Asymmetric exclusion processes with shuffled dynamics
International Nuclear Information System (INIS)
The asymmetric simple exclusion process (ASEP) with periodic boundary conditions is investigated for shuffled dynamics. In this type of update, in each discrete timestep the particles are updated in a random sequence. Such an update is important for several applications, e.g., for certain models of pedestrian flow in two dimensions. For the ASEP with shuffled dynamics and a related truncated process exact results are obtained for deterministic motion (p = 1). Since the shuffled dynamics is intrinsically stochastic, also this case is nontrivial. For the case of stochastic motion (0 < p < 1) it is shown that, in contrast to all other updates studied previously, the ASEP with shuffled update does not have a product measure steady state. Approximative formulae for the steady-state distribution and fundamental diagram are derived that are in very good agreement with simulation data
From generalized directed animals to the asymmetric simple exclusion process
Haug, Nils; Nechaev, Sergei; Tamm, Mikhail
2012-01-01
Using the generalized normally ordered form of words in a locally-free group of $n$ generators, we show that in the limit $n\\to\\infty$, the partition function of weighted directed lattice animals on a semi-infinite strip coincides with the partition function of stationary configurations of the asymmetric simple exclusion process (ASEP) with arbitrary entry/escape rates through open boundaries. We relate the features of the ASEP in the different regimes of the phase diagram to the geometric fe...
Asymmetric exclusion processes on a closed network with bottlenecks
International Nuclear Information System (INIS)
We study the generic nonequilibrium steady states in asymmetric exclusion processes on a closed network with bottlenecks. To this end we propose and study closed simple networks with multiple-connected non-identical junctions. Depending upon the parameters that define the network junctions and the particle number density, the models display phase transitions with both static and moving density inhomogeneities. The currents in the models can be tuned by the junction parameters. Our models highlight how extended and point defects may affect the density profiles in a closed directed network. Phenomenological implications of our results are discussed. (paper)
Power spectra of a constrained totally asymmetric simple exclusion process
Cook, L. Jonathan; Zia, R. K. P.
2010-07-01
In nature, all biological systems function in a far-from-equilibrium state. Here, we study the process of translation in protein synthesis, using the totally asymmetric simple exclusion process (TASEP) as a model. In particular, we explore the effects of a finite supply of particles for the TASEP, as in a living cell with a finite pool of ribosomes. Specifically, we investigate the power spectrum associated with total occupancy, utilizing both Monte Carlo simulations and theoretical analysis. New features arise, such as large suppressions at low frequencies, due to the added constraint. A theory is formulated based on a Langevin approach with discrete space and time. With good agreement between the simulation and theory, we gain some insights into the effects of finite resources on the TASEP.
From generalized directed animals to the asymmetric simple exclusion process
International Nuclear Information System (INIS)
Using the generalized normally ordered form of words in a locally-free group of n generators, we show that in the limit n → ∞, the partition function of weighted directed lattice animals on a semi-infinite strip coincides with the partition function of stationary configurations of the asymmetric simple exclusion process (ASEP) with arbitrary entry/escape rates through open boundaries. We relate the features of the ASEP in the different regimes of the phase diagram to the geometric features of the associated generalized directed animals by showing the results of numerical simulations. In particular, we show how the presence of shocks at the first order transition line translates into the directed animal picture. Using the evolution equation for generalized, weighted Lukasiewicz paths, we also provide a straightforward calculation of the known ASEP generating function. (paper)
From generalized directed animals to the asymmetric simple exclusion process
Haug, N.; Nechaev, S.; Tamm, M.
2014-10-01
Using the generalized normally ordered form of words in a locally-free group of n generators, we show that in the limit n → ∞, the partition function of weighted directed lattice animals on a semi-infinite strip coincides with the partition function of stationary configurations of the asymmetric simple exclusion process (ASEP) with arbitrary entry/escape rates through open boundaries. We relate the features of the ASEP in the different regimes of the phase diagram to the geometric features of the associated generalized directed animals by showing the results of numerical simulations. In particular, we show how the presence of shocks at the first order transition line translates into the directed animal picture. Using the evolution equation for generalized, weighted Lukasiewicz paths, we also provide a straightforward calculation of the known ASEP generating function.
Totally asymmetric exclusion processes with particles of arbitrary size
Lakatos, G
2003-01-01
The steady-state currents and densities of a one-dimensional totally asymmetric exclusion process (TASEP) with particles that occlude an integer number (d) of lattice sites are computed using various mean-field approximations and Monte Carlo simulations. TASEPs featuring particles of arbitrary size are relevant for modelling systems such as mRNA translation, vesicle locomotion along microtubules and protein sliding along DNA. We conjecture that the nonequilibrium steady-state properties separate into low-density, high-density, and maximal current phases similar to those of the standard (d = 1) TASEP. A simple mean-field approximation for steady-state particle currents and densities is found to be inaccurate. However, we find local equilibrium particle distributions derived from a discrete Tonks gas partition function yield apparently exact currents within the maximal current phase. For the boundary-limited phases, the equilibrium Tonks gas distribution cannot be used to predict currents, phase boundaries, or ...
Asymmetric exclusion process with a dynamic roadblock and open boundaries
Sahoo, Mamata; Klumpp, Stefan
2016-08-01
Motivated by complex transport processes occurring in nature, we study a totally asymmetric simple exclusion process (TASEP) with a dynamic ‘roadblock’ particle. The roadblock particle blocks the traffic of moving particles while bound to the lattice, but can stochastically unbind or switch off, thus enabling the traffic to pass. We use simulations to study the dependence of the particle flux on the on/off switching dynamics of the roadblock, which exhibits a surprisingly rich dynamic behaviour. In particular, unlike in other studied TASEP variants with defects, here we observe that the particle flux is affected by the roadblock even in the initiation-limited or low density phase if the roadblock dynamics is slow. Rapid switching off the roadblock results in the typical behaviour of a TASEP with a defect/pause with reduced maximal current, but no effect of the roadblock on the flux in the initiation-limited phase. Moreover, in an intermediate range of roadblock rates, the particle current is found to be system-size dependent.
Theoretical analysis and simulation for a facilitated asymmetric exclusion process
Hao, Qing-Yi; Chen, Zhe; Sun, Xiao-Yan; Liu, Bing-Bing; Wu, Chao-Yun
2016-08-01
Driven diffusive systems are important models in nonequilibrium state statistical mechanics. This paper studies an asymmetric exclusion process model with nearest rear neighbor interactions associated with energy. The exact flux expression of the model is obtained by a cluster mean-field method. Based on the flux expression, the properties of the fundamental diagram have been investigated in detail. To probe the energy's influence on the coarsening process of the system, Monte Carlo simulations are carried out to acquire the monotonic phase boundary in energy-density space. Above the phase boundary, the system is inhomogeneous and the normalized residence distribution p (s ) is nonmonotonically decreasing. Under the phase boundary, the system is homogeneous and p (s ) is monotonically decreasing. Further study comparatively shows that the system has turned into a microscopic inhomogeneous state from a homogeneous state before the system current arrives at maximum, if nearest rear neighbor interactions are strong. Our findings offer insights to deeply understand the dynamic features of nonequilibrium state systems.
Totally asymmetric exclusion processes with particles of arbitrary size
International Nuclear Information System (INIS)
The steady-state currents and densities of a one-dimensional totally asymmetric exclusion process (TASEP) with particles that occlude an integer number (d) of lattice sites are computed using various mean-field approximations and Monte Carlo simulations. TASEPs featuring particles of arbitrary size are relevant for modelling systems such as mRNA translation, vesicle locomotion along microtubules and protein sliding along DNA. We conjecture that the nonequilibrium steady-state properties separate into low-density, high-density, and maximal current phases similar to those of the standard (d = 1) TASEP. A simple mean-field approximation for steady-state particle currents and densities is found to be inaccurate. However, we find local equilibrium particle distributions derived from a discrete Tonks gas partition function yield apparently exact currents within the maximal current phase. For the boundary-limited phases, the equilibrium Tonks gas distribution cannot be used to predict currents, phase boundaries, or the order of the phase transitions. However, we employ a refined mean-field approach to find apparently exact expressions for the steady-state currents, boundary densities, and phase diagrams of the d ≥ 1 TASEP. Extensive Monte Carlo simulations are performed to support our analytic, mean-field results
Totally asymmetric exclusion processes with particles of arbitrary size
Energy Technology Data Exchange (ETDEWEB)
Lakatos, Greg; Chou, Tom [Department of Biomathematics and Institute for Pure and Applied Mathematics, UCLA, Los Angeles, CA 90095 (United States)
2003-02-28
The steady-state currents and densities of a one-dimensional totally asymmetric exclusion process (TASEP) with particles that occlude an integer number (d) of lattice sites are computed using various mean-field approximations and Monte Carlo simulations. TASEPs featuring particles of arbitrary size are relevant for modelling systems such as mRNA translation, vesicle locomotion along microtubules and protein sliding along DNA. We conjecture that the nonequilibrium steady-state properties separate into low-density, high-density, and maximal current phases similar to those of the standard (d = 1) TASEP. A simple mean-field approximation for steady-state particle currents and densities is found to be inaccurate. However, we find local equilibrium particle distributions derived from a discrete Tonks gas partition function yield apparently exact currents within the maximal current phase. For the boundary-limited phases, the equilibrium Tonks gas distribution cannot be used to predict currents, phase boundaries, or the order of the phase transitions. However, we employ a refined mean-field approach to find apparently exact expressions for the steady-state currents, boundary densities, and phase diagrams of the d {>=} 1 TASEP. Extensive Monte Carlo simulations are performed to support our analytic, mean-field results.
Facilitated Asymmetric Exclusion
Gabel, Alan; Krapivsky, P. L.; Redner, S.
2010-01-01
We introduce a class of facilitated asymmetric exclusion processes in which particles are pushed by neighbors from behind. For the simplest version in which a particle can hop to its vacant right neighbor only if its left neighbor is occupied, we determine the steady state current and the distribution of cluster sizes on a ring. We show that an initial density downstep develops into a rarefaction wave that can have a jump discontinuity at the leading edge, while an upstep results in a shock w...
Sun, Xiaoyan; Xie, Yanbo; He, Zhiwei; Wang, Binghong
2011-07-01
This Letter investigates a totally asymmetric simple exclusion process (TASEP) with junctions in a one-dimensional transport system. Parallel update rules and periodic boundary condition are adopted. Two cases corresponding to different update rules are studied. The results show that the stationary states of system mainly depend on the selection behavior of particle at the bifurcation point.
Jiang, Rui; Hu, Mao-Bin; Wu, Qing-Song
2008-07-01
Lakatos [Phys. Rev. E 71, 011103 (2005)] have studied a totally asymmetric exclusion process that contains periodically varying movement rates. They have presented a cluster mean-field theory for the problem. We show that their cluster mean-field theory leads to redundant equations. We present a mean-field analysis in which there is no redundant equation.
Non-stationary probabilities for the asymmetric exclusion process on a ring
Indian Academy of Sciences (India)
V B Priezzhev
2005-06-01
A solution of the master equation for a system of interacting particles for finite time and particle density is presented. By using a new form of the Bethe ansatz, the totally asymmetric exclusion process on a ring is solved for arbitrary initial conditions and time intervals.
Denisov, D V; Miedema, D M; Nienhuis, B; Schall, P
2015-11-01
Using the totally asymmetric simple-exclusion-process and mean-field transport theory, we investigate the transport in closed random networks with simple crossing topology-two incoming, two outgoing segments, as a model for molecular motor motion along biopolymer networks. Inspired by in vitro observation of molecular motor motion, we model the motor behavior at the intersections by introducing different exit rates for the two outgoing segments. Our simulations of this simple network reveal surprisingly rich behavior of the transport current with respect to the global density and exit rate ratio. For asymmetric exit rates, we find a broad current plateau at intermediate motor densities resulting from the competition of two subnetwork populations. This current plateau leads to stabilization of transport properties within such networks. PMID:26651730
Denisov, D. V.; Miedema, D. M.; Nienhuis, B.; Schall, P.
2015-11-01
Using the totally asymmetric simple-exclusion-process and mean-field transport theory, we investigate the transport in closed random networks with simple crossing topology—two incoming, two outgoing segments, as a model for molecular motor motion along biopolymer networks. Inspired by in vitro observation of molecular motor motion, we model the motor behavior at the intersections by introducing different exit rates for the two outgoing segments. Our simulations of this simple network reveal surprisingly rich behavior of the transport current with respect to the global density and exit rate ratio. For asymmetric exit rates, we find a broad current plateau at intermediate motor densities resulting from the competition of two subnetwork populations. This current plateau leads to stabilization of transport properties within such networks.
Asymmetric Exclusion Process with Constrained Hopping and Parallel Dynamics at a Junction
Liu, Mingzhe; Tuo, Xianguo; Li, Zhe; Yang, Jianbo
In this article totally asymmetric simple exclusion process (TASEP) with constrained hopping and parallel dynamics at a junction is investigated using a mean-field approximation and Monte Carlo simulations. The constrained particle hopping probability r (r ≤ 1) at a junction may correspond to a delay caused by a driver choosing the right direction or a delay waiting for green traffic light in the real world. There are six stationary phases in the system, which can reflect free flow and congested traffic situations. Correlations at the junction point are investigated via simulations. It is observed that small r leads to stronger correlations. The theoretical results are agreement with computer simulations well.
Power Spectra of a Totally Asymmetric Simple Exclusion Process with Finite Resources
Cook, L. Jonathan; Zia, Royce K. P.
2010-03-01
In a cell, a mRNA has only a finite number of ribosomes to use during protein synthesis. We take this constraint into account in the modeling of translation by a totally asymmetric simple exclusion process (TASEP). Through Monte Carlo simulations and analytical methods, we study the power spectrum of the total particle occupancy of the TASEP. New features are found, such as a severe suppression at low frequencies. We formulate a theory based on a linearized Langevin equation with discrete space and time. With good agreement between the theoretical approach and the simulations, we gain some insight in how finite resources affect a TASEP.
The Braess Paradox in a network of totally asymmetric exclusion processes
Bittihn, Stefan
2016-01-01
We study the Braess paradox in the transport network as originally proposed by Braess with totally asymmetric exclusion processes (TASEPs) on the edges. The Braess paradox describes the counterintuitive situation where adding an additional edge to a road network leads to a user optimum with higher traveltimes for all network users. Traveltimes on the TASEPs are nonlinear in the density and jammed states can occur due to the microscopic exclusion principle. Furthermore the individual edges influence each other. This leads to a much more realistic description of traffic-like transport on the network than in previously studied linear macroscopic mathematical models. Furthermore the stochastic dynamics allows to explore the effects of fluctuations on the network performance. We observe that for low densities the added edge leads to lower traveltimes. For slightly higher densities the Braess paradox in its classical sense occurs in a small density regime. In a large regime of intermediate densities strong fluctuat...
International Nuclear Information System (INIS)
The asymmetric simple exclusion process with open boundaries, which is a very simple model of out-of-equilibrium statistical physics, is known to be integrable. In particular, its spectrum can be described in terms of Bethe roots. The large deviation function of the current can be obtained as well by diagonalizing a modified transition matrix, which is still integrable: the spectrum of this new matrix can also be described in terms of Bethe roots for special values of the parameters. However, due to the algebraic framework used to write the Bethe equations in previous works, the nature of the excitations and the full structure of the eigenvectors remained unknown. This paper explains why the eigenvectors of the modified transition matrix are physically relevant, gives an explicit expression for the eigenvectors and applies it to the study of atypical currents. It also shows how the coordinate Bethe ansatz developed for the excitations leads to a simple derivation of the Bethe equations and of the validity conditions of this ansatz. All the results obtained by de Gier and Essler are recovered and the approach gives a physical interpretation of the exceptional points. The overlap of this approach with other tools such as the matrix ansatz is also discussed. The method that is presented here may be not specific to the asymmetric exclusion process and may be applied to other models with open boundaries to find similar exceptional points
Time-headway distribution for periodic totally asymmetric exclusion process with various updates
Hrabák, P.; Krbálek, M.
2016-03-01
The totally asymmetric exclusion process (TASEP) with periodic boundaries is considered as traffic flow model. The large-L approximation of the stationary state is used for the derivation of the time-headway distribution (an important microscopic characteristic of traffic flow) for the model with generalized update (genTASEP) in both, forward- and backward-sequential representations. The usually used updates, fully-parallel and regular forward- and backward-sequential, are analyzed as special cases of the genTASEP. It is shown that only for those cases, the time-headway distribution is determined by the flow regardless to the density. The qualitative comparison of the results with traffic data demonstrates that the genTASEP with backward order and attractive interaction evinces similar properties of time-headway distribution as the real traffic sample.
Zone inhomogeneity with the random asymmetric simple exclusion process in a one-lane system
Institute of Scientific and Technical Information of China (English)
Xiao Song; Cai Jiu-Ju; Liu Fei
2009-01-01
In this paper we use theoretical analysis and extensive simulations to study zone inhomogeneity with the random asymmetric simple exclusion process (ASEP). In the inhomogeneous zone, the hopping probability is less than 1. Two typical lattice geometries axe investigated here. In case A, the lattice includes two equal segments. The hopping probability in the left segment is equal to 1, and in the right segment it is equal to p, which is less than 1. In case B, there are three equal segments in the system; the hopping probabilities in the left and right segments are equal to 1, and in the middle segment it is equal to p, which is leas than 1. Through theoretical analysis, we can discover the effect on these systems when p is changed.
Ferrari, Patrik L.; Spohn, Herbert
2006-07-01
The totally asymmetric simple exclusion process (TASEP) on the one-dimensional lattice with the Bernoulli ρ measure as initial conditions, 0GUE Tracy-Widom distribution. The family [InlineMediaObject not available: see fulltext.] of distribution functions have been obtained before by Baik and Rains in the context of the PNG model with boundary sources, which requires the asymptotics of a Riemann-Hilbert problem. In our work we arrive at [InlineMediaObject not available: see fulltext.] through the asymptotics of a Fredholm determinant. [InlineMediaObject not available: see fulltext.] is simply related to the scaling function for the space-time covariance of the stationary TASEP, equivalently to the asymptotic transition probability of a single second class particle.
Directory of Open Access Journals (Sweden)
R Septiana
2014-06-01
Full Text Available Abstrak __________________________________________________________________________________________ Penelitian ini mengkaji model dinamik yaitu Totally Asymmetric Exclusion Process (TASEP khususnya dalam dua dimensi (2D. Selain itu akan dibahas pula mengenai syarat batas dan aturan dinamika yang digunakan dalam pemodelan ini. TASEP telah diaplikasikan dalam berbagai bidang, salah satunya ialah pemodelan lalu lintas kendaraan (traffic flow. Sistem dua dimensi yang akan dikaji adalah sistem yang diskrit, yakni sistem ke kisi dua dimensi. Sistem ini dimodifikasi menjadi bentuk pertigaan (junction yang searah. Lebih jauh lagi, kendaraan yang melalui pertigaan dimodelkan sebagai partikel yang melompat dari satu kisi ke ke kisi yang lain. Nilai kepadatan dan rapat arus partikel dalam sistem tersebut ditentukan secara numerik. Persamaan kontinuitas untuk menggambarkan dinamika partikel dalam TASEP diselesaikan menggunakan metode Euler. Profil kepadatan dan rapat arus partikel dipengaruhi oleh laju masukan (input rate dan laju keluaran (output rate lompatan partikel. Abstract __________________________________________________________________________________________ The research analyzed a dynamic model of Totally Asymmetric Exclusion Process (TASEP, especially in two dimensions (2D and also the boundary and rules dynamic conditions used in this modeling. TASEP has been applied in various fields, one of them is the modeling of vehicle traffic. Two-dimensional system that will be studied is the discrete system of two-dimensional lattice system. The system is modified into the form of unidirectional T-junction . Furthermore, the vehicles that pass the junction are modeled as particles that jump from one lattice to another lattice. The value of the density and current density of particles in the system is determined numerically. The continuity equation to describe the dynamics of particles in TASEP is solved by using Euler's method. The profiles of
Phase transition in 2D partially asymmetric simple exclusion process with two species
International Nuclear Information System (INIS)
The dynamics of two species of particles undergoing asymmetric simple exclusion process (ASEP) on the 2D lattice are investigated in this paper. A sharp transition from moving phase to jamming phase was shown under periodic boundary conditions. We have developed a mean field analysis for the moving phase by extending the method of [33] and this produces good agreement with simulation results. Two types of jamming phase were observed. In the first type of jamming phase, some particles at the border of the jamming cluster could move back and forth due to the ASEP rule. The first type of jamming phase reduces to the 1D ASEP with a barrier at the boundary of the lattice. We also have analyzed the average hops for the first type of jamming phase by analyzing the 1D ASEP model. The analytical results agree with the simulation results well. Under open boundary conditions, the system exhibits two phases when forward hopping probability q is larger than 0.5. The particles form a wall at the entrance when q is smaller than 0.5. The dependence of the average velocity, the density and the flow rate on the injection probability in the moving phase have also been obtained through mean field analysis. (paper)
Bi-orthogonal polynomial sequences and the asymmetric simple exclusion process
Brak, R.; Moore, W.
2015-08-01
We state the diffusion algebra equations of the stationary state of the three parameter (α, β and q) asymmetric simple exclusion Process as a linear functional {L}, acting on a tensor algebra. From {L} we construct a pair of sequences, \\{{P}n\\} and \\{{Q}m\\}, of monic polynomials which are bi-orthogonal, that is, they satisfy {L}({P}n{Q}m)={Λ }n{δ }n,m(where {Λ }n is a scalar). The uniqueness and existence of the pair of sequences arises from the determinant of the bi-moment matrix whose elements satisfy a pair of q-recurrence relations. The determinant is evaluated using an LDU-decomposition. If the linear functional is represented as an inner product, {L}(\\cdot )= then the action of the polynomials Qn on the boundary vector | V> generate a basis | {V}n> ={Q}n| V> whose orthogonal dual vectors are given by the action of Pn on the dual boundary vector Salam-Chihara polynomials obtained by Sasamoto.
Ciandrini, L.; Stansfield, I; Romano, M. C.
2009-01-01
Messenger RNA translation is often studied by means of statistical-mechanical models based on the Asymmetric Simple Exclusion Process (ASEP), which considers hopping particles (the ribosomes) on a lattice (the polynucleotide chain). In this work we extend this class of models and consider the two fundamental steps of the ribosome’s biochemical cycle following a coarse-grained perspective. In order to achieve a better understanding of the underlying biological processes and compare the theoret...
Chavez, E.; Landim, C.
2016-06-01
We consider a one-dimensional, weakly asymmetric, boundary driven exclusion process on the interval [0,N]\\cap {Z} in the quasi-static time scale N^2 ɛ ^{-1}_N, where 1≪ ɛ ^{-1}_N ≪ N^{1/4}. We assume that the external field and the chemical potentials, which fix the density at the boundaries, evolve smoothly in the macroscopic time scale. We derive an equation which describes the evolution of the density up to the order ɛ _N.
Reuveni, Shlomi; Eliazar, Iddo; Yechiali, Uri
2011-10-01
We introduce and explore the asymmetric inclusion process (ASIP), an exactly solvable bosonic counterpart of the fermionic asymmetric exclusion process (ASEP). In both processes, random events cause particles to propagate unidirectionally along a one-dimensional lattice of n sites. In the ASEP, particles are subject to exclusion interactions, whereas in the ASIP, particles are subject to inclusion interactions that coalesce them into inseparable clusters. We study the dynamics of the ASIP, derive evolution equations for the mean and probability generating function (PGF) of the sites’ occupancy vector, obtain explicit results for the above mean at steady state, and describe an iterative scheme for the computation of the PGF at steady state. We further obtain explicit results for the load distribution in steady state, with the load being the total number of particles present in all lattice sites. Finally, we address the problem of load optimization, and solve it under various criteria. The ASIP model establishes bridges between statistical physics and queueing theory as it represents a tandem array of queueing systems with (unlimited) batch service, and a tandem array of growth-collapse processes.
Ito, Hidetaka
2014-01-01
Interaction between vehicles and pedestrians is seen in many areas such as crosswalks and intersections. In this paper, we study a totally asymmetric simple exclusion process with a bottleneck at a boundary caused by an interaction. Due to the time-dependent effect originating from the speed of pedestrians, the flow of the model varies even if the average hopping probability at the last site is the same. We analyze the phenomenon by using two types of approximations: (2+1)-cluster approximation and isolated rarefaction wave approximation. The approximate results capture intriguing features of the model. Moreover, we discuss the situation where vehicles turn right at the intersection by adding a traffic light at the boundary condition. The result suggests that pedestrian scrambles are valid to eliminate traffic congestion in the right turn lane.
Ito, Hidetaka; Nishinari, Katsuhiro
2014-04-01
Interaction between vehicles and pedestrians is seen in many areas such as crosswalks and intersections. In this paper, we study a totally asymmetric simple exclusion process with a bottleneck at a boundary caused by an interaction. Due to the time-dependent effect originating from the speed of pedestrians, the flow of the model varies even if the average hopping probability at the last site is the same. We analyze the phenomenon by using two types of approximations: extended two-cluster approximation and isolated rarefaction wave approximation. The approximate results capture intriguing features of the model. Moreover, we discuss the situation where vehicles turn right at the intersection by adding a traffic light at the boundary condition. The result suggests that pedestrian scrambles are valid to eliminate traffic congestion in the right-turn lane.
Kuan, Hui-Shun
2016-01-01
Motor protein motion on biopolymers can be described by models related to the totally asymmetric simple exclusion process (TASEP). Inspired by experiments on the motion of kinesin-4 motors on antiparallel microtubule overlaps, we analyze a model incorporating the TASEP on two antiparallel lanes with binding kinetics and lane switching. We determine the steady-state motor density profiles using phase plane analysis of the steady-state mean field equations and kinetic Monte Carlo simulations. We focus on the the density-density phase plane, where we find an analytic solution to the mean-field model. By studying the phase space flows, we determine the model's fixed points and their changes with parameters. Phases previously identified for the single-lane model occur for low switching rate between lanes. We predict a new multiple coexistence phase due to additional fixed points that appear as the switching rate increases: switching moves motors from the higher-density to the lower-density lane, causing local jamm...
Pesheva, N. C.; Brankov, J. G.
2013-06-01
We report here results on the study of the totally asymmetric simple exclusion process, defined on an open network, consisting of head and tail simple-chain segments with a double-chain section inserted in between. Results of numerical simulations for relatively short chains reveal an interesting feature of the network. When the current through the system takes its maximum value, a simple translation of the double-chain section forward or backward along the network leads to a sharp change in the shape of the density profiles in the parallel chains, thus affecting the total number of particles in that part of the network. In the symmetric case of equal injection and ejection rates α=β>1/2 and equal lengths of the head and tail sections, the density profiles in the two parallel chains are almost linear, characteristic of the coexistence line (shock phase). Upon moving the section forward (backward), their shape changes to the one typical for the high- (low-) density phases of a simple chain. The total bulk density of particles in a section with a large number of parallel chains is evaluated too. The observed effect might have interesting implications for the traffic flow control as well as for biological transport processes in living cells. An explanation of this phenomenon is offered in terms of a finite-size dependence of the effective injection and ejection rates at the ends of the double-chain section.
Yeşil, Ayşe Ferhan; Yalabik, M. Cemal
2016-01-01
Driven diffusive systems have provided simple models for nonequilibrium systems with nontrivial structures. Steady-state behavior of these systems with constant boundary conditions have been studied extensively. Comparatively less work has been carried out on the responses of these systems to time-dependent parameters. We report the modifications to the probability density function of a two-particle exclusion model in response to a periodically changing perturbation to its boundary conditions. The changes in the shape of the distribution as a function of the frequency of the perturbation contains considerable structure. A dynamical phase transition in which the system response changes abruptly as a function of perturbation frequency was observed. We interpret this structure to be a consequence of the existence of a typical time scale associated with the dynamics of density shock profiles within the system.
Exclusive Processes at Colliders
Szczurek, Antoni
2009-01-01
A few examples of exclusive processes at high energy are discussed. Several mechanisms are presented. The differential distributions are shown. The possibilities to measure the processes are discussed.
Metal rolling - Asymmetrical rolling process
Alexa, V.; Raţiu, S.; Kiss, I.
2016-02-01
The development of theory and practice related to the asymmetric longitudinal rolling process is based on the general theory of metalworking by pressure and symmetric rolling theory, to which a large number of scientists brought their contribution. The rolling of metal materials was a serious problem throughout history, either economically or technically, because the plating technologies enabled the consumption of raw materials (scarce and expensive) to be reduced, while improving the mechanical properties. Knowing the force parameters related to asymmetric rolling leads to the optimization of energy and raw material consumption. This paper presents data on symmetric rolling process, in order to comparatively highlight the particularities of the asymmetric process.
Energy Technology Data Exchange (ETDEWEB)
Kugler, W.
2007-01-15
Hard exclusive processes in high energy electron proton scattering offer the opportunity to get access to a new generation of parton distributions, the so-called generalized parton distributions (GPDs). This functions provide more detailed informations about the structure of the nucleon than the usual PDFs obtained from DIS. In this work we present a detailed analysis of exclusive processes, especially of hard exclusive meson production. We investigated the influence of exclusive produced mesons on the semi-inclusive production of mesons at fixed target experiments like HERMES. Further we give a detailed analysis of higher order corrections (NLO) for the exclusive production of mesons in a very broad range of kinematics. (orig.)
Dynamics of non-Markovian exclusion processes
Khoromskaia, Diana; Rosemary J. Harris; Grosskinsky, Stefan
2014-01-01
Driven diffusive systems are often used as simple discrete models of collective transport phenomena in physics, biology or social sciences. Restricting attention to one-dimensional geometries, the asymmetric simple exclusion process (ASEP) plays a paradigmatic role to describe noise-activated driven motion of entities subject to an excluded volume interaction and many variants have been studied in recent years. While in the standard ASEP the noise is Poissonian and the process is therefore Ma...
An exclusion process with dynamic roadblocks
Ning, Guo; Jin-Yong, Chen; Mao-Bin, Hu; Rui, Jiang
2016-06-01
We study an exclusion process with multiple dynamic roadblocks. Each roadblock can move diffusively forward or backward with different rates, as well as unbind from/rebind to a free site. By Monte Carlo simulations, the two moving types are investigated in combination of roadblock number. The case of only diffusive roadblocks shows an asymmetric current-density relation. The case of only long-range jumping roadblocks presents that flux decreases with increasing roadblock number. Project supported by the National Basic Research Program of China (Grant No. 2012CB725404) and the National Natural Science Foundation of China (Grant Nos. 11422221, 71171185, and 71371175).
Exclusive processes in quantum chromodynamics
International Nuclear Information System (INIS)
Large momentum transfer exclusive processes and the short distance structure of hadronic wave functions can be systematically analyzed within the context of perturbative QCD. Predictions for meson form factors, two-photon processes γγ → M anti M, hadronic decays of heavy quark systems, and a number of other related QCD phenomena are reviewed
Exclusive Photon-Photon Processes
S. J. Brodsky
1997-01-01
Exclusive $\\gamma\\gamma \\to$ hadron pairs are among the most fundamental processes in QCD, providing a detailed examination of Compton scattering in the crossed channel. In the high momentum transfer domain $(s,t, {large},\\theta_{cm}$ for $t/s$ fixed), these processes can be computed from first principles in QCD, yielding important information on the nature of the QCD coupling $\\alpha_s$ and the form of hadron distribution amplitudes. Similarly, the transition form factors $\\gamma^*\\gamma$, $...
Exclusive processes at Jefferson Lab
Indian Academy of Sciences (India)
Haiyan Gao
2003-11-01
Mapping the transition from strongly interacting, non-perturbative quantum chromodynamics, where nucleon–meson degrees of freedom are effective to perturbative QCD of quark and gluon degrees of freedom, is one of the most fundamental, challenging tasks in nuclear and particle physics. Exclusive processes such as proton–proton elastic scattering, meson photoproduction, and deuteron photodisintegration have been pursued extensively at many laboratories over the years in the search for such a transition, particularly at Jefferson Lab in recent years, taking the advantage of the high luminosity capability of the CEBAF facility. In this talk, I review recent results from Jefferson Lab on deuteron photodisintegration and photopion production processes and the future 12 GeV program.
Dynamics of non-Markovian exclusion processes
International Nuclear Information System (INIS)
Driven diffusive systems are often used as simple discrete models of collective transport phenomena in physics, biology or social sciences. Restricting attention to one-dimensional geometries, the asymmetric simple exclusion process (ASEP) plays a paradigmatic role to describe noise-activated driven motion of entities subject to an excluded volume interaction and many variants have been studied in recent years. While in the standard ASEP the noise is Poissonian and the process is therefore Markovian, in many applications the statistics of the activating noise has a non-standard distribution with possible memory effects resulting from internal degrees of freedom or external sources. This leads to temporal correlations and can significantly affect the shape of the current-density relation as has been studied recently for a number of scenarios. In this paper we report a general framework to derive the fundamental diagram of ASEPs driven by non-Poissonian noise by using effectively only two simple quantities, viz., the mean residual lifetime of the jump distribution and a suitably defined temporal correlation length. We corroborate our results by detailed numerical studies for various noise statistics under periodic boundary conditions and discuss how our approach can be applied to more general driven diffusive systems. (paper)
Dynamics of non-Markovian exclusion processes
Khoromskaia, Diana; Harris, Rosemary J.; Grosskinsky, Stefan
2014-12-01
Driven diffusive systems are often used as simple discrete models of collective transport phenomena in physics, biology or social sciences. Restricting attention to one-dimensional geometries, the asymmetric simple exclusion process (ASEP) plays a paradigmatic role to describe noise-activated driven motion of entities subject to an excluded volume interaction and many variants have been studied in recent years. While in the standard ASEP the noise is Poissonian and the process is therefore Markovian, in many applications the statistics of the activating noise has a non-standard distribution with possible memory effects resulting from internal degrees of freedom or external sources. This leads to temporal correlations and can significantly affect the shape of the current-density relation as has been studied recently for a number of scenarios. In this paper we report a general framework to derive the fundamental diagram of ASEPs driven by non-Poissonian noise by using effectively only two simple quantities, viz., the mean residual lifetime of the jump distribution and a suitably defined temporal correlation length. We corroborate our results by detailed numerical studies for various noise statistics under periodic boundary conditions and discuss how our approach can be applied to more general driven diffusive systems.
HERMES Measurements of Hard-Exclusive Processes
Energy Technology Data Exchange (ETDEWEB)
Marianski, Bohdan
2008-11-15
Three HERMES measurements of hard-exclusive processes usefull for testing Generalized Parton Distributions (GPDs) are described. Firstly, Spin Density Matrix Elements (SDMEs) are determined from exclusive diffractive {rho}{sup 0} and {phi} electroproduction in the HERMES experiment at 27.5 GeV beam energy. Then, Transverse Target Spin Asymmetry (TTSA) in exclusive {rho}{sup 0} production and in Deeply Virtual Compton Scattering (DVCS) process on a transversally polarized hydrogen target is determined.
Perspectives on Exclusive Processes in QCD
Brodsky, Stanley J.
2002-01-01
Hard hadronic exclusive processes are now at the forefront of QCD studies, particularly because of their role in the interpretation of exclusive hadronic B decays. Perturbative QCD and its factorization properties at high momentum transfer provide an essential guide to the phenomenology of exclusive amplitudes at large momentum transfer--the leading power fall-off of form factors and fixed-angle cross sections, the dominant helicity structures, and their color transparency properties. The har...
A simulation study of an asymmetric exclusion model with open and periodic boundaries
International Nuclear Information System (INIS)
Using numerical simulations we study the effect of the jumping rate on the density, current and phase diagram in the open boundaries case, and on the velocities of particles in the case of one and two species of particles on a ring, of one dimensional asymmetric exclusion model. However, on the one hand, a passage from discontinuous to continuous transition occurs by decreasing the jumping rate in the open boundaries, on the other hand, for two species of particles on a ring the velocity of particle 1 increases while the velocity of particle 2 decreases as the jumping rate increases. (author)
Open two-species exclusion processes with integrable boundaries
International Nuclear Information System (INIS)
We give a complete classification of integrable Markovian boundary conditions for the asymmetric simple exclusion process with two species (or classes) of particles. Some of these boundary conditions lead to non-vanishing particle currents for each species. We explain how the stationary state of all these models can be expressed in a matrix product form, starting from two key components, the Zamolodchikov–Faddeev and Ghoshal–Zamolodchikov relations. This statement is illustrated by studying in detail a specific example, for which the matrix ansatz (involving nine generators) is explicitly constructed and physical observables (such as currents, densities) calculated. (paper)
Competitive exclusion principle in ecology and absolute asymmetric synthesis in chemistry.
Ribó, Josep M; Hochberg, David
2015-10-01
The key concepts underlying the Frank model (1953) for spontaneous asymmetric synthesis in chemistry are traced back to the pioneering works of Volterra (1926) and Lotka (1932) on biological species competition. The Lotka-Volterra (L-V) two-species exclusive competition model reduces to the Frank model for the special case of distinguishable but degenerate species (i.e., the enantiomers). The important ecological principle of competitive exclusion, originally derived from the L-V two-competitors model, is a consequence of sufficiently antagonistic interactions between the species competing for limited common resources, or mutual inhibition, as the term is known in the chemical literature on absolute asymmetric synthesis. The L-V and Frank models are described by the same general differential equations, nevertheless a crucial thermodynamic distinction between these models is necessary to correlate ecological selection and chemical selectivity arising from 1) the absence of reversibility in biological transformations, in marked contrast to chemical reactions, and 2) the constraints in chemical scenarios on the reaction rate constants required to fulfill the principle of micro-reversibility. PMID:26301597
Exclusive processes at high momentum transfer
Radyushkin, Anatoly; Stoker, Paul
2002-01-01
This book focuses on the physics of exclusive processes at high momentum transfer and their description in terms of generalized parton distributions, perturbative QCD, and relativistic quark models. It covers recent developments in the field, both theoretical and experimental.
Imaging partons in exclusive scattering processes
Energy Technology Data Exchange (ETDEWEB)
Diehl, Markus
2012-06-15
The spatial distribution of partons in the proton can be probed in suitable exclusive scattering processes. I report on recent performance estimates for parton imaging at a proposed Electron-Ion Collider.
Asymmetric Aldol Reaction with Formaldehyde: a Challenging Process.
Meninno, Sara; Lattanzi, Alessandra
2016-08-01
The asymmetric aldol reaction with formaldehyde is a fundamental carbon-carbon bond-forming reaction in organic synthesis, as well as in the quest of the origin of life, as it is thought to have been the first "molecular brick" involved in the synthetic path to complex sugars. Products of aldol reactions, i.e., the β-hydroxy carbonyl compounds, are versatile building blocks used to access a great variety of functionalised molecules. The employment of formaldehyde, as a C1 symmetric electrophile, in aldol reactions can be likely considered the most challenging, yet simplest, process to introduce a hydroxymethyl group in an asymmetric fashion. In this account, an overview of the progress achieved in the asymmetric metal- and organocatalysed aldol reaction, using readily available formalin or paraformaldehyde sources, is illustrated. Our recent contribution to this area, with the application of asymmetric hydroxymethylation in cascade processes for the synthesis of γ-butyrolactones, is also shown. PMID:27328802
Overview of HERMES Results on Exclusive Processes
Movsisyan Aram
2015-01-01
An overview of HERMES results on measurements of hard exclusive electroproduction of real photons and mesons on hydrogen and deuterium targets is presented. Experimental measurements of hard exclusive processes are commonly described within the formalism of generalized parton distributions (GPDs), which provide a unified description of the structure of hadrons embedding longitudinal-momentum distributions (ordinary PDFs) and transverse-position information (form factors). The HERMES experimen...
Spatiotemporally Complete Condensation in a Non-Poissonian Exclusion Process
Concannon, Robert J.; Blythe, Richard A.
2014-02-01
We investigate a non-Poissonian version of the asymmetric simple exclusion process, motivated by the observation that coarse graining the interactions between particles in complex systems generically leads to a stochastic process with a non-Markovian (history-dependent) character. We characterize a large family of one-dimensional hopping processes using a waiting-time distribution for individual particle hops. We find that when its variance is infinite, a real-space condensate forms that is complete in space (involves all particles) and time (exists at almost any given instant) in the thermodynamic limit. The mechanism for the onset and stability of the condensate is rather subtle and depends on the microscopic dynamics subsequent to a failed particle hop attempt.
Exclusive hadronic and nuclear processes in QCD
International Nuclear Information System (INIS)
Hadronic and nuclear processes are covered, in which all final particles are measured at large invariant masses compared with each other, i.e., large momentum transfer exclusive reactions. Hadronic wave functions in QCD and QCD sum rule constraints on hadron wave functions are discussed. The question of the range of applicability of the factorization formula and perturbation theory for exclusive processes is considered. Some consequences of quark and gluon degrees of freedom in nuclei are discussed which are outside the usual domain of traditional nuclear physics. 44 refs., 7 figs
Overview of HERMES Results on Exclusive Processes
Movsisyan, Aram
2015-01-01
An overview of HERMES results on measurements of hard exclusive electroproduction of real photons and mesons on hydrogen and deuterium targets is presented. Experimental measurements of hard exclusive processes are commonly described within the formalism of generalized parton distributions (GPDs), which provide a unified description of the structure of hadrons embedding longitudinal-momentum distributions (ordinary PDFs) and transverse-position information (form factors). The HERMES experiment at DESY Hamburg studies hard exclusive processes using polarized electron or positron beams from HERA and internal gas targets. Information about GPDs is gained from the measurements of asymmetries that appear in the azimuthal distributions of produced mesons and photons, together with studies of the azimuthal distribution of the decay products via spin-density matrix elements.
Overview of HERMES Results on Exclusive Processes
Directory of Open Access Journals (Sweden)
Movsisyan Aram
2015-01-01
Full Text Available An overview of HERMES results on measurements of hard exclusive electroproduction of real photons and mesons on hydrogen and deuterium targets is presented. Experimental measurements of hard exclusive processes are commonly described within the formalism of generalized parton distributions (GPDs, which provide a unified description of the structure of hadrons embedding longitudinal-momentum distributions (ordinary PDFs and transverse-position information (form factors. The HERMES experiment at DESY Hamburg studies hard exclusive processes using polarized electron or positron beams from HERA and internal gas targets. Information about GPDs is gained from the measurements of asymmetries that appear in the azimuthal distributions of produced mesons and photons, together with studies of the azimuthal distribution of the decay products via spin-density matrix elements.
Perspectives on Exclusive Processes in QCD
Brodsky, S J
2002-01-01
Hard hadronic exclusive processes are now at the forefront of QCD studies, particularly because of their role in the interpretation of exclusive hadronic B decays. Perturbative QCD and its factorization properties at high momentum transfer provide an essential guide to the phenomenology of exclusive amplitudes at large momentum transfer--the leading power fall-off of form factors and fixed-angle cross sections, the dominant helicity structures, and their color transparency properties. The hard scattering subprocess amplitude T_H controlling the leading-twist amplitude is evaluated in the perturbative domain where the propagator virtualities are above the separation scale. A critical question is the momentum transfer required such that leading-twist perturbative QCD contributions dominate. I review some of the contentious theoretical issues and empirical challenges to Perturbative QCD based analyses, such as the magnitude of the leading-twist contributions, the role of soft and higher twist QCD mechanisms, the...
Exact velocity of dispersive flow in the asymmetric avalanche process
Ivashkevich, E. V.; Povolotsky, A. M.; Priezzhev, V.B.
2000-01-01
Using the Bethe ansatz we obtain the exact solution for the one-dimensional asymmetric avalanche process. We evaluate the velocity of dispersive flow as a function of driving force and the density of particles. The obtained solution shows a dynamical transition from intermittent to continuous flow.
Perspectives on Exclusive Processes in QCD
Brodsky, S. J.
2002-12-01
Hard hadronic exclusive processes are now at the forefront of QCD studies, particularly because of their role in the interpretation of exclusive hadronic B decays, processes which are essential for determining the CKM phases and the physics of CP violation. Perturbative QCD and its factorization properties at high momentum transfer provide an essential guide to the phenomenology of exclusive amplitudes at large momentum transfer--the leading power fall-off of form factors and fixed-angle cross sections, the dominant helicity structures, and their color transparency properties. The reduced amplitude formalism provides an extension of the perturbative QCD predictions to exclusive nuclear amplitudes. The hard scattering subprocess TH controlling the leading-twist amplitude is only evaluated in the QCD perturbative domain where the propagator virtualities are above the separation scale. A critical question is the momentum transfer required such that leading-twist perturbative QCD contributions dominate. I review some of the contentious theoretical issues and empirical challenges to Perturbative QCD based analyses, such as the magnitude of the leading-twist contributions, the role of soft and higher twist QCD mechanisms, the effects of non-zero orbital angular momentum, the possibility of single-spin asymmetries in deeply virtual Compton scattering, the role of hidden color in nuclear wavefunctions, the behavior of the ratio of Pauli and Dirac nucleon form factors, the origin of anomalous J/ψ decays, the apparent breakdown of color transparency in quasi-elastic proton-proton scattering, and the measurement of hadron and photon wavefunctions in diffractive dijet production.
Perspectives on Exclusive Processes in QCD
International Nuclear Information System (INIS)
Hard hadronic exclusive processes are now at the forefront of QCD studies, particularly because of their role in the interpretation of exclusive hadronic B decays, processes which are essential for determining the CKM phases and the physics of CP violation. Perturbative QCD and its factorization properties at high momentum transfer provide an essential guide to the phenomenology of exclusive amplitudes at large momentum transfer---the leading power fall-off of form factors and fixed-angle cross sections, the dominant helicity structures, and their color transparency properties. The reduced amplitude formalism provides an extension of the perturbative QCD predictions to exclusive nuclear amplitudes. The hard scattering subprocess TH controlling the leading-twist amplitude is only evaluated in the QCD perturbative domain where the propagator virtualities are above the separation scale. A critical question is the momentum transfer required such that leading-twist perturbative QCD contributions dominate. I review some of the contentious theoretical issues and empirical challenges to Perturbative QCD based analyses, such as the magnitude of the leading-twist contributions, the role of soft and higher twist QCD mechanisms, the effects of non-zero orbital angular momentum, the possibility of single-spin asymmetries in deeply virtual Compton scattering, the role of hidden color in nuclear wavefunctions, the behavior of the ratio of Pauli and Dirac nucleon form factors, the origin of anomalous J/ψ decays, the apparent breakdown of color transparency in quasi-elastic proton-proton scattering, and the measurement of hadron and photon wavefunctions in diffractive dijet production
Asymptotic behaviour of exclusive processes in QCD
International Nuclear Information System (INIS)
The main ideas, methods and results in the investigation of the asymptotic behaviour of exclusive processes are reviewed. We discuss power behaviour and its dependence on hadron quantum numbers, logarithmic corrections and properties of nonperturbative hadronic wave functions. Applications to meson and baryon form factors, strong, electromagnetic and weak decays of heavy mesons, elastic scattering, threshold behaviour of inclusive structure functions, etc., are described. Comparison of theoretical predictions with experimental data is made whenever possible. The review may be of interest to theoreticians, experimentalists and students specializing in elementary particle physics. The experts in this field can also find new results (nonleading logarithms, higher twist processes, novel applications, etc.). (orig.)
