering of nonlinear effects using a small-time expansion. The analytical solutions for the impact force on a rigid wall and the free-surface profile are derived.
Symmetry-Breaking Plasmonic Metasurfaces for Broadband Light Bending
DEFF Research Database (Denmark)
Ni, Xingjie; Emani, Naresh K.; Kildishev, Alexander V.;
2012-01-01
We experimentally demonstrate unparalleled wave-front control in a broadband, optical wavelength range from 1.0 μm to 1.9 μm, using a thin plasmonic layer (metasurface) consisting of a nanoantenna array that breaks the symmetry along the interface.......We experimentally demonstrate unparalleled wave-front control in a broadband, optical wavelength range from 1.0 μm to 1.9 μm, using a thin plasmonic layer (metasurface) consisting of a nanoantenna array that breaks the symmetry along the interface....
Finding strongly interacting symmetry breaking at the SSC
Energy Technology Data Exchange (ETDEWEB)
Golden, M.
1989-02-01
Pairs of gauge bosons, W and Z, are a probe of the electroweak symmetry-breaking sector, since the numbers of two gauge boson events are much larger in strongly coupled models than weak. The doubly charged channels W/sup +/W/sup +/ and W/sup /minus//W/sup/minus// are cleanest, since they do not suffer from q/bar q/ or gg fusion backgrounds. The like-charged gauge boson events are observable only if the symmetry breaking sector is strongly interacting. 19 refs., 4 figs., 2 tabs.
Gauged supersymmetric σ-models and soft breaking terms
International Nuclear Information System (INIS)
Supersymmetric non-linear σ-models in four dimensions with D-term potentials can sometimes have a singular metric. As the kinetic terms of scalar fields and their chiral fermionic partners are determined by this metric, it follows that their kinetic energy vanishes in the vacuum. In previous work we have shown for a simple model that this degeneracy of the sigma-model metric can be lifted by soft supersymmetry breaking terms. In this letter I introduce soft breaking terms in more realistic models based on SO(10) and E6 and compute their resulting mass spectra. (author)
An analysis of dam-break flow on slope
Institute of Scientific and Technical Information of China (English)
潘存鸿; 王立辉
2014-01-01
The one-dimensional steep slope shallow water equations are used to model the dam-break flow down a uniform slope with arbitrary inclination, and analytical solutions are derived by the hodograph transformation and the Riemann’s method in terms of evaluated integrals. An implicit analytical solution is obtained to evaluate the spatio-temporal distributions of dam-break flood hydrographs along the slope. For convenience, the solution for representative wave profiles and velocity distributions is shown in charts. Comparing with the Dressler’s solution and WES experimental data, the analytical solution is seen reasonable.
SUSY breaking with D term and gauge mediation
International Nuclear Information System (INIS)
We classify supersymmetry breaking models with the F- and U(1) D-term potentials. In addition to the classification in our previous paper [1], we consider the other class where the F-term potential shows runaway behaviors. It is shown that the runaway in the F-term potential can be uplifted by the D-term effect, and supersymmetry breaking is realized. The vacuum in this class has no pseudomoduli and is useful for gauge mediation because gaugino masses are generated at the one-loop order. We provide such an example without the Fayet-Iliopoulous term.
Modular Ground State for SU(8) Symmetry Breaking
Adler, Stephen L
2015-01-01
We elaborate on our recent proposal of a modular ground state structure for the first stage of $SU(8)$ symmetry breaking by a scalar in the 56 representation. We review the arguments for $U(1)$ generator modularity 15, and show that this can lead to a vanishing mass for the $U(1)$ gauge boson, as needed for the symmetry breaking pattern $SU(8) \\supset SU(3) \\times SU(5) \\times U(1)$. We then give a simplified form for the modulo 5 ground state obeying clustering, that we have conjectured to lead from broken $SU(8)$ to the flipped $SU(5)$ model. Generalizations of these results are also given.
Observations on the partial breaking of N=2 rigid supersymmetry
Directory of Open Access Journals (Sweden)
Laura Andrianopoli
2015-05-01
Full Text Available We study the partial breaking of N=2 rigid supersymmetry for a generic rigid special geometry of n abelian vector multiplets in the presence of Fayet–Iliopoulos terms induced by the hyper-Kähler momentum map. By exhibiting the symplectic structure of the problem we give invariant conditions for the breaking to occur, which rely on a quartic invariant of the Fayet–Iliopoulos charges as well as on a modification of the N=2 rigid symmetry algebra by a vector central charge.