Facilitated exclusion process and Pfaffian Schur processes
Baik, Jinho; Barraquand, Guillaume; Corwin, Ivan; Suidan, Toufic
2016-01-01
We study the Facilitated TASEP, an interacting particle system on the one dimensional integer lattice. We prove that starting from step initial condition, the position of the rightmost particle has Tracy Widom GSE statistics on a cube root time scale, while the statistics in the bulk of the rarefaction fan are GUE. This uses a mapping with last-passage percolation in a half-quadrant, which we study using the formalism of Pfaffian Schur processes. For the model with exponential weights, we pro...
Inhomogeneous Generalization of a Multispecies Totally Asymmetric Zero Range Process
Kuniba, Atsuo; Maruyama, Shouya; Okado, Masato
2016-06-01
The n-species totally asymmetric zero range process (n-TAZRP) on a one-dimensional periodic chain studied recently by the authors is a continuous time Markov process where arbitrary number of particles can occupy the same sites and hop to the adjacent sites only in one direction with a priority constraint according to their species. In this paper we introduce an n-parameter generalization of the n-TAZRP having inhomogeneous transition rate. The steady state probability is obtained in a matrix product form and also by an algorithm related to combinatorial R.
Death to perturbative QCD in exclusive processes?
Energy Technology Data Exchange (ETDEWEB)
Eckardt, R.; Hansper, J.; Gari, M.F. [Institut fuer Theoretische Physik, Bochum (Germany)
1994-04-01
The authors discuss the question of whether perturbative QCD is applicable in calculations of exclusive processes at available momentum transfers. They show that the currently used method of determining hadronic quark distribution amplitudes from QCD sum rules yields wave functions which are completely undetermined because the polynomial expansion diverges. Because of the indeterminacy of the wave functions no statement can be made at present as to whether perturbative QCD is valid. The authors emphasize the necessity of a rigorous discussion of the subject and the importance of experimental data in the range of interest.
Exclusion type spatially heterogeneous processes in continuum
Blank, Michael
2011-01-01
We study deterministic discrete time exclusion type spatially heterogeneous particle processes in continuum. A typical example of this sort is a traffic flow model with obstacles: traffic lights, speed bumps, spatially varying local velocities etc. Ergodic averages of particle velocities are obtained and their connections to other statistical quantities, in particular to particle and obstacles densities (the so called Fundamental Diagram) is analyzed rigorously. The main technical tool is a "dynamical" coupling construction applied in a nonstandard fashion: instead of proving the existence of the successful coupling (which even might not hold) we use its presence/absence as an important diagnostic tool.
Generalized parton distributions and exclusive processes
Energy Technology Data Exchange (ETDEWEB)
Guzey, Vadim [Hampton U.
2013-10-01
In last fifteen years, GPDs have emerged as a powerful tool to reveal such aspects of the QCD structure of the nucleon as: - 3D parton correlations and distributions; - spin content of the nucleon. Further advances in the field of GPDs and hard exclusive processes rely on: - developments in theory and new methods in phenomenology such as new flexible parameterizations, neural networks, global QCD fits - new high-precision data covering unexplored kinematics: JLab at 6 and 12 GeV, Hermes with recoil detector, Compass, EIC. This slide-show presents: Nucleon structure in QCD, particularly hard processes, factorization and parton distributions; and a brief overview of GPD phenomenology, including basic properties of GPDs, GPDs and QCD structure of the nucleon, and constraining GPDs from experiments.
Asymmetric processing of durational differences - electrophysiological investigations in Bengali.
Roberts, Adam C; Kotzor, Sandra; Wetterlin, Allison; Lahiri, Aditi
2014-05-01
Duration is used contrastively in many languages to distinguish word meaning (e.g. in Bengali, [pata] 'leaf' vs. [pat:a] 'whereabouts'). While there is a large body of research on other contrasts in speech perception (e.g. vowel contrasts and consonantal place features), little work has been done on how durational information is used in speech processing. In non-linguistic studies of low-level processing, such as visual and non-linguistic acoustic pop-out tasks, an asymmetry is found where additional information is more readily detected than missing information. In this study, event-related potentials were recorded during two cross-modal auditory-visual semantic priming studies, where nonword mispronunciations of spoken prime words were created by changing the duration of a medial consonant (real word [dana] 'seed'>nonword [dan:a]). N400 amplitudes showed an opposite asymmetric pattern of results, where increases in consonantal duration were tolerated and led to priming of the visual target, but decreases in consonantal duration were not accepted. This asymmetrical pattern of acceptability is attributed to the fact that a longer consonant includes all essential information for the recognition of the original word with a short medial consonant (a possible default category) and any additional information can be ignored. However, when a consonant is shortened, it lacks the required durational information to activate the word with the original long consonant. PMID:24726333
Condensation and transport in the totally asymmetric inclusion process (TASIP)
Knebel, Johannes; Weber, Markus F.; Krueger, Torben; Frey, Erwin
Transport phenomena are often modeled by the hopping of particles on regular lattices or networks. Such models describe, e.g., the exclusive movement of molecular motors along microtubules: no two motors may occupy the same site. In our work, we study inclusion processes that are the bosonic analogues of the fermionic exclusion processes. In inclusion processes, many particles may occupy a single site and hopping rates depend linearly on the occupation of departure and arrival sites. Particles thus attract other particles to their own site. Condensation occurs when particles collectively cluster in one or multiple sites, whereas other sites become depleted.We showed that inclusion processes describe both the selection of strategies in evolutionary zero-sum games and the condensation of non-interacting bosons into multiple quantum states in driven-dissipative systems. The condensation is captured by the antisymmetric Lotka-Volterra equation (ALVE), which constitutes a nonlinearly coupled dynamical system. We derived an algebraic method to analyze the ALVE and to determine the condensates. Our approach allows for the design of networks that result in condensates with oscillating occupations, and yields insight into the interplay between network topology and transport properties. Deutsche Forschungsgemeinschaft (SFB-TR12), German Excellence Initiative (Nanosystems Initiative Munich), Center for NanoScience Munich.
Denton, Jai A.; Ghosh, Atiyo; Marquez-Lago, Tatiana T
2015-01-01
The asymmetrical inheritance of plasmid DNA, as well as other cellular components, has been shown to be involved in replicative aging. In Saccharomyces cerevisiae, there is an ongoing debate regarding the mechanisms underlying this important asymmetry. Currently proposed models suggest it is established via diffusion, but differ on whether a diffusion barrier is necessary or not. However, no study so far incorporated key aspects to segregation, such as dynamic morphology changes throughout an...
Two-Photon Exclusive Processes in QCD
Brodsky, Stanley J.
2000-01-01
Exclusive two-photon reactions such as Compton scattering at large angles, deeply virtual Compton scattering, and hadron production in photon-photon collisions provide important tests of QCD at the amplitude level, particularly as measures of hadron distribution amplitudes and skewed parton distributions.
International Nuclear Information System (INIS)
We treat the N-particle zero range process whose jumping rates satisfy a certain condition. This condition is required to use the Bethe ansatz and the resulting model is the q-boson model by Sasamoto and Wadati [“Exact results for one-dimensional totally asymmetric diffusion models,” J. Phys. A 31, 6057–6071 (1998)] or the q-totally asymmetric zero range process (TAZRP) by Borodin and Corwin [“Macdonald processes,” Probab. Theory Relat. Fields (to be published)]. We find the explicit formula of the transition probability of the q-TAZRP via the Bethe ansatz. By using the transition probability we find the probability distribution of the left-most particle's position at time t. To find the probability for the left-most particle's position we find a new identity corresponding to identity for the asymmetric simple exclusion process by Tracy and Widom [“Integral formulas for the asymmetric simple exclusion process,” Commun. Math. Phys. 279, 815–844 (2008)]. For the initial state that all particles occupy a single site, the probability distribution of the left-most particle's position at time t is represented by the contour integral of a determinant
Energy Technology Data Exchange (ETDEWEB)
Korhonen, Marko [Department of Mathematics and Statistics, University of Helsinki, FIN-00014 (Finland); Lee, Eunghyun [Centre de Recherches Mathématiques (CRM), Université de Montréal, Quebec H3C 3J7 (Canada)
2014-01-15
We treat the N-particle zero range process whose jumping rates satisfy a certain condition. This condition is required to use the Bethe ansatz and the resulting model is the q-boson model by Sasamoto and Wadati [“Exact results for one-dimensional totally asymmetric diffusion models,” J. Phys. A 31, 6057–6071 (1998)] or the q-totally asymmetric zero range process (TAZRP) by Borodin and Corwin [“Macdonald processes,” Probab. Theory Relat. Fields (to be published)]. We find the explicit formula of the transition probability of the q-TAZRP via the Bethe ansatz. By using the transition probability we find the probability distribution of the left-most particle's position at time t. To find the probability for the left-most particle's position we find a new identity corresponding to identity for the asymmetric simple exclusion process by Tracy and Widom [“Integral formulas for the asymmetric simple exclusion process,” Commun. Math. Phys. 279, 815–844 (2008)]. For the initial state that all particles occupy a single site, the probability distribution of the left-most particle's position at time t is represented by the contour integral of a determinant.
A short review of the theory of hard exclusive processes
Wallon, Samuel
2011-01-01
We first present an introduction to the theory of hard exclusive processes. We then illustrate this theory by a few selected examples. The last part is devoted to the most recent developments in the asymptotical energy limit.
Quark Orbital Angular Momentum and Exclusive Processes at HERMES
International Nuclear Information System (INIS)
A first attempt for a model-dependent extraction of the orbital angular momentum of quarks in the nucleon has been made, based on HERMES data on exclusive processes and their description in terms of generalized parton distributions. An overview of the HERMES data on hard exclusive electroproduction of real photons (Deeply-Virtual Compton Scattering) and mesons is given, focusing on the measurements relevant to the extraction of quark orbital angular momentum
Quark Orbital Angular Momentum and Exclusive Processes at HERMES
Ellinghaus, F.
2006-11-01
A first attempt for a model-dependent extraction of the orbital angular momentum of quarks in the nucleon has been made, based on HERMES data on exclusive processes and their description in terms of generalized parton distributions. An overview of the HERMES data on hard exclusive electroproduction of real photons (Deeply-Virtual Compton Scattering) and mesons is given, focusing on the measurements relevant to the extraction of quark orbital angular momentum.
Nikolay Gospodinov; Masayuki Hirukawa
2008-01-01
This paper considers a nonstandard kernel regression for strongly mixing processes when the regressor is nonnegative. The nonparametric regression is implemented using asymmetric kernels [Gamma (Chen, 2000b), Inverse Gaussian and Reciprocal Inverse Gaussian (Scaillet, 2004) kernels] that possess some appealing properties such as lack of boundary bias and adaptability in the amount of smoothing. The paper investigates the asymptotic and finite-sample properties of the asymmetric kernel Nadaray...
The Processes of Inclusion and Exclusion in Physical Education
DEFF Research Database (Denmark)
Jensen, Mette Munk; Agergaard, Sine
2015-01-01
Existing research on inclusion and exclusion processes in physical education (PE) has particularly focused on exclusion from PE as something being done to students and attributed to specific social categories such as (female) gender, (low) physical skills or (minority) ethnic background. This...... article aims to develop a social-relational perspective on inclusion and exclusion processes defined as students’ participation or non-participation in PE interpreted as a community of practice. In so doing, the article examines how students’ experiences of participation and non-participation in PE are...... influenced by complex interactions within the group of students and in negotiations with teachers about the values and practices of PE. The article is based on an embedded single-case study carried out over the course of 6 months through weekly observations of PE classes in a multi-ethnic school, as well as...
When push comes to shove: Exclusion processes with nonlocal consequences
Almet, Axel A.; Pan, Michael; Hughes, Barry D.; Landman, Kerry A.
2015-11-01
Stochastic agent-based models are useful for modelling collective movement of biological cells. Lattice-based random walk models of interacting agents where each site can be occupied by at most one agent are called simple exclusion processes. An alternative motility mechanism to simple exclusion is formulated, in which agents are granted more freedom to move under the compromise that interactions are no longer necessarily local. This mechanism is termed shoving. A nonlinear diffusion equation is derived for a single population of shoving agents using mean-field continuum approximations. A continuum model is also derived for a multispecies problem with interacting subpopulations, which either obey the shoving rules or the simple exclusion rules. Numerical solutions of the derived partial differential equations compare well with averaged simulation results for both the single species and multispecies processes in two dimensions, while some issues arise in one dimension for the multispecies case.
Exponential decay and ergodicity of completely asymmetric Lévy processes in a finite interval
Bertoin, Jean
1997-01-01
Consider a completely asymmetric Lévy process which has absolutely continuous transition probabilities. We determine the exponential decay parameter $\\rho$ and the quasistationary distribution for the transition probabilities of the Lévy process killed as it exits from a finite interval, prove that the killed process is $\\rho$-positive and specify the $\\rho$-invariant function and measure.
Dispersion relations and subtractions in hard exclusive processes
Anikin, I V
2007-01-01
We study analytical properties of the hard exclusive processes amplitudes. We found that QCD factorization for deeply virtual Compton scattering and hard exclusive vector meson production results in the subtracted dispersion relation with the subtraction constant determined by the Polyakov-Weiss $D$-term. The relation of this constant to the fixed pole contribution found by Brodsky, Close and Gunion and defined by parton distributions is proved, while its manifestation is spoiled by the small $x$ divergence. The continuation to the real photons limit is considered and the numerical correspondence between lattice simulations of $D$-term and low energy Thomson amplitude is found.
Exclusive processes with a leading neutron in $ep$ collisions
Goncalves, V P; Spiering, D
2015-01-01
In this paper we extend the color dipole formalism to the study of exclusive processes associated with a leading neutron in $ep$ collisions at high energies. The exclusive $\\rho$, $\\phi$ and $J/\\Psi$ production, as well as the Deeply Virtual Compton Scattering, are analysed assuming a diffractive interaction between the color dipole and the pion emitted by the incident proton. We compare our predictions with the HERA data on $\\rho$ production and estimate the magnitude of the absorption corrections. We show that the color dipole formalism is able to describe the current data. Finally, we present our estimate for the exclusive cross sections which can be studied at HERA and in future electron-proton colliders.
Inclusive and Exclusive Compton Processes in Quantum Chromodynamics
Energy Technology Data Exchange (ETDEWEB)
Ales Psaker
2005-12-31
In our work, we describe two types of Compton processes. As an example of an inclusive process, we consider the high-energy photoproduction of massive muon pairs off the nucleon. We analyze the process in the framework of the QCD parton model, in which the usual parton distributions emerge as a tool to describe the nucleon in terms of quark and gluonic degrees of freedom. To study its exclusive version, a new class of phenomenological functions is required, namely, generalized parton distributions. They can be considered as a generalization of the usual parton distributions measured in deeply inelastic lepton-nucleon scattering. Generalized parton distributions (GPDs) may be observed in hard exclusive reactions such as deeply virtual Compton scattering. We develop an extension of this particular process into the weak interaction sector. We also investigate a possible application of the GPD formalism to wide-angle real Compton scattering.
Recent progress in some exclusive and semi-exclusive processes in proton-proton collisions
Szczurek, Antoni; Luszczak, Marta; Schafer, Wolfgang
2015-01-01
We present the main results of our recent analyses of exclusive production of vector charmonia ($J/\\psi$ and $\\psi'$) in $k_t$-factorization approach and for $\\gamma \\gamma$ production of charged dilepton pairs in exclusive and semiinclusive processes in a new approach, similar in spirit to $k_t$-factorization. The results for charmonia are compared with recent results of the LHCb collaboration. We include some helicity flip contributions and quantify the effect of absorption correction. The effect of $c \\bar c$ wave function is illustrated. We present uncertainties related to $F_2$ structure function which are the main ingredient of the approach. Our results are compared with recent CMS data for dilepton production with lepton isolation cuts imposed.
Progress in the theory of hard exclusive processes
International Nuclear Information System (INIS)
Recent progresses in the theory of hard exclusive processes are reviewed. The hard scattering mechanism and the factorization of perturbative QCD amplitudes from wave-function-like quantities is now well understood. The effects of soft gluon radiation are controlled through Sudakov form factors which protect observables from dangerous end-point contributions. The phenomenology of this mature framework is eagerly waiting for precise experimental data in a domain where transfers are O(10 GeV2). (author). 11 refs., 2 figs
Dispersion relations and subtractions in hard exclusive processes
International Nuclear Information System (INIS)
We study analytical properties of the hard exclusive process amplitudes. We found that QCD factorization for deeply virtual Compton scattering and hard exclusive vector meson production results in the subtracted dispersion relation with the subtraction constant determined by the Polyakov-Weiss D-term. The relation of this constant to the fixed pole contribution found by Brodsky, Close, and Gunion and defined by parton distributions is studied and proved for momentum transfers exceeding the typical hadronic scale. The continuation to the real photon limit is considered, and the numerical correspondence between lattice simulations of the D-term and low energy Thomson amplitude is found. For sufficiently large t the subtraction may be expressed in a form similar to that suggested earlier for real Compton scattering
Asymmetric skew Bessel processes and their applications to finance
M. Decamps; M.J. Goovaerts; W. Schoutens
2006-01-01
In this paper, we extend the Harrison and Shepp's construction of the skew Brownian motion (1981) and we obtain a diffusion similar to the two-dimensional Bessel process with speed and scale densities discontinuous at one point. Natural generalizations to multi-dimensional and fractional order Besse
An Agent for Asymmetric Process Mediation in Open Environments
Czech Academy of Sciences Publication Activity Database
Vaculín, Roman; Neruda, Roman; Sycara, K.
Berlin: Springer, 2008 - (Kowalczyk, R.; Huhns, M.; Klusch, M.; Maamar, Z.; Bao Vo, Q.), s. 104-117. (Lecture Notes in Computer Science. 5006). ISBN 978-3-540-79967-2. [AAMAS 2008. International Workshop, SOCASE 2008. Estoril (PT), 12.05.2008-12.05.2008] R&D Projects: GA AV ČR 1ET100300517; GA MŠk ME08095 Institutional research plan: CEZ:AV0Z10300504 Keywords : process mediation of semantic web services * semantic web services * discovery * OWL-S Subject RIV: IN - Informatics, Computer Science
The AdS/QCD Correspondence and Exclusive Processes
Energy Technology Data Exchange (ETDEWEB)
Brodsky, Stanley J.; /SLAC /Southern Denmark U., CP3-Origins; de Teramond, Guy F.; /Costa Rica U.; Deur, Alexandre; /Jefferson Lab
2010-08-25
The AdS/CFT correspondence between theories in AdS space and conformal field theories in physical space-time provides an analytic, semi-classical, color-confining model for strongly-coupled QCD. The soft-wall AdS/QCD model modified by a positive-sign dilaton metric leads to a remarkable one-parameter description of nonperturbative hadron dynamics at zero quark mass, including a zero-mass pion and a Regge spectrum of linear trajectories with the same slope in orbital angular momentum L and radial quantum number n for both mesons and baryons. One also predicts the form of the non-perturbative effective coupling {alpha}{sub s}{sup AdS}(q) and its {beta}-function which agrees with the effective coupling {alpha}{sub ga} extracted from the Bjorken sum rule. Light-front holography, which connects the fifth-dimensional coordinate of AdS space z to an invariant impact separation variable {zeta}, allows one to compute the analytic form of the frame-independent light-front wavefunctions, the fundamental entities which encode hadron properties as well as decay constants, form factors, deeply virtual Compton scattering, exclusive heavy hadron decays and other exclusive scattering amplitudes. One thus obtains a relativistic description of hadrons in QCD at the amplitude level with dimensional counting for hard exclusive reactions at high momentum transfer. As specific examples we discuss the behavior of the pion and nucleon form factors in the space-like and time-like regions. We also review the phenomenology of exclusive processes including some anomalous empirical results.
The ADS/QCD correspondence and exclusive processes
International Nuclear Information System (INIS)
The AdS/CFT correspondence between theories in AdS space and conformal field theories in physical space-time provides an analytic, semi-classical, color-confining model for strongly-coupled QCD. The soft-wall AdS/QCD model, modified by a positive-sign dilaton metric, leads to a remarkable one-parameter description of nonperturbative hadron dynamics at zero quark mass, including a zero-mass pion and meson and baryon Regge spectra of linear trajectories with the same slope in orbital angular momentum L and radial quantum number n. One also predicts the form of the non-perturbative effective coupling alpha AdS/s (Q) and its Beta-function which agrees with the effective coupling alphag1 extracted from the Bjorken sum rule. Light-front holography, which connects the fifth-dimensional coordinate of AdS space z to an invariant impact separation variable zeta, allows one to compute the analytic form of the frame-independent light-front wave functions, the fundamental entities which encode hadron properties as well as decay constants, form factors, deeply-virtual Compton scattering, exclusive heavy hadron decays, and other exclusive scattering amplitudes. One thus obtains a relativistic description of hadrons in QCD at the amplitude level with dimensional counting for exclusive reactions at high momentum transfer. As specific examples, we discuss the behavior of the pion and nucleon form factors in the space-like and time-like regions. We also review the phenomenology of exclusive processes including some anomalous empirical results.
The AdS/QCD Correspondence and Exclusive Processes
International Nuclear Information System (INIS)
The AdS/CFT correspondence between theories in AdS space and conformal field theories in physical space-time provides an analytic, semi-classical, color-confining model for strongly-coupled QCD. The soft-wall AdS/QCD model modified by a positive-sign dilaton metric leads to a remarkable one-parameter description of nonperturbative hadron dynamics at zero quark mass, including a zero-mass pion and a Regge spectrum of linear trajectories with the same slope in orbital angular momentum L and radial quantum number n for both mesons and baryons. One also predicts the form of the non-perturbative effective coupling αsAdS(q) and its β-function which agrees with the effective coupling αga extracted from the Bjorken sum rule. Light-front holography, which connects the fifth-dimensional coordinate of AdS space z to an invariant impact separation variable ζ, allows one to compute the analytic form of the frame-independent light-front wavefunctions, the fundamental entities which encode hadron properties as well as decay constants, form factors, deeply virtual Compton scattering, exclusive heavy hadron decays and other exclusive scattering amplitudes. One thus obtains a relativistic description of hadrons in QCD at the amplitude level with dimensional counting for hard exclusive reactions at high momentum transfer. As specific examples we discuss the behavior of the pion and nucleon form factors in the space-like and time-like regions. We also review the phenomenology of exclusive processes including some anomalous empirical results.
The Ads/qcd Correspondence and Exclusive Processes
Brodsky, Stanley J.; de Téramond, Guy F.; Deur, Alexandre
2011-02-01
The AdS/CFT correspondence between theories in AdS space and conformal field theories in physical space-time provides an analytic, semi-classical, color-confining model for strongly-coupled QCD. The soft-wall AdS/QCD model, modified by a positive-sign dilaton metric, leads to a remarkable one-parameter description of nonperturbative hadron dynamics at zero quark mass, including a zero-mass pion and meson and baryon Regge spectra of linear trajectories with the same slope in orbital angular momentum L and radial quantum number n. One also predicts the form of the non-perturbative effective coupling α sAdS (Q) and its β-function which agrees with the effective coupling αg1 extracted from the Bjorken sum rule. Light-front holography, which connects the fifth-dimensional coordinate of AdS space z to an invariant impact separation variable ζ, allows one to compute the analytic form of the frame-independent light-front wave functions, the fundamental entities which encode hadron properties as well as decay constants, form factors, deeply-virtual Compton scattering, exclusive heavy hadron decays, and other exclusive scattering amplitudes. One thus obtains a relativistic description of hadrons in QCD at the amplitude level with dimensional counting for exclusive reactions at high momentum transfer. As specific examples, we discuss the behavior of the pion and nucleon form factors in the space-like and time-like regions. We also review the phenomenology of exclusive processes including some anomalous empirical results.
Globalization processes and the asymmetric nature of the crime of terrorism
Фединець, Роксолана
2016-01-01
The article analyzes the impact of modern globalization processes that are observed in international economic relations, on the international legal factors of conflict asymmetry in international economic relations and the relationship of such asymmetry with the escalation and spread of the phenomenon of global terrorism. English abstract R. Fedynets Globalization processes and the asymmetric nature of the crime of terrorism The problem that has arisen today in international law is that inte...
Standard candle central exclusive processes at the Tevatron and LHC
Harland-Lang, L A; Ryskin, M G; Stirling, W J
2010-01-01
Central exclusive production (CEP) processes in high-energy proton -- (anti)proton collisions offer a very promising framework within which to study both novel aspects of QCD and new physics signals. Among the many interesting processes that can be studied in this way, those involving the production of heavy (c,b) quarkonia and gamma gamma states have sufficiently well understood theoretical properties and sufficiently large cross sections that they can serve as `standard candle' processes with which we can benchmark predictions for new physics CEP at the CERN Large Hadron Collider. Motivated by the broad agreement with theoretical predictions of recent CEP measurements at the Fermilab Tevatron, we perform a detailed quantitative study of heavy quarkonia (chi and eta) and gamma gamma production at the Tevatron, RHIC and LHC, paying particular attention to the various uncertainties in the calculations. Our results confirm the rich phenomenology that these production processes offer at present and future high-e...
Hard exclusive processes in the one - and two - nucleon systems
International Nuclear Information System (INIS)
A description of hard exclusive processes in the one-and two-nucleon system is attempted in the quark parton approach. The discussion deals with the large momentum transfer electromagnetic form factors of nucleon and deuteron as well as the wide angle, high energy nucleon-nucleon scattering differential cross-section and spin correlation parameters. We review the perturbative Quantum Chromodynamics approach initiated in recent works. The limitations of the approach are emphasized to motivate the consideration of a phenomenological approach. The core parton model introduced some time ago is discussed in both its spinless and spin versions. The predictions are compared with measurements
Finite Element Analysis of Symmetric and Asymmetric Three-roll Rolling Process
Directory of Open Access Journals (Sweden)
Pesin A.
2015-01-01
Full Text Available A three-roll process is a significant technique in the production of wire rod, round bars and hexagonal profiles for structural applications. Better mechanical properties of wire rod, round bars and hexagonal profiles can be achieved due to large plastic deformation by the three-roll process. Asymmetric rolling is a novel technique characterised by a kinematic asymmetry linked to the difference in peripheral speed of the rolls, able to introduce additional shear strains through the bar thickness. In order to achieve this, asymmetrical three-roll rolling process was investigated to better control the deformation compared to the conventional three-roll rolling process in a stand with two three-roll calibers located very close to each other. Simulation of round-triangle-triangle pass rolling was performed. FEM simulations were carried out with using software DEFORM 3D. The influence of the friction coefficient and speed asymmetry on the shear strain and material flow was discussed. The results of simulation can be used to optimize the asymmetric three-roll rolling process to improve the mechanical properties of wire rod, round bars and hexagonal profiles.
Optimizing evacuation flow in a two-channel exclusion process
Galla, Tobias
2011-01-01
We use a basic setup of two coupled exclusion processes to model a stylised situation in evacuation dynamics, in which evacuees have to choose between two escape routes. The coupling between the two processes occurs through one common point at which particles are injected, the process can be controlled by directing incoming individuals into either of the two escape routes. Based on a mean-field approach we determine the phase behaviour of the model, and analytically compute optimal control strategies, maximising the total current through the system. Results are confirmed by numerical simulations. We also show that dynamic intervention, exploiting fluctuations about the mean-field stationary state, can lead to a further increase in total current.
Factorization of exclusive processes in perturbative quantum-chromodynamics
International Nuclear Information System (INIS)
The work carried out in this thesis presents various theoretical and phenomenological studies of the exclusive production of longitudinally polarized neutral vector rho mesons in virtual photons collisions, within the framework of quantum-chromodynamics (QCD). The virtuality of the photons makes it possible to locate our approach in the perturbative area of the theory. The kinematical regimes considered allow the use of varied theoretical tools which reveal various properties of factorization of the scattering amplitude: two types of collinear factorization (at short distance) for this process are discussed in chapter 1, revealing - according to the polarization of the virtual photons and the kinematical limit considered- Generalized Distribution Amplitudes (GDA) or Transition Distribution Amplitudes (TDA), tools commonly used in the description of exclusive processes. We introduce into the Chapter 2 in a self-consistent way, the foundations of the BFKL (Balitskii, Fadin, Kuraev and Lipatov) formalism valid within the high energy limit (Regge limit) of QCD, for its phenomenological use detailed in Chapter 3: the scattering amplitude of the process is described in this formalism by exploiting the factorization in the two-dimensional transverse momentum space, or kT-factorization. We predict the value of the cross section of the process at Born order of the BFKL resummation and we discuss its possible observation at the future international linear collider (ILC). We consider also the differential cross sections of the process without momentum transfer with complete BFKL evolution at the order of the leading logarithms (Leading-Order) and also at the Next-to-Leading-Order to establish a fine test of this process with hard BFKL Pomeron exchange, observable at the future ILC. (author)
Process Design for Hot Forging of Asymmetric to Symmetric Rib-web Shaped Steel
Directory of Open Access Journals (Sweden)
H. Cho
2003-01-01
Full Text Available The process design of hot forging, asymmetric to symmetric rib-web shaped steel, which is used for the turnout of express rails has been studied. Owing to the great difference in shape between the initial billet and the final forged product, it is impossible to hot forge the rail in a single stage operation. Therefore, multi stage forging and also die design for each stage are necessary for the production process. The numerical simulation for hot forging of asymmetric shape to symmetric shape was carried out using commercial FEM code, DEFORMTM-2D. Modification of the design and repeated simulation was carried out on the basis of the simulation results. For comparison with the simulation results, a flow analysis experiment using plasticine was also carried out. The results of the flow analysis experiment showed good agreement with those of the simulation.
Carlyon, Robert P.; Monstrey, Jolijn; Deeks, John M.; Macherey, Olivier
2014-01-01
Objective To evaluate a speech-processing strategy in which the lowest frequency channel is conveyed using an asymmetric pulse shape and “phantom stimulation”, where current is injected into one intra-cochlear electrode and where the return current is shared between an intra-cochlear and an extra-cochlear electrode. This strategy is expected to provide more selective excitation of the cochlear apex, compared to a standard strategy where the lowest-frequency channel is conveyed by symmetric pu...
Asymmetric neighborhood functions accelerate ordering process of self-organizing maps
International Nuclear Information System (INIS)
A self-organizing map (SOM) algorithm can generate a topographic map from a high-dimensional stimulus space to a low-dimensional array of units. Because a topographic map preserves neighborhood relationships between the stimuli, the SOM can be applied to certain types of information processing such as data visualization. During the learning process, however, topological defects frequently emerge in the map. The presence of defects tends to drastically slow down the formation of a globally ordered topographic map. To remove such topological defects, it has been reported that an asymmetric neighborhood function is effective, but only in the simple case of mapping one-dimensional stimuli to a chain of units. In this paper, we demonstrate that even when high-dimensional stimuli are used, the asymmetric neighborhood function is effective for both artificial and real-world data. Our results suggest that applying the asymmetric neighborhood function to the SOM algorithm improves the reliability of the algorithm. In addition, it enables processing of complicated, high-dimensional data by using this algorithm.
Putting in evidence the asymmetric fission in the desexcitation process of 47V nuclei
International Nuclear Information System (INIS)
The fusion-fission, which reflects the instability of the nuclei against the deformation and leads to a binary break up into nearly equal mass nuclei, have been considered as a general feature of the heavy ions (A>80). For lighter systems the fission decay of the compound nucleus is predicted by the rotating liquid drop model to be minor process and the fully-damped products observed in reactions between light heavy ions (A35 Cl+12 C, 31 P+16 O and 23 Na+24 Mg reactions used in order to populate the 47 V system at two excitation energies E = 59 and 64 MeV. This study shows that these fragments are the result of the emission from a source and their elemental distributions are asymmetric independently to the entrance channel asymmetry. The absence of entrance channel effect is a signature of the asymmetric fission process of the 47 V nucleus. The comparison of the experimental observations to the statistical model shows that the fission barriers in this mass region are lower than those predicted by the rotating liquid drop model and the need of introducing their angular momentum and mass asymmetry dependence is clearly shown. In conclusion, it is well established that the evidence of the asymmetric fission break up into the desexcitation process of the 47 V nucleus should be taken into account in the statistical calculations describing the complete fusion of light heavy ions
Adam, Michel; Assal, Sophie; Benicourt, Emmanuelle; Bonte, Pierre; Dorier Apprill, Élisabeth; Gillet, Marie; Giordano, Christian; Goedefroit, Sophie; Govoroff, Nicolas; Jacques-Jouvenot, Dominique; Karadimas, Dimitri; Lécrivain, Valérie; Lestage, Françoise; Lévi-Strauss, Claude; Pagès, Alexandre
2005-01-01
Sous le titre «Exclusions» sont réunis, dans ce numéro aux approches diverses, plusieurs sujets communs répondant à cet intitulé général : la pauvreté en milieu rural (France, Brésil, Madagascar) et le point de vue de la Banque mondiale sur cette question, les tensions ethniques et la territorialisation (Balkans, Mexique, Zambèze) enfin, l'importance d'une analyse anthropologique comparative pour comprendre la portée relative de la notion de productivité (C. Lévi-Strauss) et les logiques soci...
Hydrodynamic mean-field solutions of 1D exclusion processes with spatially varying hopping rates
Energy Technology Data Exchange (ETDEWEB)
Lakatos, Greg; O' Brien, John; Chou, Tom [Department of Biomathematics and Institute for Pure and Applied Mathematics, UCLA, Los Angeles, CA 90095 (United States)
2006-03-10
We analyse the open boundary partially asymmetric exclusion process with smoothly varying internal hopping rates in the infinite-size, mean-field limit. The mean-field equations for particle densities are written in terms of Ricatti equations with the steady-state current J as a parameter. These equations are solved both analytically and numerically. Upon imposing the boundary conditions set by the injection and extraction rates, the currents J are found self-consistently. We find a number of cases where analytic solutions can be found exactly or approximated. Results for J from asymptotic analyses for slowly varying hopping rates agree extremely well with those from extensive Monte Carlo simulations, suggesting that mean-field currents asymptotically approach the exact currents in the hydrodynamic limit, as the hopping rates vary slowly over the lattice. If the forward hopping rate is greater than or less than the backward hopping rate throughout the entire chain, the three standard steady-state phases are preserved. Our analysis reveals the sensitivity of the current to the relative phase between the forward and backward hopping rate functions.
An exclusion process on a tree with constant aggregate hopping rate
International Nuclear Information System (INIS)
We introduce a model of a totally asymmetric simple exclusion process (TASEP) on a tree network where the aggregate hopping rate is constant from level to level. With this choice for hopping rates the model shows the same phase diagram as the one-dimensional case. The potential applications of our model are in the area of distribution networks, where a single large source supplies material to a large number of small sinks via a hierarchical network. We show that mean-field theory (MFT) for our model is identical to that of the one-dimensional TASEP and that this MFT is exact for the TASEP on a tree in the limit of large branching ratio, b (or equivalently large coordination number). We then present an exact solution for the two level tree (or star network) that allows the computation of any correlation function and confirm how mean-field results are recovered as b → ∞. As an example we compute the steady-state current as a function of branching ratio. We present simulation results that confirm these results and indicate that the convergence to MFT with large branching ratio is quite rapid. (paper)
QED Radiative Corrections in Processes of Exclusive Pion Electroproduction
Energy Technology Data Exchange (ETDEWEB)
Andrei Afanasev; I. Akushevich; Volker Burkert; K. Joo
2002-03-01
Formalism for radiative correction (RC) calculation in exclusive pion electroproduction on the proton is presented. A FORTRAN code EXCLURAD is developed for the RC procedure. The numerical analysis is done in the kinematics of current Jefferson Lab experiments.
Quantification of asymmetric microtubule nucleation at sub-cellular structures
Zhu, Xiaodong; Kaverina, Irina
2011-01-01
Cell polarization is important for multiple physiological processes. In polarized cells, microtubules (MTs) are organized into a spatially polarized array. Generally, in non-differentiated cells, it is assumed that MTs are symmetrically nucleated exclusively from centrosome (microtubule organizing center, MTOC) and then reorganized into the asymmetric array. We have recently identified the Golgi complex as an additional MTOC that asymmetrically nucleates MTs toward one side of the cell. Metho...
Directory of Open Access Journals (Sweden)
Germán H. Gonzalez
2014-08-01
Full Text Available The usefulness of the European model of integration is currently subject to debate and the North American integration process has been largely ignored as a comparative framework. The asymmetrical relationship between Canada and the United States began a long time before NAFTA, and the study of this process could shed light on the usual problems faced by Latin American countries. This article attempts to encourage discussion about this topic. Particularly,there is evidence for a substantial and positive change in Canadian productivity at the time of the Canada-US Free Trade Agreement (CUFTA. However, the enactment of the North American Free Trade Agreement (NAFTA does not seem to have had the same effect as the earlier treaty.
Microstructures and mechanical properties of commercial purity iron processed by asymmetric rolling
International Nuclear Information System (INIS)
For the purpose of grain refinement, commercial purity iron processed by asymmetric rolling (ASR) has been studied by optical microscopy, electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). Equiaxed ultra fined grains with a grain size of about 0.9 μm and a large fraction of high angle grain boundaries were obtained. The formation of the equiaxed grains is suggested to result from the additional shear strain which is observed by the shape change of a Cu band inserted into the rolled materials. The rolled iron exhibits high yield strength with a low work hardening ability and high microhardness, which are attributed to the high dislocation density and the large fraction of the high angle boundaries.
Energy Technology Data Exchange (ETDEWEB)
Jayaweera, Indira; Krishnan, Gopala N.; Sanjurjo, Angel; Jayaweera, Palitha; Bhamidi, Srinivas
2016-04-26
The invention provides methods for preparing an asymmetric hollow fiber, the asymmetric hollow fibers prepared by such methods, and uses of the asymmetric hollow fibers. One method involves passing a polymeric solution through an outer annular orifice of a tube-in-orifice spinneret, passing a bore fluid though an inner tube of the spinneret, dropping the polymeric solution and bore fluid through an atmosphere over a dropping distance, and quenching the polymeric solution and bore fluid in a bath to form an asymmetric hollow fiber.
Measurement of diffractive and exclusive processes with the ATLAS detector
Gach, Grzegorz
2016-07-01
The ATLAS Collaboration has carried out a study of diffractive dijet production in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the LHC. The data distributions are compared with Monte Carlo models and the rapidity gap survival probability has been estimated in the kinematic region with high diffractive contribution. Prospects for exclusive jet production studies with the forward proton tagging capability of the AFP sub-detector of ATLAS are also discussed. First results based on data taken jointly with the ATLAS and the LHCf detectors in a p+Pb run will also be shown. In addition, the measurement of the cross-section for the exclusive production of di-lepton pairs in pp collisions at √s = 7 TeV is discussed.
Measurement of diffractive and exclusive processes with the ATLAS detector
Directory of Open Access Journals (Sweden)
Gach Grzegorz
2016-01-01
Full Text Available The ATLAS Collaboration has carried out a study of diffractive dijet production in proton–proton collisions at a centre-of-mass energy of √s = 7 TeV at the LHC. The data distributions are compared with Monte Carlo models and the rapidity gap survival probability has been estimated in the kinematic region with high diffractive contribution. Prospects for exclusive jet production studies with the forward proton tagging capability of the AFP sub-detector of ATLAS are also discussed. First results based on data taken jointly with the ATLAS and the LHCf detectors in a p+Pb run will also be shown. In addition, the measurement of the cross-section for the exclusive production of di-lepton pairs in pp collisions at √s = 7 TeV is discussed.
Measurement of diffractive and exclusive processes with the ATLAS detector
Gach, Grzegorz; The ATLAS collaboration
2015-01-01
The ATLAS collaboration has carried out a study diffractive dijet production at 7 TeV pp collisions at the LHC, i.e. events with a hadronic system containing at least two jets in addition to a large region of pseudorapidity devoid of hadronic activity. The data distributions are compared with Monte Carlo models and the rapidity gap survival probability has been estimated in the kinematic region with high diffractive contribution. Prospects for exclusive jet production studies with the forward proton tagging capability of the AFP sub-detector of ATLAS will be discussed. A first look at data taken jointly with the ATLAS and LHCf detectors in a p+Pb run will also be shown. In addition the measurement of the exclusive $\\gamma+\\gamma \\rightarrow ll$ production cross-section in proton-proton collisions at a centre-of-mass energy of 7 TeV has been carried out.
FRACTIONAL FICK'S LAW FOR THE BOUNDARY DRIVEN EXCLUSION PROCESS WITH LONG JUMPS
Bernardin, Cédric; Oviedo Jimenez, Byron
2016-01-01
A fractional Fick's law and fractional hydrostatics for the one dimensional exclusion process with long jumps in contact with infinite reservoirs at different densities on the left and on the right are derived.
Exclusive processes at JLab at 6 GeV
Energy Technology Data Exchange (ETDEWEB)
Kim, Andrey [Univ. of Connecticut, Storrs, CT (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2015-01-01
Deeply virtual exclusive reactions provide a unique opportunity to probe the complex internal structure of the nucleon. They allow to access information about the correlations between parton transverse spatial and longitudinal momentum distributions from experimental observables. Dedicated experiments to study Deeply Virtual Compton Scattering (DVCS) and Deeply Virtual Meson Production (DVMP) have been carried out at Jefferson Lab using continuous electron beam with energies up to 6 GeV. Unpolarized cross sections, beam, target and double spin asymmetries have been measured for DVCS as well as for π^{0} exclusive electroproduction. The data from Hall B provide a wide kinematic coverage with Q^{2}=1-4.5 GeV^{2}, x_{B}=0.1-0.5, and -t up to 2 GeV^{2}. Hall A data have limited kinematic range partially overlapping with Hall B kinematics but provide a high accuracy measurements. Scaling tests of the DVCS cross sections provide solid evidence of twist-2 dominance, which makes chiral-even GPDs accessible even at modest Q^{2}. We will discuss the interpretation of these data in terms of Generalized Parton Distributions (GPDs) model. Successful description of the recent CLAS π^{0} exclusive production data within the framework of the GPD-based model provides a unique opportunity to access the chiral-odd GPDs.
Exclusive processes at JLab at 6 GeV
International Nuclear Information System (INIS)
Deeply virtual exclusive reactions provide a unique opportunity to probe the complex internal structure of the nucleon. They allow to access information about the correlations between parton transverse spatial and longitudinal momentum distributions from experimental observables. Dedicated experiments to study Deeply Virtual Compton Scattering (DVCS) and Deeply Virtual Meson Production (DVMP) have been carried out at Jefferson Lab using continuous electron beam with energies up to 6 GeV. Unpolarized cross sections, beam, target and double spin asymmetries have been measured for DVCS as well as for π0 exclusive electroproduction. The data from Hall B provide a wide kinematic coverage with Q2=1-4.5 GeV2, xB=0.1-0.5, and -t up to 2 GeV2. Hall A data have limited kinematic range partially overlapping with Hall B kinematics but provide a high accuracy measurements. Scaling tests of the DVCS cross sections provide solid evidence of twist-2 dominance, which makes chiral-even GPDs accessible even at modest Q2. We will discuss the interpretation of these data in terms of Generalized Parton Distributions (GPDs) model. Successful description of the recent CLAS π0 exclusive production data within the framework of the GPD-based model provides a unique opportunity to access the chiral-odd GPDs.
Exclusive processes at JLab at 6 GeV
Directory of Open Access Journals (Sweden)
Kim Andrey
2015-01-01
Full Text Available Deeply virtual exclusive reactions provide a unique opportunity to probe the complex internal structure of the nucleon. They allow to access information about the correlations between parton transverse spatial and longitudinal momentum distributions from experimental observables. Dedicated experiments to study Deeply Virtual Compton Scattering (DVCS and Deeply Virtual Meson Production (DVMP have been carried out at Jefferson Lab using continuous electron beam with energies up to 6 GeV. Unpolarized cross sections, beam, target and double spin asymmetries have been measured for DVCS as well as for π0 exclusive electroproduction. The data from Hall B provide a wide kinematic coverage with Q2=1-4.5 GeV2, xB=0.1-0.5, and −t up to 2 GeV2. Hall A data have limited kinematic range partially overlapping with Hall B kinematics but provide a high accuracy measurements. Scaling tests of the DVCS cross sections provide solid evidence of twist-2 dominance, which makes chiral-even GPDs accessible even at modest Q2. We will discuss the interpretation of these data in terms of Generalized Parton Distributions (GPDs model. Successful description of the recent CLAS π0 exclusive production data within the framework of the GPD-based model provides a unique opportunity to access the chiral-odd GPDs.
Indian Academy of Sciences (India)
M K Srivastava
2005-01-01
A simple scaling law is obtained for asymmetric (, 2) process on helium isoelectronic ions by fast electrons. It is based on treating the targets as having one active electron moving in the effective Coulomb field of the atomic core with an effective charge ' = − 5/8. This effective charge is also used in the description of the scattered and ejected electrons. The model has been tested against other available (, 2) results on helium in asymmetric geometry. The scaling law is found to work reasonably well for fast incident electrons and becomes increasingly accurate as target increases.
Exclusive diffractive processes at HERA within the dipole picture
International Nuclear Information System (INIS)
We present a simultaneous analysis, within an impact parameter dependent saturated dipole model, of exclusive diffractive vector meson (J/ψ, φ and ρ) production, deeply virtual Compton scattering and the total γ*p cross section data measured at HERA. Various cross sections measured as a function of the kinematic variables Q2, W and t are well described, with little sensitivity to the details of the vector meson wave functions. We determine the properties of the gluon density in the proton in both longitudinal and transverse dimensions, including the impact parameter dependent saturation scale. The overall success of the description indicates universality of the emerging gluon distribution and proton shape. (orig.)
International Nuclear Information System (INIS)
We introduce the prioritising exclusion process, a stochastic scheduling mechanism for a priority queueing system in which high priority customers gain advantage by overtaking low priority customers. The model is analogous to a totally asymmetric exclusion process with a dynamically varying lattice length. We calculate exact local density profiles for an unbounded queue by deriving domain wall dynamics from the microscopic transition rules. The structure of the unbounded queue carries over to bounded queues where, although no longer exact, we find the domain wall theory is in very good agreement with simulation results. Within this approximation we calculate average waiting times for queueing customers. (paper)
Deeply Virtual Exclusive Processes and Generalized Parton Distributions
Energy Technology Data Exchange (ETDEWEB)
,
2011-06-01
The goal of the comprehensive program in Deeply Virtual Exclusive Scattering at Jefferson Laboratory is to create transverse spatial images of quarks and gluons as a function of their longitudinal momentum fraction in the proton, the neutron, and in nuclei. These functions are the Generalized Parton Distributions (GPDs) of the target nucleus. Cross section measurements of the Deeply Virtual Compton Scattering (DVCS) reaction ep {yields} ep{gamma} in Hall A support the QCD factorization of the scattering amplitude for Q^2 {>=} 2 GeV^2. Quasi-free neutron-DVCS measurements on the Deuteron indicate sensitivity to the quark angular momentum sum rule. Fully exclusive H(e, e'p{gamma} ) measurements have been made in a wide kinematic range in CLAS with polarized beam, and with both unpolarized and longitudinally polarized targets. Existing models are qualitatively consistent with the JLab data, but there is a clear need for less constrained models. Deeply virtual vector meson production is studied in CLAS. The 12 GeV upgrade will be essential for for these channels. The {rho} and {omega} channels reactions offer the prospect of flavor sensitivity to the quark GPDs, while the {phi}-production channel is dominated by the gluon distribution.