Load forecasting of supermarket refrigeration
DEFF Research Database (Denmark)
Rasmussen, Lisa Buth; Bacher, Peder; Madsen, Henrik;
2016-01-01
This paper presents a novel study of models for forecasting the electrical load for supermarket refrigeration. The data used for building the models consists of load measurements, local climate measurements and weather forecasts. The load measurements are from a supermarket located in a village...
Журиленко, Борис Євгенович; Национальный авиационный университет
2014-01-01
As a result of the work was proposed a method of single technical information security (TIS) system designing with probable reliability and given parameters of breaking. The general dependence between effort and time of breaking by projected frequency of breaking was defined. It is shown that the parameter that determines the probable reliability of TIS may not only be a constant with the time dimension, but depends on both the attempt of breaking and time of breaking. Through the attempt of ...
Co-breaking: Recent Advances and a Synopsis of the Literature.
David F. Hendry; Massmann, Michael
2007-01-01
This article has two aims. First, we provide a synopsis of the literature on co-breaking that has developed in several, seemingly disconnected, strands. We establish a consistent terminology, collect theoretical results, delimit co-breaking to cointegration and common features, and review recent contributions to co-breaking regressions and the budding analysis of co-breaking rank. Second, we present new results in the field, particularly, on the importance of co-breaking for policy analysis, ...
Huddleston, Rob
2012-01-01
Fully loaded with the latest tricks and tips on your new Android! Android smartphones are so hot, they're soaring past iPhones on the sales charts. And the second edition of this muscular little book is equally impressive--it's packed with tips and tricks for getting the very most out of your latest-generation Android device. Start Facebooking and tweeting with your Android mobile, scan barcodes to get pricing and product reviews, download your favorite TV shows--the book is positively bursting with practical and fun how-tos. Topics run the gamut from using speech recognition, location-based m
Multidimensional spectral load balancing
Energy Technology Data Exchange (ETDEWEB)
Hendrickson, B.; Leland, R.
1993-01-01
We describe an algorithm for the static load balancing of scientific computations that generalizes and improves upon spectral bisection. Through a novel use of multiple eigenvectors, our new spectral algorithm can divide a computation into 4 or 8 pieces at once. These multidimensional spectral partitioning algorithms generate balanced partitions that have lower communication overhead and are less expensive to compute than those produced by spectral bisection. In addition, they automatically work to minimize message contention on a hypercube or mesh architecture. These spectral partitions are further improved by a multidimensional generalization of the Kernighan-Lin graph partitioning algorithm. Results on several computational grids are given and compared with other popular methods.
DEFF Research Database (Denmark)
Kuntsche, Judith; Freisleben, Ines; Steiniger, Frank;
2010-01-01
some problems associated with the commercial formulation Foscan where the drug is dissolved in a mixture of water-free ethanol and propylene glycol. The present study focuses on the physicochemical characterization of different liposome formulations with special emphasis on the influence of drug....... In contrast, if phospholipids with longer fatty acid chains (distearoylphosphatidylcholine/-glycerol) were used, phase transitions were well above body temperature even at high drug load. Size and thermal behavior were not distinctly influenced by the addition of pegylated lipids but cryo-electron microscopic...
Directory of Open Access Journals (Sweden)
Yuan Yong
2015-01-01
Full Text Available This paper puts forward the concept of key strata in immediate roof (KSIF and studied the dynamic effect and control mechanism of KSIF. The results show that KSIR controls the caving of its upper immediate roof strata; the break of KSIR has direct dynamic impact on its lower strata and this impact increases along with the increase of the thickness and hardness of the KSIR and the decrease of the distance to the working seam. The KSIR and main roof can easily form the bilayer structure “Cantilever-Masonry beam.” Support work load is affected by the position, thickness, and hardness of KSIR. The support work load increased on the condition of increase of the thickness and hardness of KSIR and the decrease of the distance to the face.
Directory of Open Access Journals (Sweden)
Pranav Ullal
Full Text Available Efficient repair of DNA double-stranded breaks (DSB requires a coordinated response at the site of lesion. Nucleolytic resection commits repair towards homologous recombination, which preferentially occurs between sister chromatids. DSB resection promotes recruitment of the Mec1 checkpoint kinase to the break. Rtt107 is a target of Mec1 and serves as a scaffold during repair. Rtt107 plays an important role during rescue of damaged replication forks, however whether Rtt107 contributes to the repair of DSBs is unknown. Here we show that Rtt107 is recruited to DSBs induced by the HO endonuclease. Rtt107 phosphorylation by Mec1 and its interaction with the Smc5-Smc6 complex are both required for Rtt107 loading to breaks, while Rtt107 regulators Slx4 and Rtt101 are not. We demonstrate that Rtt107 has an effect on the efficiency of sister chromatid recombination (SCR and propose that its recruitment to DSBs, together with the Smc5-Smc6 complex is important for repair through the SCR pathway.
Load Control System Reliability
Energy Technology Data Exchange (ETDEWEB)
Trudnowski, Daniel [Montana Tech of the Univ. of Montana, Butte, MT (United States)
2015-04-03
This report summarizes the results of the Load Control System Reliability project (DOE Award DE-FC26-06NT42750). The original grant was awarded to Montana Tech April 2006. Follow-on DOE awards and expansions to the project scope occurred August 2007, January 2009, April 2011, and April 2013. In addition to the DOE monies, the project also consisted of matching funds from the states of Montana and Wyoming. Project participants included Montana Tech; the University of Wyoming; Montana State University; NorthWestern Energy, Inc., and MSE. Research focused on two areas: real-time power-system load control methodologies; and, power-system measurement-based stability-assessment operation and control tools. The majority of effort was focused on area 2. Results from the research includes: development of fundamental power-system dynamic concepts, control schemes, and signal-processing algorithms; many papers (including two prize papers) in leading journals and conferences and leadership of IEEE activities; one patent; participation in major actual-system testing in the western North American power system; prototype power-system operation and control software installed and tested at three major North American control centers; and, the incubation of a new commercial-grade operation and control software tool. Work under this grant certainly supported the DOE-OE goals in the area of “Real Time Grid Reliability Management.”
International Nuclear Information System (INIS)
Highlights: ► Leak-before-break (LBB) analysis for a dissimilar metal weld joint (DMWJ) is made. ► Pipe-nozzle geometry and inhomogeneous material property of DMWJ are incorporated. ► LBB behavior of a defect can be assessed by LBB assessment diagram and LBB curve. ► Feasibility region of LBB is enlarged with decreasing load and increasing JR. -- Abstract: This paper presents a leak-before-break (LBB) analysis for a dissimilar metal welded joint (DMWJ) connected the safe end to pipe-nozzle of a reactor pressure vessel of which is relevant to safety of nuclear power plant. Three-dimensional finite element analysis models were built for the DMWJ structure, and the initial inner circumferential surface cracks were postulated at the interface between A508 steel and buttering Alloy82. Based on the elastic–plastic fracture mechanics theory of J-integral, the crack growth stability was analyzed, and the pipe-nozzle geometry effect and inhomogeneous material properties of the DMWJ have been incorporated. Base on the analysis results, the LBB curves and LBB assessment diagrams were constructed for the DMWJ, and effects of applied bending moment loads and J-resistance curves of materials on LBB behavior were analyzed. The results show that the LBB behavior of a defect in the DMWJ under an upmost severe load can be assessed and predicted by plotting the defect size and its propagation path in the LBB assessment diagrams. With decreasing the maximum bending moment load and increasing the crack growth resistance of materials, the ligament instability lines shift upward and the critical crack length lines move to the right in the LBB assessment diagrams, which leads to enlargement of the feasibility region in the LBB behavior
Leak before break behaviour of austenitic and ferritic pipes containing circumferential defects
Energy Technology Data Exchange (ETDEWEB)
Stadtmueller, W.; Sturm, D.
1997-04-01
Several research projects carried out at MPA Stuttgart to investigate the Leak-before-Break (LBB) behavior of safety relevant pressure bearing components are summarized. Results presented relate to pipes containing circumferential defects subjected to internal pressure and external bending loading. An overview of the experimentally determined results for ferritic components is presented. For components containing postulated or actual defects, the dependence of the critical loading limit on the defect size is shown in the form of LBB curves. These are determined experimentally and/or by calculation for through-wall slits, and represent the boundary curve between leakage and massive fracture. For surface defects and a given bending moment and internal pressure, no fracture will occur if the length at leakage remains smaller than the critical defect length given by the LBB curve for through-wall defects. The predictive capability of engineering calculational methods are presented by way of example. The investigation programs currently underway, testing techniques, and initial results are outlined.