Production of mesons with any internal orbital angular momentum in exclusive hard processes
Energy Technology Data Exchange (ETDEWEB)
Ichola, A.; Houra-Yaou, L.; Kessler, P.; Parisi, J. [College de France, 75 - Paris (France). Lab. de Physique Corpusculaire
1994-12-31
In this paper we present an extension of the computation of exclusive hard processes to the production of (qq) mesons with any orbital angular momentum, as well as of (gg) mesons (``glueballs``). We explicitly compute two examples: tensor-meson par production and glueball plus pion production, both in {gamma} {gamma} collisions. (authors). 16 refs., 7 figs., 1 tab.
Novel Phases and Finite-Size Scaling in Two-Species Asymmetric Diffusive Processes
Leung, Kwan-tai
1994-01-01
We study a stochastic lattice gas of particles undergoing asymmetric diffusion in two dimensions. Transitions between a low-density uniform phase and high-density non-uniform phases characterized by localized or extended structure are found. We develop a mean-field theory which relates coarse-grained parameters to microscopic ones. Detailed predictions for finite-size ($L$) scaling and density profiles agree excellently with simulations. Unusual large-$L$ behavior of the transition point para...
Baumeister, Roy F; Twenge, Jean M; Nuss, Christopher K
2002-10-01
Three studies examined the effects of randomly assigned messages of social exclusion. In all 3 studies, significant and large decrements in intelligent thought (including IQ and Graduate Record Examination test performance) were found among people told they were likely to end up alone in life. The decline in cognitive performance was found in complex cognitive tasks such as effortful logic and reasoning; simple information processing remained intact despite the social exclusion. The effects were specific to social exclusion, as participants who received predictions of future nonsocial misfortunes (accidents and injuries) performed well on the cognitive tests. The cognitive impairments appeared to involve reductions in both speed (effort) and accuracy. The effect was not mediated by mood. PMID:12374437
Exclusive diffractive processes in electron-ion collisions
Toll, Tobias; Ullrich, Thomas
2012-01-01
We present a new technique to calculate the cross-section for diffractive vector meson production and DVCS in electron-ion collisions based on the dipole model. The measurement of these processes can provide valuable information on non-linear QCD phenomena, such as gluon saturation, and is the the only known way to gain insight into the spatial distribution of gluons in nuclei. We present predictions of differential cross-section distribution $d\\sigma/dQ^2$ and $d\\sigma/dt$ for $J/\\psi$ and $...
Gazeley, Louise
2012-01-01
Although a great deal of previous literature has explored the ways in which social class affects parental engagement in educational processes, there has been surprisingly little discussion of the way in which social class shapes the parent-professional interaction that occurs in school exclusion processes specifically. School exclusion processes…
Effective ergodicity breaking in an exclusion process with varying system length
Schultens, Christoph; Schadschneider, Andreas; Arita, Chikashi
2015-09-01
Stochastic processes of interacting particles in systems with varying length are relevant e.g. for several biological applications. We try to explore what kind of new physical effects one can expect in such systems. As an example, we extend the exclusive queueing process that can be viewed as a one-dimensional exclusion process with varying length, by introducing Langmuir kinetics. This process can be interpreted as an effective model for a queue that interacts with other queues by allowing incoming and leaving of customers in the bulk. We find surprising indications for breaking of ergodicity in a certain parameter regime, where the asymptotic growth behavior depends on the initial length. We show that a random walk with site-dependent hopping probabilities exhibits qualitatively the same behavior.
Processes of Inclusion and Exclusion in the Sphere of Prosumerism
Directory of Open Access Journals (Sweden)
Roberta Paltrinieri
2013-01-01
Full Text Available The term prosumer, first introduced by Toffler in the 1980s, has been developed by sociologists in response to Web 2.0 (the set of technologies that has transformed a predominantly static web into the collaborative medium initially envisaged by Tim Berners-Lee. The phenomena is now understood as a process involving the creation of meanings on the part of the consumer, who re-appropriates spaces that were dominated by institutionalized production, and this extends to the exploitation of consumer creativity on the production side. Recent consumption literature can be re-interpreted through the prosumer lens in order to understand whether prosumers are more creative or alienated in their activities. The peculiar typology of prosumption introduced by Web 2.0 leads us to analyze social capital as a key element in value creation, and to investigate its different online and offline forms. Our analysis then discusses the digital divide and critical consumerism as forms of empowerment impairment.
Processus d'exclusion asymétrique: Effet du désordre, Grandes déviations et fluctuations
Enaud, Camille
2005-01-01
This thesis presents a series of works dealing with the open asymmetric exclusion process.In a first part, we give numerical evidences showing that the position of the first order phase transition in the totally asymmetric exclusion process become sample-dependent when quenched, sitewise disorder is added to the jump rates. These numerical simulations are compared with analytic prediction based on a mean field approach. In a second part, we study the macroscopic properties of the density prof...
Scaling Limits of a Tagged Particle in the Exclusion Process with Variable Diffusion Coefficient
Gonçalves, Patrícia; Jara, Milton
2008-09-01
We prove a law of large numbers and a central limit theorem for a tagged particle in a symmetric simple exclusion process in ℤ with variable diffusion coefficient. The scaling limits are obtained from a similar result for the current through -1/2 for a zero-range process with bond disorder. For the CLT, we prove convergence to a fractional Brownian motion of Hurst exponent 1/4.
PROCESSES OF SOCIAL EXCLUSION OF HOMELESSNESS IN THE CITY OF BARCELONA
Directory of Open Access Journals (Sweden)
María Virginia Matulic Domandzic
2013-12-01
Full Text Available Processes of social exclusion of the homeless people in the city of Barcelona are addressed in thisarticle through three sections. First, an approximation to the processes of social exclusion present inEuropean societies is done, then look focuses on the conceptual dimension of homeless people andits root causes, to end with some conclusions on where the issues raised are synthesized as well asthe future challenges that are presented in this phenomenon. This article is part of the research workbeing done on the processes of social inclusion of homeless people in Barcelona. This research islinked to the Doctorate "Education and Society" at the University of Barcelona through the Departmentof Social Work and Social Services. The growing phenomenon of homelessness responds to macroprocessesthat have characterized the post-Fordist societies in recent decades where the fragility ofsupport networks and systems of social protection are crucial.
Effects of serotonin 2A/1A receptor stimulation on social exclusion processing.
Preller, Katrin H; Pokorny, Thomas; Hock, Andreas; Kraehenmann, Rainer; Stämpfli, Philipp; Seifritz, Erich; Scheidegger, Milan; Vollenweider, Franz X
2016-05-01
Social ties are crucial for physical and mental health. However, psychiatric patients frequently encounter social rejection. Moreover, an increased reactivity to social exclusion influences the development, progression, and treatment of various psychiatric disorders. Nevertheless, the neuromodulatory substrates of rejection experiences are largely unknown. The preferential serotonin (5-HT) 2A/1A receptor agonist, psilocybin (Psi), reduces the processing of negative stimuli, but whether 5-HT2A/1A receptor stimulation modulates the processing of negative social interactions remains unclear. Therefore, this double-blind, randomized, counterbalanced, cross-over study assessed the neural response to social exclusion after the acute administration of Psi (0.215 mg/kg) or placebo (Pla) in 21 healthy volunteers by using functional magnetic resonance imaging (fMRI) and resting-state magnetic resonance spectroscopy (MRS). Participants reported a reduced feeling of social exclusion after Psi vs. Pla administration, and the neural response to social exclusion was decreased in the dorsal anterior cingulate cortex (dACC) and the middle frontal gyrus, key regions for social pain processing. The reduced neural response in the dACC was significantly correlated with Psi-induced changes in self-processing and decreased aspartate (Asp) content. In conclusion, 5-HT2A/1A receptor stimulation with psilocybin seems to reduce social pain processing in association with changes in self-experience. These findings may be relevant to the normalization of negative social interaction processing in psychiatric disorders characterized by increased rejection sensitivity. The current results also emphasize the importance of 5-HT2A/1A receptor subtypes and the Asp system in the control of social functioning, and as prospective targets in the treatment of sociocognitive impairments in psychiatric illnesses. PMID:27091970
Test practice and processes of in- and exclusion in school classes
DEFF Research Database (Denmark)
Andreasen, Karen Egedal
Recently national mandatory standardized testing has been implemented in compulsory school in both Norway and Denmark. In Sweden the national school reform from emphasize such pedagogical practice. Assessment has profound impact on processes of marginalization and in- and exclusion in school (Mc......Dermott & Varenne, 1995). Such impact are depending on what can be understood as local test practice, referring to local discourses and ways of using test in specific school contexts. Based on results from a two year study of the implementation of national standardized testing in Denmark in three school classes...... and drawing on the theory of Etienne Wenger (1998) about communities of practice this paper will discuss the impact from testing on processes of in- and exclusion. The empirical study is ethnographically inspired and includes observations, interviews, documents etc. The analysis shows that even it is framed...
Pire, B
2009-01-01
QCD is the theory of strong interactions and non-perturbative methods have been developed to address the confinement property of QCD. Many experimental measurements probe the confining dynamics, and it is well-known that hard scattering processes allow the extraction of non perturbative hadronic matrix elements. To study exclusive hard processes, such as electromagnetic form factors and reactions like gamma* N -> gamma N', gamma* N -> pi N', gamma* gamma -> pi pi, antiproton proton ->gamma* pi in particular kinematics (named as generalized Bjorken regime), one introduces specific non-perturbative objects, namely generalized parton distributions (GPDs), distribution amplitudes (DA) and transition distribution amplitudes (TDA), which are Fourier transformed non-diagonal matrix elements of non-local operators on the light-cone. We review here a selected sample of exclusive amplitudes in which the quark and gluon content of hadrons is probed, and emphasize that much remains to be done to successfully compute thei...
Identifying the production process of new physics at colliders; symmetric or asymmetric?
Lim, Sung Hak
2016-01-01
We propose a class of kinematic variables, which is a smooth generalization of min-max type mass variables such as the Cambridge-$M_{T2}$ and $M_2$, for measuring a mass spectrum of intermediate resonances in a semi-invisibly decaying pair production. While kinematic endpoints of min-max type mass variables are only sensitive to a heavier resonance mass, kinematic endpoints of new variables are sensitive to all masses. These new mass variables can be used to resolve a mass spectrum, so that if the true mass spectrum is asymmetric, then the kinematic endpoints are separate while the endpoints are the same for the symmetric true mass spectrum. We demonstrate the behavior of kinematic endpoint of these new variables in pair production of two-body and three-body decays with one invisible particle.
Meemken, Fabian; Hungerbühler, Konrad; Baiker, Alfons
2014-08-11
Surface processes occurring at the catalytic chiral surface of a cinchona-modified Pt catalyst during the asymmetric hydrogenation of activated ketones have been monitored for the first time using operando ATR-IR spectroscopy. Fundamental information about this catalytic system could be gained, including the chiral modification process of the catalyst, the surface interaction of reactant ketone with preadsorbed chiral modifier, the role of hydrogen as well as the influence of the product enantiomers in the catalytic cycle. The formation of a diastereomeric transient surface complex between ketone and chiral modifier was found to be related to the ketone consumption. Among the studied activated ketones, a correlation between stereoselection and the strength of the intermolecular hydrogen bond was identified. Dissociated hydrogen from the catalytic surface is found to play a crucial role in the formation of the diastereomeric surface complex. PMID:24777839
Directory of Open Access Journals (Sweden)
Melanie Bungert
Full Text Available There is a general agreement that physical pain serves as an alarm signal for the prevention of and reaction to physical harm. It has recently been hypothesized that "social pain," as induced by social rejection or abandonment, may rely on comparable, phylogenetically old brain structures. As plausible as this theory may sound, scientific evidence for this idea is sparse. This study therefore attempts to link both types of pain directly. We studied patients with borderline personality disorder (BPD because BPD is characterized by opposing alterations in physical and social pain; hyposensitivity to physical pain is associated with hypersensitivity to social pain, as indicated by an enhanced rejection sensitivity.Twenty unmedicated female BPD patients and 20 healthy participants (HC, matched for age and education played a virtual ball-tossing game (cyberball, with the conditions for exclusion, inclusion, and a control condition with predefined game rules. Each cyberball block was followed by a temperature stimulus (with a subjective pain intensity of 60% in half the cases. The cerebral responses were measured by functional magnetic resonance imaging. The Adult Rejection Sensitivity Questionnaire was used to assess rejection sensitivity.Higher temperature heat stimuli had to be applied to BPD patients relative to HCs to reach a comparable subjective experience of painfulness in both groups, which suggested a general hyposensitivity to pain in BPD patients. Social exclusion led to a subjectively reported hypersensitivity to physical pain in both groups that was accompanied by an enhanced activation in the anterior insula and the thalamus. In BPD, physical pain processing after exclusion was additionally linked to enhanced posterior insula activation. After inclusion, BPD patients showed reduced amygdala activation during pain in comparison with HC. In BPD patients, higher rejection sensitivity was associated with lower activation differences during
Institute of Scientific and Technical Information of China (English)
Feng-li SUI; Xin WANG; Jun ZHAO; Biao MA; Chang-sheng LI
2015-01-01
Based on the rigid-plastic ifnite element method (FEM), the shear stress ifeld of deformation region for high manganese austenite steel during hot asymmetrical rolling process was analyzed. The inlfuences of rolling parameters, such as thevelocity ratio of upper to lower rolls, theinitial temperature of workpiece and the reduction rate, on the shear deformation of three nodes in the upper, center and lower layers were discussed. As the rolling parameters change, distinct shear deformation appears in the up-per and lower layers, but the shear deformation in the center layer appears only when the velocity ratio is more than 1.00, and the absolute value of the shear stress in this layer is changed with rolling parameters. A mathematical model which relfected the change of the maximal absolute shear stress for the center layer was established, by which the maximal absolute shear stress for the center layer can be easily calculated and the appropriate rolling technology can be designed.
Scaling of cross-sections for asymmetric (, 3) process on helium-like ions by fast electrons
Indian Academy of Sciences (India)
M K Srivastava
2004-11-01
An approximate simple scaling law is obtained for asymmetric (, 3) process on helium-like ions for double ionization by fast electrons. It is based on the equation $(Z'^{3} /)$ exp$[−Z' (r_{1} + r_{2})]$, $Z' = Z − (5/16)$ for ground state wave function of helium- like ions and $Z'^{2}$ scaling of energies. The scaling law is found to work very well if the lower energy electron is ejected along the momentum transfer direction and the other one is ejected in the opposite direction. It also works quite well if this electron is ejected within about 90° of the momentum transfer direction with the other electron going in the opposite direction. The scaling law becomes increasingly accurate as the target nuclear charge and the energy increase.
International Nuclear Information System (INIS)
The concepts of exclusion, exemption and clearance have been established in international recommendations and, standards for radiation protection and the management of radioactive waste in recent years. The consistent application of these concepts has given rise to various problems in different spheres of use. This is particularly the case in the mining and minerals processing industries dealing with materials exhibiting elevated concentrations of naturally occurring radionuclides. This paper takes the South African mining industry as an example and highlights some of the issues that have arisen in applying these concepts within a regulatory control regime. (author)
Studies of semi-inclusive and hard exclusive processes at Jlab
International Nuclear Information System (INIS)
The main goal of experiments proposed for the CLAS12 detector in conjunction with the 12-GeV CEBAF accelerator is the study of the nucleon through hard exclusive, semi-inclusive, and inclusive processes. This will provide new insights into nucleon dynamics at the elementary quark and gluon level. In this contribution we provide an overview of ongoing studies of the structure of nucleon in terms of quark and gluon degrees of freedom and future physics program planned with CLAS and CLAS12
Studying the neutron orbital structure by coherent hard exclusive processes off 3He
International Nuclear Information System (INIS)
Hard exclusive processes, such as Deeply Virtual Compton Scattering (DVCS), allows to access generalized parton distributions (GPDs). By means of an Impulse Approximation (IA) calculation, it is shown here how, in the low momentum transfer region, the sum of the GPDs H and E, is dominated by the neutron contribution. Thanks to this property, 3He could open a new way to access the neutron structure information. In this work, a simple and efficient extraction procedure of the neutron GPDs, able to take into account the nuclear effects included in IA analysis, is proposed.
Cube Root Fluctuations for the Corner Growth Model Associated to the Exclusion Process
Balazs, Marton; Cator, Eric; Seppalainen, Timo
2006-01-01
We study the last-passage growth model on the planar integer lattice with exponential weights. With boundary conditions that represent the equilibrium exclusion process as seen from a particle right after its jump we prove that the variance of the last-passage time in a characteristic direction is of order $t^{2/3}$. With more general boundary conditions that include the rarefaction fan case we show that the last-passage time fluctuations are still of order $t^{1/3}$, and also that the transv...
Studies of semi-inclusive and hard exclusive processes at Jlab
Energy Technology Data Exchange (ETDEWEB)
Harutyun Avagyan
2008-06-19
The main goal of experiments proposed for the {\\tt CLAS12} detector in conjunction with the 12-GeV CEBAF accelerator is the study of the nucleon through hard exclusive, semi-inclusive, and inclusive processes. This will provide new insights into nucleon dynamics at the elementary quark and gluon level. In this contribution we provide an overview of ongoing studies of the structure of nucleon in terms of quark and gluon degrees of freedom and future physics program planned with CLAS and {\\tt CLAS12}.
On the constituent counting rules for hard exclusive processes involving multiquark states
Guo, Feng-Kun; Wang, Wei
2016-01-01
At high energies, the cross section of a hard exclusive process at finite scattering angle falls off as a negative power of the center-of-mass energy $\\sqrt{s}$. If all involved quark-gluon compositions undergo hard momentum transfers, the scaling of the fall-off is determined by the underlying valence structures of the initial and final states, known as the constituent counting rules. It was argued in the literature that the counting rules are a powerful tool to determine the valence degrees of freedom inside multiquark states when applied to exclusive production processes. However, we demonstrate that for hadrons with hidden flavors the naive application of the constituent counting rules is problematic, since it is not mandatory for all components to participate the hard scattering at the scale $\\sqrt{s}$. The correct scaling rules can be obtained easily by using effective field theory. A few examples involving the $Z_c(3900)^\\pm$ and $X(3872)$ are discussed.
Comment on Gauge invariance and kT-factorization of exclusive processes
International Nuclear Information System (INIS)
We point out mistakes made in the one-loop calculation of some diagrams for the process π γ* → γ in the preprint arXiv:0807.0296, and present correct results. Especially, we have difficulty to understand their argument that a highly off-shell gluon generates a light-cone (infrared) singularity. It is shown by means of the Ward identity that the gauge-dependent light-cone singularity found in arXiv:0807.0296 does not exist. It is then shown that a hard kernel derived in the kT factorization of exclusive processes is gauge invariant and free of the light-cone singularity. (orig.)
Corianò, C; Savkli, C; Coriano, Claudio; Li, Hsiang-nan; Savkli, Cetin
1998-01-01
Experiments at CEBAF will scan the intermediate-energy region of the QCD dynamics for the nucleon form factors and for Compton Scattering. These experiments will definitely clarify the role of resummed perturbation theory and of quark-hadron duality (QCD sum rules) in this regime. With this perspective in mind, we review the factorization theorem of perturbative QCD for exclusive processes at intermediate energy scales, which embodies the transverse degrees of freedom of a parton and the Sudakov resummation of the corresponding large logarithms. We concentrate on the pion and proton electromagnetic form factors and on pion Compton scattering. New ingredients, such as the evolution of the pion wave function and the complete two-loop expression of the Sudakov factor, are included. The sensitivity of our predictions to the infrared cutoff for the Sudakov evolution is discussed. We also elaborate on QCD sum rule methods for Compton Scattering, which provide an alternative description of this process. We show that...
Uncovering the scaling laws of hard exclusive hadronic processes in a comprehensive endpoint model
International Nuclear Information System (INIS)
We show that an endpoint-overlap model can explain the scaling laws observed in exclusive hadronic reactions at large momentum transfer. The model assumes one of the valence quarks carries most of the hadron momentum. Hadron form factors and fixed-angle scattering are related directly to the quark wave function, which can be directly extracted from experimental data. A universal linear endpoint behavior explains the proton electromagnetic form factor, proton-proton fixed-angle scattering, and the t-dependence of proton-proton scattering at large s >> t. Endpoint constituent counting rules relate the number of quarks in a hadron to the power-law behavior. All proton reactions surveyed are consistent with three quarks participating. The model is applicable at laboratory energies and does not need assumptions of asymptotically high energy regime. A rich phenomenology of lepton-hadron scattering and hadron-hadron scattering processes is found in remarkably simple relationships between diverse processes. (orig.)
Directory of Open Access Journals (Sweden)
Joanna Rajchert
2015-11-01
Full Text Available The relationship between exclusion or rejection and aggression is already well documented, but there is still a debate about the mechanisms that underlie this effect. In two studies we focused on the propensity to react aggressively (readiness for aggression on the bases of emotional, cognitive or self-enhancement (personality-immanent processes. In both studies we first measured readiness for aggression and then ego-depleted participants. Next, in Study 1 we excluded participants (n = 96 using an online ball throwing game and measured displaced aggressive behavior - intensity and duration of an unpleasant noise administrated to a stranger. In Study 2 participants (n = 140 were rejected by a peer on the basis of an interview that they gave and then could retaliate by reducing peer's chance for getting a job. The results show that exclusion effect on displaced aggression was moderated by cognitive readiness for aggression, while rejection effect on retaliatory aggression was shaped by emotional and personality-immanent readiness for aggression as well as ego-depletion. The results were discussed in light of the strength model of self-control by Baumeister, Vohs, and Tice (2007.
Characteristics of Flux Decline in Forward Osmosis Process for Asymmetric Cellulose Membrane
Energy Technology Data Exchange (ETDEWEB)
Han, Myeong-Jin; Nam, Suk-Tae [Kyungil University, Gyeongsan (Korea, Republic of); Lee, Keun-Woo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2014-06-15
This study examined the effect of concentration polarization on permeate flux in forward osmosis (FO) membrane process for saline and sucrose solution. The reduction in permeate flux during the FO membrane process is largely due to the formation of concentration polarization on membrane surfaces. The flux reduction due to internal concentration polarization formed on the porous support layer was larger than that due to the external concentration polarization on the active membrane surface. Water permeate flux through the FO membrane increased nonlinearly with the increase in osmotic pressure. The water permeability coefficient was 1.8081x10{sup -7} m/s·atm for draw solution on active layer (DS-AL) mode and 1.0957-10{sup -7} m/s·atm for draw solution on support layer (DS-SL) mode in NaCl solution system. The corresponding membrane resistance was 5.5306x10{sup 6} and 9.1266x10{sup 6} s·atm/m, respectively. With respect to the sucrose solution, the permeate flux for DS-AL mode was 1.33-1.90 times higher than that for DS-SL mode. The corresponding variation in the permeation flux (J) due to osmotic pressure (π) would be expressed as J=-0.0177+0.4506π-0.0032π{sup 2} for the forward and J=0.0948+0.3292π-0.0037π{sup 2} for the latter.
Borgmann, Karl; Fugelsang, Jonathan; Ansari, Daniel; Besner, Derek
2011-06-01
When the proportion of congruent trials in conflict tasks is manipulated (e.g., Stroop, Simon), the typical result is that the magnitude of the conflict effect increases as the proportion of congruent trials increases. The present experiment investigated the influence of Congruency Proportion in the context of the Size Congruity Paradigm. Congruency Proportion had a significant impact on the Numerical Judgement Task (judging which of two numbers is numerically larger), but not on the Physical Judgement Task (judging which of two numbers is printed in a larger font). These data support the inference that physical size information is processed before, and more fluently than, numerical size information. The implications of this asymmetry are discussed in terms of the relative role of semantic and physical size information in representations of magnitude, and the role they play in both of these tasks. PMID:21668091
Zhu, Chen-Ping; Yang, Hui-Jie; Xiong, Shi-Jie; Gu, Zhi-Ming; Shi, Da-Ning; He, Da-Ren; Wang, Bing-Hong
2007-01-01
Competitive exclusion, a key principle of ecology, can be generalized to understand many other complex systems. Individuals under surviving pressure tend to be different from others, and correlations among them change correspondingly to the updating of their states. We show with numerical simulation that these aptitudes can contribute to group formation or speciation in social fields. Moreover, they can lead to power-law topological correlations of complex networks. By coupling updating states of nodes with variation of connections in a network, structural properties with power-laws and functions like multifractality, spontaneous ranking and evolutionary branching of node states can emerge out simultaneously from the present self-organized model of coevolutionary process.
Institute of Scientific and Technical Information of China (English)
Kazuaki ITO; Kazuhiko TANAKA; Jun SAKAMOTO; Kazuya NAGAOKA; Yohichi TAKAYAMA; Takashi KANAHORI; Hiroshi SUNAHARA; Tsuneo HAYASHI; Shinji SATO; Takeshi HIROKAWA
2012-01-01
The analysis of seven aliphatic carboxylic acids ( formic,acetic,propionic,iso-butyric,n-butyric,iso-valeric and n-valeric acid) in anaerobic digestion process waters for biogas production was examined by ion-exclusion chromatography with dilute acidic eluents (benzoic acid,perfluorobutyric acid (PFBA) and sulfuric acid) and non-suppressed conductivity/ultraviolet (UV) detection.The columns used were a styrene/divinylbenzene-based strongly acidic cation-exchange resin column ( TSKgel SCX) and a polymethacrylate-based weakly acidic cation-exchange resin column ( TSKgel Super IC-A/C ).Good separation was performed on the TSKgel SCX in shorter retention times.For the TSKgel Super IC-A/C,peak shape of the acids was sharp and symmetrical in spite of longer retention times.In addition,the mutual separation of the acids was good except for iso- and n-butyric acids.The better separation and good detection was achieved by using the two columns (TSKgel SCX and TSKgel Super IC-A/C connected in series),lower concentrations of PFBA and sulfuric acid as eluents,non-suppressed conductivity detection and UV detection at 210 nm.This analysis was applied to anaerobic digestion process waters.The chromatograms with conductivity detection were relatively simpler compared with those of UV detection.The use of two columns with different selectivities for the aliphatic carboxylic acids and the two detection modes was effective for the determination and identification of the analytes in anaerobic digestion process waters containing complex matrices.
Extreme fluctuations of current in the symmetric simple exclusion process: a non-stationary setting
International Nuclear Information System (INIS)
We use the macroscopic fluctuation theory (MFT) to evaluate the probability distribution P of extreme values of integrated current J at a specified time t = T in the symmetric simple exclusion process (SSEP) on an infinite line. As shown recently (Meerson and Sasorov 2014 Phys. Rev. E 89 010101), the SSEP belongs to the elliptic universality class. Here, for very large currents, the diffusion terms of the MFT equations can be neglected compared with the terms coming from the shot noise. Using the hodograph transformation and an additional change of variables, we reduce the ‘inviscid’ MFT equations to Laplace’s equation in an extended space. This opens the way to an exact solution. Here we solve the extreme-current problem for a flat deterministic initial density profile with an arbitrary density 0 0 0)J3/T, in agreement with Derrida and Gerschenfeld (2009 J. Stat. Phys. 137 978). We calculate the function Φ(n0) analytically. It is symmetric with respect to the half-filling density n0 = 1/2, diverges at n0 → 0 and n0 → 1 and exhibits a singularity Φ(n0) ∼ |n0−1/2| at the half-filling density n0 = 1/2. (paper)
Jaime A Usma Wilches
2009-01-01
This paper examines the National Bilingual Program in connection with other education and language reforms in Colombia and some of the processes of inclusion, exclusion, and stratification that accompany current school reforms. The author outlines some patterns that have accompanied language innovations in the country and highlights some interconnected processes that seem to be favored in international reform and are reflected in current national policy agendas; namely, the externalization...
Quantification of asymmetric microtubule nucleation at sub-cellular structures
Zhu, Xiaodong; Kaverina, Irina
2012-01-01
Cell polarization is important for multiple physiological processes. In polarized cells, microtubules (MTs) are organized into a spatially polarized array. Generally, in non-differentiated cells, it is assumed that MTs are symmetrically nucleated exclusively from centrosome (microtubule organizing center, MTOC) and then reorganized into the asymmetric array. We have recently identified the Golgi complex as an additional MTOC that asymmetrically nucleates MTs toward one side of the cell. Methods used for alternative MTOC identification include microtubule re-growth after complete drug-induced depolymerization and tracking of growing microtubules using fluorescence labeled MT +TIP binding proteins in living cells. These approaches can be used for quantification of MT nucleation sites at diverse sub-cellular structures. PMID:21773933
Xu, Liren
2012-12-01
In this paper, the development of asymmetric carbon molecular sieve (CMS) hollow fiber membranes and advanced processes for olefin/paraffin separations based on the CMS membranes are reported. Membrane-based olefin/paraffin separations have been pursued extensively over the past decades. CMS membranes are promising to exceed the performance upper bound of polymer materials and have demonstrated excellent stability for gas separations. Previously, a substructure collapse phenomenon was found in Matrimid ® precursor derived CMS fiber. To overcome the permeance loss due to the increased separation layer thickness, 6FDA-DAM and 6FDA/BPDA-DAM precursors were selected as potential new precursors for carbon membrane formation. Defect-free asymmetric 6FDA-DAM and 6FDA/BPDA-DAM hollow fibers were successfully fabricated from a dry-jet/wet-quench spinning process. Polymer rigidity, glass-rubber transition and asymmetric morphology were correlated. CMS hollow fiber membranes produced from 6FDA-polymer precursors showed significant improvement in permeance for ethylene/ethane and propylene/propane separations. Further studies revealed that the CMS membranes are olefins-selective, which means the membranes are able to effectively separate olefins (ethylene and propylene) from paraffins (ethane and propane). This unique feature of CMS materials enables advanced hybrid membrane-distillation process designs. By using the olefins-selective membranes, these new processes may provide advantages over previously proposed retrofitting concepts. Further applications of the membranes are explored for hydrocarbons processes. Significant energy savings and even reduced footprint may be achieved in olefins production units. © 2012 Elsevier B.V.
International Nuclear Information System (INIS)
The study of CP violation in beauty decay is one of the key challenges facing high energy physics. Much work has not yielded a definitive answer how this study might best be performed. However, one clear conclusion is that new accelerator facilities are needed. Proposals include experiments at asymmetric electron-positron colliders and in fixed-target and collider modes at LHC and SSC. Fixed-target and collider experiments at existing accelerators, while they might succeed in a first observation of the effect, will not be adequate to study it thoroughly. Giomataris has emphasized the potential of a new approach to the study of beauty CP violation: the asymmetric proton collider. Such a collider might be realized by the construction of a small storage ring intersecting an existing or soon-to-exist large synchrotron, or by arranging collisions between a large synchrotron and its injector. An experiment at such a collider can combine the advantages of fixed-target-like spectrometer geometry, facilitating triggering, particle identification and the instrumentation of a large acceptance, while the increased √s can provide a factor > 100 increase in beauty-production cross section compared to Tevatron or HERA fixed-target. Beams crossing at a non-zero angle can provide a small interaction region, permitting a first-level decay-vertex trigger to be implemented. To achieve large √s with a large Lorentz boost and high luminosity, the most favorable venue is the high-energy booster (HEB) at the SSC Laboratory, though the CERN SPS and Fermilab Tevatron are also worth considering
Flores, J C
2016-03-01
This work applies the competitive exclusion principle and the concept of potential competitors as simple axiomatic tools to generalized situations in ecology. These tools enable apparent competition and its dual counterpart to be explicitly evaluated in poorly understood ecological systems. Within this set-theory framework we explore theoretical symmetries and invariances, De Morgan's laws, frozen evolutionary diversity and virtual processes. In particular, we find that the exclusion principle compromises the geometrical growth of the number of species. By theoretical extending this principle, we can describe interspecific depredation in the dual case. This study also briefly considers the debated situation of intraspecific competition. The ecological consequences of our findings are discussed; particularly, the use of our framework to reinterpret coupled mathematical differential equations describing certain ecological processes. PMID:26801920
2006-11-01
Astronomers are reporting remarkable new findings that shed light on a decade-long debate about one kind of supernovae, the explosions that mark a star's final demise: does the star die in a slow burn or with a fast bang? From their observations, the scientists find that the matter ejected by the explosion shows significant peripheral asymmetry but a nearly spherical interior, most likely implying that the explosion finally propagates at supersonic speed. These results are reported today in Science Express, the online version of the research journal Science, by Lifan Wang, Texas A&M University (USA), and colleagues Dietrich Baade and Ferdinando Patat from ESO. "Our results strongly suggest a two-stage explosion process in this type of supernova," comments Wang. "This is an important finding with potential implications in cosmology." ESO PR Photo 44/06 ESO PR Photo 44/06 Clumpy Explosion (Artist's Impression) Using observations of 17 supernovae made over more than 10 years with ESO's Very Large Telescope and the McDonald Observatory's Otto Struve Telescope, astronomers inferred the shape and structure of the debris cloud thrown out from Type Ia supernovae. Such supernovae are thought to be the result of the explosion of a small and dense star - a white dwarf - inside a binary system. As its companion continuously spills matter onto the white dwarf, the white dwarf reaches a critical mass, leading to a fatal instability and the supernova. But what sparks the initial explosion, and how the blast travels through the star have long been thorny issues. The supernovae Wang and his colleagues observed occurred in distant galaxies, and because of the vast cosmic distances could not be studied in detail using conventional imaging techniques, including interferometry. Instead, the team determined the shape of the exploding cocoons by recording the polarisation of the light from the dying stars. Polarimetry relies on the fact that light is composed of electromagnetic waves
Searching saturation effects in inclusive and exclusive eA processes
Directory of Open Access Journals (Sweden)
Goncalves V. P.
2016-01-01
Full Text Available The searching of saturation effects in inclusive and exclusive eA collisions is reviewed. In particular, we present a comparison between the linear and non-linear predictions for the nuclear structure functions as well as for the Deep Virtual Compton Scattering and vector meson production in future eA colliders.
An anti-symmetric exclusion process for two particles on an infinite 1D lattice
International Nuclear Information System (INIS)
A system of two biased, mutually exclusive random walkers on an infinite 1D lattice is studied whereby the intrinsic bias of one particle is equal and opposite to that of the other. The propagator for this system is solved exactly and expressions for the mean displacement and mean square displacement (MSD) are found. Depending on the nature of the intrinsic bias, the system’s behaviour displays two regimes, characterised by (i) the particles moving towards each other and (ii) away from each other, both qualitatively different from the case of no bias. The continuous-space limit of the propagator is found and is shown to solve a Fokker–Planck equation for two biased, mutually exclusive Brownian particles with equal and opposite drift velocity. Connections to territorial dynamics in animal populations are discussed. (paper)
An anti-symmetric exclusion process for two particles on an infinite 1D lattice
Energy Technology Data Exchange (ETDEWEB)
Potts, J R; Giuggioli, L [Bristol Centre for Complexity Sciences, University of Bristol, Bristol (United Kingdom); Harris, S, E-mail: jonathan.potts.08@bris.ac.uk [School of Biological Sciences, University of Bristol, Bristol (United Kingdom)
2011-12-02
A system of two biased, mutually exclusive random walkers on an infinite 1D lattice is studied whereby the intrinsic bias of one particle is equal and opposite to that of the other. The propagator for this system is solved exactly and expressions for the mean displacement and mean square displacement (MSD) are found. Depending on the nature of the intrinsic bias, the system's behaviour displays two regimes, characterised by (i) the particles moving towards each other and (ii) away from each other, both qualitatively different from the case of no bias. The continuous-space limit of the propagator is found and is shown to solve a Fokker-Planck equation for two biased, mutually exclusive Brownian particles with equal and opposite drift velocity. Connections to territorial dynamics in animal populations are discussed. (paper)
An anti-symmetric exclusion process for two particles on an infinite 1D lattice
Potts, J. R.; Harris, S.; Giuggioli, L.
2011-12-01
A system of two biased, mutually exclusive random walkers on an infinite 1D lattice is studied whereby the intrinsic bias of one particle is equal and opposite to that of the other. The propagator for this system is solved exactly and expressions for the mean displacement and mean square displacement (MSD) are found. Depending on the nature of the intrinsic bias, the system’s behaviour displays two regimes, characterised by (i) the particles moving towards each other and (ii) away from each other, both qualitatively different from the case of no bias. The continuous-space limit of the propagator is found and is shown to solve a Fokker-Planck equation for two biased, mutually exclusive Brownian particles with equal and opposite drift velocity. Connections to territorial dynamics in animal populations are discussed.
Sawada, Takahiro; Kumano, Shunzo; Peng, Jen-Chieh; Sawada, Shinya; Tanaka, Kazuhiro
2016-01-01
Generalized parton distributions (GPDs) encoding multi-dimensional information of hadron partonic structure appear as the building blocks in a factorized description of hard exclusive reactions. The nucleon GPDs have been accessed by deeply virtual Compton scattering and deeply virtual meson production with lepton beam. A complementary probe with hadron beam is the exclusive pion-induced Drell-Yan process. In this paper, we discuss recent theoretical advances on describing this process in terms of nucleon GPDs and pion distribution amplitudes. Furthermore, we address the feasibility of measuring the exclusive pion-induced Drell-Yan process $\\pi^- p \\to \\mu^+\\mu^- n$ via a spectrometer at the High Momentum Beamline being constructed at J-PARC in Japan. Realization of such measurement at J-PARC will provide a new test of perturbative QCD descriptions of a novel class of hard exclusive reactions. It will also offer the possibility of experimentally accessing nucleon GPDs at large timelike virtuality.
International Nuclear Information System (INIS)
Connections between exclusive and inclusive electron scattering are explored within the framework of the relativistic plane-wave impulse approximation, beginning with an analysis of the model-independent kinematical constraints to be found in the missing-energy - missing-momentum plane. From the interplay between these constraints and the spectral function basic features of the exclusive and inclusive nuclear responses are seen to arise. In particular, the responses of the relativistic Fermi gas and of a specific hybrid model with bound nucleons in the initial state are compared. The latter facilitates extrapolations from light nuclei to very heavy ones where the former model has some validity. As expected, the exclusive responses are significantly different in the two models, whereas the inclusive ones are rather similar. By extending previous work on the relativistic Fermi gas, a reduced response is introduced for the hybrid model such that it fulfills the Coulomb and the higher-power energy-weighted sum rules. Although incorporating specific classes of off-shellness for the struck nucleons, it is found that the reducing factor required is largely model independent and, as such, yields a reduced response that is useful for studies of scaling and of the Coulomb sum rule. In particular, guided by the difference between the energy-weighted sum rules of the two models a new scaling variable appropriate for heavy nuclei is devised. Finally, a version of the relativistic Fermi gas which has zeroth, first, and second energy-weighted moments of the longitudinal response that agree rather well with those of the hybrid model is constructed: this version thus incorporates a priori the binding effects of the struck nucleons while retaining the simplicity of the original Fermi gas and provides the basis for future extensions of the model. copyright 1997 The American Physical Society
Exclusive $J/\\psi$ Production in Diffractive Process with AdS/QCD Holographic Wave Function in BLFQ
Xie, Ya-ping; Zhao, Xingbo
2016-01-01
The AdS/QCD holographic wave function of basis light-front quantization (BLFQ) for vector meson $J/\\psi$ is applied in this manuscript. The exclusive production of $J/\\psi$ in diffractive process is computed in dipole model with AdS/QCD holographic wave function. We use IP-Sat and IIM model in the calculation of the differential cross section of the dipole scattering off the proton. The prediction of AdS/QCD holographic wave function in BLFQ gives a good agreement to the experimental data.
GASTOF: Ultra-fast ToF forward detector for exclusive processes at the LHC
Bonnet, L; Piotrzkowski, K; Rodeghiero, P
2007-01-01
GASTOF (Gas Time-of-Flight) detector is a Cherenkov detector proposed for very precise (10--20 ps) arrival time measurements of forward protons at some 420 m from the central detectors of CMS and ATLAS. Such an excellent time resolution will allow by z-by-timing technique for precise measurement of the z-coordinate of the event vertex in exclusive production at the LHC, when two colliding protons are scattered at very small angles. In the paper we present first GASTOF prototype, simulations of its performance as well as first tests using a cosmic muon telescope.
Asymmetric Parton Distributions
Radyushkin, A V
1997-01-01
Applications of perturbative QCD to hard exclusive electroproduction processes in the Bjorken limit at small invariant momentum transfer t bring in a new type of parton distributions which have hybrid properties, resembling both the parton distribution functions and the distribution amplitudes. Their t-dependence is analogous to that of hadronic form factors. We discuss general properties of these new parton distributions, their relation to usual parton densities and the evolution equations which they satisfy.
Asymmetric Wettability Directs Leidenfrost Droplets
Energy Technology Data Exchange (ETDEWEB)
Agapov, Rebecca L [ORNL; Boreyko, Jonathan B [ORNL; Briggs, Dayrl P [ORNL; Srijanto, Bernadeta R [ORNL; Retterer, Scott T [ORNL; Collier, Pat [ORNL; Lavrik, Nickolay V [ORNL
2014-01-01
Leidenfrost phenomena on nano- and microstructured surfaces are of great importance for increasing control over heat transfer in high power density systems utilizing boiling phenomena. They also provide an elegant means to direct droplet motion in a variety of recently emerging fluidic systems. Here, we report the fabrication and characterization of tilted nanopillar arrays (TNPAs) that exhibit directional Leidenfrost water droplets under dynamic conditions, namely on impact with Weber numbers 40 at T 325 C. The batch fabrication of the TNPAs was achieved by glancing-angle anisotropic reactive ion etching of a thermally dewet platinum mask, with mean pillar diameters of 100 nm and heights of 200-500 nm. In contrast to previously implemented macro- and microscopic Leidenfrost ratchets, our TNPAs induce no preferential directional movement of Leidenfrost droplets under conditions approaching steady-state film boiling, suggesting that the observed droplet directionality is not a result of asymmetric vapor flow. Using high-speed imaging, phase diagrams were constructed for the boiling behavior upon impact for droplets falling onto TNPAs, straight nanopillar arrays, and smooth silicon surfaces. The asymmetric impact and directional trajectory of droplets was exclusive to the TNPAs for impacts corresponding to the transition boiling regime, revealing that asymmetric wettability upon impact is the mechanism for the droplet directionality.
Musatov, I V
1997-01-01
We analyze effects due to transverse degrees of freedom in QCD calculations of the fundamental hard exclusive amplitude of $\\gamma^*\\gamma \\to \\pi^0$ transition. A detailed discussion is given of the relation between the modified factorization approach (MFA) of Sterman {\\it et al.} and standard factorization (SFA). Working in Feynman gauge, we construct basic building blocks of MFA from the one-loop coefficient function of the SFA, demonstrating that Sudakov effects are distinctly different from higher-twist corrections. We show also that the handbag-type diagram, contrary to naive expectations, does not contain an infinite chain of $(M^2/Q^2)^n$ corrections: they come only from diagrams with transverse gluons emitted from the hard propagator. A simpler picture emerges within the QCD sum rule approach: the sum over soft $\\bar q G \\ldots G q$ Fock components is dual to $\\bar qq$ states generated by the local axial current. We combine the results based on QCD sum rules with pQCD radiative corrections and observ...
Asymmetric interference in molecular photoprocesses
International Nuclear Information System (INIS)
For the first time, the Coulomb continuum effects in asymmetric molecular interference have been studied analytically in photoionization, photorecombination, bremsstrahlung and Compton ionization. Simple, closed-form factors describe the interference not only in monochromatic photoprocesses, but also in the continuous photoelectron spectra generated by attosecond x-ray pulses with a frequency-dependent phase and broad bandwidth. Using HeH2+ molecular ion as an example, we show how the plane wave interference pattern is strongly modified by the two-centre Coulomb continuum. Asymmetric Coulomb continuum introduces qualitative changes in a photoionization process
Analytic coupling and Sudakov effects in exclusive processes: pion and γ*γ→π0 form factors
International Nuclear Information System (INIS)
We develop and discuss in technical detail an infrared-finite factorization and optimized renormalization scheme for calculating exclusive processes, which enables the inclusion of transverse degrees of freedom without entailing suppression of calculated observables, like form factors. This is achieved by employing an analytic, i.e., infrared stable, running strong-coupling αs(Q2) which removes the Landau singularity at Q2=ΛQCD2 by a minimum power-behaved correction. The ensuing contributions to the cusp anomalous dimension - related to the Sudakov form factor - and to the quark anomalous dimension - which controls evolution - lead to an enhancement at high Q2 of the hard part of exclusive amplitudes, calculated in perturbative QCD, while simultaneously improving its scaling behavior. The phenomenological implications of this framework are analyzed by applying it to the pion's electromagnetic form factor, including the NLO contribution to the hard-scattering amplitude, and also to the pion-photon transition at LO. For the pion wave function, an improved ansatz of the Brodsky-Huang-Lepage type is employed, which includes an effective (constituent-like) quark mass, mq=0.33 GeV. Predictions for both form factors are presented and compared to the experimental data, applying Brodsky-Lepage-Mackenzie commensurate scale setting. We find that the perturbative hard part prevails at momentum transfers above about 20 GeV2, while at lower Q2 values the pion form factor is dominated by Feynman-type contributions. The theoretical prediction for the γ*γ→π0 form factor indicates that the true pion distribution amplitude may be somewhat broader than the asymptotic one. (orig.)
Kessler, David A.; Levine, Herbert
2015-02-01
One of the most popular models for quantitatively understanding the emergence of drug resistance both in bacterial colonies and in malignant tumors was introduced long ago by Luria and Delbrück. Here, individual resistant mutants emerge randomly during the birth events of an exponentially growing sensitive population. A most interesting limit of this process occurs when the population size is large and mutation rates are low, but not necessarily small compared to . Here we provide a scaling solution valid in this limit, making contact with the theory of Levy -stable distributions, in particular one discussed long ago by Landau. One consequence of this association is that moments of the distribution are highly misleading as far as characterizing typical behavior. A key insight that enables our solution is that working in the fixed population size ensemble is not the same as working in a fixed time ensemble. Some of our results have been presented previously in abbreviated form [12].
NLO corrections to $\\chi_{bJ}$ two-body exclusive decay processes
Chen, Long-Bin
2014-01-01
The next-to-leading order QCD corrections for $\\chi_{bJ}$, the p-wave bottomonium, to $J/\\psi$ pair decay processes were evaluated utilizing NRQCD factorization formalism. It was determined that the scale dependence was depressed with NLO corrections, and hence the uncertainties in the leading order results were greatly reduced. The total branch ratios were found to be the order of $10^{-5}$ for all three $\\chi_{bJ}\\rightarrow J/\\psi J/\\psi$ processes,indicating that they were observable in the LHC and super-B experiments.
Directory of Open Access Journals (Sweden)
Anthea Vogl
2016-03-01
Full Text Available State-based processes for determining refugee claims are crucial sites of inclusion or exclusion for onshore refugee applicants. This paper argues that cultures of disbelief and exclusion towards onshore refugee applicants are increasingly being enacted indirectly, via procedural reforms to Refugee Status Determination (RSD, which limit the ability of applicants to establish and articulate their claims. Focusing on Australia and Canada, this paper tracks the acceleration and truncation of RSD procedures, which first reflect and then frequently achieve the exclusion of onshore applicants. Two sets of reforms in particular have profoundly limited the terms on which applicants may present their claims. In Canada, this occurred as the result of a major overhaul of RSD that took place in December 2012. In Australia, the policy of ‘enhanced screening’ of applicants achieves the immediate screening-out of certain claims from the Australian determination system. Alongside analysing these reforms as a means of exclusion, this paper argues that the new procedures most disadvantage applicants making claims on the basis of gender-related persecution. Los procesos estatales para resolver las concesiones de asilo son situaciones cruciales para la inclusión o exclusión de los solicitantes de asilo una vez están en el territorio de acogida. Este artículo defiende que cada vez más, se está promulgando indirectamente la cultura de la desconfianza y exclusión hacia los solicitantes de asilo, a través de reformas procesuales de la Determinación del Estatus de Refugiado (DER, lo que limita la capacidad de los solicitantes para establecer y articular sus demandas de asilo. Centrándose en Australia y Canadá, este artículo realiza un seguimiento de la aceleración y el truncamiento de los procedimientos de DER que primero reflejan y después a menudo consiguen la exclusión de los solicitantes en el propio territorio de acogida. Dos grupos de reformas
The Transition Process: Towards Exclusion or Financial Sufficiency. A French-Irish Comparison.
Grelet, Yvette; Mansuy, Michele; Thomas, Gwenaelle
Data from longitudinal school leavers' surveys in France and Ireland were compared to determine types of transition pathways leading to unsuccessful conclusions. Focus was on outcomes of the transition process for school leavers unemployed five years after leaving and for employed young people whose earnings did not allow them to be financially…
Asymmetric Wettability Directs Leidenfrost Droplets
Agapov, Rebecca; Boreyko, Jonathan; Briggs, Dayrl; Srijanto, Bernadeta; Retterer, Scott; Collier, C. Patrick; Lavrik, Nickolay
2014-03-01
Exploration of Leidenfrost droplets on nano- and microstructured surfaces are of great importance for increasing control over heat transfer in high power density systems using boiling phenomena. They also provide an elegant way to direct droplet motion in a variety of emerging fluidic systems. Here, we report the fabrication and characterization of tilted nanopillar arrays (TNPAs) that exhibit directional Leidenfrost water droplets under dynamic conditions. The batch fabrication of the TNPAs was achieved by glancing-angle anisotropic reactive ion etching of a thermally dewet platinum mask. In contrast to previously implemented macro- and microscopic Leidenfrost ratchets, our TNPAs induce no preferential directional movement of Leidenfrost droplets under conditions approaching steady-state film boiling. This suggests that the observed droplet directionality is not a result of asymmetric vapor flow. Phase diagrams were constructed for the boiling behavior upon droplet impact onto TNPAs, straight nanopillar arrays, and smooth silicon surfaces. Asymmetric wettability and directional trajectory of droplets was exclusive to the TNPAs for impacts corresponding to the transition boiling regime, revealing this to be the mechanism for the droplet directionality. This work was conducted at the Center for Nanophase Materials Sciences, which is sponsored at Oak Ridge National Lab by the Division of Scientific User Facilities, US Dept. of Energy.
Analysis of hard exclusive scattering processes of the HERMES recoil experiment
International Nuclear Information System (INIS)
Deeply virtual Compton Scattering (DVCS), ep → epγ is the simplest reaction giving indication of generalized parton distributions (GPD) of the nucleon. The DVCS process has the same final state as the Bethe-Heitler process (BH). For this reason the access is taken not through the cross-sections directly but through asymmetries between DVCS events depending on charge and polarization of the 27.6 GeV beam. For the first time the azimuthal asymmetry amplitudes according the charge of the lepton beam are extracted using a kinematically complete reconstruction method at the HERMES experiment. The recoil detector installed in 2006 allows the reconstruction of recoiling protons that completes the measurements of the forward detector to cover almost the complete angle range around the vertex. This approach allows suppressing the background processes by almost a complete magnitude compared to the traditional method using only the information of the forward spectrometer. The analysis of the asymmetries was carried out at different values of the kinematic variables tc' xB and Q2 to investigate the dependence of these variables. This work pushes the limits of the readability of data and shows which periods have been found to be unstable in the data acquisition. It points out the impact of this finding to previous HERMES publications.
Analysis of hard exclusive scattering processes of the HERMES recoil experiment
Energy Technology Data Exchange (ETDEWEB)
Brodski, Irina
2014-11-15
Deeply virtual Compton Scattering (DVCS), ep → epγ is the simplest reaction giving indication of generalized parton distributions (GPD) of the nucleon. The DVCS process has the same final state as the Bethe-Heitler process (BH). For this reason the access is taken not through the cross-sections directly but through asymmetries between DVCS events depending on charge and polarization of the 27.6 GeV beam. For the first time the azimuthal asymmetry amplitudes according the charge of the lepton beam are extracted using a kinematically complete reconstruction method at the HERMES experiment. The recoil detector installed in 2006 allows the reconstruction of recoiling protons that completes the measurements of the forward detector to cover almost the complete angle range around the vertex. This approach allows suppressing the background processes by almost a complete magnitude compared to the traditional method using only the information of the forward spectrometer. The analysis of the asymmetries was carried out at different values of the kinematic variables t{sub c'} x{sub B} and Q{sup 2} to investigate the dependence of these variables. This work pushes the limits of the readability of data and shows which periods have been found to be unstable in the data acquisition. It points out the impact of this finding to previous HERMES publications.
Exploring the nucleon structure through GPDs and TDAs in hard exclusive processes
Pire, B; Szymanowski, L; Wagner, J
2011-01-01
Generalized Parton Distributions (GPDs) offer a new way to access the quark and gluon nucleon structure. We review recent progress in this domain, emphasizing the need to supplement the experimental study of deeply virtual Compton scattering by its crossed version, timelike Compton scattering. We also describe the extension of the GPD concept to three quark operators and the relevance of their nucleon to meson matrix elements, namely the transition distribution amplitudes (TDAs) which factorize in backward meson electroproduction and related processes. We discuss the main properties of the TDAs. \\
Regenerating a symmetry in asymmetric dark matter.
Buckley, Matthew R; Profumo, Stefano
2012-01-01
Asymmetric dark matter theories generically allow for mass terms that lead to particle-antiparticle mixing. Over the age of the Universe, dark matter can thus oscillate from a purely asymmetric configuration into a symmetric mix of particles and antiparticles, allowing for pair-annihilation processes. Additionally, requiring efficient depletion of the primordial thermal (symmetric) component generically entails large annihilation rates. We show that unless some symmetry completely forbids dark matter particle-antiparticle mixing, asymmetric dark matter is effectively ruled out for a large range of masses, for almost any oscillation time scale shorter than the age of the Universe. PMID:22304253
The Asymmetric Leximin Solution
Driesen, Bram W.
2012-01-01
In this article we define and characterize a class of asymmetric leximin solutions, that contains both the symmetric leximin solution of Imai[5] and the two-person asymmetric Kalai-Smorodinsky solution of Dubra [3] as special cases. Solutions in this class combine three attractive features: they are defined on the entire domain of convex n-person bargaining problems, they generally yield Pareto efficient solution outcomes, and asymmetries among bargainers are captured by a single parameter ve...
Graesser, Michael L.; Shoemaker, Ian M.; Vecchi, Luca
2011-01-01
In existing dark matter models with global symmetries the relic abundance of dark matter is either equal to that of anti-dark matter (thermal WIMP), or vastly larger, with essentially no remaining anti-dark matter (asymmetric dark matter). By exploring the consequences of a primordial asymmetry on the coupled dark matter and anti-dark matter Boltzmann equations we find large regions of parameter space that interpolate between these two extremes. Interestingly, this new asymmetric WIMP framewo...
Troy Jollimore
2008-01-01
Friendship and romantic love are, by their very nature, exclusive relationships. This paper suggests that we can better understand the nature of the exclusivity in question by understanding what is wrong with the view of practical reasoning I call the Comprehensive Surveyor View. The CSV claims that practical reasoning, in order to be rational, must be a process of choosing the best available alternative from a perspective that is as detached and objective as possible. But this view, while it...
International Nuclear Information System (INIS)
Transient and asymmetric density distributions of butane flow have been investigated from laser image signals by developed three-dimensional digital speckle tomography. Moved signals of speckles have been captured by multiple CCD images in three angles of view simultaneously because the flows were asymmetric and transient. The signals of speckle movements between no flow and downward butane flow from a circular half opening have been calculated by a cross-correlation tracking method so that those distances can be transferred to deflection angles of laser rays fur density gradients. The three-dimensional density fields have been reconstructed from the fringe shift signal which is integrated from the deflection angle by a real-time multiplicative algebraic reconstruction technique (MART)
Nepstad, D. C.; Moutinho, P.; Dias-Filho, M. B.; Davidson, E.; Cardinot, G.; Markewitz, D.; Figueiredo, R.; Vianna, N.; Chambers, J.; Ray, D.; Guerreiros, J. B.; Lefebvre, P.; Sternberg, L.; Moreira, M.; Barros, L.; Ishida, F. Y.; Tohlver, I.; Belk, E.; Kalif, K.; Schwalbe, K.
2002-10-01
Moist tropical forests in Amazonia and elsewhere are subjected to increasingly severe drought episodes through the El Niño-Southern Oscillation (ENSO) and possibly through deforestation-driven reductions in rainfall. The effects of this trend on tropical forest canopy dynamics, emissions of greenhouse gases, and other ecological functions are potentially large but poorly understood. We established a throughfall exclusion experiment in an east-central Amazon forest (Tapajós National Forest, Brazil) to help understand these effects. After 1-year intercalibration period of two 1-ha forest plots, we installed plastic panels and wooden gutters in the understory of one of the plots, thereby excluding ˜890 mm of throughfall during the exclusion period of 2000 (late January to early August) and ˜680 mm thus far in the exclusion period of 2001 (early January to late May). Average daily throughfall reaching the soil during the exclusion period in 2000 was 4.9 and 8.3 mm in the treatment and control plots and was 4.8 and 8.1 mm in 2001, respectively. During the first exclusion period, surface soil water content (0-2 m) declined by ˜100 mm, while deep soil water (2-11 m) was unaffected. During the second exclusion period, which began shortly after the dry season when soil water content was low, surface and deep soil water content declined by ˜140 and 160 mm, respectively. Although this depletion of soil water provoked no detectable increase in leaf drought stress (i.e., no reduction in predawn leaf water potential), photosynthetic capacity declined for some species, the canopy thinned (greater canopy openness and lower leaf area index) during the second exclusion period, stem radial growth of trees litter production) declined by one fourth, from 15.1 to 11.4 Mg ha-1 yr-1, in the treatment plot and decreased slightly, from 11.9 to 11.5 Mg ha-1 yr-1, in the control plot. Stem respiration varied seasonally and was correlated with stem radial growth but showed no treatment
Ito, Kazuaki; Takayama, Yohichi; Ikedo, Mikaru; Mori, Masanobu; Taoda, Hiroshi; Xu, Qun; Hu, Wenzhi; Sunahara, Hiroshi; Hayashi, Tsuneo; Sato, Shinji; Hirokawa, Takeshi; Tanaka, Kazuhiko
2004-06-11
The determination of seven aliphatic carboxylic acids, formic, acetic, propionic, isobutyric, n-butyric, isovaleric and n-valeric acids in anaerobic digestion process waters was examined using ion-exclusion chromatography with conductimetric detection. The analysis of these biologically important carboxylic acids is necessary as a measure for evaluating and controlling the process. The ion-exclusion chromatography system employed consisted of polymethacrylate-based weakly acidic cation-exchange resin columns (TSKgel OApak-A or TSKgel Super IC-A/C). weakly acidic eluent (benzoic acid), and conductimetric detection. Particle size and cation-exchange capacity were 5 microm and 0.1 meq./ml for TSKgel OApak-A and 3 microm and 0.2 meq./ml for TSKgel Super IC-A/C, respectively. A dilute eluent (1.0-2.0 mM) of benzoic acid was effective for the high resolution and highly conductimetric detection of the carboxylic acids. The good separation of isobutyric and n-butyric acids was performed using the TSKgel Super IC-A/C column (150 mm x 6.0 mm i.d. x 2). The simple and good chromatograms were obtained by the optimized ion-exclusion chromatography conditions for real samples from mesophilic anaerobic digestors, thus the aliphatic carboxylic acids were successfully determined without any interferences. PMID:15250416
RELATIONSHIP OF TRANSVERSAL ASYMMETRIC FACE AND UNILATERAL POSTERIOR CROSSBITE
Indah Dwinursanty; Krisnawati Krisnawati; Maria Purbiati
2006-01-01
Unilateral posterior crossbite is commonly seen in mixed dentition, but it couldn’t be self corrected. If this condition is not treated properly, it could lead to asymmetric face. Asymmetric face with unilateral posterior crossbite could make the treatment process more difficult. The objective of this study is to find out the relationship between transversal skeletal asymmetry and unilateral posterior crossbite. Patients older than 13 years with skeletal asymmetric face, who had never undergo...
International Nuclear Information System (INIS)
An ion trap having two end cap electrodes disposed asymmetrically about a center of a ring electrode is disclosed. The inner surface of the end cap electrodes are conformed to an asymmetric pair of equipotential lines of the harmonic formed by the application of voltages to the electrodes. The asymmetry of the end cap electrodes allows ejection of charged species through the closer of the two electrodes which in turn allows for simultaneously detecting anions and cations expelled from the ion trap through the use of two detectors charged with opposite polarity. 4 figs
Asymmetric reactions in continuous flow
Directory of Open Access Journals (Sweden)
Xiao Yin Mak
2009-04-01
Full Text Available An overview of asymmetric synthesis in continuous flow and microreactors is presented in this review. Applications of homogeneous and heterogeneous asymmetric catalysis as well as biocatalysis in flow are discussed.
Control of apoptosis by asymmetric cell division.
Hatzold, Julia; Conradt, Barbara
2008-04-01
Asymmetric cell division and apoptosis (programmed cell death) are two fundamental processes that are important for the development and function of multicellular organisms. We have found that the processes of asymmetric cell division and apoptosis can be functionally linked. Specifically, we show that asymmetric cell division in the nematode Caenorhabditis elegans is mediated by a pathway involving three genes, dnj-11 MIDA1, ces-2 HLF, and ces-1 Snail, that directly control the enzymatic machinery responsible for apoptosis. Interestingly, the MIDA1-like protein GlsA of the alga Volvox carteri, as well as the Snail-related proteins Snail, Escargot, and Worniu of Drosophila melanogaster, have previously been implicated in asymmetric cell division. Therefore, C. elegans dnj-11 MIDA1, ces-2 HLF, and ces-1 Snail may be components of a pathway involved in asymmetric cell division that is conserved throughout the plant and animal kingdoms. Furthermore, based on our results, we propose that this pathway directly controls the apoptotic fate in C. elegans, and possibly other animals as well. PMID:18399720
One-transit paths and the steady state of a non-equilibrium process in a discrete-time update
International Nuclear Information System (INIS)
We have shown that the partition function of the asymmetric simple exclusion process with open boundaries in a sublattice-parallel updating scheme is equal to that of a two-dimensional one-transit walk model defined on a diagonally rotated square lattice. It has also been shown that the physical quantities defined in these systems are related through a similarity transformation
Effects of Noise on Asymmetric Bidirectional Controlled Teleportation
Nie, Yi-you; Sang, Ming-huang
2016-07-01
We present a scheme for asymmetric bidirectional controlled teleportation via a six-qubit cluster state in noisy environments, which includes the phase-damping and amplitude-damping channels. We analytically derive the fidelities of the asymmetric bidirectional controlled teleportation process in these two noise channels. We show that the fidelities only depend on the initial state and the noisy rate.
Directory of Open Access Journals (Sweden)
Wierzba A.
2015-12-01
Full Text Available The paper presents the results of the experimental study of the three-layer Al-Mg-Al sheets rolling process by the ARB method. The tests carried out were limited to single-pass symmetric and asymmetric rolling processes. An Al-Mg-Al package with an initial thickness of 4 mm (1-2-1 mm was subjected to the process of rolling with a relative reduction of 50%. To activate the shear band in the strip being deformed, an asymmetry factor of av=2 was applied. From the test results, an increase in the tensile strength of the multi-layer Al-Mg-Al sheets obtained from the asymmetric process was observed. Microhardness tests did not show any significant differences in aluminium layer between respective layers of sheets obtained from the symmetric and the asymmetric process. By contrast, for the magnesium layer, an increase in microhardness from 72 HV to 79 HV could be observed for the asymmetric rolling. The analysis of the produced Al-Mg-Al sheets shows that the good bond between individual layers and grain refinement in the magnesium layer contributed to the obtaining of higher mechanical properties in the multi-layer sheets produced in the asymmetric process compared to the sheets obtained from the symmetric process.
Asymmetric information and economics
Frieden, B. Roy; Hawkins, Raymond J.
2010-01-01
We present an expression of the economic concept of asymmetric information with which it is possible to derive the dynamical laws of an economy. To illustrate the utility of this approach we show how the assumption of optimal information flow leads to a general class of investment strategies including the well-known Q theory of Tobin. Novel consequences of this formalism include a natural definition of market efficiency and an uncertainty principle relating capital stock and investment flow.
Asymmetric Organocatalytic Cycloadditions
DEFF Research Database (Denmark)
Mose, Rasmus
2016-01-01
were pioneered by Otto Paul Hermann Diels and Kurt Alder who discovered what later became known as the Diels Alder reaction. The Diels Alder reaction is a [4+2] cycloaddition in which a π4 component reacts with a π2 component via a cyclic transition state to generate a 6 membered ring. This reaction...... reactions constitute the first organocatalytic asymmetric higher order cycloadditions and a rational for the periselectivity and stereoselectivity is provided based on experimental and computational investigations....
Asymmetric extractions in orthodontics
Directory of Open Access Journals (Sweden)
Camilo Aquino Melgaço
2012-04-01
Full Text Available INTRODUCTION: Extraction decisions are extremely important in during treatment planning. In addition to the extraction decision orthodontists have to choose what tooth should be extracted for the best solution of the problem and the esthetic/functional benefit of the patient. OBJECTIVE: This article aims at reviewing the literature relating the advantages, disadvantages and clinical implications of asymmetric extractions to orthodontics. METHODS: Keywords were selected in English and Portuguese and the EndNote 9 program was used for data base search in PubMed, Web of Science (WSc and LILACS. The selected articles were case reports, original articles and prospective or retrospective case-control studies concerning asymmetrical extractions of permanent teeth for the treatment of malocclusions. CONCLUSION: According to the literature reviewed asymmetric extractions can make some specific treatment mechanics easier. Cases finished with first permanent molars in Class II or III relationship in one or both sides seem not to cause esthetic or functional problems. However, diagnosis knowledge and mechanics control are essential for treatment success.
Asymmetric Evolutionary Games.
McAvoy, Alex; Hauert, Christoph
2015-08-01
Evolutionary game theory is a powerful framework for studying evolution in populations of interacting individuals. A common assumption in evolutionary game theory is that interactions are symmetric, which means that the players are distinguished by only their strategies. In nature, however, the microscopic interactions between players are nearly always asymmetric due to environmental effects, differing baseline characteristics, and other possible sources of heterogeneity. To model these phenomena, we introduce into evolutionary game theory two broad classes of asymmetric interactions: ecological and genotypic. Ecological asymmetry results from variation in the environments of the players, while genotypic asymmetry is a consequence of the players having differing baseline genotypes. We develop a theory of these forms of asymmetry for games in structured populations and use the classical social dilemmas, the Prisoner's Dilemma and the Snowdrift Game, for illustrations. Interestingly, asymmetric games reveal essential differences between models of genetic evolution based on reproduction and models of cultural evolution based on imitation that are not apparent in symmetric games. PMID:26308326
Microstructure evolution and grain refinement in asymmetrically rolled aluminium
International Nuclear Information System (INIS)
Aluminium alloy sheets were asymmetrically rolled and annealed. Asymmetric rolling was applied by imposing different velocity ratios between the top and bottom rolls, from 1 to 1.5. After cold rolling, the microstructures of various samples were analysed by electron back scatter diffraction, whereas the mechanical properties were characterized by stress–strain curves and microhardness measurements. The asymmetrical rolling process was examined as an alternative method to obtain fine- or even ultrafine-grained aluminium. The main purpose of this paper is to describe, qualitatively and quantitatively, the influence of asymmetrical rolling on microstructure evolution. Grain size, misorientation, image quality factor and other parameters were characterized and analysed in some detail. In the present study, a unique approach has been used for the first time to examine the possibility of applying the asymmetric rolling process in the preparation of materials with controlled heterogeneity
Directory of Open Access Journals (Sweden)
Kaba, Mariama
2007-07-01
Full Text Available During the 19th century, an unprecedented process of medicalisation and institutionalisation took place in Europe. The parallel development of urbanised and industrialised areas furthered the densification of a network of care institutions such as infirmaries and dispensaries, whilst medical tourism was developed among the upper classes stimulating the founding of new private clinics. A more institutional kind of care structure for people suffering from a disability also emerged. This medical and/or social care structure was part of a process of integration or exclusion, according to whether the disabled person’s state of health was likely to improve or not. This paper will focus on physically disabled persons, who were vaguely referred to as invalids or as “incurable” in 19th century institutional documents. Being mainly interested in French-speaking Switzerland, I will present the access to social and health care in the cantons of Geneva, Vaud and Neuchâtel.
Achard, P; Aguilar-Benítez, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Anderhub, H; Andreev, V P; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Bajo, A; Baksay, G; Baksay, L; Baldew, S V; Banerjee, S; Barczyk, A; Barillère, R; Bartalini, P; Basile, M; Batalova, N; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berbeco, R; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Biasini, M; Biglietti, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, G J; Böhm, A; Boldizsar, L; Borgia, B; Bottai, S; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brochu, F; Burger, J D; Burger, W J; Cai, X D; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A; Casaus, J; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada, M; Chamizo-Llatas, M; Chang, Y H; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chiefari, G; Cifarelli, Luisa; Cindolo, F; Clare, I; Clare, R; Coignet, G; Colino, N; Costantini, S; de la Cruz, B; Cucciarelli, S; van Dalen, J A; De Asmundis, R; Déglon, P L; Debreczeni, J; Degré, A; Dehmelt, K; Deiters, K; Della Volpe, D; Delmeire, E; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Dierckxsens, M; Dionisi, C; Dittmar, M; Doria, A; Dova, M T; Duchesneau, D; Duda, M; Echenard, B; Eline, A; El-Hage, A; El-Mamouni, H; Engler, A; Eppling, F J; Extermann, P; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, M; Ferguson, T; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, F; Fisher, P H; Fisher, W; Fisk, I; Forconi, G; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gentile, S; Giagu, S; Gong, Z F; Grenier, G; Grimm, O; Grünewald, M W; Guida, M; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hirschfelder, J; Hofer, H; Hohlmann, M; Holzner, G; Hou, S R; Hu, Y; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kaur, M; Kienzle-Focacci, M N; Kim, J K; Kirkby, Jasper; Kittel, E W; Klimentov, A; König, A C; Kopal, M; Koutsenko, V F; Kraber, M; Krämer, R W; Krüger, A; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Le Goff, J M; Leiste, R; Levtchenko, M; Levchenko, P M; Li, C; Likhoded, S; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Luci, C; Luminari, L; Lustermann, W; Ma Wen Gan; Malgeri, L; Malinin, A; Maña, C; Mans, J; Martin, J P; Marzano, F; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Mihul, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Muanza, G S; Muijs, A J M; Musicar, B; Musy, M; Nagy, S; Natale, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Nisati, A; Novák, T; Nowak, H; Ofierzynski, R A; Organtini, G; Pal, I; Palomares, C; Paolucci, P; Paramatti, R; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pioppi, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Pothier, J; Prokofev, D; Prokofiev, D O; Quartieri, J; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Ranieri, R; Raspereza, A V; Razis, P; Ren, D; Rescigno, M; Reucroft, S; Riemann, S; Riles, K; Roe, B P; Romero, L; Rosca, A; Rosemann, C; Rosenbleck, C; Rosier-Lees, S; Roth, S; Rubio, J A; Ruggiero, G; Rykaczewski, H; Sakharov, A; Saremi, S; Sarkar, S; Salicio, J; Sánchez, E; Schäfer, C; Shchegelskii, V; Schopper, Herwig Franz; Schotanus, D J; Sciacca, C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A; Son, D; Souga, C; Spillantini, P; Steuer, M; Stickland, D P; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Sushkov, S; Suter, H; Swain, J D; Szillási, Z; Tang, X W; Tarjan, P; Tauscher, L; Taylor, L; Tellili, B; Teyssier, D; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Ulbricht, J; Valente, E; Van de Walle, R T; Vásquez, R; Veszpremi, V; Vesztergombi, G; Vetlitskii, I; Vicinanza, D; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Wadhwa, M; Wang, Q; Wang, X L; Wang, Z M; Weber, M; Wilkens, H; Wynhoff, S; Xia, L; Xu, Z Z; Yamamoto, J; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Yeh, S C; Zalite, A; Zalite, Yu; Zhang, Z P; Zhao, J; Zhu, G Y; Zhu, R Y; Zhuang, H L; Zichichi, A; Zimmermann, B; Zöller, M
2005-01-01
Exclusive rho+rho- production in two-photon collisions between a quasi-real photon, gamma, and a mid-virtuality photon, gamma*, is studied with data collected at LEP at centre-of-mass energies root(s)=183-209GeV with a total integrated luminosity of 684.8pb^-1. The cross section of the gamma gamma* -> rho+ rho- process is determined as a function of the photon virtuality, Q^2, and the two-photon centre-of-mass energy, W_gg, in the kinematic region: 0.2GeV^2 rho rho process over the Q^2-region 0.2GeV^2 < Q^2 < 30 GeV^2.
Central Exclusive Production at LHCb
McNulty, Ronan
2015-01-01
Central Exclusive Production is a unique QCD process in which particles are produced via colourless propagators. Several results have been obtained at LHCb for the production of single charmonia, pairs of charmonia, and single bottomonia.
Morrison, James
1984-01-01
Asymmetric Synthesis, Volume 4: The Chiral Carbon Pool and Chiral Sulfur, Nitrogen, Phosphorus, and Silicon Centers describes the practical methods of obtaining chiral fragments. Divided into five chapters, this book specifically examines initial chiral transmission and extension. The opening chapter describes the so-called chiral carbon pool, the readily available chiral carbon fragments used as building blocks in synthesis. This chapter also provides a list of 375 chiral building blocks, along with their commercial sources, approximate prices, and methods of synthesis. Schemes involving
Asymmetric quantum cloning machines
International Nuclear Information System (INIS)
A family of asymmetric cloning machines for quantum bits and N-dimensional quantum states is introduced. These machines produce two approximate copies of a single quantum state that emerge from two distinct channels. In particular, an asymmetric Pauli cloning machine is defined that makes two imperfect copies of a quantum bit, while the overall input-to-output operation for each copy is a Pauli channel. A no-cloning inequality is derived, characterizing the impossibility of copying imposed by quantum mechanics. If p and p' are the probabilities of the depolarizing channels associated with the two outputs, the domain in (√p,√p')-space located inside a particular ellipse representing close-to-perfect cloning is forbidden. This ellipse tends to a circle when copying an N-dimensional state with N→∞, which has a simple semi-classical interpretation. The symmetric Pauli cloning machines are then used to provide an upper bound on the quantum capacity of the Pauli channel of probabilities px, py and pz. The capacity is proven to be vanishing if (√px, √py, √pz) lies outside an ellipsoid whose pole coincides with the depolarizing channel that underlies the universal cloning machine. Finally, the tradeoff between the quality of the two copies is shown to result from a complementarity akin to Heisenberg uncertainty principle. (author)
Brownian ratchets driven by asymmetric nucleation of hydrolysis waves
Lakhanpal, Amit; Chou, Tom
2007-01-01
We propose a stochastic process wherein molecular transport is mediated by asymmetric nucleation of domains on a one-dimensional substrate. Track-driven mechanisms of molecular transport arise in biophysical applications such as Holliday junction positioning and collagenase processivity. In contrast to molecular motors that hydrolyze nucleotide triphosphates and undergo a local molecular conformational change, we show that asymmetric nucleation of hydrolysis waves on a track can also result i...
2010-07-01
... Cathode Ray Tubes (CRTs) and Processed CRT Glass Undergoing Recycling. 261.39 Section 261.39 Protection of... (CRTs) and Processed CRT Glass Undergoing Recycling. Used, broken CRTs are not solid wastes if they meet... complete until any such claim is resolved in accordance with 40 CFR 260.2. (v) The export of CRTs...
Alternative Asymmetric Stochastic Volatility Models
M. Asai (Manabu); M.J. McAleer (Michael)
2010-01-01
textabstractThe stochastic volatility model usually incorporates asymmetric effects by introducing the negative correlation between the innovations in returns and volatility. In this paper, we propose a new asymmetric stochastic volatility model, based on the leverage and size effects. The model is
Engineered Asymmetric Synthetic Vesicles
Lu, Li; Chiarot, Paul
2013-11-01
Synthetic vesicles are small, fluid-filled spheres that are enclosed by a bilayer of lipid molecules. They can be used as models for investigating membrane biology and as delivery vehicles for pharmaceuticals. In practice, it is difficult to simultaneously control membrane asymmetry, unilamellarity, vesicle size, vesicle-to-vesicle uniformity, and luminal content. Membrane asymmetry, where each leaflet of the bilayer is composed of different lipids, is of particular importance as it is a feature of most natural membranes. In this study, we leverage microfluidic technology to build asymmetric vesicles at high-throughput. We use the precise flow control offered by microfluidic devices to make highly uniform emulsions, with controlled internal content, that serve as templates to build the synthetic vesicles. Flow focusing, dielectrophoretic steering, and interfacial lipid self-assembly are critical procedures performed on-chip to produce the vesicles. Fluorescent and confocal microscopy are used to evaluate the vesicle characteristics.
Directory of Open Access Journals (Sweden)
I. Cabrera-Munguia
2015-04-01
Full Text Available A 6-parametric asymptotically flat exact solution, describing a two-body system of asymmetric black dyons, is studied. The system consists of two unequal counterrotating Kerr–Newman black holes, endowed with electric and magnetic charges which are equal but opposite in sign, separated by a massless strut. The Smarr formula is generalized in order to take into account their contribution to the mass. The expressions for the horizon half-length parameters σ1 and σ2, as functions of the Komar parameters and of the coordinate distance, are displayed, and the thermodynamic properties of the two-body system are studied. Furthermore, the seven physical parameters satisfy a simple algebraic relation which can be understood as a dynamical scenario, in which the physical properties of one body are affected by the ones of the other body.
International Nuclear Information System (INIS)
We study a natural implementation of Asymmetric Dark Matter in Twin Higgs models. The mirroring of the Standard Model strong sector suggests that a twin baryon with mass around 5 GeV is a natural Dark Matter candidate once a twin baryon number asymmetry comparable to the SM asymmetry is generated. We explore twin baryon Dark Matter in two different scenarios, one with minimal content in the twin sector and one with a complete copy of the SM, including a light twin photon. The essential requirements for successful thermal history are presented, and in doing so we address some of the cosmological issues common to many Twin Higgs models. The required interactions we introduce predict signatures at direct detection experiments and at the LHC
Organizing for Asymmetric Collaboration
DEFF Research Database (Denmark)
Nielsen, Jørn Flohr; Sørensen, Henrik B.
meet each other. On the contrary, we assume that asymmetry is both important and normal; moreover, asymmetry should be considered to be more complex than economists indicate with their concept of asymmetric information. Thus, the aim of the paper is to explore how asymmetries related to partners...... The vision of new organizational forms consists of less-organized networks and alliances between organizations, in which collaborative capabilities are assumed to be crucial (Miles et al., 2005). The path to such new forms may go through fragile cooperative efforts. Despite the good will of many......' different motives and different situational factors appear in an interorganizational setting. We classify interfaces according to the symmetry/asymmetry in the respective parent organizations' resources, commitment, and control of representatives and indicate how classification schemes can be used to...
Annihilating Asymmetric Dark Matter
Bell, Nicole F; Shoemaker, Ian M
2014-01-01
The relic abundance of particle and antiparticle dark matter (DM) need not be vastly different in thermal asymmetric dark matter (ADM) models. By considering the effect of a primordial asymmetry on the thermal Boltzmann evolution of coupled DM and anti-DM, we derive the requisite annihilation cross section. This is used in conjunction with CMB and Fermi-LAT gamma-ray data to impose a limit on the number density of anti-DM particles surviving thermal freeze-out. When the extended gamma-ray emission from the Galactic Center is reanalyzed in a thermal ADM framework, we find that annihilation into $\\tau$ leptons prefer anti-DM number densities 1-4$\\%$ that of DM while the $b$-quark channel prefers 50-100$\\%$.
Neuronal alignment on asymmetric textured surfaces
Beighley, Ross; Spedden, Elise; Sekeroglu, Koray; Atherton, Timothy; Demirel, Melik C.; Staii, Cristian
2012-01-01
Axonal growth and the formation of synaptic connections are key steps in the development of the nervous system. Here, we present experimental and theoretical results on axonal growth and interconnectivity in order to elucidate some of the basic rules that neuronal cells use for functional connections with one another. We demonstrate that a unidirectional nanotextured surface can bias axonal growth. We perform a systematic investigation of neuronal processes on asymmetric surfaces and quantify...
Do Daily Retail Gasoline Prices adjust Asymmetrically?
Bettendorf, Leon; Geest, Stéphanie; Kuper, G.
2005-01-01
This paper analyzes adjustments in the Dutch retail gasoline prices. We estimate an error correction model on changes in the daily retail price for gasoline (taxes excluded) for the period 1996-2004 taking care of volatility clustering by estimating an EGARCH model. It turns out the volatility process is asymmetrical: an unexpected increase in the producer price has a larger effect on the variance of the producer price than an unexpected decrease. We do not find evidence for amount asymmetry,...
Gupta, Arvind Kumar
2016-03-01
Motivated by the recent experimental observations on clustering of motor proteins on microtubule filament, we study an open system of two parallel totally asymmetric simple exclusion processes under asymmetric coupling conditions, which incorporates the mutual interaction with the surrounding environment through Langmuir Kinetics (LK) in both the lanes. In the modified LK, the attachment and detachment rates depends on the configuration of nearest neighboring sites. We analyse the model within the framework of continuum mean-field theory and the phase diagrams along with density profiles are obtained using boundary layer analysis. The effect of mutual interactions on the phase diagram for two different situations of attachment and detachment (LK) rates is discussed. Under the symmetric LK dynamics, the topological structure of the phase diagram remains similar to the one in without mutual interaction; while for the antisymmetric case, after a certain critical value of attractive/repulsive mutual attraction, significant changes are found in the qualitative nature of phase diagram. Moreover, it is shown that the type of mutual interaction affects the dynamic properties of motor proteins. The theoretical findings are examined by extensive Monte-Carlo simulations.
Ciric, Jelena; Rolland-Sabate, Agnes; Guilois, Sophie; Loos, Katja
2014-01-01
Asymmetrical flow field flow fractionation (AF4), when coupled with multi-angle laser light scattering (MALLS), is a very powerful technique for determination of the macromolecular structure of high molar mass (branched) polysaccharides. AF4 is a size fractionation technique just as size exclusion c
Exclusive dimuon production with LHCb
Shears, Tara
2011-01-01
We report on studies of exclusive dimuon production using LHCb experimental data. Exclusively produced muon pairs can be produced by two photon fusion (a QED process ideally suited to obtaining a precise integrated luminosity measure), or through resonances produced by pomeron-photon fusion or double pomeron exchange.We present cross-section measurements for exclusive dimuon production, and the first observations at a proton-proton collider of exclusive J/psi, psi’ and chi_c states, obtained with 37 pb-1 of data at centre of mass energy of 7 TeV. The resolution of the LHCb detectors allow the chic0, chic1 and chic2 states to be separated. We compare our results to theoretical predictions.
Asymmetric Gepner Models (Revisited)
Gato-Rivera, B
2010-01-01
We reconsider a class of heterotic string theories studied in 1989, based on tensor products of N=2 minimal models with asymmetric simple current invariants. We extend this analysis from (2,2) and (1,2) spectra to (0,2) spectra with SO(10) broken to the Standard Model. In the latter case the spectrum must contain fractionally charged particles. We find that in nearly all cases at least some of them are massless. However, we identify a large subclass where the fractional charges are at worst half-integer, and often vector-like. The number of families is very often reduced in comparison to the 1989 results, but there are no new tensor combinations yielding three families. All tensor combinations turn out to fall into two classes: those where the number of families is always divisible by three, and those where it is never divisible by three. We find an empirical rule to determine the class, which appears to extend beyond minimal N=2 tensor products. We observe that distributions of physical quantities such as th...
Magnetically Modified Asymmetric Supercapacitors Project
National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project is for the development of an asymmetric supercapacitor that will have improved energy density and cycle...
Energy Technology Data Exchange (ETDEWEB)
Akushevich, Igor V. [Duke University, JLAB; Ilyichev, Alexander [Byelorussian State University; Shumeiko, Nikolai M [Byelorussian State University
2014-08-01
Radiative effects in the electroproduction of photons in polarized ep-scattering are calculated with the next-to-leading (NLO) accuracy. The contributions of loops and two photon emission were presented in analytical form. The covariant approach of Bardin and Shumeiko was used to extract the infrared divergence. All contributions to the radiative correction were presented in the form of the correction to the leptonic tensor thus allowing for further applications in other experiments, e.g., deep inelastic scattering. The radiative corrections (RC) to the cross sections and polarization asymmetries were analyzed numerically for kinematical conditions of the current measurement at Jefferson Lab. Specific attention was paid on analyzing kinematical conditions for the process with large radiative effect when momenta of two photons in the final state are collinear to momenta of initial and final electrons, respectively.
Directory of Open Access Journals (Sweden)
Robert Boldt
Full Text Available Earlier studies have shown considerable intersubject synchronization of brain activity when subjects watch the same movie or listen to the same story. Here we investigated the across-subjects similarity of brain responses to speech and non-speech sounds in a continuous audio drama designed for blind people. Thirteen healthy adults listened for ∼19 min to the audio drama while their brain activity was measured with 3 T functional magnetic resonance imaging (fMRI. An intersubject-correlation (ISC map, computed across the whole experiment to assess the stimulus-driven extrinsic brain network, indicated statistically significant ISC in temporal, frontal and parietal cortices, cingulate cortex, and amygdala. Group-level independent component (IC analysis was used to parcel out the brain signals into functionally coupled networks, and the dependence of the ICs on external stimuli was tested by comparing them with the ISC map. This procedure revealed four extrinsic ICs of which two-covering non-overlapping areas of the auditory cortex-were modulated by both speech and non-speech sounds. The two other extrinsic ICs, one left-hemisphere-lateralized and the other right-hemisphere-lateralized, were speech-related and comprised the superior and middle temporal gyri, temporal poles, and the left angular and inferior orbital gyri. In areas of low ISC four ICs that were defined intrinsic fluctuated similarly as the time-courses of either the speech-sound-related or all-sounds-related extrinsic ICs. These ICs included the superior temporal gyrus, the anterior insula, and the frontal, parietal and midline occipital cortices. Taken together, substantial intersubject synchronization of cortical activity was observed in subjects listening to an audio drama, with results suggesting that speech is processed in two separate networks, one dedicated to the processing of speech sounds and the other to both speech and non-speech sounds.
Hwang, Da Young; Suh, Dong Hack
2014-05-01
Unlike nanoscrolls of 2D graphene, those of 2D h-BN have not been demonstrated, except for only a few experimental reports. Nanoscrolls of h-BN with high yields and reproducibility are first synthesized by a simple solution process. Inner-tube diameters of BNSs including LCAs, N-(2-aminoethyl)-3α-hydroxy-5β-cholan-24-amide, a bile acid derivative and self-assembling material, can be controlled by adjusting the diameter of the LCA fiber which is grown by self-assembly. TEM and SEM images show that BNSs have a tube-like morphology and the inner-tube diameter of BNSs can be controlled in the range from 20 to 60 nm for a smaller diameter, up to 300 nm for a larger diameter by LCA fiber growth inside the BNSs. Finally, open cylindrical BNSs with hollow cores were obtained by dissolving LCAs inside BNSs.Unlike nanoscrolls of 2D graphene, those of 2D h-BN have not been demonstrated, except for only a few experimental reports. Nanoscrolls of h-BN with high yields and reproducibility are first synthesized by a simple solution process. Inner-tube diameters of BNSs including LCAs, N-(2-aminoethyl)-3α-hydroxy-5β-cholan-24-amide, a bile acid derivative and self-assembling material, can be controlled by adjusting the diameter of the LCA fiber which is grown by self-assembly. TEM and SEM images show that BNSs have a tube-like morphology and the inner-tube diameter of BNSs can be controlled in the range from 20 to 60 nm for a smaller diameter, up to 300 nm for a larger diameter by LCA fiber growth inside the BNSs. Finally, open cylindrical BNSs with hollow cores were obtained by dissolving LCAs inside BNSs. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr00897a
Active Matter on Asymmetric Substrates
Reichhardt, C. J. Olson; Drocco, J.; Mai, T.; Wan, M. B.; Reichhardt, C.
2011-01-01
For collections of particles in a thermal bath interacting with an asymmetric substrate, it is possible for a ratchet effect to occur where the particles undergo a net dc motion in response to an ac forcing. Ratchet effects have been demonstrated in a variety of systems including colloids as well as magnetic vortices in type-II superconductors. Here we examine the case of active matter or self-driven particles interacting with asymmetric substrates. Active matter systems include self-motile c...
Mobile Termination with Asymmetric Networks
Dewenter, Ralf; Haucap, Justus
2003-01-01
This paper examines mobile termination fees and their regulation when networks are asymmetric in size. It is demonstrated that with consumer ignorance about the exact termination rates (a) a mobile network?s termination rate is the higher the smaller the network?s size (as measured through its subscriber base) and (b) asymmetric regulation of only the larger operators in a market will, ce-teris paribus, induce the smaller operators to increase their termination rates. The results are supporte...
Multicatalyst system in asymmetric catalysis
Zhou, Jian
2014-01-01
This book introduces multi-catalyst systems by describing their mechanism and advantages in asymmetric catalysis. Helps organic chemists perform more efficient catalysis with step-by-step methods Overviews new concepts and progress for greener and economic catalytic reactions Covers topics of interest in asymmetric catalysis including bifunctional catalysis, cooperative catalysis, multimetallic catalysis, and novel tandem reactions Has applications for pharmaceuticals, agrochemicals, materials, and flavour and fragrance
Asymmetric Dark Matter from Leptogenesis
Falkowski, Adam; Ruderman, Joshua T.; Volansky, Tomer
2011-01-01
We present a new realization of asymmetric dark matter in which the dark matter and lepton asymmetries are generated simultaneously through two-sector leptogenesis. The right-handed neutrinos couple both to the Standard Model and to a hidden sector where the dark matter resides. This framework explains the lepton asymmetry, dark matter abundance and neutrino masses all at once. In contrast to previous realizations of asymmetric dark matter, the model allows for a wide range of dark matter mas...
Directory of Open Access Journals (Sweden)
Troy Jollimore
2008-02-01
Full Text Available Friendship and romantic love are, by their very nature, exclusive relationships. This paper suggests that we can better understand the nature of the exclusivity in question by understanding what is wrong with the view of practical reasoning I call the Comprehensive Surveyor View. The CSV claims that practical reasoning, in order to be rational, must be a process of choosing the best available alternative from a perspective that is as detached and objective as possible. But this view, while it means to be neutral between various value-bearers, in fact incorporates a bias against those value-bearers that can only be appreciated from a perspective that is not detached—that can only be appreciated, for instance, by agents who bear long-term commitments to the values in question. In the realm of personal relationships, such commitments tend to give rise to the sort of exclusivity that characterizes friendship and romantic love; they prevent the agent from being impartial between her beloved’s needs, interests, etc., and those of other persons. In such contexts, I suggest, needs and claims of other persons may be silenced in much the way that, as John McDowell has suggested, the temptations of immorality are silenced for the virtuous agent.
Polarization dependent switching of asymmetric nanorings with a circular field
Directory of Open Access Journals (Sweden)
Nihar R. Pradhan
2016-01-01
Full Text Available We experimentally investigated the switching from onion to vortex states in asymmetric cobalt nanorings by an applied circular field. An in-plane field is applied along the symmetric or asymmetric axis of the ring to establish domain walls (DWs with symmetric or asymmetric polarization. A circular field is then applied to switch from the onion state to the vortex state, moving the DWs in the process. The asymmetry of the ring leads to different switching fields depending on the location of the DWs and direction of applied field. For polarization along the asymmetric axis, the field required to move the DWs to the narrow side of the ring is smaller than the field required to move the DWs to the larger side of the ring. For polarization along the symmetric axis, establishing one DW in the narrow side and one on the wide side, the field required to switch to the vortex state is an intermediate value.
Korhonen, Marko; Lee, Eunghyun
2014-01-01
We treat the $N$-particle ZRP whose jumping rates satisfy a certain condition. This condition is required to use the Bethe ansatz and the resulting model is the $q$-boson model that appeared in [J. Phys. A, \\textbf{31} 6057--6071 (1998)] by Sasamoto and Wadati or the $q$-TAZRP in \\textit{MacDonald processes} by Borodin and Corwin. We find the explicit formula of the transition probability of the $q$-TAZRP via the Bethe ansatz. By using the transition probability we find the probability distri...
DEFF Research Database (Denmark)
Börner, Tim; Rehn, Gustav; Grey, Carl;
2015-01-01
For the amine transaminase (ATA)-catalyzed synthesis of chiral amines, the choice of donor substrate is of high importance for reaction and process design. Alanine was investigated as an amine donor for the reductive amination of a poorly water-soluble ketone (4-phenyl-2-butanone) in a combined...... in situ product removal (ISPR) approach using liquid-membrane extraction together with an enzyme cascade. This ISPR strategy facilitates very high (>98%) product purity with an integrated enrichment step and eliminates product as well as coproduct inhibition. In the presented proof-of-concept alanine...