High Temperature Structure Leak Before Break Assessment Guideline(V1.0)
Energy Technology Data Exchange (ETDEWEB)
Park, Chang-Gyu; Kim, Jong-Bum; Lee, Hyeong-Yeon; Joo, Young-Sang; Lee, Jae-Han
2007-03-15
This study describes the Leak Before Break(LBB) procedure applicable to the reactor structure of Liquid Metal Reactor(LMR) which is operated at a high temperature. The purpose of LBB in LMR is to assure the defence in depth safety. The technically advanced countries of LMR development, such as Japan, UK and France, have their own LBB evaluation code. Their procedures are investigated thoroughly and the draft edition of LBB assessment guideline for the high temperature LMR structures is proposed. The key issues are the defect initiation, the defect propagation and the fast rupture of structures under the fatigue loading or the creep-fatigue loading condition. Additionlly, the detectable defect length and crack opening evaluation for the leakage detection method are analyzed and included in this guideline. Additionally, the detectable defect length and the creep-fatigue defect growth with a circumferential through wall defect for a KALIMER-600 IHTS hot leg piping based on this high temperature LBB assessment guideline were evaluated.
Physical Activity Breaks and Facilities in US Secondary Schools
Hood, Nancy E.; Colabianchi, Natalie; Terry-McElrath, Yvonne M.; O'Malley, Patrick M.; Johnston, Lloyd D.
2014-01-01
Background: Research on physical activity breaks and facilities (indoor and outdoor) in secondary schools is relatively limited. Methods: School administrators and students in nationally representative samples of 8th (middle school) and 10th/12th grade (high school) students were surveyed annually from 2008-2009 to 2011-2012. School administrators…
Experiments and computation of onshore breaking solitary waves
DEFF Research Database (Denmark)
Jensen, A.; Mayer, Stefan; Pedersen, G.K.
2005-01-01
This is a combined experimental and computational study of solitary waves that break on-shore. Velocities and accelerations are measured by a two-camera PIV technique and compared to theoretical values from an Euler model with a VOF method for the free surface. In particular, the dynamics of a so...
Breaking into the World of Coaching: The Graduate Student Coach.
Zeidler, Tom; Kirch, Michael W.
A pilot study examined whether there is a "caste system" within the forensics community; what graduate students, faculty coaches, and tournament administrators can do to foster a sense of community and break down the caste system; and the role that formal and informal mentoring can play in this process. A survey was completed by 17 graduate…
Generalized unitary Bogoliubov transformation that breaks fermion number parity
Moussa, Jonathan E.
2012-01-01
The standard Bogoliubov transformation is generalized to enable fermion number parity breaking. The new transformation can diagonalize fermion Hamiltonians that are quadratic in fermion and number parity operators. This new variational freedom cannot lower the energy of Hamiltonians that conserve number parity. However, it has value as a minimal mechanism for continuously varying between states of different fermion number, regardless of number parity.
Small break LOCA analysis for Maanshan nuclear power plant
Energy Technology Data Exchange (ETDEWEB)
Jer-Cherng Kang; Shou-Chuan Chiang; Lang-Chen Wang [Taiwan Power Company, Taipei (China)
1994-12-31
Since 1990, Taiwan Power Company has conducted a LWR LOCA technology transfer program on RELAP5YA computer code from Yankee Atomic Electric Company (YAEC). One objective of this program is to acquire the RELAP5YA computer code from YAEC for Taipower in-house licensing analysis. The RELAP5YA is a computer program developed at YAEC for analysing the dynamic behaviour of thermal-hydraulic systems, and it can cover most of the postulated accidents and transients in light water reactor systems. In this paper, Taipower`s engineers have performed a small break loss of coolant accidents analysis for Maanshan nuclear power plant. Thais action is used to perform the licensing actions for increasing the operation margin on the steam generator tube plugging. The result is shown that the steam generator tube can be plugged slightly without a reduction in safety margins. This analysis covers a spectrum of break size for a small break LOCA. For a complete spectrum of the transient and accident analysis, the large break LOCA and the non-LOCA analysis were performed by the fuel vendor for the reload safety evaluation.