Why Do Nucleosomes Unwrap Asymmetrically?
de Bruin, Lennart; Tompitak, Marco; Eslami-Mossallam, Behrouz; Schiessel, Helmut
2016-07-01
Nucleosomes, DNA spools with a protein core, engage about three-quarters of eukaryotic DNA and play a critical role in chromosomal processes, ranging from gene regulation, recombination, and replication to chromosome condensation. For more than a decade, micromanipulation experiments where nucleosomes are put under tension, as well as the theoretical interpretations of these experiments, have deepened our understanding of the stability and dynamics of nucleosomes. Here we give a theoretical explanation for a surprising new experimental finding: nucleosomes wrapped onto the 601 positioning sequence (the sequence used in most laboratories) respond highly asymmetrically to external forces by always unwrapping from the same end. Using a computational nucleosome model, we show that this asymmetry can be explained by differences in the DNA mechanics of two very short stretches on the wrapped DNA portion. Our finding suggests that the physical properties of nucleosomes, here the response to forces, can be tuned locally by the choice of the underlying base-pair sequence. This leads to a new view of nucleosomes: a physically highly varied set of DNA-protein complexes whose properties can be tuned on evolutionary time scales to their specific function in the genomic context. PMID:26991771
Asymmetric Gepner models (revisited)
Energy Technology Data Exchange (ETDEWEB)
Gato-Rivera, B. [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands)] [Instituto de Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain); Schellekens, A.N., E-mail: t58@nikhef.n [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands)] [Instituto de Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain)] [IMAPP, Radboud Universiteit, Nijmegen (Netherlands)
2010-12-11
We reconsider a class of heterotic string theories studied in 1989, based on tensor products of N=2 minimal models with asymmetric simple current invariants. We extend this analysis from (2,2) and (1,2) spectra to (0,2) spectra with SO(10) broken to the Standard Model. In the latter case the spectrum must contain fractionally charged particles. We find that in nearly all cases at least some of them are massless. However, we identify a large subclass where the fractional charges are at worst half-integer, and often vector-like. The number of families is very often reduced in comparison to the 1989 results, but there are no new tensor combinations yielding three families. All tensor combinations turn out to fall into two classes: those where the number of families is always divisible by three, and those where it is never divisible by three. We find an empirical rule to determine the class, which appears to extend beyond minimal N=2 tensor products. We observe that distributions of physical quantities such as the number of families, singlets and mirrors have an interesting tendency towards smaller values as the gauge groups approaches the Standard Model. We compare our results with an analogous class of free fermionic models. This displays similar features, but with less resolution. Finally we present a complete scan of the three family models based on the triply-exceptional combination (1,16{sup *},16{sup *},16{sup *}) identified originally by Gepner. We find 1220 distinct three family spectra in this case, forming 610 mirror pairs. About half of them have the gauge group SU(3)xSU(2){sub L}xSU(2){sub R}xU(1){sup 5}, the theoretical minimum, and many others are trinification models.
Asymmetric dimethylarginine (ADMA and endothelial dysfunction: implications for atherogenesis
Directory of Open Access Journals (Sweden)
Maurício Batista Paes Landim
2009-05-01
Full Text Available Atherosclerotic coronary heart disease is the leading cause of morbidity and mortality in industrialized countries, and endothelial dysfunction is considered a precursor phenomenon. The nitric oxide produced by the endothelium under the action of endothelial nitric oxide synthase has important antiatherogenic functions. Its reduced bioavailabilty is the beginning of the atherosclerotic process. The addition of two methyl radicals to arginine, through the action of methyltransferase nuclear proteins, produces asymmetric dimethylarginine, which competes with L-arginine and promotes a reduction in nitric oxide formation in the vascular wall. The asymmetric dimethylarginine, which is itself considered a mediator of the vascular effects of the several risk factors for atherosclerosis, can be eliminated by renal excretion or by the enzymatic action of the dimethylarginine dimethylaminohydrolases. Several basic science and clinical research studies suggest that the increase in asymmetric dimethylarginine occurs in the context of chronic renal insufficiency, dyslipidemia, high blood pressure, diabetes mellitus, and hyperhomocysteinemy, as well as with other conditions. Therapeutic measures to combat atherosclerosis may reverse these asymmetric dimethylarginine effects or at least reduce the concentration of this chemical in the blood. Such an effect can be achieved with competitor molecules or by increasing the expression or activity of its degradation enzyme. Studies are in development to establish the true role of asymmetric dimethylarginine as a marker and mediator of atherosclerosis, with possible therapeutic applications. The main aspects of the formation and degradation of asymmetric dimethylarginine and its implication in the atherogenic process will be addressed in this article.
Generation of central exclusive final states
Lönnblad, Leif
2016-01-01
We present a scheme for the generation of central exclusive final states in the Pythia 8 program. The implementation allows for the investigation of higher order corrections to such exclusive processes as approximated by the initial-state parton shower in Pythia 8. To achieve this, the spin and colour decomposition of the initial-state shower has been worked out, in order to determine the probability that a partonic state generated from an inclusive sub-process followed by a series of initial-state parton splittings can be considered as an approximation of an exclusive colour- and spin-singlet process. We use our implementation to investigate effects of parton showers on some examples of central exclusive processes, and find sizeable effects on di-jet production, while the effects on e.g. central exclusive Higgs production are minor.
Hard exclusive pion leptoproduction
Kroll, Peter
2016-01-01
In this talk it is reported on an analysis of hard exclusive leptoproduction of pions within the handbag approach. It is argued that recent measurements of this process performed by HERMES and CLAS clearly indicate the occurrence of strong contributions from transversely polarized photons. Within the handbag approach such gamma*_T -> pi transitions are described by the transversity GPDs accompanied by twist-3 pion wave functions. It is shown that the handbag approach leads to results on cross sections and single-spin asymmetries in fair agreement with experiment. Predictions for other pseudoscalar meson channels are also briefly discussed.8 pages
Kaziannis, S.; Kotsina, N.; Kosmidis, C.
2014-09-01
The interaction of toluene with strong asymmetric two-color laser irradiation of 40 fs duration is studied by means of Time of flight mass spectrometry. Highly energetic H2+ and H3+ fragment ions are produced through an isomerization process taking place within transient multiply charged parent ions. Comparative study of deuterium labeled toluene isotopes enables the discrimination between molecular hydrogen fragments formed exclusively within the CH3- part from those that require hydrogen atom exchange between the former and the phenyl moiety. It is demonstrated that by manipulating the relative phase of the ω/2ω field components the selective ionization of oriented toluene molecules can be used as a tool to control the directional emission of the H2+, H3+ species.
Energy Technology Data Exchange (ETDEWEB)
Kaziannis, S.; Kotsina, N.; Kosmidis, C. [Department of Physics, Atomic and Molecular Physics Laboratory, University of Ioannina, University Campus, Ioannina GR-45110 (Greece)
2014-09-14
The interaction of toluene with strong asymmetric two-color laser irradiation of 40 fs duration is studied by means of Time of flight mass spectrometry. Highly energetic H{sub 2}{sup +} and H{sub 3}{sup +} fragment ions are produced through an isomerization process taking place within transient multiply charged parent ions. Comparative study of deuterium labeled toluene isotopes enables the discrimination between molecular hydrogen fragments formed exclusively within the CH{sub 3}- part from those that require hydrogen atom exchange between the former and the phenyl moiety. It is demonstrated that by manipulating the relative phase of the ω/2ω field components the selective ionization of oriented toluene molecules can be used as a tool to control the directional emission of the H{sub 2}{sup +}, H{sub 3}{sup +} species.
International Nuclear Information System (INIS)
The interaction of toluene with strong asymmetric two-color laser irradiation of 40 fs duration is studied by means of Time of flight mass spectrometry. Highly energetic H2+ and H3+ fragment ions are produced through an isomerization process taking place within transient multiply charged parent ions. Comparative study of deuterium labeled toluene isotopes enables the discrimination between molecular hydrogen fragments formed exclusively within the CH3- part from those that require hydrogen atom exchange between the former and the phenyl moiety. It is demonstrated that by manipulating the relative phase of the ω/2ω field components the selective ionization of oriented toluene molecules can be used as a tool to control the directional emission of the H2+, H3+ species
Hydroxamic acids in asymmetric synthesis.
Li, Zhi; Yamamoto, Hisashi
2013-02-19
Metal-catalyzed stereoselective reactions are a central theme in organic chemistry research. In these reactions, the stereoselection is achieved predominantly by introducing chiral ligands at the metal catalyst's center. For decades, researchers have sought better chiral ligands for asymmetric catalysis and have made great progress. Nevertheless, to achieve optimal stereoselectivity and to catalyze new reactions, new chiral ligands are needed. Because of their high metal affinity, hydroxamic acids play major roles across a broad spectrum of fields from biochemistry to metal extraction. Dr. K. Barry Sharpless first revealed their potential as chiral ligands for asymmetric synthesis in 1977: He published the chiral vanadium-hydroxamic-acid-catalyzed, enantioselective epoxidation of allylic alcohols before his discovery of Sharpless asymmetric epoxidation, which uses the titanium-tartrate complex as the chiral reagent. However, researchers have reported few highly enantioselective reactions using metal-hydroxamic acid as catalysts since then. This Account summarizes our research on metal-catalyzed asymmetric epoxidation using hydroxamic acids as chiral ligands. We designed and synthesized a series of new hydroxamic acids, most notably the C2-symmetric bis-hydroxamic acid (BHA) family. V-BHA-catalyzed epoxidation of allylic and homoallylic alcohols achieved higher activity and stereoselectivity than Sharpless asymmetric epoxidation in many cases. Changing the metal species led to a series of unprecedented asymmetric epoxidation reactions, such as (i) single olefins and sulfides with Mo-BHA, (ii) homoallylic and bishomoallylic alcohols with Zr- and Hf-BHA, and (iii) N-alkenyl sulfonamides and N-sulfonyl imines with Hf-BHA. These reactions produce uniquely functionalized chiral epoxides with good yields and enantioselectivities. PMID:23157425
Asymmetric counterpropagating fronts without flow.
Andrade-Silva, I; Clerc, M G; Odent, V
2015-06-01
Out-of-equilibrium systems exhibit domain walls between different states. These walls, depending on the type of connected states, can display rich spatiotemporal dynamics. In this Rapid Communication, we investigate the asymmetrical counterpropagation of fronts in an in-plane-switching cell filled with a nematic liquid crystal. Experimentally, we characterize the different front shapes and propagation speeds. These fronts present dissimilar elastic deformations that are responsible for their asymmetric speeds. Theoretically, using a phenomenological model, we describe the observed dynamics with fair agreement. PMID:26172647
Incompressibility of asymmetric nuclear matter
Chen, Lie-Wen; Cai, Bao-Jun; Shen, Chun; Ko, Che Ming; Xu, Jun; Li, Bao-An(Department of Physics and Astronomy, Texas A&M University-Commerce, Commerce, TX, 75429-3011, USA)
2009-01-01
The incompressibility $K_sat(\\delta)$ of isospin asymmetric nuclear matter at its saturation density. Our results show that in the expansion of $K_sat(\\delta)$ in powers of isospin asymmetry $\\delta$, i.e., $K_sat(\\delta )$=K_{0}+K_{sat,2}\\delta^{2}+K_{sat,4}\\delta^{4}+O(\\delta^{6})$, the magnitude of the 4th-order K_{sat,4} parameter is generally small. The 2nd-order K_{sat,2} parameter thus essentially characterizes the isospin dependence of the incompressibility of asymmetric nuclear matte...
Buss, Ginters
2011-01-01
The paper proposes an extension of the symmetric Baxter-King band pass filter to an asymmetric Baxter-King filter. The optimal correction scheme of the ideal filter weights is the same as in the symmetric version, i.e, cut the ideal filter at the appropriate length and add a constant to all filter weights to ensure zero weight on zero frequency. Since the symmetric Baxter-King filter is unable to extract the desired signal at the very ends of the series, the extension to an asymmetric filter...
Forces between asymmetric polymer brushes
Shim, D.F.K.; Cates, M. E.
1990-01-01
We study the equilibrium compression of asymmetric polymer brushes grafted on flat plates, under athermal and theta solvent conditions, using a lattice self-consistent field (SCF) approach. We find that the separation d between two plates coated asymmetrically with brushes of type 1 and 2, as a function of the force F, obeys the "bisection rule", d(F) = (d1(F) + d 2(F)) /2 where d1(F)and d 2(F) are the corresponding separations for the symmetric brushes of type 1 and 2 respectively.The bisect...
Research on asymmetric "Jerusalem" unit
Institute of Scientific and Technical Information of China (English)
Jun Lu; Jianbo Wang
2009-01-01
An asymmetric Jerusalem unit and the frequency selective surface(FSS)structure composed of such units are designed.The transmittance of the designed FSS structure is calculated by mode-matching method and compared with the test results.The comparison results show that the FSS center frequency of the asymmetric structure unit drifts little with the variation of the incident angles of the electromagnetic waves and keeps relatively stable.The research offers a new choice for the application of FSS under the large scanning angle of electromagnetic waves.
Maria Cristina Tissi
2000-01-01
Este estudo abordou a condição de trabalho com deficiência no comércio ambulante de São Paulo, enquanto vivência de processos de exclusão e, paradoxalmente, de inclusão social. O trabalho é concebido pelos ambulantes como elemento que proporciona relacionamentos sociais e confere dignidade e respeito na rede de relações das próprias vidas, mas o plano da sociabilidade, porém, mostra-se contraditório. No ponto de vista do processo de trabalho, a atuação no comércio ambulante revela traços de d...
Neuronal Alignment On Asymmetric Textured Surfaces
Beighley, Ross; Sekeroglu, Koray; Atherton, Timothy; Demirel, Melik C; Staii, Cristian
2013-01-01
Axonal growth and the formation of synaptic connections are key steps in the development of the nervous system. Here we present experimental and theoretical results on axonal growth and interconnectivity in order to elucidate some of the basic rules that neuronal cells use for functional connections with one another. We demonstrate that a unidirectional nanotextured surface can bias axonal growth. We perform a systematic investigation of neuronal processes on asymmetric surfaces and quantify the role that biomechanical surface cues play in neuronal growth. These results represent an important step towards engineering directed axonal growth for neuro-regeneration studies.
Pre-Auction Offers in Asymmetric First-Price and Second-Price Auctions
DEFF Research Database (Denmark)
Kirkegaard, René; Overgaard, Per Baltzer
We consider “must-sell” auctions with asymmetric buyers. First, we study auctions with two asymmetric buyers, where the distribution of valuations of the strong buyer is “stretched” relative to that of the weak buyer. Then, it is known that ineffcient first-price auctions aremore profitable for the...... seller than effcient second-price auctions. This is because the former favor the weak buyer. However, we show that the seller can do one better by augmenting the first-price auction by a pre-auction offer made exclusively to the strong buyer. Should thestrong buyer reject the offer, the object is simply...
JET and COMPASS asymmetrical disruptions
Czech Academy of Sciences Publication Activity Database
Gerasimov, S.N.; Abreu, P.; Baruzzo, M.; Drozdov, V.; Dvornova, A.; Havlíček, Josef; Hender, T.C.; Hronová-Bilyková, Olena; Kruezi, U.; Li, X.; Markovič, Tomáš; Pánek, Radomír; Rubinacci, G.; Tsalas, M.; Ventre, S.; Villone, F.; Zakharov, L.E.
2015-01-01
Roč. 55, č. 11 (2015), s. 113006-113006. ISSN 0029-5515 R&D Projects: GA MŠk(CZ) LM2011021 Institutional support: RVO:61389021 Keywords : tokamak * asymmetrical disruption * JET * COMPASS Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.062, year: 2014
Synthesis of Asymmetric Propanetriol Analogues
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
From natural tartaric acid, (R)-2-benzyloxy-3-(2-tetrahydropyranyloxy) propanol 3 was designed and synthesized, and (R)-2-benzyloxy-3-(4-methoxybenzyloxy) propanol 7 was prepared in a new method. They can be used as chiral synthons of lysophosphatidic acid and other compounds with asymmetric propanetriol backbone.
Asymmetrical Switch Costs in Children
Ellefson, Michelle R.; Shapiron, Laura R.; Chater, Nick
2006-01-01
Switching between tasks produces decreases in performance as compared to repeating the same task. Asymmetrical switch costs occur when switching between two tasks of unequal difficulty. This asymmetry occurs because the cost is greater when switching to the less difficult task than when switching to the more difficult task. Various theories about…
Asymmetric Synthesis via Chiral Aziridines
DEFF Research Database (Denmark)
Tanner, David Ackland; Harden, Adrian; Wyatt, Paul; Andersson, Pher G.; Johansson, Fredrik
1996-01-01
A series of chiral bis(aziridines) has been synthesised and evaluated as chelating ligands for a variety of asymmetric transformations mediated by metals [Os (dihydroxylation), Pd (allylic alkylation) Cu (cyclopropanation and aziridination, Li (1,2-addition of organolithiums to imines)]. In the...
Experimental Quantification of Asymmetric Einstein-Podolsky-Rosen Steering.
Sun, Kai; Ye, Xiang-Jun; Xu, Jin-Shi; Xu, Xiao-Ye; Tang, Jian-Shun; Wu, Yu-Chun; Chen, Jing-Ling; Li, Chuan-Feng; Guo, Guang-Can
2016-04-22
Einstein-Podolsky-Rosen (EPR) steering describes the ability of one observer to nonlocally "steer" the other observer's state through local measurements. EPR steering exhibits a unique asymmetric property; i.e., the steerability can differ between observers, which can lead to one-way EPR steering in which only one observer obtains steerability in the steering process. This property is inherently different from the symmetric concepts of entanglement and Bell nonlocality, and it has attracted increasing interest. Here, we experimentally demonstrate asymmetric EPR steering for a class of two-qubit states in the case of two measurement settings. We propose a practical method to quantify the steerability. We then provide a necessary and sufficient condition for EPR steering and clearly demonstrate one-way EPR steering. Our work provides new insight into the fundamental asymmetry of quantum nonlocality and has potential applications in asymmetric quantum information processing. PMID:27152778
Experimental Quantification of Asymmetric Einstein-Podolsky-Rosen Steering
Sun, Kai; Ye, Xiang-Jun; Xu, Jin-Shi; Xu, Xiao-Ye; Tang, Jian-Shun; Wu, Yu-Chun; Chen, Jing-Ling; Li, Chuan-Feng; Guo, Guang-Can
2016-04-01
Einstein-Podolsky-Rosen (EPR) steering describes the ability of one observer to nonlocally "steer" the other observer's state through local measurements. EPR steering exhibits a unique asymmetric property; i.e., the steerability can differ between observers, which can lead to one-way EPR steering in which only one observer obtains steerability in the steering process. This property is inherently different from the symmetric concepts of entanglement and Bell nonlocality, and it has attracted increasing interest. Here, we experimentally demonstrate asymmetric EPR steering for a class of two-qubit states in the case of two measurement settings. We propose a practical method to quantify the steerability. We then provide a necessary and sufficient condition for EPR steering and clearly demonstrate one-way EPR steering. Our work provides new insight into the fundamental asymmetry of quantum nonlocality and has potential applications in asymmetric quantum information processing.
Selfhealing of asymmetric Bessel-like modes
DEFF Research Database (Denmark)
Israelsen, Stine Møller; Rishøj, Lars Søgaard; Rottwitt, Karsten
2014-01-01
We numerically investigate asymmetric Bessel-like modes in an aircladding fiber. The selfhealing ability of asymmetric Bessel-like modes is demonstrated and quantified including the angular dependency of this ability.......We numerically investigate asymmetric Bessel-like modes in an aircladding fiber. The selfhealing ability of asymmetric Bessel-like modes is demonstrated and quantified including the angular dependency of this ability....
Marracci, Silvia; Michelotti, Valentina; Casola, Claudio; Giacoma, Cristina; Ragghianti, Matilde
2011-07-15
In many organisms, the specification of cell fate and the formation of embryonic axes depend on a proper distribution of maternal mRNAs during oogenesis. Asymmetrically localized determinants are required both for embryonic axes and germline determination in anuran amphibians. As a model system of these processes, we have used a species complex of the genus Pelophylax (Rana), characterized by a hybridogenetic reproduction that involves events of genome exclusion and endoreduplication during meiosis in both sexes. With the aim of characterizing the still largely unknown molecular events regulating Pelophylax gametogenesis, we have isolated in this animal model homologues of the deleted in AZoospermia-like (DAZl) and pumilio gene families (named RlDazl and RlPum1, respectively), which encode posttranscriptional regulators. Expression pattern analysis of these genes showed that RlDazl is exclusively expressed in gonadal tissues, whereas RlPum1 is expressed in both somatic tissues and gonads. In situ hybridization carried out on gonads revealed that the two transcripts were asymmetrically localized along the animal-vegetal (A-V) axis of oocytes. In particular, the RlDazl transcript progressively collected to the vegetal pole during oogenesis, whereas the RlPum1 mRNA was preferentially enriched at the animal hemisphere. In adult testes, RlDazl and RlPum1 were expressed in specific phases of spermatogenetic divisions as shown by immunostaining with anti-H3 phosphohistone antibody. Our results indicate that RlDazl and RlPum1 represent two early indicators of oocyte polarity in this hybridogenetic vertebrate model. Additionally, RlDazl share with vertebrate DAZ- like genes a germ cell-specific expression pattern. PMID:21344644
Asymmetric Stochastic Transport Models with {{U}}_q({su}(1,1)) Symmetry
Carinci, Gioia; Giardinà, Cristian; Redig, Frank; Sasamoto, Tomohiro
2016-04-01
By using the algebraic construction outlined in Carinci et al. (arXiv:1407.3367, 2014), we introduce several Markov processes related to the {{U}}_q({su}(1,1)) quantum Lie algebra. These processes serve as asymmetric transport models and their algebraic structure easily allows to deduce duality properties of the systems. The results include: (a) the asymmetric version of the Inclusion Process, which is self-dual; (b) the diffusion limit of this process, which is a natural asymmetric analogue of the and which turns out to have the Symmetric Inclusion Process as a dual process; (c) the asymmetric analogue of the KMP Process, which also turns out to have a symmetric dual process. We give applications of the various duality relations by computing exponential moments of the current.
Originally Asymmetric Dark Matter
Okada, Nobuchika; Seto, Osamu
2012-01-01
We propose a scenario with a fermion dark matter, where the dark matter particle used to be the Dirac fermion, but it takes the form of the Majorana fermion at a late time. The relic number density of the dark matter is determined by the dark matter asymmetry generated through the same mechanism as leptogenesis when the dark matter was the Dirac fermion. After efficient dark matter annihilation processes have frozen out, a phase transition of a scalar field takes place and generates Majorana ...
Domain-wall theory and nonstationarity in driven flow with exclusion
Stinchcombe, R. B.; de Queiroz, S. L. A.
2016-07-01
We study the dynamical evolution toward steady state of the stochastic nonequilibrium model known as the totally asymmetric simple exclusion process, in both uniform and nonuniform (staggered) one-dimensional systems with open boundaries. Domain-wall theory and numerical simulations are used and, where pertinent, their results are compared to existing mean-field predictions and exact solutions where available. For uniform chains we find that the inclusion of fluctuations inherent to the domain-wall formulation plays a crucial role in providing good agreement with simulations, which is severely lacking in the corresponding mean-field predictions. For alternating-bond chains the domain-wall predictions for the features of the phase diagram in the parameter space of injection and ejection rates turn out to be realized only in an incipient and quantitatively approximate way. Nevertheless, significant quantitative agreement can be found between several additional domain-wall theory predictions and numerics.
Cyclodextrins in Asymmetric and Stereospecific Synthesis
Directory of Open Access Journals (Sweden)
Fliur Macaev
2015-09-01
Full Text Available Since their discovery, cyclodextrins have widely been used as green and easily available alternatives to promoters or catalysts of different chemical reactions in water. This review covers the research and application of cyclodextrins and their derivatives in asymmetric and stereospecific syntheses, with their division into three main groups: (1 cyclodextrins promoting asymmetric and stereospecific catalysis in water; (2 cyclodextrins’ complexes with transition metals as asymmetric and stereospecific catalysts; and (3 cyclodextrins’ non-metallic derivatives as asymmetric and stereospecific catalysts. The scope of this review is to systematize existing information on the contribution of cyclodextrins to asymmetric and stereospecific synthesis and, thus, to facilitate further development in this direction.
Rectification of motion in nonlinear media with asymmetric random drive
International Nuclear Information System (INIS)
We consider moving particles in media with nonlinear friction and drive them by an asymmetric dichotomic Markov process. Due to different energy dissipations, during the forward and backward stroke, we obtain a mean non-vanishing directed flow of the particles. Starting with the stationary velocity distribution, we calculate the stationary current of particles, the variance and the relative variance in dependence on the degree of nonlinearity of the friction, on the asymmetry and for different strengths of friction. In two dimensions the particle performs diffusional motion, if in addition the direction of the asymmetric drive changes stochastically.
Climate agreements under limited participation, asymmetric information and market imperfections
Energy Technology Data Exchange (ETDEWEB)
Hagem, Cathrine
1996-12-31
This thesis relates to climate agreements and cost efficiency by analysing the formation of a system of quota leading to distributed discharge of emissions between countries. Main fields concerned are the greenhouse effect, the political process, efficient and cost-effective climate agreements, and climate agreements under limited participation, asymmetric information and market imperfections covering fields like limited participation in climate agreements, limited participation and indirect impact on non-participating countries` emissions, limited participation and direct impact on non-participating countries` emissions under asymmetric information, and non-competitive market for tradeable quotas. 166 refs., 7 tabs.
Smurfs have "fused" into the asymmetric division of stem cells
Institute of Scientific and Technical Information of China (English)
Steven Y. Cheng; Ying E. Zhang
2011-01-01
@@ The asymmetric cell division is the way in which a stem cell divides into one daughter stem cell and one differentiated daughter cell.This process is one of the key principles of developmental biology that ensures the perpetual supply of stem cells while allowing a particular cell lineage to be populated.During Drosophila oogenesis, the fate of the daughter stem cell produced from the asymmetric division of germline stem cells (GSCs) is specified by Decapentaplegic (Dpp), but the other daughter cell has almost equal access to the Dpp signal.
Exact solution of the totally asymmetric Oslo model
International Nuclear Information System (INIS)
Recently it has been found (Pruessner G and Jensen H J 2003 Phys. Rev. Lett. 91 244303) that a totally asymmetric variant of the Oslo model (Christensen K et al 1996 Phys. Rev. Lett. 77 107) represents the entire universality class of the Oslo model with anisotropy. The totally asymmetric model can be solved without scaling assumptions by finding recursively the eigenvectors of the Markov matrix, which can be suitably modified to produce the moment generating function of the relevant observable. This method should be applicable to many other stochastic processes
Limit process of stationary TASEP near the characteristic line
Baik, Jinho; Péché, Sandrine
2009-01-01
The totally asymmetric simple exclusion process (TASEP) on Z with the Bernoulli-rho measure as initial conditions, 0
Cooperative optical trapping in asymmetric plasmon nanocavity arrays.
Guo, Ling; Sun, Zhijun
2015-11-30
We propose a scheme using cooperative interaction of antiphase resonance modes to enhance optical trapping in plasmonic nanostructures. This is implemented with a subwavelength array of asymmetric binary nanogrooves (e.g. different depths) in metal. When damping and inter-coupling of antiphase fields in the nanogrooves are mediated satisfying a critical condition, light can be cooperatively trapped in the nanogrooves, demonstrating perfect absorption at nearly the intrinsic resonance frequency of the deeper nanogrooves. A harmonic oscillator model is developed to interpret the cooperative interaction processes. The phenomenon has been also implemented in asymmetric ternary nanogroove arrays. In terms of compositions and intra-coupling mechanisms, the asymmetric binary/ternary plasmonic nanostructure arrays are crystalline molecular-metamaterials, analogous to electronic crystals composed of covalence-bond molecules. PMID:26698759
Stable walking with asymmetric legs
International Nuclear Information System (INIS)
Asymmetric leg function is often an undesired side-effect in artificial legged systems and may reflect functional deficits or variations in the mechanical construction. It can also be found in legged locomotion in humans and animals such as after an accident or in specific gait patterns. So far, it is not clear to what extent differences in the leg function of contralateral limbs can be tolerated during walking or running. Here, we address this issue using a bipedal spring-mass model for simulating walking with compliant legs. With the help of the model, we show that considerable differences between contralateral legs can be tolerated and may even provide advantages to the robustness of the system dynamics. A better understanding of the mechanisms and potential benefits of asymmetric leg operation may help to guide the development of artificial limbs or the design novel therapeutic concepts and rehabilitation strategies.
Originally Asymmetric Dark Matter
Okada, Nobuchika
2012-01-01
We propose a scenario with a fermion dark matter, where the dark matter particle used to be the Dirac fermion, but it takes the form of the Majorana fermion at a late time. The relic number density of the dark matter is determined by the dark matter asymmetry generated through the same mechanism as leptogenesis when the dark matter was the Dirac fermion. After efficient dark matter annihilation processes have frozen out, a phase transition of a scalar field takes place and generates Majorana mass terms to turn the dark matter particle into the Majorana fermion. In order to address this scenario in detail, we propose two simple models. The first one is based on the Standard Model (SM) gauge group and the dark matter originates the $SU(2)_L$ doublet Dirac fermion, analogous to the Higgsino-like neutralino in supersymmetric models. We estimate the spin-independent/dependent elastic scattering cross sections of this late-time Majorana dark matter with a proton and find the possibility to discover it by the direct...
Asymmetric condensed dark matter
Aguirre, Anthony; Diez-Tejedor, Alberto
2016-04-01
We explore the viability of a boson dark matter candidate with an asymmetry between the number densities of particles and antiparticles. A simple thermal field theory analysis confirms that, under certain general conditions, this component would develop a Bose-Einstein condensate in the early universe that, for appropriate model parameters, could survive the ensuing cosmological evolution until now. The condensation of a dark matter component in equilibrium with the thermal plasma is a relativistic process, hence the amount of matter dictated by the charge asymmetry is complemented by a hot relic density frozen out at the time of decoupling. Contrary to the case of ordinary WIMPs, dark matter particles in a condensate must be lighter than a few tens of eV so that the density from thermal relics is not too large. Big-Bang nucleosynthesis constrains the temperature of decoupling to the scale of the QCD phase transition or above. This requires large dark matter-to-photon ratios and very weak interactions with standard model particles.
Time Asymmetric Quantum Mechanics
Directory of Open Access Journals (Sweden)
Arno R. Bohm
2011-09-01
Full Text Available The meaning of time asymmetry in quantum physics is discussed. On the basis of a mathematical theorem, the Stone-von Neumann theorem, the solutions of the dynamical equations, the Schrödinger equation (1 for states or the Heisenberg equation (6a for observables are given by a unitary group. Dirac kets require the concept of a RHS (rigged Hilbert space of Schwartz functions; for this kind of RHS a mathematical theorem also leads to time symmetric group evolution. Scattering theory suggests to distinguish mathematically between states (defined by a preparation apparatus and observables (defined by a registration apparatus (detector. If one requires that scattering resonances of width Γ and exponentially decaying states of lifetime τ=h/Γ should be the same physical entities (for which there is sufficient evidence one is led to a pair of RHS's of Hardy functions and connected with it, to a semigroup time evolution t_0≤t<∞, with the puzzling result that there is a quantum mechanical beginning of time, just like the big bang time for the universe, when it was a quantum system. The decay of quasi-stable particles is used to illustrate this quantum mechanical time asymmetry. From the analysis of these processes, we show that the properties of rigged Hilbert spaces of Hardy functions are suitable for a formulation of time asymmetry in quantum mechanics.
Asymmetrically coupled directed percolation systems
Noh, Jae Dong; Park, Hyunggyu
2005-01-01
We introduce a dynamical model of coupled directed percolation systems with two particle species. The two species $A$ and $B$ are coupled asymmetrically in that $A$ particles branch $B$ particles whereas $B$ particles prey on $A$ particles. This model may describe epidemic spreading controlled by reactive immunization agents. We study nonequilibrium phase transitions with focused attention to the multicritical point where both species undergo the absorbing phase transition simultaneously. In ...
Asymmetric information and macroeconomic dynamics
Hawkins, Raymond J.; Aoki, Masanao; Roy Frieden, B.
2010-09-01
We show how macroeconomic dynamics can be derived from asymmetric information. As an illustration of the utility of this approach we derive the equilibrium density, non-equilibrium densities and the equation of motion for the response to a demand shock for productivity in a simple economy. Novel consequences of this approach include a natural incorporation of time dependence into macroeconomics and a common information-theoretic basis for economics and other fields seeking to link micro-dynamics and macro-observables.
Entrepreneurship, Asymmetric Information and Unemployment
Robin Boadway; Nicolas Marceau; Maurice Marchand; Marianne Vigneault
1998-01-01
We examine how three sources of asymmetric information affect the supply of entrepreneurs and unemployment. In the first case, banks cannot observe entrepreneurs' risk of failure so ration credit. This increases the number of entrepreneurs and the level of unemployment. In the second case, firms cannot observe workers' effort so offer a wage above the market clearing one. This results in unemployment and too few entrepreneurs. The final case arises when firms cannot observe workers' abilities...
Asymmetric Microscopic Driving Behavior Theory
Yeo, Hwasoo
2008-01-01
Numerous theories on traffic have been developed as traffic congestion gains more and more interest in our daily life. To model traffic phenomena, many traffic theorists have adopted theories from other fields such as fluid mechanics and thermodynamics. However, their efforts to model the traffic at a microscopic level have not been successful yet. Therefore, to overcome the limitations of the existing theories we propose a microscopic asymmetric traffic theory based on analysis of individual...
Effciency Concern under Asymmetric Information
Winschel, Evguenia; Zahn, Philipp
2012-01-01
Experimental evidence from simple distribution games supports the view that some individuals have a concern for the effciency of allocations. This motive could be important for the implementation of economic policy proposals. In a typical lab experiment, however, individuals have much more information available than outside the lab. We conduct a lab experiment to test whether asymmetric information influences prosocial behavior in a simple non-strategic interaction. In our setting, a dictator...
Efficient algorithms for Asymmetric Flow Field Flow Fractionation
Nagapetyan, Tigran
2014-01-01
This thesis is devoted to the modeling and simulation of Asymmetric Flow Field Flow Fractionation, which is a technique for separating particles of submicron scale. This process is a part of large family of Field Flow Fractionation techniques and has a very broad range of industrial applications, e. g. in microbiology, chemistry, pharmaceutics, environmental analysis. Mathematical modeling is crucial for this process, as due to the own nature of the process, lab ex- periments are difficult...
Continuous microfluidic fabrication of synthetic asymmetric vesicles.
Lu, Li; Schertzer, Jeffrey W; Chiarot, Paul R
2015-09-01
We report on a novel microfluidic strategy for the continuous fabrication of monodisperse asymmetric vesicles with customized membrane composition, size, and luminal content. The microfluidic device encompasses a triangular post region and two flow-focusing regions. The major steps involved in the vesicle fabrication process include: (1) forming highly uniform water emulsions in an oil/inner-leaflet-lipid solution, (2) replacing the inner-leaflet-lipid solution with an outer-leaflet-lipid solution inside the microchannel network, (3) forming water-in-oil-in-water double emulsions, and (4) extracting excess oil/outer-leaflet-lipid solution from the double emulsions. Bilayer membrane asymmetry and unilamellarity are evaluated using a fluorescence quenching assay and a transmembrane protein insertion assay, respectively. Our approach addresses many of the deficiencies found in existing technologies for building vesicles, and yields strong membrane asymmetry. The ability to create and sustain membrane asymmetry is an important feature, as it is a characteristic of nearly all natural membranes. Over 80% of the vesicles remain stable for at least 6 weeks and the membrane asymmetry is maintained for over 30 hours. The asymmetric vesicles built using this strategy are collected off-chip and hold the potential to be used as model systems in membrane biology or as vehicles for drug delivery. PMID:26220822
João Leão
2008-01-01
This paper examines the use of exclusive dealing agreements to prevent the entry of rival firms. An exclusive dealing agreement is a contract between a buyer and a seller where the buyer commits to buy a good exclusively from the seller. One main concern of the literature is to explain how an incumbent seller is able to persuade the buyers to sign an exclusive dealing agreement that deters the entry of a more efficient rival seller. We propose a new explanation when the buyers are downstream ...
Directory of Open Access Journals (Sweden)
Kelsom Corey
2012-11-01
Full Text Available Abstract Asymmetric cell division is a developmental process utilized by several organisms. On the most basic level, an asymmetric division produces two daughter cells, each possessing a different identity or fate. Drosophila melanogaster progenitor cells, referred to as neuroblasts, undergo asymmetric division to produce a daughter neuroblast and another cell known as a ganglion mother cell (GMC. There are several features of asymmetric division in Drosophila that make it a very complex process, and these aspects will be discussed at length. The cell fate determinants that play a role in specifying daughter cell fate, as well as the mechanisms behind setting up cortical polarity within neuroblasts, have proved to be essential to ensuring that neurogenesis occurs properly. The role that mitotic spindle orientation plays in coordinating asymmetric division, as well as how cell cycle regulators influence asymmetric division machinery, will also be addressed. Most significantly, malfunctions during asymmetric cell division have shown to be causally linked with neoplastic growth and tumor formation. Therefore, it is imperative that the developmental repercussions as a result of asymmetric cell division gone awry be understood.
Ikedo, Mikaru; Mori, Masanobu; Kurachi, Kazumasa; Hu, Wenzhi; Tanaka, Kazuhiko
2006-01-01
The selective and simultaneous ion-exclusion chromatography (IEC) with UV-detection on a weakly acidic cation-exchange resin column in the H+ -form (TSKgel Super IC-A/C) was developed and applied for the simultaneous determination of phosphate and silicate ions as the water quality parameters required for optimizing the water-leaching process for ceramics glaze raw materials of natural origin including feldspar, woods-ash, and straw-ash. Phosphate and silicate ions in these water-leaching process water samples were separated selectively from the coexisting anions such as sulfate, chloride, nitrate and carbonate ions, based on the ion-exclusion separation mechanism. They were detected selectively and simultaneously by a postcolumn derivatization with molybdenum-yellow using the UV-detector. Under the optimized separation and detection conditions (eluent, 0-1 mM sulfuric acid; reactant, 10 mM sodium molybdate-25 mM sulfuric acid; detector, UV at 370 nm; temperature, 45 degrees C), the linearity of calibration was in the range 0.1 - 10 ppm for both phosphate and silicate ions, and the detection limits at S/N = 3 were 2.58 ppb for silicate ions and 4.75 ppb for phosphate ions. The effectiveness of this method was demonstrated in practical applications to the water-leaching process for some ceramics glaze raw materials. PMID:16429785
Incompressibility of asymmetric nuclear matter
International Nuclear Information System (INIS)
Using an isospin- and momentum-dependent modified Gogny (MDI) interaction, the Skyrme-Hartree-Fock (SHF) approach, and a phenomenological modified Skyrme-like (MSL) model, we have studied the incompressibility Ksat(δ) of isospin asymmetric nuclear matter at its saturation density. Our results show that in the expansion of Ksat(δ) in powers of isospin asymmetry δ, i.e., Ksat(δ) = K0 + Ksat,2δ2 + Ksat,4δ4 + O(δ6), the magnitude of the 4th-order Ksat,4 parameter is generally small. The 2nd-order Ksat,2 parameter thus essentially characterizes the isospin dependence of the incompressibility of asymmetric nuclear matter at saturation density. Furthermore, the Ksat,2 can be expressed as Ksat,2 = Ksym – 6L – J0/K0 L in terms of the slope parameter L and the curvature parameter Ksym of the symmetry energy and the third-order derivative parameter J0 of the energy of symmetric nuclear matter at saturation density, and we find the higher order J0 contribution to Ksat,2 generally cannot be neglected. Also, we have found a linear correlation between Ksym and L as well as between J0/K0 and K0. Using these correlations together with the empirical constraints on K0 and L, the nuclear symmetry energy Esym(ρ0) at normal nuclear density, and the nucleon effective mass, we have obtained an estimated value of Ksat,2 = -370 ± 120 MeV for the 2nd-order parameter in the isospin asymmetry expansion of the incompressibility of asymmetric nuclear matter at its saturation density. (author)
Enhanced Information Exclusion Relations
Xiao, Yunlong; Jing, Naihuan; Li-Jost, Xianqing
2016-01-01
In Hall's reformulation of the uncertainty principle, the entropic uncertainty relation occupies a core position and provides the first nontrivial bound for the information exclusion principle. Based upon recent developments on the uncertainty relation, we present new bounds for the information exclusion relation using majorization theory and combinatoric techniques, which reveal further characteristic properties of the overlap matrix between the measurements.
Asymmetric Information and Consumer Demand
Ismagilova G. N.; Danilina E. I.; Gafurov I. R.; Ismagilov R. I.; Safiullin L. N.
2014-01-01
In the paper study the peculiarities of the formation the consumer demand for durable goods, the so-called «experience goods» in markets with asymmetric information. In the known literature sources studying of the demand is based on the assumption that at the moment of the purchase of goods and services people know exactly what price they are willing to pay for them and what utility they are going to obtain using those goods and services. Consider the signal model in which the initial price a...
Transient Stability During Asymmetrical Faults
Couturier, Nicolas
2015-01-01
This research project has been conducted at RTE in order to study the transient stability after asymmetrical faults. When three-phase short-circuits occur in a network, almost all the electrical power is lost on the relevant line(s). Among all short-circuit types, it is the most drastic event and the issue has to be solved very quickly. But oddly, it is also the easiest problem to solve mathematically speaking. This comes from the fact that the system stays balanced, and equations can be simp...
Phase equilibria in asymmetric mixtures
International Nuclear Information System (INIS)
The simplified version of the Perturbed Hard-Chain Theory (SPHCT) is used to compute the phase equilibria and Henry's constants for mixtures in which the molecules are highly asymmetric both in shape and in the intermolecular potential. These mixtures include binary systems such as CO2/hydrocarbons and hydrocarbons/hydrocarbons, which are of particular interest for the oil industry. For this type of mixtures a single parameter (which is calculated from available experimental data of liquid-vapor equilibrium) is introduced. The approach yields results which compare well with the experimental behavior reported in the literature (Author)
Asymmetric morphology of the propagating jet
Hardee, Philip E.; Norman, Michael L.
1990-12-01
Simulations of slab jets propagating in constant atmospheres are reported for a range of jet velocities and Mach numbers. At early times, the jet maintains approximate axisymmetry within a backflowing cocoon. When the jet has penetrated farther into the external medium, the symmetry is broken by sideways oscillation and the leading edge of the jet moves about within a growing lobe. The oscillation results from nonlinear resonant amplification of the initial perturbation by the Kelvin-Helmholtz instability. Finally, the jet flaps chaotically within the growing lobe. The flapping is driven by turbulent vortices in the lobe. The basic picture of Scheuer's (1982) 'dentist's drill' model of the physical processes underlying asymmetric morphologies in radio galaxies is confirmed. The fluid motions in the lobe are found to govern the location of the drill bit. The morphology is time-dependent on relatively short time scales.
Tripartite fully asymmetric universal quantum cloning
International Nuclear Information System (INIS)
Full text: We investigate the universal asymmetric cloning of states in a Hilbert space of arbitrary dimension d. We derive the class of optimal and fully asymmetric universal 1 → 3 cloners, which produce three copies, each having a different fidelity. A simple parametric expression for the maximum achievable cloning fidelity triplets will be provided. As a side-product, we also prove the optimality of the 1 → 2 asymmetric cloning machines that have been proposed in the literature. (author)
Enhanced Asymmetric Bilinear Model for Face Recognition
Wenjuan Gong; Weishan Zhang; Jordi Gonzàlez; Yan Ren; Zhen Li
2015-01-01
Bilinear models have been successfully applied to separate two factors, for example, pose variances and different identities in face recognition problems. Asymmetric model is a type of bilinear model which models a system in the most concise way. But seldom there are works exploring the applications of asymmetric bilinear model on face recognition problem with illumination changes. In this work, we propose enhanced asymmetric model for illumination-robust face recognition. Instead of initiali...
Positioning of polarity formation by extracellular signaling during asymmetric cell division.
Seirin Lee, Sungrim
2016-07-01
Anterior-posterior (AP) polarity formation of cell membrane proteins plays a crucial role in determining cell asymmetry, which ultimately generates cell diversity. In Caenorhabditis elegans, a single fertilized egg cell (P0), its daughter cell (P1), and the germline precursors (P2 and P3 cells) form two exclusive domains of different PAR proteins on the membrane along the anterior-posterior axis. However, the phenomenon of polarity reversal has been observed in which the axis of asymmetric cell division of the P2 and P3 cells is formed in an opposite manner to that of the P0 and P1 cells. The extracellular signal MES-1/SRC-1 has been shown to induce polarity reversal, but the detailed mechanism remains elusive. Here, using a mathematical model, I explore the mechanism by which MES-1/SRC-1 signaling can induce polarity reversal and ultimately affect the process of polarity formation. I show that a positive correlation between SRC-1 and the on-rate of PAR-2 is the essential mechanism underlying polarity reversal, providing a mathematical basis for the orientation of cell polarity patterns. PMID:27086039
DEFF Research Database (Denmark)
Søndergaard, Dorte Marie
2014-01-01
The purpose of this chapter is to introduce a thinking technology that will foster a deeper understanding of some of the more complicated social processes that emerge in the day-to-day functioning of a school classroom, with a particular focus on the interactions that culminate in bullying . The ...... transformative effects of the many entangling forces that are involved in the enactment of bullying practices, and the chapter ends with a description of a few of these forces and how they may entangle.......The purpose of this chapter is to introduce a thinking technology that will foster a deeper understanding of some of the more complicated social processes that emerge in the day-to-day functioning of a school classroom, with a particular focus on the interactions that culminate in bullying . The...... concepts I work with are the need for belonging, social exclusion anxiety and the production of contempt and dignity by both children and adults. I develop a new definition of bullying, drawing upon Judith Butler’s (1999) concept of ‘abjection’ as well as Karen Barad’s concept of ‘intra-acting forces...
Egalitarian Equivalence under Asymmetric Information
Geoffroy de Clippel; David Pérez-Castrillo and David Wettstein
2015-01-01
We propose a definition of egalitarian equivalence that extends Pazner and Schmeidler's (1978) concept to environments with incomplete information. If every feasible allocation rule can be implemented by an incentive compatible mechanism (as, for instance, in the case of non-exclusive information), then interim egalitarian equivalence and interim incentive efficiency remain compatible, as they were under complete information. When incentive constraints are more restrictive, on the other hand,...
Egalitarian equivalence under asymmetric information
DE CLIPPEL, Geoffroy; Pérez-Castrillo, David; WETTSTEIN, David
2010-01-01
We propose a definition of egalitarian equivalence that extends Pazner and Schmeidler's (1978) concept to environments with incomplete information. If every feasible allocation rule can be implemented by an incentive compatible mechanism (as, for instance, in the case of non-exclusive information), then interim egalitarian equivalence and interim incentive efficiency remain compatible, as they were under complete information. When incentive constraints are more restrictive, on the other hand,...
Asymmetric AgPd-AuNR heterostructure with enhanced photothermal performance and SERS activity
Zhang, Han; Liu, Zeke; Kang, Xiaolin; Guo, Jun; Ma, Wanli; Cheng, Si
2016-01-01
Most as-reported nanostructures through galvanic replacement reactions are still symmetric hollow structures, until now. Asymmetric structures fabricated through a galvanic replacement reaction have been rarely reported. However, asymmetric heterostructures can generally lead to new intriguing properties through asymmetric synergistic coupling. Here, we report a simple synthesis of an asymmetric one-ended AgPd bimetal on Au nanorods (AuNR) by combining a galvanic replacement reaction with an Ostwald ripening process. The morphological evolution from a nanodumbbell to a dandelion structure is thoroughly investigated. The unique asymmetric AgPd-AuNR heterostructures possess the required plasmonic performance and avoid strong damping caused by the poor plasmonic metal Pd, resulting in a superior photothermal heating performance and enhanced SERS sensitivity for in situ monitoring of a catalytic reaction compared with the symmetric counterparts.Most as-reported nanostructures through galvanic replacement reactions are still symmetric hollow structures, until now. Asymmetric structures fabricated through a galvanic replacement reaction have been rarely reported. However, asymmetric heterostructures can generally lead to new intriguing properties through asymmetric synergistic coupling. Here, we report a simple synthesis of an asymmetric one-ended AgPd bimetal on Au nanorods (AuNR) by combining a galvanic replacement reaction with an Ostwald ripening process. The morphological evolution from a nanodumbbell to a dandelion structure is thoroughly investigated. The unique asymmetric AgPd-AuNR heterostructures possess the required plasmonic performance and avoid strong damping caused by the poor plasmonic metal Pd, resulting in a superior photothermal heating performance and enhanced SERS sensitivity for in situ monitoring of a catalytic reaction compared with the symmetric counterparts. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07333b
Aberrations in asymmetrical electron lenses
International Nuclear Information System (INIS)
Starting from well established knowledge in light-optics we explore the question if electron-optical aberration can be improved in asymmetrical electron lenses. We show that spherical as well as chromatic aberration coefficients are reduced in asymmetric electrostatic einzel lenses when the center electrode is moved away from the center position towards the entrance electrode. Relative improvements up to 40% for both the chromatic and the spherical aberration coefficients can be obtained. We use analytical and numerical calculations to confirm this result for exemplary cases of a lens with fixed length and working distance. The agreement of the two calculation methods is very good. We then derive an estimate for the electron-optical aberration coefficients from light-optics. The derived expressions for chromatic and spherical aberrations are somewhat simpler than the ones derived from electron-optics as they involve integrals only over the electrostatic potential, not over the electron paths. The estimated formulas still agree well with the electron optical calculations. Overall, we are tempted to suggest that the enormous knowledge base of light optics can provide considerable guidance for electron-optical applications. -- Highlights: ► Develops the analogy between light and electron optics in aberration calculations. ► Optimized spherical and chromatic aberrations for an electrostatic einzel lens. ► Comparison between analytic and numerical aberration calculations.
Aberrations in asymmetrical electron lenses.
Fitzgerald, J P S; Word, R C; Könenkamp, R
2012-08-01
Starting from well established knowledge in light-optics we explore the question if electron-optical aberration can be improved in asymmetrical electron lenses. We show that spherical as well as chromatic aberration coefficients are reduced in asymmetric electrostatic einzel lenses when the center electrode is moved away from the center position towards the entrance electrode. Relative improvements up to 40% for both the chromatic and the spherical aberration coefficients can be obtained. We use analytical and numerical calculations to confirm this result for exemplary cases of a lens with fixed length and working distance. The agreement of the two calculation methods is very good. We then derive an estimate for the electron-optical aberration coefficients from light-optics. The derived expressions for chromatic and spherical aberrations are somewhat simpler than the ones derived from electron-optics as they involve integrals only over the electrostatic potential, not over the electron paths. The estimated formulas still agree well with the electron optical calculations. Overall, we are tempted to suggest that the enormous knowledge base of light optics can provide considerable guidance for electron-optical applications. PMID:22206603
Excitons in asymmetric quantum wells
Grigoryev, P. S.; Kurdyubov, A. S.; Kuznetsova, M. S.; Ignatiev, I. V.; Efimov, Yu. P.; Eliseev, S. A.; Petrov, V. V.; Lovtcius, V. A.; Shapochkin, P. Yu.
2016-09-01
Resonance dielectric response of excitons is studied for the high-quality InGaAs/GaAs heterostructures with wide asymmetric quantum wells (QWs). To highlight effects of the QW asymmetry, we have grown and studied several heterostructures with nominally square QWs as well as with triangle-like QWs. Several quantum confined exciton states are experimentally observed as narrow exciton resonances. A standard approach for the phenomenological analysis of the profiles is generalized by introducing different phase shifts for the light waves reflected from the QWs at different exciton resonances. Good agreement of the phenomenological fit to the experimentally observed exciton spectra for high-quality structures allowed us to reliably obtain parameters of the exciton resonances: the exciton transition energies, the radiative broadenings, and the phase shifts. A direct numerical solution of the Schrödinger equation for the heavy-hole excitons in asymmetric QWs is used for microscopic modeling of the exciton resonances. Remarkable agreement with the experiment is achieved when the effect of indium segregation is taken into account. The segregation results in a modification of the potential profile, in particular, in an asymmetry of the nominally square QWs.
ASYMMETRIC SOLAR POLAR FIELD REVERSALS
International Nuclear Information System (INIS)
The solar polar fields reverse because magnetic flux from decaying sunspots moves toward the poles, with a preponderance of flux from the trailing spots. If there is a strong asymmetry, in the sense that most activity is in the northern hemisphere, then that excess flux will move toward the north pole and reverse that pole first. If there is more activity in the south later on, then that flux will help to reverse the south pole. In this way, two humps in the solar activity and a corresponding difference in the time of reversals develop (in the ideal case). Such a difference was originally noted in the very first observation of polar field reversal just after the maximum of the strongly asymmetric solar cycle 19, when the southern hemisphere was most active before sunspot maximum and the south pole duly reversed first, followed by the northern hemisphere more than a year later, when that hemisphere became most active. Solar cycles since then have had the opposite asymmetry, with the northern hemisphere being most active before solar maximum. We show that polar field reversals for these cycles have all happened in the north first, as expected. This is especially noteworthy for the present solar cycle 24. We suggest that the association of two or more peaks of solar activity when separated by hemispheres with correspondingly different times of polar field reversals is a general feature of the cycle, and that asymmetric polar field reversals are simply a consequence of the asymmetry of solar activity.
Asymmetric Laguerre-Gaussian beams
Kovalev, A. A.; Kotlyar, V. V.; Porfirev, A. P.
2016-06-01
We introduce a family of asymmetric Laguerre-Gaussian (aLG) laser beams. The beams have been derived via a complex-valued shift of conventional LG beams in the Cartesian plane. While propagating in a uniform medium, the first bright ring of the aLG beam becomes less asymmetric and the energy is redistributed toward peripheral diffraction rings. The projection of the orbital angular momentum (OAM) onto the optical axis is calculated. The OAM is shown to grow quadratically with increasing asymmetry parameter of the aLG beam, which equals the ratio of the shift to the waist radius. Conditions for the OAM becoming equal to the topological charge have been derived. For aLG beams with zero radial index, we have deduced an expression to define the intensity maximum coordinates and shown the crescent-shaped intensity pattern to rotate during propagation. Results of the experimental generation and rotation of aLG beams agree well with theoretical predictions.
Active matter on asymmetric substrates
Olson Reichhardt, C. J.; Drocco, J.; Mai, T.; Wan, M. B.; Reichhardt, C.
2011-10-01
For collections of particles in a thermal bath interacting with an asymmetric substrate, it is possible for a ratchet effect to occur where the particles undergo a net dc motion in response to an ac forcing. Ratchet effects have been demonstrated in a variety of systems including colloids as well as magnetic vortices in type-II superconductors. Here we examine the case of active matter or self-driven particles interacting with asymmetric substrates. Active matter systems include self-motile colloidal particles undergoing catalysis, swimming bacteria, artificial swimmers, crawling cells, and motor proteins. We show that a ratchet effect can arise in this type of system even in the absence of ac forcing. The directed motion occurs for certain particle-substrate interaction rules and its magnitude depends on the amount of time the particles spend swimming in one direction before turning and swimming in a new direction. For strictly Brownian particles there is no ratchet effect. If the particles reflect off the barriers or scatter from the barriers according to Snell's law there is no ratchet effect; however, if the particles can align with the barriers or move along the barriers, directed motion arises. We also find that under certain motion rules, particles accumulate along the walls of the container in agreement with experiment. We also examine pattern formation for synchronized particle motion. We discuss possible applications of this system for self-assembly, extracting work, and sorting as well as future directions such as considering collective interactions and flocking models.
Some Remarks on Asymmetric Syntheses from Recent Studies
Baba, Naomichi
1990-01-01
Some asymmetric syntheses were presented here and discussed briefly including NADH model reactions, phase transfer-catalyzed asymmetric epoxidation, enantiotopic group-selective hydrolysis of a malonic anhydride with alkoxide anion, intramolecular acid-catalyzed lactonizations, catalytic asymmetric Diels-Alder synthesis, asymmetric aldol condensation, chiral homoallyl alcohol synthesis, asymmetric addition of diethylzinc to aldehyde, kinetic resolution of racemic hydroperoxides and binaphthol...
Asymmetric facial skin viscoelasticity during climacteric aging
Directory of Open Access Journals (Sweden)
Piérard GE
2014-04-01
Full Text Available Gérald E Piérard,1 Trinh Hermanns-Lê,1 Ulysse Gaspard,2 Claudine Piérard-Franchimont11Laboratory of Skin Bioengineering and Imaging, Department of Clinical Sciences, University of Liège, 2Department of Gynecology and Obstetrics, University Hospital of Liège, Liège, BelgiumBackground: Climacteric skin aging affects certain biophysical characteristics of facial skin. The purpose of the present study was to assess the symmetric involvement of the cheeks in this stage of the aging process.Methods: Skin viscoelasticity was compared on both cheeks in premenopausal and post-menopausal women with indoor occupational activities somewhat limiting the influence of chronic sun exposure. Eighty-four healthy women comprising 36 premenopausal women and 48 early post-menopausal women off hormone replacement therapy were enrolled in two groups. The tensile characteristics of both cheeks were tested and compared in each group. A computerized suction device equipped with a 2 mm diameter hollow probe was used to derive viscoelasticity parameters during a five-cycle procedure of 2 seconds each. Skin unfolding, intrinsic distensibility, biological elasticity, and creep extension were measured.Results: Both biological elasticity and creep extension were asymmetric on the cheeks of the post-menopausal women. In contrast, these differences were more discrete in the premenopausal women.Conclusion: Facial skin viscoelasticity appeared to be asymmetric following menopause. The possibility of asymmetry should be taken into account in future studies of the effects of hormone replacement therapy and any antiaging procedure on the face in menopausal women.Keywords: climacteric aging, biomechanics, photoaging, skin unfolding, biological elasticity, skin tensile properties
Model of reversible vesicular transport with exclusion
Bressloff, Paul C.; Karamched, Bhargav R.
2016-08-01
A major question in neurobiology concerns the mechanics behind the motor-driven transport and delivery of vesicles to synaptic targets along the axon of a neuron. Experimental evidence suggests that the distribution of vesicles along the axon is relatively uniform and that vesicular delivery to synapses is reversible. A recent modeling study has made explicit the crucial role that reversibility in vesicular delivery to synapses plays in achieving uniformity in vesicle distribution, so called synaptic democracy (Bressloff et al 2015 Phys. Rev. Lett. 114 168101). In this paper we generalize the previous model by accounting for exclusion effects (hard-core repulsion) that may occur between molecular motor-cargo complexes (particles) moving along the same microtubule track. The resulting model takes the form of an exclusion process with four internal states, which distinguish between motile and stationary particles, and whether or not a particle is carrying vesicles. By applying a mean field approximation and an adiabatic approximation we reduce the system of ODEs describing the evolution of occupation numbers of the sites on a 1D lattice to a system of hydrodynamic equations in the continuum limit. We find that reversibility in vesicular delivery allows for synaptic democracy even in the presence of exclusion effects, although exclusion does exacerbate nonuniform distributions of vesicles in an axon when compared with a model without exclusion. We also uncover the relationship between our model and other models of exclusion processes with internal states.
Asymmetric sequential Landau-Zener dynamics of Bose condensed atoms in a cavity
Huang, Jiahao; Qin, Xizhou; Zhong, Honghua; Lee, Chaohong
2016-01-01
We explore the asymmetric sequential Landau-Zener (LZ) dynamics in an ensemble of interacting Bose condensed two-level atoms coupled with a cavity field. Assuming the couplings between all atoms and the cavity field are identical, the interplay between atom-atom interaction and detuning may lead to a series of LZ transitions. Unlike the conventional sequential LZ transitions, which are symmetric to the zero detuning, the LZ transitions of Bose condensed atoms in a cavity field are asymmetric and sensitively depend on the photon number distribution of the cavity. In LZ processes involving single excitation numbers, both the variance of the relative atom number and the step slope of the sequential population ladder are asymmetric, and the asymmetry become more significant for smaller excitation numbers. Furthermore, in LZ processes involving multiple excitation numbers, there may appear asymmetric population ladders with decreasing step heights. During a dynamical LZ process, due to the atom-cavity coupling, th...
Condensation on Slippery Asymmetric Bumps
Park, Kyoo-Chul; He, Neil; Aizenberg, Joanna
2015-01-01
Bumps are omnipresent from human skin to the geological structures on planets, which offer distinct advantages in numerous phenomena including structural color, drag reduction, and extreme wettability. Although the topographical parameters of bumps such as radius of curvature of convex regions significantly influence various phenomena including anti-reflective structures and contact time of impacting droplets, the effect of the detailed bump topography on growth and transport of condensates have not been clearly understood. Inspired by the millimetric bumps of the Namib Desert beetle, here we report the identified role of radius of curvature and width of bumps with homogeneous surface wettability in growth rate, coalescence and transport of water droplets. Further rational design of asymmetric convex topography and synergetic combination with slippery coating simultaneously enable self-transport, leading to unseen five-fold higher growth rate and an order of magnitude faster shedding time of droplets compared...
Asymmetric diffusion of cosmic rays
Medvedev, Mikhail V
2015-01-01
Cosmic ray propagation is diffusive because of pitch angle scattering by waves. We demonstrate that if the high-amplitude magnetohydrodynamic turbulence with $\\tilde B/\\langle B\\rangle \\sim 1$ is present on top of the mean field gradient, the diffusion becomes asymmetric. As an example, we consider the vertical transport of cosmic rays in our Galaxy propagating away from a point-like source. We solve this diffusion problem analytically using a one-dimensional Markov chain analysis. We obtained that the cosmic ray density markedly differs from the standard diffusion prediction and has a sizable effect on their distribution throughout the galaxy. The equation for the continuous limit is also derived, which shows limitations of the convection-diffusion equation.
New asymmetric quantum codes over Fq
Ma, Yuena; Feng, Xiaoyi; Xu, Gen
2016-07-01
Two families of new asymmetric quantum codes are constructed in this paper. The first family is the asymmetric quantum codes with length n=qm-1 over Fq, where qge 5 is a prime power. The second one is the asymmetric quantum codes with length n=3m-1. These asymmetric quantum codes are derived from the CSS construction and pairs of nested BCH codes. Moreover, let the defining set T1=T2^{-q}, then the real Z-distance of our asymmetric quantum codes are much larger than δ _max+1, where δ _max is the maximal designed distance of dual-containing narrow-sense BCH code, and the parameters presented here have better than the ones available in the literature.
Jolie, Ruben P; Duvetter, Thomas; Verlinde, Philippe H C J; Van Buggenhout, Sandy; Van Loey, Ann M; Hendrickx, Marc E
2009-12-01
A size exclusion chromatography (HPSEC) method was implemented to study complex formation between carrot pectin methylesterase (PME) and its inhibitor (PMEI) from kiwi fruit in the context of traditional thermal and novel high-pressure processing. Evidence was gained that both thermal and high-pressure treatments of PME give rise to two distinct enzyme subpopulations: a catalytically active population, eluting from the size exclusion column, and an inactive population, aggregated and excluded from the column. When mixing a partly denatured PME sample with a fixed amount of PMEI, a PME-PMEI complex peak was observed on HPSEC, of which the peak area was highly correlated with the residual enzyme activity of the corresponding PME sample. This observation indicates complex formation to be restricted to the active PME fraction. When an equimolar mixture of PME and PMEI was subjected to either a thermal or a high-pressure treatment, marked differences were observed. At elevated temperature, enzyme and inhibitor remained united and aggregated as a whole, thus gradually disappearing from the elution profile. Conversely, elevated pressure caused the dissociation of the PME-PMEI complexes, followed by a separate action of pressure on enzyme and inhibitor. Remarkably, PMEI appeared to be pressure-resistant when compressed at acidic pH (ca. 4). PMID:19908835
Exclusive scattering off the deuteron
International Nuclear Information System (INIS)
Exclusive processes are a special class of processes giving insight into the inner structure of hadrons. In this thesis we consider two exclusive processes and compute their total cross sections as well as the beam charge and beam polarization asymmetries for different kinematical constraints. These calculations o er the opportunity to get access to the nonperturbative GPDs. Theoretically they can be described with the help of models. The rst process we investigate contains a GPD of the pion, which is basically unknown so far. We include different models and make predictions for observables that could in principle be measured at HERMES at DESY and CLAS at JLab. The second process we consider is electron-deuteron scattering in the kinematical range where the deuteron breaks up into a proton and a neutron. This can be used to investigate the neutron, which cannot be taken as a target due to its lifetime of approximately 15 minutes. For the calculation of the electron-deuteron cross section we implement models for the proton and neutron GPDs. Once there are experimental data available our calculations are ready for comparison. (orig.)
Exclusive scattering off the deuteron
Energy Technology Data Exchange (ETDEWEB)
Amrath, D.
2007-12-15
Exclusive processes are a special class of processes giving insight into the inner structure of hadrons. In this thesis we consider two exclusive processes and compute their total cross sections as well as the beam charge and beam polarization asymmetries for different kinematical constraints. These calculations o er the opportunity to get access to the nonperturbative GPDs. Theoretically they can be described with the help of models. The rst process we investigate contains a GPD of the pion, which is basically unknown so far. We include different models and make predictions for observables that could in principle be measured at HERMES at DESY and CLAS at JLab. The second process we consider is electron-deuteron scattering in the kinematical range where the deuteron breaks up into a proton and a neutron. This can be used to investigate the neutron, which cannot be taken as a target due to its lifetime of approximately 15 minutes. For the calculation of the electron-deuteron cross section we implement models for the proton and neutron GPDs. Once there are experimental data available our calculations are ready for comparison. (orig.)
Enhanced Information Exclusion Relations
Xiao, Yunlong; Jing, Naihuan; Li-Jost, Xianqing
2016-01-01
In Hall’s reformulation of the uncertainty principle, the entropic uncertainty relation occupies a core position and provides the first nontrivial bound for the information exclusion principle. Based upon recent developments on the uncertainty relation, we present new bounds for the information exclusion relation using majorization theory and combinatoric techniques, which reveal further characteristic properties of the overlap matrix between the measurements. PMID:27460975
Exclusion, employment and opportunity
Atkinson, Tony; Hills, John
1998-01-01
The relationships between employment, education, opportunity, social exclusion and poverty are central to current policy debates. Atkinson argues that the concepts of poverty, unemployment and social exclusion are closely related, but are not the same. People may be poor without being socially excluded, and vice versa. Unemployment may cause poverty, but this can be prevented. Equally, marginal jobs do not ensure social inclusion. Britton argues that convential economic analysis misses a key ...
Localization of Asymmetric Brain Function in Emotion and Depression
Herrington, John D.; Heller, Wendy; Mohanty, Aprajita; Engels, Anna S.; Banich, Marie T.; Webb, Andrew G.; Miller, Gregory A.
2011-01-01
Although numerous EEG studies have shown that depression is associated with abnormal functional asymmetries in frontal cortex, fMRI and PET studies have largely failed to identify specific brain areas showing this effect. The present study tested the hypothesis that emotion processes are related to asymmetric patterns of fMRI activity, particularly within dorsolateral prefrontal cortex (DLPFC). Eleven depressed and 18 control participants identified the color in which pleasant, neutral, and unpleasant words were printed. Both groups showed a leftward lateralization for pleasant words in DLPFC. In a neighboring DLPFC area, the depression group showed more right-lateralized activation than controls, replicating EEG findings. These data confirm that emotional stimulus processing and trait depression are associated with asymmetric brain functions in distinct subregions of the DLPFC that may go undetected unless appropriate analytic procedures are used. PMID:20070577
Tunable asymmetric mode conversion using the dark-mode of three-mode waveguide system.
Kim, Joonsoo; Lee, Seung-Yeol; Lee, Yohan; Kim, Hwi; Lee, Byoungho
2014-11-17
A design scheme for low-reflection asymmetric mode conversion structure in three-mode waveguide system is proposed. By using a dark-mode of three-mode system, which can be interpreted in terms of destructive interference of transition amplitudes, the transmission characteristics for forward and backward directions can be designed separately. After explanation of the proposed design scheme, we demonstrate an example of asymmetric mode converter that consists of two gratings. The proposed scheme may be useful for the design of tunable asymmetric transmission devices due to its design flexibility and efficient design process. PMID:25402109
International Nuclear Information System (INIS)
To predict parameters of radionuclide resuspension, transport and deposition during forest and grassland fires, several model modules were developed and adapted. Experimental data of controlled burning of prepared experimental plots in the Chernobyl exclusion zone have been used to evaluate the prognostic power of the models. The predicted trajectories and elevations of the plume match with those visually observed during the fire experiments in the grassland and forest sites. Experimentally determined parameters could be successfully used for the calculation of the initial plume parameters which provide the tools for the description of various fire scenarios and enable prognostic calculations. In summary, the model predicts a release of some per mille from the radionuclide inventory of the fuel material by the grassland fires. During the forest fire, up to 4% of 137Cs and 9Sr and up to 1% of the Pu isotopes can be released from the forest litter according to the model calculations. However, these results depend on the parameters of the fire events. In general, the modeling results are in good accordance with the experimental data. Therefore, the considered models were successfully validated and can be recommended for the assessment of the resuspension and redistribution of radionuclides during grassland and forest fires in contaminated territories
Asymmetric coherent transmission for single particle diode and gyroscope
Yang, S.; Song, Z; Sun, C. P.
2009-01-01
We study the single particle scattering process in a coherent multi-site system consisting of a tight-binding ring threaded by an Aharonov-Bohm flux and several attaching leads. The asymmetric behavior of scattering matrix is discovered analytically in the framework of both Bethe Ansatz and Green's function formalism. It is found that, under certain conditions, a three-site electronic system can behave analogous to a perfect semiconductor diode where current flows only in one direction. The g...
Localization of Asymmetric Brain Function in Emotion and Depression
Herrington, John D.; Heller, Wendy; Mohanty, Aprajita; Engels, Anna S.; Banich, Marie T; Webb, Andrew G; Miller, Gregory A.
2010-01-01
Although numerous EEG studies have shown that depression is associated with abnormal functional asymmetries in frontal cortex, fMRI and PET studies have largely failed to identify specific brain areas showing this effect. The present study tested the hypothesis that emotion processes are related to asymmetric patterns of fMRI activity, particularly within dorsolateral prefrontal cortex (DLPFC). Eleven depressed and 18 control participants identified the color in which pleasant, neutral, and u...
DIFLUORPHOS and SYNPHOS in asymmetric catalysis: Synthetic applications
Indian Academy of Sciences (India)
Sebastien Prevost; Tahar Ayad; Jean-Pierre Genet; Phannarath Phansavath; Virginie Ratovelomanana-Vidal
2014-03-01
Enantiomerically pure diphosphines play an important role in various homogeneous metalcatalyzed asymmetric reactions. Over the last few years, our group has been involved in the design and synthesis of atropisomeric ligands named SYNPHOS and DIFLUORPHOS with complementary stereoelectronic properties. This paper shows the high catalytic performances of DIFLUORPHOS, SYNPHOS and SYNPHOS analogues for some C-H and C-C bond forming processes as well as for the synthesis of biorelevant targets.
Bargaining with asymmetric information in non-stationary markets
Daniel Trefler
1999-01-01
The Rubinstein and Wolinsky bargaining-in-markets framework is modified by the introduction of asymmetric information and non-stationarity. Non-stationarity is introduced in the form of an arbitrary stochastic Markov process which captures the dynamics of market entry and pairwise matching. A new technique is used for establishing existence and characterizing the unique outcome of a non-stationary market equilibrium. The impact of market supply and demand on bilateral bargaining outcomes and ...
Staircase polygons, scaling functions and asymmetric compact directed percolation
International Nuclear Information System (INIS)
The scaling function for compact directed percolation on a square lattice is investigated for the asymmetric case where two parameters control the critical behaviour. A simple representation for the area-perimeter generating function for staircase polygons is found, which can be recast as a non-linear functional equation. From this, the exact scaling function is extracted. In the process, the most concise derivations to date are given for the exact low order cluster moments. (letter to the editor)
Asymmetric acetylcholinesterase is assembled in the Golgi apparatus.
Rotundo, R. L.
1984-01-01
The synthesis, assembly, and processing of the multiple molecular forms of acetylcholinesterase (AcChoEase; acetylcholine acetylhydrolase, EC 3.1.1.7) in quail muscle cultures was studied by using lectins to distinguish enzyme molecules residing in different subcellular compartments. Special emphasis was given to the assembly of asymmetric AcChoEase molecules because these appear to be the predominant, if not unique, forms of AcChoEase at the vertebrate neuromuscular junction. All cell surfac...
Asymmetric Superradiant Scattering Patterns from Bose–Einstein Condensates
International Nuclear Information System (INIS)
The asymmetric patterns of superradiance from Bose–Einstein condensates are studied for the spatially inhomogeneous pump pulse with the semiclassical Maxwell-Schrödinger equations. The coupling dynamics between the optical field and condensate in the strong pulse and a faded wing in the weak coupling regime are discussed, which not only explain the spatial effects in the process of superradiance, but also supply a new method to control its patterns
Modelling asymmetric growth in crowded plant communities
DEFF Research Database (Denmark)
Damgaard, Christian
2010-01-01
A class of models that may be used to quantify the effect of size-asymmetric competition in crowded plant communities by estimating a community specific degree of size-asymmetric growth for each species in the community is suggested. The model consists of two parts: an individual size......-asymmetric growth part, where growth is assumed to be proportional to a power function of the size of the individual, and a term that reduces the relative growth rate as a decreasing function of the individual plant size and the competitive interactions from other plants in the neighbourhood....
Asymmetric warfare and the will to win
Quinn, Matthew D.
2001-01-01
This thesis explores the will to win in asymmetric war. Asymmetric war, in which one side has an overwhelming advantage over its opponent, will likely be the war of the future for the United States in the post-Cold War uni-polar world. To win an asymmetric war, the individual and then the masses must be motivated to fight and, ultimately, the will to win must be cultivated and sustained for victory. Religion is a highly effective motivat or for both the individual and the masses. This motiva...
Institute of Scientific and Technical Information of China (English)
赵勇; 杨慎华; 寇淑清; 金文明
2012-01-01
Asymmetric structure affects on cracking order and quality when oblique incision connecting rod is split by way of fracture.The finite element models of oblique incision connecting rod with different cracking groove depth were set up.Using this model and the fracture toughness of oblique incision connecting rod material which was measured by test as the onset criterion,the onset of cracking of oblique incision connecting rod fracture splitting was numerically simulated in the quasi-static loading case by FEM software.Simulation results show that the optimization of the depth parameters on both sides of cracking groove of oblique incision connecting rod can reduce the time lag of onset of cracking groove on both sides which is caused by the asymmetric structure in the course of fracture splitting of the oblique incision connecting rod.Experiments of fracture splitting of the oblique incision connecting rod were carried out and the time lag of onset of cracking groove on both sides was measured by electromotive strain method.Good agreement is found between experimental and numerical results.%分析了斜切口连杆结构不对称对裂解加工中两侧裂解槽起裂时序及裂解质量的影响.建立了斜切口裂解连杆有限元模型,以试验确定的斜切口连杆材料断裂韧性参数为起裂判据,变化斜切口裂解连杆有限元模型的两侧裂解槽深差,进行了斜切口连杆裂解起裂准静态有限元分析.模拟结果表明,通过优化斜切口连杆两侧裂解槽深度参数可以减小由于结构不对称引起的斜切口连杆裂解加工中两侧裂解槽的起裂时间差.进行了不同槽深情况的斜切口连杆裂解试验研究,通过电测方法测定了试验中斜切口连杆两侧裂解起裂时间差,试验结果与数值模拟结果相比有较好的一致性.
Asymmetric Information and Consumer Demand
Directory of Open Access Journals (Sweden)
Ismagilova G. N.
2014-11-01
Full Text Available In the paper study the peculiarities of the formation the consumer demand for durable goods, the so-called «experience goods» in markets with asymmetric information. In the known literature sources studying of the demand is based on the assumption that at the moment of the purchase of goods and services people know exactly what price they are willing to pay for them and what utility they are going to obtain using those goods and services. Consider the signal model in which the initial price and advertising expenditures are the signals of the quality influencing the formation of the demand for new goods offered by the company of unknown quality through consumer behavior. The basis of this model is the study of producers by consumers, acquisition of knowledge, information about price and quality, as well as their use in order to determine the market share of high-quality goods and low-quality goods in the asymmetry of information.
Chaos suppression through asymmetric coupling
Bragard, J.; Vidal, G.; Mancini, H.; Mendoza, C.; Boccaletti, S.
2007-12-01
We study pairs of identical coupled chaotic oscillators. In particular, we have used Roessler (in the funnel and no funnel regimes), Lorenz, and four-dimensional chaotic Lotka-Volterra models. In all four of these cases, a pair of identical oscillators is asymmetrically coupled. The main result of the numerical simulations is that in all cases, specific values of coupling strength and asymmetry exist that render the two oscillators periodic and synchronized. The values of the coupling strength for which this phenomenon occurs is well below the previously known value for complete synchronization. We have found that this behavior exists for all the chaotic oscillators that we have used in the analysis. We postulate that this behavior is presumably generic to all chaotic oscillators. In order to complete the study, we have tested the robustness of this phenomenon of chaos suppression versus the addition of some Gaussian noise. We found that chaos suppression is robust for the addition of finite noise level. Finally, we propose some extension to this research.
Twin Higgs Asymmetric Dark Matter.
García García, Isabel; Lasenby, Robert; March-Russell, John
2015-09-18
We study asymmetric dark matter (ADM) in the context of the minimal (fraternal) twin Higgs solution to the little hierarchy problem, with a twin sector with gauged SU(3)^{'}×SU(2)^{'}, a twin Higgs doublet, and only third-generation twin fermions. Naturalness requires the QCD^{'} scale Λ_{QCD}^{'}≃0.5-20 GeV, and that t^{'} is heavy. We focus on the light b^{'} quark regime, m_{b^{'}}≲Λ_{QCD}^{'}, where QCD^{'} is characterized by a single scale Λ_{QCD}^{'} with no light pions. A twin baryon number asymmetry leads to a successful dark matter (DM) candidate: the spin-3/2 twin baryon, Δ^{'}∼b^{'}b^{'}b^{'}, with a dynamically determined mass (∼5Λ_{QCD}^{'}) in the preferred range for the DM-to-baryon ratio Ω_{DM}/Ω_{baryon}≃5. Gauging the U(1)^{'} group leads to twin atoms (Δ^{'}-τ^{'}[over ¯] bound states) that are successful ADM candidates in significant regions of parameter space, sometimes with observable changes to DM halo properties. Direct detection signatures satisfy current bounds, at times modified by dark form factors. PMID:26430985
Twin Higgs Asymmetric Dark Matter
García, Isabel García; March-Russell, John
2015-01-01
We study Asymmetric Dark Matter (ADM) in the context of the minimal (Fraternal) Twin Higgs solution to the little hierarchy problem, with a twin sector with gauged $SU(3)' \\times SU(2)'$, a twin Higgs, and only third generation twin fermions. Naturalness requires the QCD$^\\prime$ scale $\\Lambda'_{\\rm QCD} \\simeq 0.5 - 20 \\ {\\rm GeV}$, and $t'$ to be heavy. We focus on the light $b'$ quark regime, $m_{b'} \\lesssim \\Lambda'_{\\rm QCD}$, where QCD$^\\prime$ is characterised by a single scale $\\Lambda'_{\\rm QCD}$ with no light pions. A twin baryon number asymmetry leads to a successful DM candidate: the spin-3/2 twin baryon, $\\Delta' \\sim b'b'b'$, with a dynamically determined mass ($\\sim 5 \\Lambda'_{\\rm QCD}$) in the preferred range for the DM-to-baryon ratio $\\Omega_{\\rm DM}/\\Omega_{\\rm baryon} \\simeq 5$. Gauging the $U(1)'$ group leads to twin atoms ($\\Delta'$ - $\\bar {\\tau'}$ bound states) that are successful ADM candidates in significant regions of parameter space, sometimes with observable changes to DM halo ...
Liberal-conservative differences in inclusion-exclusion strategy choice,
Directory of Open Access Journals (Sweden)
John D. Jasper
2008-06-01
Full Text Available Inclusion and exclusion strategies for allocation of scarce goods involve different processes. The conditions under which one strategy is chosen in favor of the other, however, have not been fully explicated. In the present study, decision makers chose a single strategy after reading through descriptions of 16 potential organ recipients; they then narrowed the list of transplant candidates. Most liberals chose to use exclusion under conditions of abundance and inclusion under scarcity. In contrast, conservatives preferred an inclusion strategy under abundance and exclusion (though not significantly under scarcity. Theoretical implications as well as ongoing work in inclusion-exclusion strategy choice, political ideology, and distributive justice are discussed.
Tunable asymmetric reflectance in silver films near the percolation threshold
Chen, Aiqing
2010-01-01
We demonstrate semi-transparent thin films exhibiting unique tunable asymmetry in reflectance and simultaneously preserve symmetry in transmittance under light illuminations from opposite directions. The films are obtained using a multi-step process, where a nanocrystalline silver film is first deposited on a glass substrate and then subsequently coated with additional silver via thermal vacuum-deposition. We show that the dispersions of reflectance asymmetries may be tuned both in sign and in magnitude, as well as a universal, tunable spectral crossover point near percolation threshold, which are attributed to asymmetric losses from surface plasmon enhanced absorption and scatterings. The broadband and tunable asymmetric reflectors may have potential applications to light enhancement and light harvesting of photovoltaics.
Corporate governance ratings as a means to reduce asymmetric information
DEFF Research Database (Denmark)
Holm, Claus; Balling, Morten; Poulsen, Thomas
2014-01-01
Can corporate governance ratings reduce problems of asymmetric information between companies and investors? To answer this question, we set out to examine the information basis for providing such ratings by reviewing corporate governance attributes that are required or recommended in laws......, accounting standards, and codes, respectively. After that, we scrutinize and organize the publicly available information on the methodologies actually used by rating providers. However, important details of these methodologies are treated as confidential property, thus we approach the evaluation of corporate...... governance ratings as a means to reduce asymmetric information in a more general manner. We propose that the rating process may be seen as consisting of two general activities, namely a data reduction phase, and a data weighting, aggregation, and classification phase. Findings based on a Danish data...
Corporate governance ratings as a means to reduce asymmetric information
DEFF Research Database (Denmark)
Balling, Morten; Holm, Claus; Poulsen, Thomas
Can corporate governance ratings reduce problems of asymmetric information between companies and investors? To answer this question, we set out to examine the information basis for providing such ratings by reviewing corporate governance attributes that are required or recommended in laws......, accounting standards and codes, respectively. After that, we scrutinize and organize the publicly available information on the methodologies actually used by rating providers. However, important details of these methodologies are treated as confidential property, thus we approach the evaluation of corporate...... governance ratings as a means to reduce asymmetric information in a more general manner. We propose that the rating process may be seen as consisting of two general activities, namely a data reduction phase, and a data weighting, aggregation and classification phase. Findings based on a Danish data set...
High performance of junctionless MOSFET with asymmetric gate
Wang, Ying; Tang, Yan; Sun, Ling-ling; Cao, Fei
2016-09-01
In this work, we propose a junctionless MOSFET with asymmetric gates (AG-JL MOSFET). This device is a double gate structure with a lateral offset between the gate, and this leads to different characteristic than a conventional double gate structure. Specifically, the asymmetric gate modulates the effective channel length depending on whether the device is in the ON or OFF state, which this leads to more ideal device characteristics. A comprehensive device performance comparison including the ION/IOFF ratio, subthreshold slope (SS), and drain-induced barrier lowering (DIBL) between the proposed device and a conventional device is presented. The proposed device exhibits superior performance when compared a conventional device, and results show that it is also less sensitive to process variations.
Asymmetric excitation of surface plasmons by dark mode coupling.
Zhang, Xueqian; Xu, Quan; Li, Quan; Xu, Yuehong; Gu, Jianqiang; Tian, Zhen; Ouyang, Chunmei; Liu, Yongmin; Zhang, Shuang; Zhang, Xixiang; Han, Jiaguang; Zhang, Weili
2016-02-01
Control over surface plasmons (SPs) is essential in a variety of cutting-edge applications, such as highly integrated photonic signal processing systems, deep-subwavelength lasing, high-resolution imaging, and ultrasensitive biomedical detection. Recently, asymmetric excitation of SPs has attracted enormous interest. In free space, the analog of electromagnetically induced transparency (EIT) in metamaterials has been widely investigated to uniquely manipulate the electromagnetic waves. In the near field, we show that the dark mode coupling mechanism of the classical EIT effect enables an exotic and straightforward excitation of SPs in a metasurface system. This leads to not only resonant excitation of asymmetric SPs but also controllable exotic SP focusing by the use of the Huygens-Fresnel principle. Our experimental findings manifest the potential of developing plasmonic metadevices with unique functionalities. PMID:26989777
Asymmetric excitation of surface plasmons by dark mode coupling
Zhang, X.
2016-02-19
Control over surface plasmons (SPs) is essential in a variety of cutting-edge applications, such as highly integrated photonic signal processing systems, deep-subwavelength lasing, high-resolution imaging, and ultrasensitive biomedical detection. Recently, asymmetric excitation of SPs has attracted enormous interest. In free space, the analog of electromagnetically induced transparency (EIT) in metamaterials has been widely investigated to uniquely manipulate the electromagnetic waves. In the near field, we show that the dark mode coupling mechanism of the classical EIT effect enables an exotic and straightforward excitation of SPs in a metasurface system. This leads to not only resonant excitation of asymmetric SPs but also controllable exotic SP focusing by the use of the Huygens-Fresnel principle. Our experimental findings manifest the potential of developing plasmonic metadevices with unique functionalities.
R & D STRATEGIC INVESTMENT IN AN ASYMMETRICAL CASE
Institute of Scientific and Technical Information of China (English)
Minggao XUE; Pu GONG
2006-01-01
This article analyzes R & D investment decisions in an asymmetrical case. The investment decisions share three important characteristics. First, the investment is completely irreversible. Second,there are two kinds of uncertainties over the future returns from the investment and over technology in R & D process, respectively. Third, there is strategic competition in the asymmetrical case. This article presents the optimal investment threshold values and the optimal investment rule of high-efficient firm (leader), and shows that the investment threshold values are reduced by competition of two firms.Finally, the mixed investment strategies for two firms, the probability that each firm separately exercises the option to invest, and the probability that two firms simultaneously exercise the option are given in the paper.
Proper symmetric and asymmetric endoplasmic reticulum partitioning requires astral microtubules.
Smyth, Jeremy T; Schoborg, Todd A; Bergman, Zane J; Riggs, Blake; Rusan, Nasser M
2015-08-01
Mechanisms that regulate partitioning of the endoplasmic reticulum (ER) during cell division are largely unknown. Previous studies have mostly addressed ER partitioning in cultured cells, which may not recapitulate physiological processes that are critical in developing, intact tissues. We have addressed this by analysing ER partitioning in asymmetrically dividing stem cells, in which precise segregation of cellular components is essential for proper development and tissue architecture. We show that in Drosophila neural stem cells, called neuroblasts, the ER asymmetrically partitioned to centrosomes early in mitosis. This correlated closely with the asymmetric nucleation of astral microtubules (MTs) by centrosomes, suggesting that astral MT association may be required for ER partitioning by centrosomes. Consistent with this, the ER also associated with astral MTs in meiotic Drosophila spermatocytes and during syncytial embryonic divisions. Disruption of centrosomes in each of these cell types led to improper ER partitioning, demonstrating the critical role for centrosomes and associated astral MTs in this process. Importantly, we show that the ER also associated with astral MTs in cultured human cells, suggesting that this centrosome/astral MT-based partitioning mechanism is conserved across animal species. PMID:26289801
Duby, Françoise; Francq, Bernard
2013-01-01
Il est devenu aujourd’hui de plus en plus difficile de faire entendre la parole de ceux qui sont considérés comme exclus, marginaux, surnuméraires, désocialisés. C’est pourtant là l’enjeu du livre de Françoise Duby. En quoi les instances d’accueil et autres dispositifs disponibles dans le secteur de l’exclusion sont-ils au premier chef concernés par le maintien ou non de l’exclusion sociale ? Pour avoir vécu un temps avec la marginalité urbaine de la rue, F. Duby retrouve une nouvelle fois, à...
Affective privilege: Asymmetric interference by emotional distracters
Directory of Open Access Journals (Sweden)
TobiasEgner
2011-09-01
Full Text Available Numerous theories posit that affectively salient stimuli are privileged in their capacity to capture attention and disrupt ongoing cognition. Two underlying assumptions in this theoretical position are that the potency of affective stimuli transcends task boundaries (i.e., emotional distracters do not have to belong to a current task-set to disrupt processing and that there is an asymmetry between emotional and cognitive processing (i.e., emotional distracters disrupt cognitive processing, but not vice versa. These assumptions have remained largely untested, as common experimental probes of emotion-cognition interaction rarely manipulate task-relevance and only examine one side of the presumed asymmetry of interference. To test these propositions directly, a face-word Stroop protocol was adapted to independently manipulate (a the congruency between target and distracter stimulus features, (b the affective salience of distracter features, and (c the task-relevance of emotional compared to non-emotional target features. A three-way interaction revealed interdependent effects of distracter relevance, congruence, and affective salience. Compared to task-irrelevant distracters, task-relevant congruent distracters facilitated performance and task-relevant incongruent distracters impaired performance, but the latter effect depended on the nature of the target feature and task. Specifically, task-irrelevant emotional distracters resulted in equivalent performance costs as task-relevant non-emotional distracters, whereas task-irrelevant non-emotional distracters did not produce performance costs comparable to those generated by task-relevant emotional distracters. These results document asymmetric cross-task interference effects for affectively salient stimuli, supporting the notion of affective prioritization in human information processing.
Dual-Layer Asymmetric Microporous Silica Membranes
Energy Technology Data Exchange (ETDEWEB)
TSAI,CHUNG-YI; TAM,SIU-YUE; LU,YUNFENG; BRINKER,C. JEFFREY
1999-11-19
We report a novel sol-gel dip-coating process to form dual-layer microporous silica membranes with improved membrane performance and reproducibility. First, we deposit a surfactant-templated silica (STS) intermediate layer on top of a commercial {gamma}-alumina support both to improve its ''surface finish'' and to prevent a subsequently deposited microporous overlayer from penetrating into the support. Second, membranes are processed under clean room conditions to avoid dust contamination and, third, membranes are vacuum-calcined to promote further pore shrinkage and impart surface hydrophobicity. The resulting asymmetric membrane exhibits a gradual change in pore diameter from 50{angstrom} ({gamma}-alumina support layer) to 10-12{angstrom} (STS intermediate layer), and then to 3-4{angstrom} (30nm thick, ultramicroporous silica top-layer). Compared to a single-layer process using only the microporous overlayer, the dual-layer process improves both flux and selectivity. For the industrially important problem of natural gas purification, the combined CO{sub 2} flux [(3{approx} 0.5) x 10{sup {minus}4} cm{sup 3}(STP)/(s{center_dot}cm{sup 2}{center_dot}cm-Hg)] and CO{sub 2}/CH{sub 4} separation factors [200{approx}600] are superior to all previously reported values for separation of a 50/50 (v/v) CO{sub 2}/CH{sub 4} gas mixture. In addition, the membrane selectively separated hydrogen from a simulated reformate from partial oxidation of methanol as evidenced by a high concentration of hydrogen recovery.
Dual-Layer Asymmetric Microporous Silica Membranes
International Nuclear Information System (INIS)
We report a novel sol-gel dip-coating process to form dual-layer microporous silica membranes with improved membrane performance and reproducibility. First, we deposit a surfactant-templated silica (STS) intermediate layer on top of a commercial(gamma)-alumina support both to improve its ''surface finish'' and to prevent a subsequently deposited microporous overlayer from penetrating into the support. Second, membranes are processed under clean room conditions to avoid dust contamination and, third, membranes are vacuum-calcined to promote further pore shrinkage and impart surface hydrophobicity. The resulting asymmetric membrane exhibits a gradual change in pore diameter from 50(angstrom) ((gamma)-alumina support layer) to 10-12(angstrom) (STS intermediate layer), and then to 3-4(angstrom) (30nm thick, ultramicroporous silica top-layer). Compared to a single-layer process using only the microporous overlayer, the dual-layer process improves both flux and selectivity. For the industrially important problem of natural gas purification, the combined CO(sub 2) flux[(3(approx) 0.5) x 10(sup(minus)4) cm(sup 3)(STP)/(s(centerdot)cm(sup 2)(centerdot)cm-Hg)] and CO(sub 2)/CH(sub 4) separation factors[200(approx)600] are superior to all previously reported values for separation of a 50/50 (v/v) CO(sub 2)/CH(sub 4) gas mixture. In addition, the membrane selectively separated hydrogen from a simulated reformate from partial oxidation of methanol as evidenced by a high concentration of hydrogen recovery
Asymmetric dense matter in holographic QCD
Directory of Open Access Journals (Sweden)
Shin Ik Jae
2012-02-01
Full Text Available We study asymmetric dense matter in holographic QCD.We construct asymmetric dense matter by considering two quark flavor branes with dierent quark masses in a D4/D6/D6 model. To calculate the symmetry energy in nuclear matter, we consider two quarks with equal masses and observe that the symmetry energy increases with the total charge showing the stiff dependence. This behavior is universal in the sense that the result is independent of parameters in the model. We also study strange (or hyperon matter with one light and one intermediate mass quarks. In addition to the vacuum properties of asymmetric matter, we calculate meson masses in asymmetric dense matter and discuss our results in the light of in-medium kaon masses.
Massless sunset diagrams in finite asymmetric volumes
Niedermayer, Ferenc
2016-01-01
In this paper we present methods to compute massless sunset diagrams in finite asymmetric volumes in the framework of dimensional regularization and lattice regularization. We also consider 1-loop sums in both regularizations.
Worst Asymmetrical Short-Circuit Current
DEFF Research Database (Denmark)
Arana Aristi, Iván; Holmstrøm, O; Grastrup, L;
2010-01-01
In a typical power plant, the production scenario and the short-circuit time were found for the worst asymmetrical short-circuit current. Then, a sensitivity analysis on the missing generator values was realized in order to minimize the uncertainty of the results. Afterward the worst asymmetrical...... short-circuit current was analyzed in order to compare the results with the allowable DC current component based in the IEC. Finally the normal operating condition for the power plant was modeled....
Renewable resource management under asymmetric information
DEFF Research Database (Denmark)
Jensen, Frank; Andersen, Peder; Nielsen, Max
Asymmetric information between fishermen and the regulator is important within fisheries. The regulator may have less information about stock sizes, prices, costs, effort, productivity and catches than fishermen. With asymmetric information, a strong analytical tool is principal-agent analysis. In......-productivity agents receive an information rent. The information rent is equivalent to the total incentive cost. The incentive costs arise as we want to reveal the agent's type....