Jet spectral breaks in black hole X-ray binaries
D.M. Russell; S. Markoff; P. Casella; A.G. Cantrell; R. Chatterjee; R.P. Fender; E. Gallo; P. Gandhi; J. Homan; D. Maitra; J.C.A. Miller Jones; K. O'Brien; T. Shahbaz
2013-01-01
In X-ray binaries, compact jets are known to commonly radiate at radio to infrared frequencies, whereas at optical to γ-ray energies, the contribution of the jet is debated. The total luminosity, and hence power of the jet, is critically dependent on the position of the break in its spectrum, betwee
A Benders approach for the constrained minimum break problem
DEFF Research Database (Denmark)
Rasmussen, Rasmus Vinther; Trick, Michael
2007-01-01
This paper presents a hybrid IP/CP algorithm for designing a double round robin schedule with a minimal number of breaks. Both mirrored and non-mirrored schedules with and without place constraints are considered. The algorithm uses Benders cuts to obtain feasible home-away pattern sets in few...
Radiative breaking of conformal symmetry in the Standard Model
Arbuzov, A. B.; Nazmitdinov, R. G.; Pavlov, A. E.; Pervushin, V. N.; Zakharov, A. F.
2016-02-01
Radiative mechanism of conformal symmetry breaking in a comformal-invariant version of the Standard Model is considered. The Coleman-Weinberg mechanism of dimensional transmutation in this system gives rise to finite vacuum expectation values and, consequently, masses of scalar and spinor fields. A natural bootstrap between the energy scales of the top quark and Higgs boson is suggested.
Breaking Classroom Silences: A View from Linguistic Ethnography
Rampton, Ben; Charalambous, Constadina
2016-01-01
This paper addresses potentially problematic classroom episodes in which someone foregrounds a social division that is normally taken for granted. It illustrates the way in which linguistic ethnography can unpack the layered processes that collide in the breaking of silence, showing how linguistic form and practice, individual positioning, local…
Using Appreciative Intelligence for Ice-Breaking: A New Design
Verma, Neena; Pathak, Anil Anand
2011-01-01
Purpose: The purpose of this paper is to highlight the importance of applying appreciative intelligence and appreciative inquiry concepts to design a possibly new model of ice-breaking, which is strengths-based and very often used in any training in general and team building training in particular. Design/methodology/approach: The design has…
Breaking the Silence: Helping Battered Moms and Their Children.
Texas Child Care, 2000
2000-01-01
Discusses issues of domestic violence to help child caregivers care for children more effectively. Considers the causes of domestic violence and its impact on children and families, and offers resources for more information as well as suggestions for helping an abused person get help. Includes lists of "Do's and don'ts for breaking the silence"…
Positive role of peptidoglycan breaks in lactococcal biofilm formation
Mercier, C; Durrieu, C; Briandet, R; Domakova, E; Tremblay, J; Buist, G; Kulakauskas, S
2002-01-01
Bacterial attachment to solid matrices depends on adhesive molecules present on the cell surface. Here we establish a positive correlation between peptidoglycan (PG) breaks, rather than particular molecules, and biofilm-forming capacity in the Gram-positive bacterium Lactococcus lactis. The L. lacti
Chiral symmetry breaking with the Curtis-Pennington vertex
Atkinson, D.; Gusynin, V. P.; Maris, P.