An asymmetric pericyclic cascade approach to oxindoles
Richmond, Edward
2014-01-01
The research in this thesis describes an asymmetric pericyclic cascade approach to the synthesis of a range of enantioenriched oxindoles using enantiopure oxazolidine derived nitrones and disubstituted ketenes. Chapter 1 aims to place this work in the context of the literature, describing other commonly employed or state-of-the-art asymmetric approaches to oxindoles and related compounds. Examples of where these approaches have been used successfully in the total synthesis of related indol...
Asymmetric Federalism in Russia: Cure or Poison?
Jorge Martinez-Vazquez
2003-01-01
In the early years of its existence, the Russian Federation adopted a system of differential treatment of its regions in order to cope with the great degree of diversity present in them. This paper examines the Russian Federation’s asymmetric federalism by evaluating the system’s role, significance and effects on the Federation’s development. The study incorporates a detailed description of the asymmetric federalism over time along with the benefits and costs incurred by its implementation. I...
Asymmetric Membrane Osmotic Capsules for Terbutaline Sulphate
Gobade, N. G.; Marina Koland; K H Harish
2012-01-01
The aim of the present study was to design an asymmetric membrane capsule, an osmotic pump-based drug delivery system of ethyl cellulose for controlled release of terbutaline sulphate. asymmetric membrane capsules contains pore-forming water soluble additive, sorbitol in different concentrations in the capsule shell membrane, which after coming in contact with water, dissolves, resulting in an in situ formation of a microporous structure. The terbutaline sulphate is a β-adrenoreceptor agonist...
Asymmetric septal hypertrophy and hypothyroidism in children.
Altman, D I; Murray, J.; Milner, S.; Dansky, R; Levin, S. E.
1985-01-01
Any echocardiographic study of two children with hypothyroidism demonstrated the presence of asymmetric septal hypertrophy. One child died aged 11 months, and pronounced thickening of the interventricular septum was confirmed at necropsy. There was also hypertrophy of the left ventricular free wall. Histological examination showed only slight muscle fibre disarray, but there was striking vacuolation and hypertrophy of muscle fibres. In the second case, a child aged five years, the asymmetric ...
Contrasting Stories of Inclusion/Exclusion in the Chemistry Classroom
Gomes, Maria de Fatima Cardoso; Mortimer, Eduardo F.; Kelly, Gregory J.
2011-01-01
This article reports on the construction process of inclusion/exclusion for high school chemistry students in two schools in Belo Horizonte, the capital of Minas Gerais State, Brazil. We examined the interactional accomplishment of inclusion/exclusion of four students, two from a private school and two from a public school. The aim of this article…
Finite Element Modeling of Roll Wear during Cold Asymmetric Sheet Rolling of Aluminum Alloy 5083
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Pesin A.
2015-01-01
Full Text Available Since the main purpose of asymmetrical rolling is to impose high shear strains on the sheet, in order to obtain ultrafine grain structure, the friction between the rolls and the sheet has to be kept relatively high. This means that asymmetric rolling is performed with dry rolls. The paper presents a numerical analysis of the roll wear during asymmetric cold rolling of 5083 aluminum alloy. The finite element simulation was used to calculate the amount of roll wear by Usui’s equation. FEM simulations were carried out with using software DEFORM 2D. The influence of the friction coefficient on the roll wear and the material flow was discussed. The sliding velocity, interface pressure and temperature were used to calculate the roll wear. The results of simulation can be used to optimize the asymmetric rolling process to improve surface quality of aluminum sheets.
Primary fragment mass-yield distributions for asymmetric fission path of heavy nuclei
International Nuclear Information System (INIS)
The primary fragment mass-yield distribution for the asymmetric fission path in heavy nuclei, 233Pa, 239Np, 245Am and 249Bk at the excitation energy of ∼20 MeV are experimentally constructed based on the intensities of total kinetic energies for individual mass splits. The results revealed an interesting phenomenon: in all the studied fissioning systems, the inner wings of the mass-yield distributions in the asymmetric fission path appear along the same mass-wall of A = 130 fragment mass. The asymmetric mass-yield distribution indicates the strong effect of structural shells in fragments on the final mass division process of the asymmetric fission path. (author)
Barbed congruence of the asymmetric chi calculus
Institute of Scientific and Technical Information of China (English)
DONG Xiao-ju; FU Yu-xi
2006-01-01
The chi calculus is a model of mobile processes. It has evolved from the pi-calculus with motivations from simplification and communication-as-cut-elimination. This paper studies the chi calculus in the framework incorporating asymmetric communication. The major feature of the calculus is the identification of two actions:x/x and τ. The investigation on the barbed bisimilarity shows how the property affects the observational theory.Based on the definition of the barbed bisimilarity, the simulation properties of the barbed bisimilarity are studied. It shows that the algebraic properties of the barbed bisimilarity have changed greatly compared with the chi calculus. Although the definition of the barbed bisimilarity is very simple, the property of closeness under contexts makes it difficult to understand the barbed bisimilarity directly. Therefore an open style definition of the barbed bisimilarity is given, which is a context free description of barbed bisimilarity. Its definition is complex,but it is a well-behaved relation for it coincides with the barbed bisimilarity. It also helps to build an axiomatization system for the barbed congruence. Besides the axioms for the strong barbed bisimilarity, the paper proposes a new tau law and four new update laws for the barbed congruence. Both the operational and algebraic properties of the enriched calculus improve the understanding of the bisimulation behaviors of the model.
Ombuds' Corner: Social exclusion
Vincent Vuillemin
2012-01-01
In this special video edition of the Ombuds' Corner, Vincent Vuillemin takes a look at a social exclusion at CERN. Please note that the characters and situations appearing in this work are fictitious, and any resemblance to real persons or events is purely coincidental. Contact the Ombuds Early!
Ombuds' Corner: Social exclusion
CERN bulletin
2012-01-01
In this special video edition of the Ombuds' Corner, Ombudsman Vincent Vuillemin takes a look at a social exclusion at CERN. Please note that the characters and situations appearing in this work are fictitious, and any resemblance to real persons or events is purely coincidental.
Dimensions of social exclusion
Stella Hoff; Cok Vrooman
2011-01-01
Original title: Dimensies van sociale uitsluiting SCP has carried out research since 2004 on the occurrence and causes of social exclusion, both among the Dutch population as a whole and within certain groups (the elderly, children). The questionnaire used for this has been regularly updated on the
Central Exclusive Production at the LHC
Forshaw, J R
2009-01-01
After a brief resume of the theory underpinning the central exclusive process (CEP) pp \\to p+H+p, attention is focussed upon Higgs bosons produced in the Standard Model, the MSSM and the NMSSM. In all cases, CEP adds significantly to the physics potential of the LHC and in some scenarios it may be crucial.
Hydrogen migration in methanol studied under asymmetric fs laser irradiation
Kotsina, N.; Kaziannis, S.; Kosmidis, C.
2014-06-01
Hydrogen migration processes in deuterated methanol (CH3OD) under the irradiation of ultrashort (30 fs) two color (400/800 nm) laser field have been investigated by means of time-of-flight mass spectrometry. The utilization of an asymmetric ω/2ω laser field contributes to a better understanding of hydrogen migration processes. Based on the comparative study of the asymmetry dependence and the angular distributions of the H2D+, HOD+ and H2OD+ fragment ions, whose formation requires hydrogen migration, it was feasible to distinguish the most probable site of the molecular skeleton where the hydrogen migrates from.
Fatigue in asymmetric-field-driven ferroelectric thin films
International Nuclear Information System (INIS)
The polarization fatigue problems in asymmetric-field-driven ferroelectric thin films is investigated in present Letter. The refreshment of fatigue induced by the application of asymmetric voltage to the top and bottom electrodes is modeled by asymmetric Schottky voltage barrier of a quantum well structure. The fatigue behavior under various asymmetric driving voltages and asymmetric driving pulses have been studied. Theoretical calculations are shown to be in agreement with experimental results
All-optical adder/subtractor based on tera-hertz optical asymmetric demultiplexer
Institute of Scientific and Technical Information of China (English)
Dilip Kumar Gayen; Rajat Kumar Pal; Jitendra Nath Roy
2009-01-01
An all-optical adder/subtractor (A/S) unit with the help of terahertz optical asymmetric demultiplexer (TOAD) is proposed.Tile all-optical A/S unit with a set of all-optical full-adders and optical exclusive-ORs (XORs),can be used to perform a fast central processor unit using optical hardware components.We try to exploit the advantages of TOAD-based optical switch to design an integrated all-optical circuit which can perform binary addition and subtraction.With computer simulation results confirming the described methods,conclusions are given.
Egedal, J; Daughton, W; Wetherton, B; Cassak, P A; Chen, L -J; Lavraud, B; Trobert, R B; Dorelli, J; Gershman, D J; Avanov, L A
2016-01-01
Supported by a kinetic simulation, we derive an exclusion energy parameter $\\cal{E}_X$ providing a lower kinetic energy bound for an electron to cross from one inflow region to the other during magnetic reconnection. As by a Maxwell Demon, only high energy electrons are permitted to cross the inner reconnection region, setting the electron distribution function observed along the low density side separatrix during asymmetric reconnection. The analytic model accounts for the two distinct flavors of crescent-shaped electron distributions observed by spacecraft in a thin boundary layer along the low density separatrix.
Stochastic modeling of cell growth with symmetric or asymmetric division.
Marantan, Andrew; Amir, Ariel
2016-07-01
We consider a class of biologically motivated stochastic processes in which a unicellular organism divides its resources (volume or damaged proteins, in particular) symmetrically or asymmetrically between its progeny. Assuming the final amount of the resource is controlled by a growth policy and subject to additive and multiplicative noise, we derive the recursive integral equation describing the evolution of the resource distribution over subsequent generations and use it to study the properties of stable resource distributions. We find conditions under which a unique stable resource distribution exists and calculate its moments for the class of affine linear growth policies. Moreover, we apply an asymptotic analysis to elucidate the conditions under which the stable distribution (when it exists) has a power-law tail. Finally, we use the results of this asymptotic analysis along with the moment equations to draw a stability phase diagram for the system that reveals the counterintuitive result that asymmetry serves to increase stability while at the same time widening the stable distribution. We also briefly discuss how cells can divide damaged proteins asymmetrically between their progeny as a form of damage control. In the appendixes, motivated by the asymmetric division of cell volume in Saccharomyces cerevisiae, we extend our results to the case wherein mother and daughter cells follow different growth policies. PMID:27575162
Stochastic modeling of cell growth with symmetric or asymmetric division
Marantan, Andrew; Amir, Ariel
2016-07-01
We consider a class of biologically motivated stochastic processes in which a unicellular organism divides its resources (volume or damaged proteins, in particular) symmetrically or asymmetrically between its progeny. Assuming the final amount of the resource is controlled by a growth policy and subject to additive and multiplicative noise, we derive the recursive integral equation describing the evolution of the resource distribution over subsequent generations and use it to study the properties of stable resource distributions. We find conditions under which a unique stable resource distribution exists and calculate its moments for the class of affine linear growth policies. Moreover, we apply an asymptotic analysis to elucidate the conditions under which the stable distribution (when it exists) has a power-law tail. Finally, we use the results of this asymptotic analysis along with the moment equations to draw a stability phase diagram for the system that reveals the counterintuitive result that asymmetry serves to increase stability while at the same time widening the stable distribution. We also briefly discuss how cells can divide damaged proteins asymmetrically between their progeny as a form of damage control. In the appendixes, motivated by the asymmetric division of cell volume in Saccharomyces cerevisiae, we extend our results to the case wherein mother and daughter cells follow different growth policies.
Asymmetric double-well potential for single-atom interferometry
International Nuclear Information System (INIS)
We consider the evolution of a single-atom wave function in a time-dependent double-well interferometer in the presence of a spatially asymmetric potential. We examine a case where a single trapping potential is split into an asymmetric double well and then recombined again. The interferometer involves a measurement of the first excited state population as a sensitive measure of the asymmetric potential. Based on a two-mode approximation a Bloch vector model provides a simple and satisfactory description of the dynamical evolution. We discuss the roles of adiabaticity and asymmetry in the double-well interferometer. The Bloch model allows us to account for the effects of asymmetry on the excited state population throughout the interferometric process and to choose the appropriate splitting, holding, and recombination periods in order to maximize the output signal. We also compare the outcomes of the Bloch vector model with the results of numerical simulations of the multistate time-dependent Schroedinger equation
RELATIONSHIP OF TRANSVERSAL ASYMMETRIC FACE AND UNILATERAL POSTERIOR CROSSBITE
Directory of Open Access Journals (Sweden)
Indah Dwinursanty
2006-04-01
Full Text Available Unilateral posterior crossbite is commonly seen in mixed dentition, but it couldn’t be self corrected. If this condition is not treated properly, it could lead to asymmetric face. Asymmetric face with unilateral posterior crossbite could make the treatment process more difficult. The objective of this study is to find out the relationship between transversal skeletal asymmetry and unilateral posterior crossbite. Patients older than 13 years with skeletal asymmetric face, who had never undergone orthodontic treatment or facial surgery were selected. The sample consisted of 15 females and 6 males (15 – 32 years old. Anteroposterior cephalogram was used for determining the difference between right and left of antegonial and the deviation of menton. Criteria for asymmetry were more than 3 mm on Antegonial and 2 mm or more on Menton. Mid Sagital Reference (MSR was used as reference line. Unilateral posterior crossbite could be seen in the dental model. The data was analyzed using Mann Whitney test. It was revealed that from 21 samples, 38.1% was found to have unilateral posterior crossbite involving four posterior teeth. Conclusion: There is no relationship between transveral skeletal symmetry and unilateral posterior crossbite.
Hammer, Bryan
2013-01-01
With increasing usage of social networking sites like Facebook there is a need to study privacy. Previous research has placed more emphasis on outcome-oriented contexts, such as e-commerce sites. In process-oriented contexts, like Facebook, privacy has become a source of conflict for users. The majority of architectural privacy (e.g. privacy…
Central Exclusive Production at LHCb
McNulty, Ronan
2016-01-01
Central Exclusive Production (CEP) is a unique process at hadron machines in which particles are produced via colourless propagators. LHCb have measured the cross-sections for the CEP of vector mesons, $J/\\psi,\\psi(2S),\\Upsilon(1S),\\Upsilon(2S)$ and $\\Upsilon(3S)$, which are photo-produced. In the double pomeron exchange process, preliminary measurements have been made of $\\chi_{c0},\\chi_{c1}, \\chi_{c2}$ meson production while the first observations of the CEP of pairs of charmonia, $J/\\psi J/\\psi$ and $J/\\psi \\psi(2S)$, have been made and limits obtained on the pair production of other charmonia.
Central exclusive production at RHIC
Adamczyk, Leszek; Guryn, Włodek; Turnau, Jacek
2014-11-01
The present status and future plans of the physics program of Central Exclusive Production (CEP) at RHIC are described. The measurements are based on the detection of the forward protons from the Double Pomeron Exchange (DPE) process in the Roman Pot system and of the recoil system of charged particles from the DPE process measured in the STAR experiment's Time Projection Chamber (TPC). The data described here were taken using polarized proton-proton collisions at √ {s} = 200 GeV. The preliminary spectra of two-pion mass reconstructed by STAR TPC in central region of pseudorapidity |η| < 1, are presented. Near future plans to take data with the current system at center-of-mass energy √ {s} = 200 GeV and plans to upgrade the forward proton tagging system are presented. Also a possible addition of the RPs to the sPHENIX detector is discussed.
Analysis of Capillary Rise in Asymmetric Branch-Like Capillary
Li, Caoxiong; Shen, Yinghao; Ge, Hongkui; Yang, Zhihui; Su, Shuai; Ren, Kai; Huang, Heyu
2016-05-01
Transport in porous media is common in nature, attracting many attentions for a long time. Tree-like network model is often used as a simplification for porous space, expressing the complexity of pore spaces instead of capillary bundle. To investigate spontaneous imbibition characteristics in this network, a dynamic asymmetric branch-like capillary model is used to represent basic network structure, using fractal method to represent tortuosity. This work investigates the influence of parameters on imbibition process in the branch-like capillary model. An analytical equation for the imbibition mass versus time is derived. Parameters from capillary structures to liquid properties are taken into account and analyzed based on the numerical solution of the equation. It is found that the imbibition process in asymmetric branch-like capillary model can be recognized by four sections and brunching tubes are positive for imbibition process. Concomitantly, meniscus arrest event is simulated and discussed. Moreover, the influence of parameters on imbibition process is discussed. These parameters can be classified as static and dynamic. Static parameters mainly change the capillary force, which are related to the ultimate imbibition mass or imbibition ability, while dynamic parameters mainly have influence on resistance of flowing fluid, which are related to the imbibition speed in the imbibition process.
Social exclusion in finite populations
Li, Kun; Cong, Rui; Wu, Te; Wang, Long
2015-04-01
Social exclusion, keeping free riders from benefit sharing, plays an important role in sustaining cooperation in our world. Here we propose two different exclusion regimes, namely, peer exclusion and pool exclusion, to investigate the evolution of social exclusion in finite populations. In the peer exclusion regime, each excluder expels all the defectors independently, and thus bears the total cost on his own, while in the pool exclusion regime, excluders spontaneously form an institution to carry out rejection of the free riders, and each excluder shares the cost equally. In a public goods game containing only excluders and defectors, it is found that peer excluders outperform pool excluders if the exclusion costs are small, and the situation is converse once the exclusion costs exceed some critical points, which holds true for all the selection intensities and different update rules. Moreover, excluders can dominate the whole population under a suitable parameters range in the presence of second-order free riders (cooperators), showing that exclusion has prominent advantages over common costly punishment. More importantly, our finding indicates that the group exclusion mechanism helps the cooperative union to survive under unfavorable conditions. Our results may give some insights into better understanding the prevalence of such a strategy in the real world and its significance in sustaining cooperation.
Directory of Open Access Journals (Sweden)
Nivaldo Carneiro Junior
2006-12-01
city of Sao Paulo. The social transformations observed in the region are complex, marked by the heterogeneity of the population groups within the social inclusion/exclusion processes. Inclusion through social policies is an essential item of integration policies, guided by the need to decrease social inequalities. It is necessary to organize work processes that give visibility to these social groups and incorporate their demands into health care, linking them to other social practices. For this aim, primary health care services are ideal. Barra Funda Educational Health Center organized work processes to provide visibility and differentiated attention to these segments. During this process, some groups became visible and were included in health care: the street population; the sex professionals in the region of Luz; the Bolivian immigrants and those living in shantytowns. As part of its technology, the service incorporated the health care of differentiated groups of the population in general, individualizing them, creating specific "entrance doorways", and promoting equanimity in access. Conceptual and methodological challenges were employed in the consolidation of these practices, which required analyses of the social inclusion/exclusion processes, and of the styles of health care, such as integrality and autonomy of the subjects.
Asymmetric Magnon Excitation by Spontaneous Toroidal Ordering
Hayami, Satoru; Kusunose, Hiroaki; Motome, Yukitoshi
2016-05-01
The effects of spontaneous toroidal ordering on magnetic excitation are theoretically investigated for a localized spin model that includes a staggered Dzyaloshinsky-Moriya interaction and anisotropic exchange interactions, which arise from the antisymmetric spin-orbit coupling and the multiorbital correlation effect. We show that the model exhibits a Néel-type antiferromagnetic order, which simultaneously accompanies a ferroic toroidal order. We find that the occurrence of toroidal order modulates the magnon dispersion in an asymmetric way with respect to the wave number: a toroidal dipole order on the zigzag chain leads to a band-bottom shift, while a toroidal octupole order on the honeycomb lattice gives rise to a valley splitting. These asymmetric magnon excitations could be a source of unusual magnetic responses, such as nonreciprocal magnon transport. A variety of modulations are discussed while changing the lattice and magnetic symmetries. The implications regarding candidate materials for asymmetric magnon excitations are presented.
Dc SQUIDs with asymmetric shunt resistors
International Nuclear Information System (INIS)
We have investigated asymmetrically shunted Nb/Al-AlOx/Nb dc SQUIDs. Simulations based on the coupled Langevin equations predict that the optimum energy resolution ε, and thus also the noise performance of such an asymmetric SQUID, can be 3-4 times better than that of its symmetric counterpart. While keeping the total resistance R identical to a comparable symmetric SQUID with R-1 = R1-1 + R2-1, we shunted only one of the two Josephson junctions with R = R1,2/2. Both types of SQUIDs were characterized with respect to their transport and noise properties at temperature T = 4.2 K, and we compared the experimental results with numerical simulations. Experiments yielded ε ∼ 32 ℎ for an asymmetric SQUID with an inductance L = 22 pH, whereas a comparable symmetric device achieved ε = 110 ℎ.
DNA SECURITY USING SYMMETRIC AND ASYMMETRIC CRYPTOGRAPHY
Directory of Open Access Journals (Sweden)
Radu Terec
2011-01-01
Full Text Available This paper presents alternative security methods based on DNA. From the available alternative security methods, symmetric DNA algorithms were developed and implemented. The first symmetric DNA algorithm was implemented in the Java language, while the second DNA algorithm was implemented in BioJava and MatLab. Comparisons have been made between the performances of different standard symmetrical algorithms and the DNA proposed algorithms. As a new step to enhance the security, an asymmetric key generation inside a DNA security algorithm is presented. The asymmetric key generation algorithm starts from a password phrase. The asymmetric DNA algorithm proposes a mechanism which makes use of more encryption technologies. Therefore, it is more reliable and more powerful than the OTP DNA symmetric algorithms.
Asymmetric Composite Nanoparticles with Anisotropic Surface Functionalities
Directory of Open Access Journals (Sweden)
Donglu Shi
2009-01-01
Full Text Available Asymmetric inorganic/organic composite nanoparticles with anisotropic surface functionalities represent a new approach for creating smart materials, requiring the selective introduction of chemical groups to dual components of composite, respectively. Here, we report the synthesis of snowman-like asymmetric silica/polystyrene heterostructure with anisotropic functionalities via a chemical method, creating nanostructure possibly offering two-sided biologic accessibility through the chemical groups. Carboxyl group was introduced to polystyrene component of the snowman-like composites by miniemulsion polymerization of monomer on local surface of silica particles. Moreover, amino group was then grafted to remained silica surface through facile surface modification of the composite nanoparticles. The asymmetric shape of these composites was confirmed by TEM characterization. Moreover, characteristics of anisotropic surface functionalities were indicated by Zeta potential measurement and confocal laser microscopy after being labeled with fluorescent dyes. This structure could find potential use as carriers for biological applications.
Latest Results in Central Exclusive Production: A Summary
Harland-Lang, L A; Ryskin, M G; Stirling, W J
2013-01-01
Selected new results in central exclusive production (CEP) processes within the pQCD-based Durham model are discussed. Topics covered include the CEP of SM and BSM Higgs-like particles, meson pair CEP and the gap survival probability.
Asymmetric membrane osmotic capsules for terbutaline sulphate
Directory of Open Access Journals (Sweden)
N G Gobade
2012-01-01
Full Text Available The aim of the present study was to design an asymmetric membrane capsule, an osmotic pump-based drug delivery system of ethyl cellulose for controlled release of terbutaline sulphate. asymmetric membrane capsules contains pore-forming water soluble additive, sorbitol in different concentrations in the capsule shell membrane, which after coming in contact with water, dissolves, resulting in an in situ formation of a microporous structure. The terbutaline sulphate is a β-adrenoreceptor agonist widely used in the treatment of asthma. The oral dosage regimen of terbutaline sulphate is 5 mg twice or thrice daily, the plasma half-life is approximate 3-4 h and it produces GI irritation with extensive first pass metabolism. Hence, terbutaline sulphate was chosen as a model drug with an aim to develop controlled release system. Different formulations of ethyl cellulose were prepared by phase inversion technique using different concentrations of sorbitol as pore forming agent. It was found that the thickness of the prepared asymmetric membrane capsules was increased with increase in concentration of ethyl cellulose and pore forming agent, i.e. sorbitol. The dye release study in water and 10% sodium chloride solution indicates that, the asymmetric membrane capsules follow osmotic principle to release content. The pores formed due to sorbitol were confirmed by microscopic observation of transverse section of capsule membrane. Data of in vitro release study of terbutaline sulphate from asymmetric membrane capsules indicated that, the capsules prepared with 10% and 12.5% of ethyl cellulose and 25% of sorbitol released as much as 97.44% and 76.27% in 12 h, respectively with zero order release rate. Hence asymmetric membrane capsule of 10% ethyl cellulose and 25% of sorbitol is considered as optimum for controlled oral delivery of terbutaline sulphate.
Asymmetric membrane osmotic capsules for terbutaline sulphate.
Gobade, N G; Koland, Marina; Harish, K H
2012-01-01
The aim of the present study was to design an asymmetric membrane capsule, an osmotic pump-based drug delivery system of ethyl cellulose for controlled release of terbutaline sulphate. asymmetric membrane capsules contains pore-forming water soluble additive, sorbitol in different concentrations in the capsule shell membrane, which after coming in contact with water, dissolves, resulting in an in situ formation of a microporous structure. The terbutaline sulphate is a β-adrenoreceptor agonist widely used in the treatment of asthma. The oral dosage regimen of terbutaline sulphate is 5 mg twice or thrice daily, the plasma half-life is approximate 3-4 h and it produces GI irritation with extensive first pass metabolism. Hence, terbutaline sulphate was chosen as a model drug with an aim to develop controlled release system. Different formulations of ethyl cellulose were prepared by phase inversion technique using different concentrations of sorbitol as pore forming agent. It was found that the thickness of the prepared asymmetric membrane capsules was increased with increase in concentration of ethyl cellulose and pore forming agent, i.e. sorbitol. The dye release study in water and 10% sodium chloride solution indicates that, the asymmetric membrane capsules follow osmotic principle to release content. The pores formed due to sorbitol were confirmed by microscopic observation of transverse section of capsule membrane. Data of in vitro release study of terbutaline sulphate from asymmetric membrane capsules indicated that, the capsules prepared with 10% and 12.5% of ethyl cellulose and 25% of sorbitol released as much as 97.44% and 76.27% in 12 h, respectively with zero order release rate. Hence asymmetric membrane capsule of 10% ethyl cellulose and 25% of sorbitol is considered as optimum for controlled oral delivery of terbutaline sulphate. PMID:23204625
Asymmetric transfer of auditory perceptual learning
Directory of Open Access Journals (Sweden)
SygalAmitay
2012-11-01
Full Text Available Perceptual skills can improve dramatically even with minimal practice. A major and practical benefit of learning, however, is in transferring the improvement on the trained task to untrained tasks or stimuli, yet the mechanisms underlying this process are still poorly understood. Reduction of internal noise has been proposed as a mechanism of perceptual learning, and while we have evidence that frequency discrimination (FD learning is due to a reduction of internal noise, the source of that noise was not determined. In this study, we examined whether reducing the noise associated with neural phase locking to tones can explain the observed improvement in behavioural thresholds. We compared FD training between two tone durations (15 and 100 ms that straddled the temporal integration window of auditory nerve fibers upon which computational modeling of phase locking noise was based. Training on short tones resulted in improved FD on probe tests of both the long and short tones. Training on long tones resulted in improvement only on the long tones. Simulations of FD learning, based on the computational model and on signal detection theory, were compared with the behavioral FD data. We found that improved fidelity of phase locking accurately predicted transfer of learning from short to long tones, but also predicted transfer from long to short tones. The observed lack of transfer from long to short tones suggests the involvement of a second mechanism. Training may have increased the temporal integration window which could not transfer because integration time for the short tone is limited by its duration. Current learning models assume complex relationships between neural populations that represent the trained stimuli. In contrast, we propose that training-induced enhancement of the signal-to-noise ratio offers a parsimonious explanation of learning and transfer that easily accounts for asymmetric transfer of learning.
Directory of Open Access Journals (Sweden)
Henry de-Graft Acquah
2013-01-01
Full Text Available Information Criteria provides an attractive basis for selecting the best model from a set of competing asymmetric price transmission models or theories. However, little is understood about the sensitivity of the model selection methods to model complexity. This study therefore fits competing asymmetric price transmission models that differ in complexity to simulated data and evaluates the ability of the model selection methods to recover the true model. The results of Monte Carlo experimentation suggest that in general BIC, CAIC and DIC were superior to AIC when the true data generating process was the standard error correction model, whereas AIC was more successful when the true model was the complex error correction model. It is also shown that the model selection methods performed better in large samples for a complex asymmetric data generating process than with a standard asymmetric data generating process. Except for complex models, AIC's performance did not make substantial gains in recovery rates as sample size increased. The research findings demonstrate the influence of model complexity in asymmetric price transmission model comparison and selection.
Algebraic Davis Decomposition and Asymmetric Doob Inequalities
Hong, Guixiang; Junge, Marius; Parcet, Javier
2016-04-01
In this paper we investigate asymmetric forms of Doob maximal inequality. The asymmetry is imposed by noncommutativity. Let {({M}, τ)} be a noncommutative probability space equipped with a filtration of von Neumann subalgebras {({M}_n)_{n ≥ 1}} , whose union {bigcup_{n≥1}{M}_n} is weak-* dense in {{M}} . Let {{E}_n} denote the corresponding family of conditional expectations. As an illustration for an asymmetric result, we prove that for {1 algebraic atomic description for the involved Hardy spaces. The latter results are new even for commutative von Neumann algebras.
Improved DFIG Capability during Asymmetrical Grid Faults
DEFF Research Database (Denmark)
Zhou, Dao; Blaabjerg, Frede
In the wind power application, different asymmetrical types of the grid fault can be categorized after the Y/d transformer, and the positive and negative components of a single-phase fault, phase-to-phase fault, and two-phase fault can be summarized. Due to the newly introduced negative and even......, the capability of a 2 MW DFIG to ride through asymmetrical grid faults can be estimated at the existing design of the power electronics converter. Finally, a control scheme aimed to improve the DFIG capability is proposed and the simulation results validate its feasibility....
Hot and flowing, asymmetric nuclear matter
International Nuclear Information System (INIS)
We develop a consistent treatment for hot and flowing asymmetric nuclear matter. Using the mean-field theory, predictions of the σ- ω Walecka model at finite temperature are compared with the corresponding results of the Zimanyi-Moszlowski and the non-linear models. The statistical theory of grand-canonical potentials is incorporated to the formalism. We also describe the behavior, at finite temperature, of the asymmetric and flowing nuclear matter. As an application, we describe bulk properties of neutron and protoneutron stars by considering the Tolman-Oppenheimer-Volkoff equations. (author)
Asymmetric acoustic transmission in multiple frequency bands
International Nuclear Information System (INIS)
We report both experimentally and numerically that the multi-band device of the asymmetric acoustic transmission is realized by placing two periodic gratings with different periods on both sides of two brass plates immersed in water. The asymmetric acoustic transmission can exist in four frequency bands below 1500 kHz, which arises from the interaction between various diffractions from the two gratings and Lamb modes in the brass plates immersed in water. The results indicate that the device has the advantages of multiple band, broader bandwidth, and simpler structure. Our finding should have great potential applications in ultrasonic devices
Jaime A Usma Wilches
2009-01-01
This paper examines the National Bilingual Program in connection with other education and language reforms in Colombia and some of the processes of inclusion, exclusion, and stratification that accompany current school reforms. The author outlines some patterns that have accompanied language innovations in the country and highlights some interconnected processes that seem to be favored in international reform and are reflected in current national policy agendas; namely, the externalization of...
Asymmetric Synthesis Using Enzymes in Supercritical CO2
Institute of Scientific and Technical Information of China (English)
T. Matsuda
2005-01-01
@@ 1Introduction Great efforts have been extended to catalysis in supercritical CO2 (scCO2) since the early 1990's due to the environmental friendliness, high diffusivity, high solubilizing power, easiness of the product separation,etc.. A combined process of scCO2 and enzymatic catalyst system would be a promising synthetic tool to produce optically active compounds because the enzyme has advantages of being natural and having high enantioselectivity in nature. Here we report asymmetric synthesis using lipase and alcohol dehydrogenase in scCO2[1,2].
Pairing effects on spinodal decomposition of asymmetric nuclear matter
Directory of Open Access Journals (Sweden)
Burrello S.
2015-01-01
Full Text Available We present an analysis framed in the general context of two-component fermionic systems subjected to pairing correlations. The study is conducted for unstable asymmetric nuclear matter at low temperature, along the clusterization process driven by spinodal instabilities. It is shown that, especially around the transition temperature from the superfluid to the normal phase, pairing correlations may have non-negligible effects on the isotopic features of the clusterized low-density matter, which could be of interest also in the astrophysical context.
CERN Summer Student Project: Central Exclusive Diffraction and Glueball Searches
van Beest, Marieke
2016-01-01
CERN Summer Student work project report on work conducted in the Diffraction group at the ALICE experiment as well as the obtained results. These include a kinematical calculation with respect to a generic central exclusive process, the selection rules for a centrally produced system with respect to a specific central exclusive diffraction process, and finally a case study of one of the first contributions to the search for glueballs at CERN.
Exclusive quarkonium production in pp collisions
International Nuclear Information System (INIS)
Central exclusive production (CEP) processes in high-energy proton - (anti)proton collisions offer a very promising framework within which to study both novel aspects of QCD and new physics signals. Among the many interesting processes that can be studied in this way, those involving the production of heavy (c,b) quarkonia states are of particular importance, serving as 'standard candle' processes with which we can benchmark predictions for new physics CEP at the CERN Large Hadron Collider, as well as being of interest in their own right. We report on our recent quantitative studies of exclusive heavy quarkonia (χ and η) production, and make cross section predictions for the LHC, Tevatron and RHIC. We also examine the possibility of observing quarkonium CEP at RHIC with tagged forward protons, for which measurements of the outgoing proton momenta would provide interesting spin-parity information about the centrally produced state.
Asymmetric and axisymmetric dynamics of tropical cyclones
Directory of Open Access Journals (Sweden)
J. Persing
2013-05-01
into annular rings, the azimuthally-averaged heating rate and radial gradient thereof is considerably less than that in the AX model. This lack of organization results broadly in a slower intensification rate in the 3-D model and leads ultimately to a weaker mature vortex after 12 days of model integration. While axisymmetric heating rates in the 3-D model are weaker than those in the AX model, local heating rates in the 3-D model exceed those in the AX model and at times the vortex in the 3-D model intensifies more rapidly than AX. Analyses of the 3-D model output do not support a recent hypothesis concerning the key role of small-scale vertical mixing processes in the upper-tropospheric outflow in controlling the intensification process. In the 3-D model, surface drag plays a particularly important role in the intensification process for the prototype intensification problem on meteorologically relevant time scales by helping foster the organization of convection in azimuth. There is a radical difference in the behaviour of the 3-D and AX simulations when the surface drag is reduced or increased from realistic values. Borrowing from ideas developed in a recent paper, we give a partial explanation for this difference in behaviour. Our results provide new qualitative and quantitative insight into the differences between the asymmetric and symmetric dynamics of tropical cyclones and would appear to have important consequences for the formulation of a fluid dynamical theory of tropical cyclone intensification and mature intensity. In particular, the results point to some fundamental limitations of strict axisymmetric theory and modelling for representing the azimuthally-averaged behaviour of tropical cyclones in three dimensions.
Is Amino-Acid Homochirality Due To Asymmetric Photolysis In Space?
Cerf, C
1999-01-01
Amino acids occurring in proteins are, with rare exceptions, exclusively of the L-configuration. Among the many scenarios put forward to explain the origin of this chiral homogeneity (i.e., homochirality), one involves the asymmetric photolysis of amino acids present in space, triggered by circularly polarized UV radiation. The recent observation of circularly polarized light (CPL) in the Orion OMC-1 star-forming region (Bailey et al. 1998, Science 281, 672) has been presented as providing a strong validation of this scenario. The present paper reviews the situation. It is stressed for example that one important condition for the asymmetric photolysis by CPL to be at the origin of the terrestrial homochirality of natural amino acids is generally overlooked, namely, the asymmetric photolysis should favour the L-enantiomer for ALL the primordial amino acids involved in the genesis of life (i.e., biogenic amino acids). Although this condition is probably satisfied for aliphatic amino acids, some non-aliphatic am...
Institute of Scientific and Technical Information of China (English)
无
2008-01-01
One-pass asymmetric hot extrusion performed at 673 K was applied to fabricate an AZ31 magnesium alloy sheet.Finite element method(FEM)was used to model the process of asymmetric hot-extrusion.Simulation results indicate that strain rate gradient througa the thickness introduced a grain size gradient along the thickness direction and shear deformation during the asymmetric hot-extrusion results in weakened and tilted(0002)basal texture.The asymmetric hot extrusion effectively weakens the basal texture and improves the ductility,at room temperature.
Asymmetric cell division: a persistent issue?
Aakre, Christopher D.; Laub, Michael T.
2012-01-01
Heterogeneity within a clonal population of cells can increase survival in the face of environmental stress. In a recent issue of Science, Aldridge et al. (2012) demonstrate that cell division in mycobacteria is asymmetric, producing daughter cells that differ in size, growth rate, and susceptibility to antibiotics.
Asymmetric demand for energy: A cointegration approach
Maclean, Thomas Frank
1997-12-01
This paper uses time series data in a study of the demand for energy. One goal is to compare the results from the traditional autoregressive distributed lag (ADL) model to the error correction model (ECM) using cointegration. The second goal is to determine if the demand elasticity is asymmetric with respect to increasing and decreasing prices. This paper discusses three topics that are important to the use of time series data. The first topic is the presence and consequences unit roots which are common in time series data. The second topic is the identification of cointegrated variables and the third topic is a development of the ECM. This results in a model that can be used in either a single equation or multivariate system context and it will estimate both long run and short run elasticities. Asymmetry theory and its implications are studied along with an investigation into competing methods of creating the asymmetric variables. Simulations provided evidence that the use of dummy variables results in biased estimates and that the cumulative difference method of Wolffram/Houck gives valid estimates. The results of the empirical part of the paper show that the short run estimates of the ADL model are like those of the error correction model, but the cointegration method's long run estimates are better since they are known to be consistent and asymptotically unbiased. Tests for asymmetry do not support the theory of asymmetric long run price elasticities; however there is evidence to support the presence of asymmetric demand in the short run.
Leverage bounds with default and asymmetric information
Czech Academy of Sciences Publication Activity Database
Boháček, Radim
2014. [2014 North American Summer Meeting of the Econometric Society. Minneapolis (US), 19.06.2014-22.06.2014] R&D Projects: GA ČR GA402/09/1340 Institutional support: RVO:67985998 Keywords : financial markets and the macroeconomy * asymmetric and private information * occupational choice Subject RIV: AH - Economics http://editorialexpress.com/conference/NASM2014/program/NASM2014.html
Asymmetric Taxation under Incremental and Sequential Investment
Panteghini, Paolo
2002-01-01
This article discusses the effects of an asymmetric tax scheme on incremental and sequential investment strategies. The tax base is equal to the firms return, net of an imputation rate. When the firms return is less than this rate, however, no tax refunds are allowed. This scheme is neutral under both income and capital uncertainty.
Beam-beam issues in asymmetric colliders
Energy Technology Data Exchange (ETDEWEB)
Furman, M.A.
1992-07-01
We discuss generic beam-beam issues for proposed asymmetric e{sup +}- e{sup -} colliders. We illustrate the issues by choosing, as examples, the proposals by Cornell University (CESR-B), KEK, and SLAC/LBL/LLNL (PEP-II).
Catalytic asymmetric synthesis of mycocerosic acid
ter Horst, B.; Feringa, B.L.; J. Minnaard, A.
2007-01-01
The first catalytic asymmetric total synthesis of mycocerosic acid was achieved via the application of iterative enantioselective 1,4-addition reactions and allows for the efficient construction of 1,3-polymethyl arrays with full stereocontrol; further exemplified by the synthesis of tetramethyl-dec
Evidence of asymmetric top in 130Ba
International Nuclear Information System (INIS)
Introduced is a new relation connecting moment of inertia, Lipas parameter and asymmetric rotor model energies and put forward much closer trend in odd even staggering of quasi γ-band. A different view point regarding generation of quasi γ-band in 130Ba have been presented
Asymmetric conditional volatility in international stock markets
Ferreira, Nuno B.; Menezes, Rui; Mendes, Diana A.
2007-08-01
Recent studies show that a negative shock in stock prices will generate more volatility than a positive shock of similar magnitude. The aim of this paper is to appraise the hypothesis under which the conditional mean and the conditional variance of stock returns are asymmetric functions of past information. We compare the results for the Portuguese Stock Market Index PSI 20 with six other Stock Market Indices, namely the SP 500, FTSE 100, DAX 30, CAC 40, ASE 20, and IBEX 35. In order to assess asymmetric volatility we use autoregressive conditional heteroskedasticity specifications known as TARCH and EGARCH. We also test for asymmetry after controlling for the effect of macroeconomic factors on stock market returns using TAR and M-TAR specifications within a VAR framework. Our results show that the conditional variance is an asymmetric function of past innovations raising proportionately more during market declines, a phenomenon known as the leverage effect. However, when we control for the effect of changes in macroeconomic variables, we find no significant evidence of asymmetric behaviour of the stock market returns. There are some signs that the Portuguese Stock Market tends to show somewhat less market efficiency than other markets since the effect of the shocks appear to take a longer time to dissipate.
Detection loophole in asymmetric Bell experiments
Brunner, Nicolas; Gisin, Nicolas; Scarani, Valerio; Simon, Christoph
2007-01-01
The problem of closing the detection loophole with asymmetric systems, such as entangled atom-photon pairs, is addressed. We show that, for the Bell inequality I_3322, a minimal detection efficiency of 43% can be tolerated for one of the particles, if the other one is always detected. We also study the influence of noise and discuss the prospects of experimental implementation.
Directory of Open Access Journals (Sweden)
Nandakumar Sundararaju
2014-05-01
Full Text Available This paper proposes novel hybrid asymmetric space vector modulation technique for inverter operated direct torque control induction motor drive. The hybridization process is performed by the combination of continuous asymmetric space vector modulation pulse width technique (ASVPWM and fuzzy operated discontinuous ASVPWM technique. Combination process is based on pulse mismatching technique. Pulse mismatching technique helps to reduce the active region of the switch. Finally, optimal pulses are applied to control the inverter. The optimal hybrid pulse condense switching losses of the inverter and also improves the operating performance of the direct torque control (DTC based drive system like smooth dynamic response in speed reversal, minimum torque error, settling time of speed. Simulation results of proposed hybrid asymmetric space vector pulse width modulation technique to direct torque control (HASVPWM-DTC approach has been carried out by using Matlab-Simulink environment.
Arbitrary Truncated Levy Flight: Asymmetrical Truncation and High-Order Correlations
Vinogradov, Dmitry V
2012-01-01
The generalized correlation approach, which has been successfully used in statistical radio physics to describe non-Gaussian random processes, is proposed to describe stochastic financial processes. The generalized correlation approach has been used to describe a non-Gaussian random walk with independent, identically distributed increments in the general case, and high-order correlations have been investigated. The cumulants of an asymmetrically truncated Levy distribution have been found. The behaviors of asymmetrically truncated Levy flight, as a particular case of a random walk, are considered. It is shown that, in the Levy regime, high-order correlations between values of asymmetrically truncated Levy flight exist. The source of high-order correlations is the non-Gaussianity of the increments: the increment skewness generates threefold correlation, and the increment kurtosis generates fourfold correlation.
Standards vs. labels with imperfect competition and asymmetric information
DEFF Research Database (Denmark)
Baltzer, Kenneth Thomas
2012-01-01
I demonstrate that providing information about product quality is not necessarily the best way to address asymmetric information problems when markets are imperfectly competitive. In a vertical differentiation model I show that a Minimum Quality Standard, which retains asymmetric information...
Standards vs. labels with imperfect competition and asymmetric information
DEFF Research Database (Denmark)
Baltzer, Kenneth Thomas
I demonstrate that providing information about product quality is not necessarily the best way to address asymmetric information problems when markets are imperfectly competitive. In a vertical dierentiation model I show that a Minimum Quality Standard, which retains asymmetric information...
Asymmetric Bulkheads for Cylindrical Pressure Vessels
Ford, Donald B.
2007-01-01
Asymmetric bulkheads are proposed for the ends of vertically oriented cylindrical pressure vessels. These bulkheads, which would feature both convex and concave contours, would offer advantages over purely convex, purely concave, and flat bulkheads (see figure). Intended originally to be applied to large tanks that hold propellant liquids for launching spacecraft, the asymmetric-bulkhead concept may also be attractive for terrestrial pressure vessels for which there are requirements to maximize volumetric and mass efficiencies. A description of the relative advantages and disadvantages of prior symmetric bulkhead configurations is prerequisite to understanding the advantages of the proposed asymmetric configuration: In order to obtain adequate strength, flat bulkheads must be made thicker, relative to concave and convex bulkheads; the difference in thickness is such that, other things being equal, pressure vessels with flat bulkheads must be made heavier than ones with concave or convex bulkheads. Convex bulkhead designs increase overall tank lengths, thereby necessitating additional supporting structure for keeping tanks vertical. Concave bulkhead configurations increase tank lengths and detract from volumetric efficiency, even though they do not necessitate additional supporting structure. The shape of a bulkhead affects the proportion of residual fluid in a tank that is, the portion of fluid that unavoidably remains in the tank during outflow and hence cannot be used. In this regard, a flat bulkhead is disadvantageous in two respects: (1) It lacks a single low point for optimum placement of an outlet and (2) a vortex that forms at the outlet during outflow prevents a relatively large amount of fluid from leaving the tank. A concave bulkhead also lacks a single low point for optimum placement of an outlet. Like purely concave and purely convex bulkhead configurations, the proposed asymmetric bulkhead configurations would be more mass-efficient than is the flat
Directory of Open Access Journals (Sweden)
Márcia Lazaro de Carvalho
2006-06-01
Full Text Available O estudo do perfil sociodemográfico, história penal, uso de drogas e doenças sexualmente transmissíveis da população carcerária do Estado do Rio de Janeiro, em 1998, permitiu conhecer diferentes características da população prisional por sexo. O objetivo deste estudo é identificar se o perfil de exclusão social a que essa população é submetida difere quanto ao sexo. Foram entrevistados 2.039 presos por estudo seccional, e utilizada a razão de prevalência como medida de associação entre sexo e as demais variáveis. A análise multivariada, através de regressão logística, compõe um modelo final de explicação dessas diferenças. A população é jovem, de baixa escolaridade, e apresenta ruptura de vínculos da vida social em várias dimensões para ambos os sexos. Fatores mais fortemente associados ao sexo masculino: visita íntima na prisão, estar preso por sete anos ou mais, ser casado, condenação por roubo, ter ainda três anos ou mais a cumprir de pena e uso de maconha antes de ser preso; para o sexo feminino: doença sexualmente transmissível, ser viúva, estrangeira, usar tranqüilizante na prisão, ter visitado alguém na prisão antes de ser presa e ter 35 anos ou mais. A análise dos dados permitiu concluir que embora esses homens e mulheres sejam igualmente excluídos da "vida social" muito antes e também depois da prisão, existem algumas características que os diferenciam nesse processo de injustiça social.The study of the social and demographic profile, criminal records, drug use and sexually transmitted diseases of the prison population of Rio de Janeiro State in 1998 offered a view of different aspects of this population by gender. The objective of this study is to identify if the profile of social exclusion this population is submitted differs by gender. Through a sectional study, 2,039 prisoners were interviewed, using the prevalence ratio as an association measure between gender and the other
Exclusive dimuon measurements with LHCb
Shears, Tara
2011-01-01
A measurement of exclusive dimuon production provides a clean test of QED and QCD predictions in a low multiplicity environment. Exclusively produced dimuon pairs can be produced by two photon fusion, or through resonances produced by pomeron-photon fusion or double pomeron exchange. We present cross-section measurements for exclusive dimuon production, and the first observations at a proton proton collider of exclusive J/$\\psi$, $\\psi(2S)$ and $\\chi_c$ states, obtained with 37 pb$^{-1}$ of data at a centre-of-mass energy of 7 TeV, collected by the LHCb experiment.