1992-01-01
Published in: Phys. Lett. B 303 (1993) 157-162 citations recorded in [Science Citation Index] Abstract: We study chiral symmetry breaking in quenched QED$_4$, using a vertex Ansatz recently proposed by Curtis and Pennington. Bifurcation analysis is employed to establish the existence of a critical c
Numerical Prediction of Regular Wave Breaking on Very Gentle Slopes
Institute of Scientific and Technical Information of China (English)
李玉成; 于洋; 孙大鹏
2002-01-01
Regular wave deformation and breaking on very gentle slopes is calculated by Mixed-Eulerian-Lagrangian procedure.The velocity potentials and their normal derivatives on the boundary are calculated through the mixed 0-1 boundary elementmethod. The wave elevation and the potentials of time-stepping integration are determined by the 2nd-order Taylor expansionat the nodes of free surface boundary elements. During calculation the x-coordinates of the free surface element nodes aresupposed to remain unchanged, i.e. the partial derivatives of wave elevation and potentials with respect to x are consideredas zero. The numerical results of asymmetric parameters of breaking waves are verified by experimental study. It is shownthat when the wave asymmetry is weak, the maximum horizontal velocity of water particales occurs at the wave peak and, theaverage ratio of this maximum velocity to wave celerity is 0.96. However, when the wave asymmetry is strong, the maximumhorizontal velocity of water particles occurs just before the wave crest, and the average ratio of the maximum velocity to wavecelerity is about 0.98. The numerical results also show that the asymmetry of wave profiles affects the value of the wavebreaking index (H/d)b, that is, when the asymmetric characteristics are weak, the value of wave breaking index coincideswith that given by Coda; on the contrary, when the asymmetry of wave profiles is notable, the value of wave breaking indexis close to Nelson's result. The experimental study gives the same couclusions.
Spontaneous disordering and symmetry breaking in complex plasmas
Zhdanov, Sergey K; Morfill, Gregor E
2010-01-01
Spontaneous symmetry breaking is an essential feature of modern science. We demonstrate that it also plays an important role in the physics of complex plasmas. Complex plasmas can serve as a powerful tool for observing and studying discrete types of symmetry and disordering at the kinetic level that numerous many-body systems exhibit.
Experimental study of breaking and energy dissipation in surface waves
Ruiz Chavarria, Gerardo; Le Gal, Patrice; Le Bars, Michael
2014-11-01
We present an experimental study of the evolution of monochromatic waves produced by a parabolic wave maker. Because of the parabolic shape of the wave front, the waves exhibit spatial focusing and their amplitude dramatically increases over distances of a few wavelengths. Unlike linear waves, the amplitude of the free surface deformation cannot exceed a certain threshold and when this happens the waves break. In order to give a criterion for the appearance of breaking, we calculate the steepness defined as ɛ = H/ λ (where H is the wave height and λ their wavelength) for waves of frequencies in the range 4-10 Hz. We found that wave breaking develops when ɛ attains approximately a value of 0.10. We also evaluate the lost of energy carried by the waves during their breaking by a detailed and accurate measurement of their amplitude using an optical Fourier transform profilometry. G. Ruiz Chavarria acknowledges DGAPA-UNAM by support under Project IN 116312 (Vorticidad y ondas no lineales en fluidos).
Modeling radar backscatter from breaking waves on the surface
Melief, H.W.; Greidanus, H.S.F.; Hoogeboom, P.; Genderen, P. van
2003-01-01
A model for describing radar sea clutter is proposed. It consists of two parts, an oceanographic and an electromagnetic one. The former contains swell, small capillary and gravity waves as well as breaking wave events. The latter combines ray tracing, Bragg scattering and the Method of Moments. It i
Symmetry Breaking of Vibrating Interfaces a Mechanism for Morphogenesis
García, N
2000-01-01
We show that very small-amplitude oscillations of a highly symmetric, spheric or cylindrical, interface (thin membrane) between two fluids can result in inhomogeneous instability and breaking of the interface symmetry: the frequency of the breathing vibration selects the spatial symmetry. This mechanism may govern morphogenesis.
Breaking the Pedagogic Contract: Teachers' and Students' Voices.
Hildebrand, Gaell M.
When teachers try to dramatically change the "pedagogic contract" - the prevailing classroom norms - their efforts are frequently met by resistance from students. My central question is: what do students' and teachers' voices tell us about breaking the pedagogic contract through the use of creative/imaginative writing in science classrooms? This…
Towards breaking temperature equilibrium in multi-component Eulerian schemes
Energy Technology Data Exchange (ETDEWEB)
Grove, John W [Los Alamos National Laboratory; Masser, Thomas [Los Alamos National Laboratory
2009-01-01
We investigate the effects ofthermal equilibrium on hydrodynamic flows and describe models for breaking the assumption ofa single temperature for a mixture of components in a cell. A computational study comparing pressure-temperature equilibrium simulations of two dimensional implosions with explicit front tracking is described as well as implementation and J-D calculations for non-equilibrium temperature methods.