DEFF Research Database (Denmark)
1995-01-01
turbidity-causing components from beer, wine, fruit juice, milk and blood, and from bacterial and enzyme suspensions. ADVANTAGE-The process greatly reduces the lost production time associated with earlier filtration methods, and beneficial components can pass through the membrane, thereby improving the...
Hydrodynamic Limit For An Active Exclusion Process
Clément, Erignoux
2016-01-01
Collective dynamics can be observed among many animal species, and have given rise in the last decades to an active and interdisciplinary field of study. Such behaviors are often modeled by active matter, in which each individual is self-driven and tends to update its velocity depending on the one of its neighbors. In a classical model introduced by Vicsek \\and al., as well as in numerous related active matter models, a phase transition between chaotic behavior at high temperature and global ...
Concise Review: Asymmetric Cell Divisions in Stem Cell Biology
Directory of Open Access Journals (Sweden)
Florian Murke
2015-11-01
Full Text Available Somatic stem cells are rare cells with unique properties residing in many organs and tissues. They are undifferentiated cells responsible for tissue regeneration and homeostasis, and contain both the capacity to self-renew in order to maintain their stem cell potential and to differentiate towards tissue-specific, specialized cells. However, the knowledge about the mechanisms controlling somatic stem cell fate decisions remains sparse. One mechanism which has been described to control daughter cell fates in selected somatic stem cell systems is the process of asymmetric cell division (ACD. ACD is a tightly regulated and evolutionary conserved process allowing a single stem or progenitor cell to produce two differently specified daughter cells. In this concise review, we will summarize and discuss current concepts about the process of ACD as well as different ACD modes. Finally, we will recapitulate the current knowledge and our recent findings about ACD in human hematopoiesis.
Mini review of Central Exclusive Production at LHC
Brona, Grzegorz
2009-01-01
The LHC experiments provide an unprecedented coverage in pseudo-rapidity. This advantage and the high LHC luminosity allow for broad studies of central exclusive production (CEP) \\mbox{processes} such as exclusive production of $\\Upsilon$, di-leptons, di-photons and di-jets. With the proposed near beam detectors (FP420 and FP220) exclusive Higgs and SUSY states will be also \\mbox{accesible}. The \\mbox{discussion} is focused on the CMS programme, but both CMS and ATLAS have similar \\mbox{kinematical} coverage and may perform similar studies.
Mini review of Central Exclusive Production at LHC
Brona, Grzegorz
2009-01-01
The LHC experiments provide an unprecedented coverage in pseudo-rapidity. This advantage and high LHC luminosity allow for broad studies of central exclusive production (CEP) processes such as exclusive production of ¡, di-leptons, di-photons and di-jets. Finally, with the proposed near beam detectors (FP420 and FP220) the exclusive Higgs and SUSY states will be also accesible. The discussion is focused on the CMS programme, as both CMS and ATLAS have similar kinematical coverage and may perform similar studies.
International Nuclear Information System (INIS)
Studies results on heat transfer by forced convection of highly sub-heated water in a smooth tube and with a worm feeder under asymmetric heating are presented. Experimental data file on stationary heat transfer during asymmetric tube heating by electron scanning beam with ultimately high density of heat fluxes, exceeding 100 MW/m2, are obtained. Brief description of an approximative model for temperature field calculation, simplifying experimental data processing, is given
Exclusive pi^+ production at HERMES
C. Hadjidakis; Hasch, D.; Thomas, E.; collaboration, for the HERMES
2004-01-01
Hard exclusive production in deep inelastic lepton scattering provides access to the unknown Generalized Parton Distributions (GPDs) of the nucleon. At HERMES, different observables for hard exclusive pi^+ production have been measured with a 27.6 GeV positron beam on an internal hydrogen gas target. First preliminary results for the unpolarized ep->enpi^+ total cross section for 1.5
Asymmetric magnetic reconnection with out-of-plane shear flows in a two dimensional hybrid model
International Nuclear Information System (INIS)
Effects of out-of-plane shear flows on asymmetric magnetic reconnect are investigated in a two-dimensional (2D) hybrid model with an initial Harris sheet equilibrium. It is found that the out-of-plane flow with an in-plane shear can significantly change the asymmetric reconnection process as well as the related geometry. The magnetic flux, out-of-plane magnetic field, in-plane flow vorticity, plasma density, and the reconnection rate are discussed in detail. The results are in comparison with the cases without the shear flows to further understand the effect
Institute of Scientific and Technical Information of China (English)
LIAO Ming-Yi; YAO Wen-Gang; FENG Hai-Tao; WANG Jian-Bo
2003-01-01
@@ Enantioselective aldol condensation under catalytic condition remains a challenging task in modern organic synthesis, and numerous efforts have been directed to this area. In particular, the direct catalytic asymmetric aldol reaction is very attractive considering the requirement of atom efficiency. This has been studied only recently, and several very practical processes have been developed. We have recently initiated a study on the direct asymmetric aldol type reaction with ethyl diazoacetate as nucleophile. Moderate enantioselectivities (65% ～91% ee ) were achieved in the condensation of aldehydes with ethyl diazoacetate catalyzed by the chiral complex of BINOL derivatives-Zr (OBu- t )4. [1
International Nuclear Information System (INIS)
This Resolution authorizes the direct contracting of the Geophysical AS petroleum firm by Ancap. This contract has the purpose of the execution, marketing and revenue participation in a program for the acquisition and processing of three dimensional seismic data 'Costa afuera del Uruguay' no exclusive. ANCAP is the only organization that authorizes the execution of the activities, businesses and operations of the oil industry according to regulations.
Abnormal Neural Responses to Social Exclusion in Schizophrenia
Gradin, Victoria B.; Gordon Waiter; Poornima Kumar; Catriona Stickle; Maarten Milders; Keith Matthews; Ian Reid; Jeremy Hall; J Douglas Steele
2012-01-01
Social exclusion is an influential concept in politics, mental health and social psychology. Studies on healthy subjects have implicated the medial prefrontal cortex (mPFC), a region involved in emotional and social information processing, in neural responses to social exclusion. Impairments in social interactions are common in schizophrenia and are associated with reduced quality of life. Core symptoms such as delusions usually have a social content. However little is known about the neural ...
Central exclusive meson pair production in the perturbative regime
Harland-Lang, L A; Ryskin, M G; Stirling, W J
2011-01-01
We present a study of the central exclusive production (CEP) of meson pairs, MMbar, at sufficiently high invariant mass that a perturbative QCD formalism is applicable. Within this framework, MMbar production proceeds via the gg --> MMbar hard scattering sub-process, which can be calculated within the hard exclusive formalism. We present explicit calculations for the gg --> MMbar helicity amplitudes for different meson states and, using these, show results for meson pair CEP in the perturbative regime.
Asymmetric Catalysis with CO2 : The Direct α-Allylation of Ketones.
Pupo, Gabriele; Properzi, Roberta; List, Benjamin
2016-05-10
Quaternary stereocenters are found in numerous bioactive molecules. The Tsuji-Trost reaction has proven to be a powerful C-C bond forming process, and, at least in principle, should be well suited to access quaternary stereocenters via the α-allylation of ketones. However, while indirect approaches are known, the direct, catalytic asymmetric α-allylation of branched ketones has been elusive until today. By combining "enol catalysis" with the use of CO2 as a formal catalyst for asymmetric catalysis, we have now developed a solution to this problem: we report a direct, highly enantioselective and highly atom-economic Tsuji-Trost allylation of branched ketones with allylic alcohol. Our reaction delivers products bearing quaternary stereocenters with high enantioselectivity and water as the sole by-product. We expect our methodology to be of utility in asymmetric catalysis and inspire the design of other highly atom-economic transformations. PMID:27071633
Effect of plate asymmetric rolling parameters on the change of the total unit pressure of roll
Directory of Open Access Journals (Sweden)
A. Kawalek
2011-07-01
Full Text Available This work shows the results of theoretical analysis of asymmetric rolling process of plates in the finishing mill of plate rolling. Its aim was to determine the influence of asymmetry velocity of working rolls on decrease of unit pressure of metal on the rolls. The lower value of the unit pressure will reduce the elastic deflection of the finishing stand and improve the cross-section shape of plate. Three-dimensional simulation of asymmetric hot rolling of S355J2G3 steel plates was done with the aid of FORGE 2008® software. The tensor polynomial interpolation was used for comparing the values of the unit pressure obtaining from symmetric and asymmetric rolling.
Turning Cucurbit[8]uril into a Supramolecular Nanoreactor for Asymmetric Catalysis.
Zheng, Lifei; Sonzini, Silvia; Ambarwati, Masyitha; Rosta, Edina; Scherman, Oren A; Herrmann, Andreas
2015-10-26
Chiral macromolecules have been widely used as synthetic pockets to mimic natural enzymes and promote asymmetric reactions. An achiral host, cucurbit[8]uril (CB[8]), was used for an asymmetric Lewis acid catalyzed Diels-Alder reaction. We achieved a remarkable increase in enantioselectivity and a large rate acceleration in the presence of the nanoreactor by using an amino acid as the chiral source. Mechanistic and computational studies revealed that both the amino acid-Cu(2+) complex and the dienophile substrate are included inside the macrocyclic host cavity, suggesting that contiguity and conformational constraints are fundamental to the catalytic process and rate enhancement. These results pave the way towards new studies on asymmetric reactions catalyzed in confined achiral cavities. PMID:26383272
International Nuclear Information System (INIS)
This paper presents the results of vibration tests of PWR core barrel model, which were performed in liquid flow of hydrodynamic testing circuit in symmetrical/asymmetrical flow conditions simulating 4 and 3 loop operations. The measurements of dynamic stresses and displacements were carried out, processed stochastically and analyzed by correlation techniques
Rahman, Shaikh Mahfuzur; Helal, Uddin
2006-01-01
Exploration of an exhaustible resource with cost recovery under asymmetric information about cost is modeled and analyzed employing Principal-Agent theory. Allocation of lower than full information level of effort for the high-cost firms is found socially optimal. However, distortion is less in a two-stage process of exploration and extraction.
Direct asymmetric dearomatization of 2-naphthols by scandium-catalyzed electrophilic amination.
Nan, Jiang; Liu, Jingjing; Zheng, Huayu; Zuo, Zhijun; Hou, Lei; Hu, Huaiming; Wang, Yaoyu; Luan, Xinjun
2015-02-16
Catalytic asymmetric aminative dearomatization of 1-substituted 2-naphthols was successfully implemented with electrophilic azodicarboxylates under the catalysis of chiral Sc(III)/pybox complexes. This intermolecular reaction represents a hitherto unknown enantioselective C-N bond-forming process through direct dearomatization of phenolic compounds to generate chiral nitrogen-containing quaternary carbon stereocenters. PMID:25564754
Asymmetric fuel assembly for BWR type reactor
International Nuclear Information System (INIS)
A coolant turning introduction member is properly extended at coolant flow channels on the side of control rod of an inner frame for supporting the insertion of a water channel. With such a constitution, the thermal margin of the fuel rods can be made uniform over the entire region of the channel box by supplying coolants uniformly for an asymmetrical fuel assembly which can effectively suppress local peaking coefficient thereby enabling to improve performances at limit power. In addition, in the asymmetrical fuel assembly, a flow vane disposed to the outer frame plate of a spacer is increased in the size at coolant flow channels on the side of the control rod. Then, sufficient amount of coolants can surely be supplied to fuel rods at coolant flow channels on the side of the control rod. (N.H.)
ON ASYMMETRIC DISTRIBUTIONS OF SATELLITE GALAXIES
International Nuclear Information System (INIS)
We demonstrate that the asymmetric distribution of M31 satellites cannot be produced by tides from the Milky Way as such effects are too weak. However, loosely bound associations and groups of satellites can fall into larger halos and give rise to asymmetries. We compute the survival times for such associations. We prove that the survival time is always shortest in Keplerian potentials, and can be ∼3 times longer in logarithmic potentials. We provide an analytical formula for the dispersal time in terms of the size and velocity dispersion of the infalling structure. We show that, if an association of ∼10 dwarfs fell into the M31 halo, its present aspect would be that of an asymmetric disk of satellites. We also discuss the case of cold substructure in the Andromeda II and Ursa Minor dwarfs
Cosmological signatures of time-asymmetric gravity
Cortês, Marina; Smolin, Lee
2016-01-01
We develop the model proposed by Cort\\^es, Gomes & Smolin, to predict cosmological signatures of time-asymmetric extensions of general relativity they proposed recently. Within this class of models the equation of motion of chiral fermions is modified by a torsion term. This term leads to a dispersion law for neutrinos that associates a new time-varying energy with each particle. We find a new neutrino contribution to the Friedmann equation resulting from the torsion term in the Ashtekar connection. In this note we explore the phenomenology of this term and observational consequences for cosmological evolution. We show that constraints on the critical energy density will ordinarily render this term unobservably small, a maximum of order $10^{-25}$ of the neutrino energy density today. However, if the time-asymmetric dark energy is tuned to cancel the cosmological constant, the torsion effect may be a dark matter candidate.
Effects of asymmetric sitting on spinal balance
Woo, Hee Soon; Oh, Jong Chi; Won, Sung Yoon
2016-01-01
[Purpose] To investigate the effects of two common asymmetric sitting positions on spinal balance. [Subjects and Methods] Thirty-seven healthy subjects in their twenties were enrolled and randomly divided into two groups. Asymmetric positions of resting the chin on a hand and crossing the legs were performed by each group for 1 hour. After 1 hour, the subjects lay in the supine position again and spinal imbalance was measured using a device. [Results] After 1 hour of resting with the chin on a hand, sagittal imbalance, coronal imbalance, pelvic obliquity and lordosis angle presented spinal imbalance worsening of 1 hour of crossing legs, sagittal imbalance, pelvic torsion showed in mainly learned spinal imbalance living. [Conclusion] Good posture could be an innate ability, however it through habits. So this study is meaningful from the perspective of the importance of good posture. PMID:27065291
Mixtures of Shifted Asymmetric Laplace Distributions
Franczak, Brian C.; Browne, Ryan P.; McNicholas, Paul D.
2012-01-01
A mixture of shifted asymmetric Laplace distributions is introduced and used for clustering and classification. A variant of the EM algorithm is developed for parameter estimation by exploiting the relationship with the general inverse Gaussian distribution. This approach is mathematically elegant and relatively computationally straightforward. Our novel mixture modelling approach is demonstrated on both simulated and real data to illustrate clustering and classification applications. In thes...
New ruthenium catalysts for asymmetric hydrogenation
Diaz Valenzuela, Maria Belen
2007-01-01
A review on catalytic asymmetric hydrogenation of C=O double bonds is presented in the first chapter. Noyori’s pioneering research on ruthenium complexes containing both phosphine and diamine ligands using [i superscript]PrOH and [t superscript]BuOK is described, this system gave impressive highly chemeo-selectivity for C=O bonds and extremely high enantioselectivity for a range of acetophenone derivatives. Numerous groups have been inspired by Noyori’s catalyst of the ty...
Competitive Price and Quality Under Asymmetric Information
Gerard J. Tellis; Birger Wernerfelt
1987-01-01
We present an analysis of equilibrium in markets with asymmetrically informed consumers. Some consumers know both price and quality of all sellers, whereas others know neither but may search among sellers. The equilibrium correlation between price and quality generally increases with the level of information in the market and can be negative when this level is sufficiently small. A meta-analysis of the available empirical studies strongly supports the model's predictions.
Cosmological signatures of time-asymmetric gravity
Cortês, Marina; Liddle, Andrew R; Smolin, Lee
2016-01-01
We develop the model proposed by Cort\\^es, Gomes & Smolin, to predict cosmological signatures of time-asymmetric extensions of general relativity they proposed recently. Within this class of models the equation of motion of chiral fermions is modified by a torsion term. This term leads to a dispersion law for neutrinos that associates a new time-varying energy with each particle. We find a new neutrino contribution to the Friedmann equation resulting from the torsion term in the Ashtekar conn...
Relative profit maximization in asymmetric oligopoly
Satoh, Atsuhiro; Tanaka, Yasuhito
2014-01-01
We analyze Bertrand and Cournot equilibria in an asymmetric oligopoly in which the firms produce differentiated substitutable goods and seek to maximize their relative profits instead of their absolute profits. Assuming linear demand functions and constant marginal costs we show the following results. If the marginal cost of a firm is lower (higher) than the average marginal cost over the industry, its output at the Bertrand equilibrium is larger (smaller) than that at the Cournot equilibrium...
Asymmetric inheritance of cytoophidia in Schizosaccharomyces pombe
Jing Zhang; Lydia Hulme; Ji-Long Liu
2014-01-01
ABSTRACT A general view is that Schizosaccharomyces pombe undergoes symmetric cell division with two daughter cells inheriting equal shares of the content from the mother cell. Here we show that CTP synthase, a metabolic enzyme responsible for the de novo synthesis of the nucleotide CTP, can form filamentous cytoophidia in the cytoplasm and nucleus of S. pombe cells. Surprisingly, we observe that both cytoplasmic and nuclear cytoophidia are asymmetrically inherited during cell division. Our t...
Interfacial properties of charge asymmetric ionic liquids
Alejandre, Jose; Bresme, Fernando; Gonzalez-Melchor, Minerva
2009-01-01
We report molecular dynamics simulations of the coexistence and interfacial properties of ionic liquids as a function of cation/anion, (z$_+$ : z$_-$) = (2:-1), (4:-1), charge asymmetry. Our results correct previous computations of the coexistence curve of (2:-1) charge asymmetric systems, obtained via the fine-lattice discretization method. In agreement with previous computations we report a reduction in the critical temperature and an increase in the critical density with charge asymmetry. ...
Asymmetric directed polymers in random environments
Flores, Gregorio R. Moreno
2010-01-01
The model of Brownian Percolation has been introduced as an approximation of discrete last-passage percolation models close to the axis. It allowed to compute some explicit limits and prove fluctuation theorems for these, based on the relations between the Brownian percolation and random matrices. Here, we present two approaches that allow to treat discrete asymmetric models of directed polymers. In both cases, the behaviour is universal, meaning that the results do not depend on the precise ...
On asymmetric collisions with large disruption parameters
International Nuclear Information System (INIS)
Collisions between a weak electron bunch and a strong positron bunch are studied within a flat model. Electrons are tracked through the transverse space charge field of the positron bunch, and it is shown that positrons in a storage ring may remain stable after asymmetric collisions with a weak electron bunch in spite of large values of the electron disruption parameter. The plasma oscillations that affect collisions with large disruption parameters may be suppressed by properly matching the electrons. 8 refs., 5 figs
Asymmetric dark matter from hidden sector baryogenesis
Energy Technology Data Exchange (ETDEWEB)
Dutta, Bhaskar [Department of Physics and Astronomy, Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States); Kumar, Jason, E-mail: jkumar@hawaii.edu [Department of Physics and Astronomy, University of Hawai' i, Honolulu, HI 96822 (United States)
2011-05-23
We consider the production of asymmetric dark matter during hidden sector baryogenesis. We consider a particular supersymmetric model where the dark matter candidate has a number density approximately equal to the baryon number density, with a mass of the same scale as the b, c and {tau}. Both baryon asymmetry and dark matter are created at the same time in this model. We describe collider and direct detection signatures of this model.
Trapdoor Privacy in Asymmetric Searchable Encryption Schemes
Delerue Arriaga, Afonso; TANG, QIANG; Ryan, Peter
2014-01-01
Asymmetric searchable encryption allows searches to be carried over ciphertexts, through delegation, and by means of trapdoors issued by the owner of the data. Public Key Encryption with Keyword Search (PEKS) is a primitive with such functionality that provides delegation of exact-match searches. As it is important that ciphertexts preserve data privacy, it is also important that trapdoors do not expose the user’s search criteria. The difficulty of formalizing a security model for trapdoor pr...
Asymmetric deformation of contracting human gastrocnemius muscle
Kinugasa, Ryuta; Hodgson, John A.; Edgerton, V. Reggie; Sinha, Shantanu
2011-01-01
Muscle fiber deformation is related to its cellular structure, as well as its architectural arrangement within the musculoskeletal system. While playing an important role in aponeurosis displacement, and efficiency of force transmission to the tendon, such deformation also provides important clues about the underlying mechanical structure of the muscle. We hypothesized that muscle fiber cross section would deform asymmetrically to satisfy the observed constant volume of muscle during a contra...
Interfacial properties of charge asymmetric ionic liquids
2009-01-01
Abstract We report molecular dynamics simulations of the coexistence and interfacial properties of ionic liquids as a function of cation/anion, (z$_+$ : z$_-$) = (2:-1), (4:-1), charge asymmetry. Our results correct previous computations of the coexistence curve of (2:-1) charge asymmetric systems, obtained via the fine-lattice discretization method. In agreement with previous computations we report a reduction in the critical temperature and an increase in the critical density wit...
OFFICER AND COMMANDER IN ASYMMETRIC WARFARE OPERATIONS
Giuseppe CAFORIO
2013-01-01
Starting from the data of a field research conducted among soldiers with asymmetric warfare experiences from nine different countries, the author seeks to identify and shed light on the various problems that officers with command responsibilities had to face during their missions. A picture emerges of feelings and experiences relating to their first impression upon arriving in the theatre, relations with local armed forces, relations with the local population and local authorities, relations ...
Dust temperatures in asymmetric prestellar cores
Stamatellos, D.; Whitworth, A. P.
2004-01-01
We present 2D Monte Carlo radiative transfer simulations of flattened prestellar cores. We argue the importance of observing prestellar cores near the peak of their emission spectra, and we point out observable characteristic features on isophotal maps of asymmetric cores at FIR wavelengths that are indicative of the cores' density and temperature structure. These features are on scales 1/5 to 1/3 of the overall core size, and so high resolution observations are needed to observe them. Finall...
Prospects for Asymmetric PNe with ALMA
Huggins, P J
2010-01-01
Millimeter and sub-millimeter observations have made fundamental contributions to our current understanding of the transition from AGB stars to white dwarfs. The approaching era of ALMA brings significantly enhanced observing capabilities at these wavelengths and promises to push back the frontiers in a number of ways. We examine the scientific prospects of this new era for PNe, with an emphasis on how developments may contribute to the goals of the asymmetric PNe community.
Surface segregation of conformationally asymmetric polymer blends
Stepanow, Semjon; Fedorenko, Andrei A.
2005-01-01
We have generalized the Edwards' method of collective description of dense polymer systems in terms of effective potentials to polymer blends in the presence of a surface. With this method we have studied conformationally asymmetric athermic polymer blends in the presence of a hard wall to the first order in effective potentials. For polymers with the same gyration radius $R_g$ but different statistical segment lengths $l_{A}$ and $l_{B}$ the excess concentration of stiffer polymers at the su...
Legal Dilemmas in Fighting Asymmetrical Conflicts
Directory of Open Access Journals (Sweden)
Pnina Sharvit Baruch
2012-04-01
Full Text Available What legal rules apply to armed confrontations against non-state elements in areas populated by civilians? What rules apply when the enemy does not honor the basic laws of warfare - does not distinguish itself from the local population, and even uses it for shelter and as a base of operations? This essay, which presents my position on the issue, refers to such confrontations as "asymmetrical conflicts."
Venture Capital Contracting Under Asymmetric Information
Jeffrey Trester
1993-01-01
The author develops a model of venture capital contracting in which the entrepreneur and venture capitalist contract under symmetric information. A condition of asymmetric information may arise subsequent to the first contract. The author shows that this condition makes debt contracts infeasible and leads to the use of preferred equity contracts. The author notes that discussions of the relation between venture capital and capital structure are rare. This paper expands the literature by addre...
Applications of Chiral Anions in Asymmetric Catalysis
Hamilton, Gregory Lawrence
2011-01-01
The synthesis of molecules with control over their three-dimensional configuration, known as absolute stereochemistry, is one of the highest goals of synthetic organic chemists. As is so often the case, we strive to reach the facility and efficiency with which Nature achieves this goal. Fortunately, the chemist's imagination allows us to envision nearly unlimited possibilities for new modes of catalysis. In this dissertation, I discuss one branch of asymmetric catalysis that has in a short ti...
Asymmetric Reversal in Inhomogeneous Magnetic Heterostructures
Li, Zhi-Pan; Petracic, Oleg; Morales, Rafael; Olamit, Justin; Batlle, Xavier; Liu, Kai; Schuller, Ivan K.
2006-01-01
Asymmetric magnetization reversal is an unusual phenomenon in antiferromagnet/ferromagnet (AF/FM) exchange biased bilayers. We investigated this phenomenon in a simple model system experimentally and by simulation assuming inhomogeneously distributed interfacial AF moments. The results suggest that the observed asymmetry originates from the intrinsic broken symmetry of the system, which results in local incomplete domain walls parallel to the interface in reversal to negative saturation of th...
Asymmetric threat data mining and knowledge discovery
Gilmore, John F.; Pagels, Michael A.; Palk, Justin
2001-03-01
Asymmetric threats differ from the conventional force-on- force military encounters that the Defense Department has historically been trained to engage. Terrorism by its nature is now an operational activity that is neither easily detected or countered as its very existence depends on small covert attacks exploiting the element of surprise. But terrorism does have defined forms, motivations, tactics and organizational structure. Exploiting a terrorism taxonomy provides the opportunity to discover and assess knowledge of terrorist operations. This paper describes the Asymmetric Threat Terrorist Assessment, Countering, and Knowledge (ATTACK) system. ATTACK has been developed to (a) data mine open source intelligence (OSINT) information from web-based newspaper sources, video news web casts, and actual terrorist web sites, (b) evaluate this information against a terrorism taxonomy, (c) exploit country/region specific social, economic, political, and religious knowledge, and (d) discover and predict potential terrorist activities and association links. Details of the asymmetric threat structure and the ATTACK system architecture are presented with results of an actual terrorist data mining and knowledge discovery test case shown.
Multiple Traveling Salesmen in Asymmetric Metrics
Friggstad, Zachary
2011-01-01
We consider some generalizations of the Asymmetric Traveling Salesman Path problem. Suppose we have an asymmetric metric G = (V,A) with two distinguished nodes s,t. We are also given a positive integer k. The goal is to find k paths of minimum total cost from s to t whose union spans all nodes. We call this the k-Person Asymmetric Traveling Salesmen Path problem (k-ATSPP). Our main result for k-ATSPP is a bicriteria approximation that, for some parameter b >= 1 we may choose, finds between k and k + k/b paths of total length O(b log |V|) times the optimum value of an LP relaxation based on the Held-Karp relaxation for the Traveling Salesman problem. On one extreme this is an O(log |V|)-approximation that uses up to 2k paths and on the other it is an O(k log |V|)-approximation that uses exactly k paths. Next, we consider the case where we have k pairs of nodes (s_1,t_1), ..., (s_k,t_k). The goal is to find an s_i-t_i path for every pair such that each node of G lies on at least one of these paths. Simple appro...
Asymmetric Conditional Volatility in International Stock Markets
Ferreira, N B; Menezes, R; Ferreira, Nuno B.; Mendes, Diana A.; Menezes, Rui
2006-01-01
Recent studies show that a negative shock in stock prices will generate more volatility than a positive shock of similar magnitude. The aim of this paper is to appraise the hypothesis under which the conditional mean and the conditional variance of stock returns are asymmetric functions of past information. We compare the results for the Portuguese Stock Market Index PSI 20 with six other Stock Market Indices, namely the S&P 500, FTSE100, DAX 30, CAC 40, ASE 20, and IBEX 35. In order to assess asymmetric volatility we use autoregressive conditional heteroskedasticity specifications known as TARCH and EGARCH. We also test for asymmetry after controlling for the effect of macroeconomic factors on stock market returns using TAR and M-TAR specifications within a VAR framework. Our results show that the conditional variance is an asymmetric function of past innovations raising proportionately more during market declines, a phenomenon known as the leverage effect. However, when we control for the effect of chan...
Fourier domain asymmetric cryptosystem for privacy protected multimodal biometric security
Choudhury, Debesh
2016-04-01
We propose a Fourier domain asymmetric cryptosystem for multimodal biometric security. One modality of biometrics (such as face) is used as the plaintext, which is encrypted by another modality of biometrics (such as fingerprint). A private key is synthesized from the encrypted biometric signature by complex spatial Fourier processing. The encrypted biometric signature is further encrypted by other biometric modalities, and the corresponding private keys are synthesized. The resulting biometric signature is privacy protected since the encryption keys are provided by the human, and hence those are private keys. Moreover, the decryption keys are synthesized using those private encryption keys. The encrypted signatures are decrypted using the synthesized private keys and inverse complex spatial Fourier processing. Computer simulations demonstrate the feasibility of the technique proposed.
Low Viscosity Imides Based on Asymmetric Oxydiphthalic Anhydride
Chuang, Kathy C.; Criss, Jim M., Jr.; Mintz, Eric A.; Scheiman, Daniel A.; Nguyen, Baochau N.; McCorkle, Linda S.
2008-01-01
A series of low-melt viscosity imide resins were prepared from asymmetric oxydiphthalic dianhydride (a-ODPA) and 4-phenylethynylphthalic anhydride as the endcap, along with 3,4' - oxydianiline (3,4' -ODA), 3,4' -methylenedianiline (3,4' -MDA), 3,3' -methylenedianiline (3,3' - MDA) and 3,3'-diaminobenzophenone (3,3'-DABP), using a solvent-free melt process. These imide oligomers displays low-melt viscosities (2-15 poise) at 260-280 C, which made them amenable to low-cost resin transfer molding (RTM) process. The a-ODPA based RTM resins exhibits glass transition temperatures (Tg's) in the range of 265-330 C after postcure at 343 C. The mechanical properties of these polyimide/carbon fiber composites fabricated by RTM will be discussed.
A Proof of Principle of Asymmetric Bunch Pair Merging
Benedikt, Michael; Vallet, J L; CERN. Geneva. AB Department
2003-01-01
Bunch splitting was established as a routine operation in the arsenal of rf gymnastics in the PS Complex long before it became the saving grace of the beam for the LHC. Historically, however, it was born out of the time-reversed analogue process of merging, in which a pair of bunches are combined. Hitherto, both operations have been performed with bunches of equal longitudinal emittance. Now an asymmetric merging process has been demonstrated. By combining a bunch with a small empty bucket, it is possible to deplete only the central density of the resultant particle distribution. This would allow bunches to be tailored with quasi-flat line densities. The details of the method are presented together with some measurements.
Asymmetrically interacting spreading dynamics on complex layered networks
Wang, Wei; Yang, Hui; Do, Younghae; Lai, Ying-Cheng; Lee, GyuWon
2014-01-01
The spread of disease through a physical-contact network and the spread of information about the disease on a communication network are two intimately related dynamical processes. We investigate the asymmetrical interplay between the two types of spreading dynamics, each occurring on its own layer, by focusing on the two fundamental quantities underlying any spreading process: epidemic threshold and the final infection ratio. We find that an epidemic outbreak on the contact layer can induce an outbreak on the communication layer, and information spreading can effectively raise the epidemic threshold. When structural correlation exists between the two layers, the information threshold remains unchanged but the epidemic threshold can be enhanced, making the contact layer more resilient to epidemic outbreak. We develop a physical theory to understand the intricate interplay between the two types of spreading dynamics.
Orientation of the X-line in asymmetric magnetic reconnection
Aunai, N.; Hesse, M.; Lavraud, B.; Dargent, J.; Smets, R.
2016-08-01
> Magnetic reconnection can occur in current sheets separating magnetic fields sheared by any angle and of arbitrarily different amplitudes. In such asymmetric and non-coplanar systems, it is not yet understood what the orientation of the X-line will be. Studying how this orientation is determined locally by the reconnection process is important to understand systems such as the Earth magnetopause, where reconnection occurs in regions with large differences in upstream plasma and field properties. This study aims at determining what the local X-line orientation is for different upstream magnetic shear angles in an asymmetric set-up relevant to the Earth's magnetopause. We use two-dimensional hybrid simulations and vary the simulation plane orientation with regard to the fixed magnetic field profile and search for the plane maximizing the reconnection rate. We find that the plane defined by the bisector of upstream fields maximizes the reconnection rate and this appears not to depend on the magnetic shear angle, domain size or upstream plasma and asymmetries.
Corporate governance ratings as a means to reduce asymmetric information
Directory of Open Access Journals (Sweden)
Claus Holm
2014-12-01
Full Text Available Can corporate governance ratings reduce problems of asymmetric information between companies and investors? To answer this question, we set out to examine the information basis for providing such ratings by reviewing corporate governance attributes that are required or recommended in laws, accounting standards, and codes, respectively. After that, we scrutinize and organize the publicly available information on the methodologies actually used by rating providers. However, important details of these methodologies are treated as confidential property, thus we approach the evaluation of corporate governance ratings as a means to reduce asymmetric information in a more general manner. We propose that the rating process may be seen as consisting of two general activities, namely a data reduction phase, and a data weighting, aggregation, and classification phase. Findings based on a Danish data-set suggest that rating providers by selecting relevant attributes in an intelligent way can improve the screening of companies according to governance quality. In contrast, it seems questionable that weighting, aggregation, and classification of corporate governance attributes considerably improve discrimination according to governance quality.
Asymmetric Supernovae, Pulsars, Magnetars, and Gamma-Ray Bursts
Wheeler, J C; Höflich, P; Wang, L; Yi, Insu; Hoeflich, Peter; Wang, Lifan
1999-01-01
We outline the possible physical processes, associated timescales, and energetics that could lead to the production of pulsars, jets, asymmetric supernovae, and weak gamma-ray bursts in routine circumstances and to a magnetar and perhaps stronger gamma-ray burst in more extreme circumstances in the collapse of the bare core of a massive star. The production of a LeBlanc-Wilson MHD jet could provide an asymmetric supernova and result in a weak gamma-ray burst when the jet accelerates down the stellar density gradient of a hydrogen-poor photosphere. The matter-dominated jet would be formed promptly, but requires 5 to 10 s to reach the surface of the progenitor of a Type Ib/c supernova. During this time, the newly-born neutron star could contract, spin up, and wind up field lines or turn on an $\\alpha-\\Omega$ dynamo. In addition, the light cylinder will contract from a radius large compared to the Alfvén radius to a size comparable to that of the neutron star. This will disrupt the structure of any organized di...
Asymmetric switching in a homodimeric ABC transporter: a simulation study.
Directory of Open Access Journals (Sweden)
Jussi Aittoniemi
2010-04-01
Full Text Available ABC transporters are a large family of membrane proteins involved in a variety of cellular processes, including multidrug and tumor resistance and ion channel regulation. Advances in the structural and functional understanding of ABC transporters have revealed that hydrolysis at the two canonical nucleotide-binding sites (NBSs is co-operative and non-simultaneous. A conserved core architecture of bacterial and eukaryotic ABC exporters has been established, as exemplified by the crystal structure of the homodimeric multidrug exporter Sav1866. Currently, it is unclear how sequential ATP hydrolysis arises in a symmetric homodimeric transporter, since it implies at least transient asymmetry at the NBSs. We show by molecular dynamics simulation that the initially symmetric structure of Sav1866 readily undergoes asymmetric transitions at its NBSs in a pre-hydrolytic nucleotide configuration. MgATP-binding residues and a network of charged residues at the dimer interface are shown to form a sequence of putative molecular switches that allow ATP hydrolysis only at one NBS. We extend our findings to eukaryotic ABC exporters which often consist of two non-identical half-transporters, frequently with degeneracy substitutions at one of their two NBSs. Interestingly, many residues involved in asymmetric conformational switching in Sav1866 are substituted in degenerate eukaryotic NBS. This finding strengthens recent suggestions that the interplay of a consensus and a degenerate NBS in eukaroytic ABC proteins pre-determines the sequence of hydrolysis at the two NBSs.
Exclusive vector meson production at HERMES
Directory of Open Access Journals (Sweden)
Movsisyan Aram
2014-06-01
Full Text Available Exclusive electroproduction of vector mesons has been measured on hydrogen and deuterium targets at HERMES using the 27.6 GeV electron/positron beam of HERA. From this process, more information can be obtained about generalized parton distributions (GPDs, which provide a unified description of the structure of hadrons embedding longitudinal-momentum distributions (ordinary PDFs and transverse-position information (form factors. The study of the azimuthal distribution of the decay products via spin-density matrix elements provide constraints on helicity-amplitudes used to describe exclusive vector-meson production. Recent results from the HERMES experiment on the production of rho, omega and phi mesons will be presented.
Exclusive vector meson production at HERMES
Movsisyan, Aram
2014-06-01
Exclusive electroproduction of vector mesons has been measured on hydrogen and deuterium targets at HERMES using the 27.6 GeV electron/positron beam of HERA. From this process, more information can be obtained about generalized parton distributions (GPDs), which provide a unified description of the structure of hadrons embedding longitudinal-momentum distributions (ordinary PDFs) and transverse-position information (form factors). The study of the azimuthal distribution of the decay products via spin-density matrix elements provide constraints on helicity-amplitudes used to describe exclusive vector-meson production. Recent results from the HERMES experiment on the production of rho, omega and phi mesons will be presented.
A study of Central Exclusive Production
Energy Technology Data Exchange (ETDEWEB)
Monk, James; /Manchester U.
2008-09-01
Central exclusive production of a system X in a collision between two hadrons h is defined as hh {yields} h + X + h with no other activity apart from the decay products of X. This thesis presents predictions for the production cross section of a CP violating supersymmetric Higgs boson and the radion of the Randall-Sundrum model. The ExHuME Monte Carlo generator was written to simulate central exclusive processes and is described and explored. A comparison to di-jet observations made by the D0 detector at the Tevatron, Fermilab between January and June 2004 is made and the distributions found support the predictions of ExHuME.
Directory of Open Access Journals (Sweden)
Márcia de Fátima Morais
2010-01-01
Full Text Available Este artigo apresenta uma investigação sobre o problema de programação da produção em ambientes flow shop com múltiplas máquinas (híbridos e tempos de preparação (setup das máquinas assimétricos e dependentes da sequência, e propõe métodos heurísticos construtivos para a minimização do tempo médio de fluxo (Mean Flow Time, que objetiva uma resposta rápida à demanda e à redução do estoque em processamento. Os algoritmos propostos foram comparados entre si, uma vez que nenhum método de solução para o problema investigado foi encontrado na literatura. Um estudo da influência da relação entre as ordens de grandeza dos tempos de processamento das tarefas e de preparação das máquinas em cada método de solução, bem como a influência do procedimento de programação adotado, foi efetuado com o intuito de avaliar o desempenho dos métodosThis paper presents an investigation about the hybrid flow shop problem with asymmetric sequence dependent setup times and proposes constructive heuristic methods to minimize the mean flow time aiming at fast demand response and work in process reduction. The proposed heuristic methods were compared among themselves since no constructive heuristic method was found in the literature on the scheduling problem considered in this work. A study on the influence of the relation between the orders of magnitude of processing and setup time for each method was carried out. The influence of the scheduling procedure adopted was investigated to assess the performance of the methods use
Problems of Chernobyl Exclusion Zone
International Nuclear Information System (INIS)
The collection comprises the results of researches and design activity in the ChNPP exclusion zone, aimed at the development of technologies, equipment and devices for radioactive waste management and ChNPP accident clean-up, at studying the composition and structure of the Exclusion zone soil activity solid bearers, form transformation of the fission products of fuel fallout radionuclide composition in the ChNPP near zone, the spatial distribution of radionuclides and other radioecological issues.. Much attention is paid to medical and biological aspects of the accident influence on the flora, fauna and people's health, labour conditions and incidence of the workers of the Exclusion zone
Lu, Wenlian; Zheng, Ren; Chen, Tianping
2016-03-01
In this paper, we discuss outer-synchronization of the asymmetrically connected recurrent time-varying neural networks. By using both centralized and decentralized discretization data sampling principles, we derive several sufficient conditions based on three vector norms to guarantee that the difference of any two trajectories starting from different initial values of the neural network converges to zero. The lower bounds of the common time intervals between data samples in centralized and decentralized principles are proved to be positive, which guarantees exclusion of Zeno behavior. A numerical example is provided to illustrate the efficiency of the theoretical results. PMID:26702550
Durrani, Shiraz
2000-01-01
This is the first of two linked working papers analysing social exclusion at an international level (the second being by John Pateman). It reviews struggles against exclusion and poverty in different societies, emphasising the role of information, and the potential of role of libraries. Social exclusion is described in the context of global capitalism. The process of exclusion is seen as having intensified with the rise of the ‘information age.’ The paper then looks at resistance to this exc...
Missing persons and social exclusion
Directory of Open Access Journals (Sweden)
Myrna Dawson
2012-01-01
Full Text Available The concept of social exclusion is used to explore the relationship between people and groups who may be socially and economically disadvantaged and the phenomenon of going missing. Police data about missing persons are compared to census data to determine whether groups who experience family dissolution, labour market exclusion, and other forms of disadvantage and social exclusion are overrepresented among people reported missing compared to the general population. The analysis shows that disadvantaged youth, women, Aboriginal people, people who are not in the labour force, unemployed people, and homeless people are all overrepresented among people reported missing.People occupying the intersections of multiple high risk categories are at particularly high risk of being reported missing. Linking missing persons with the concept of social exclusion shows that social and economic disadvantage can lead directly and indirectly to peoples’ disappearances.
Data Exclusivity: An Absolute Monopoly
Directory of Open Access Journals (Sweden)
Gopal Dabade
2010-03-01
Full Text Available The paper describes data exclusivity, its implication on generic drug manufacturers, and on cost of life-saving drugs in developing countries like India.http://dx.doi.org/10.14429/djlit.27.4.185
Asymmetric-Structure Analysis of Carbon and Energy Markets
Xu, Wei; Cao, Guangxi
2016-02-01
This study aimed to investigate the asymmetric structure between the carbon and energy markets from two aspects of different trends (up or down) and volatility-transmission direction using asymmetric detrended cross-correlation analysis (DCCA) cross-correlation coefficient test, multifractal asymmetric DCCA (MF-ADCCA) method, asymmetric volatility-constrained correlation metric and time rate of information-flow approach. We sampled 1283 observations from January 2008 to December 2012 among pairs of carbon and energy markets for analysis. Empirical results show that the (1) asymmetric characteristic from the cross-correlation between carbon and returns in the energy markets is significant, (2) asymmetric cross-correlation between carbon and energy market price returns is persistent and multifractral and (3) volatility of the base assets of energy market returns is more influential to the base asset of the carbon market than that of the energy market.
Asymmetrically deformed states of thorium isotopes during fission process
International Nuclear Information System (INIS)
Some theoretical considerations are recalled on fission barriers calculated from macroscopic, microscopic or macroscopic-microscopic and ''thorium anomaly'' problem is set. Experimental techniques used to measure fission cross sections in (n,f) reactions near the threshold are described. Fission dectector is described; stray resonance problems and retrodiffused neutrons are discussed. Results obtained in experimental study of 230Th(n,f) and 232Th(n,f) reactions are presented. They are compared with results obtained in other laboratories. The analysis model which allows to describe a (n,f) reaction is exposed. The compound nucleus formation cross section and transmission coefficients in neutron and gamma output channel are presented according to neutron energy for each value of angular moment and parity. Cross-section analysis and angular distribution obtained respectively in 230Th(n,f) and 232Th(n,f) reactions is exposed. Result interpretation show new aspects of nuclei rotational spectra and new nuclear forms
47 CFR 76.107 - Exclusivity contracts.
2010-10-01
... CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout § 76.107 Exclusivity contracts. A distributor or television station exercising exclusivity pursuant to... exclusivity contracts, such portions to be signed by both the distributor and the television station,...
Nanotribology of Symmetric and Asymmetric Liquid Lubricants
Directory of Open Access Journals (Sweden)
Shinji Yamada
2010-03-01
Full Text Available When liquid molecules are confined in a narrow gap between smooth surfaces, their dynamic properties are completely different from those of the bulk. The molecular motions are highly restricted and the system exhibits solid-like responses when sheared slowly. This solidification behavior is very dependent on the molecular geometry (shape of liquids because the solidification is induced by the packing of molecules into ordered structures in confinement. This paper reviews the measurements of confined structures and friction of symmetric and asymmetric liquid lubricants using the surface forces apparatus. The results show subtle and complex friction mechanisms at the molecular scale.
Analysis of Asymmetric Piezoelectric Composite Beam
Chen, J -S; Wu, K -C
2008-01-01
This paper deals with the vibration analysis of an asymmetric composite beam composed of glass a piezoelectric material. The Bernoulli's beam theory is adopted for mechanical deformations, and the electric potential field of the piezoelectric material is assumed such that the divergence-free requirement of the electrical displacements is satisfied. The accuracy of the analytic model is assessed by comparing the resonance frequencies obtained by the analytic model with those obtained by the finite element method. The model developed can be used as a tool for designing piezoelectric actuators such as micro-pumps.
On asymmetric causal relationships in Petropolitics
Directory of Open Access Journals (Sweden)
Balan Feyza
2016-01-01
Full Text Available The aim of this paper is to examine whether the First Law of Petropolitics denominated by Friedman in 2006 is valid for OPEC countries. To do this, this paper analyses the relationship between political risk and oil supply by applying the asymmetric panel causality test suggested by Hatemi-J (2011 to these countries for the period 1984-2014. The results show that the First Law of Petropolitics is valid for Angola, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, and the UAE, given that positive oil supply shocks significantly lead to negative political stability shocks, and negative oil supply shocks significantly lead to positive shocks in political stability.
RHIC operation with asymmetric collisions in 2015
Energy Technology Data Exchange (ETDEWEB)
Liu, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Aschenauer, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Atoian, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Brown, K. A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Bruno, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Connolly, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ottavio, T. D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Drees, K. A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gardner, C. J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gu, X. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hayes, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Huang, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Laster, J. S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Luo, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Makdisi, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Marr, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Marusic, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Meot, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Mernick, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Michnoff, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Minty, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Montag, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Morris, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Narayan, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Nayak, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Nemesure, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Pile, P. [Brookhaven National Lab. (BNL), Upton, NY (United States); Poblaguev, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ranjbar, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Robert-Demolaize, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Roser, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Schmidke, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Schoefer, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Severino, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Shrey, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Smith, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Steski, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tepikian, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trbojevic, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tsoupas, N. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wang, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); White, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Yip, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zaltsman, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zeno, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zhang, S. Y. [Brookhaven National Lab. (BNL), Upton, NY (United States)
2015-08-07
To study low-x shadowing/saturation physics as well as other nuclear effects [1], [2], proton-gold (p-Au, for 5 weeks) and proton-Aluminum (p-Al, for 2 weeks) collisions were provided for experiments in 2015 at the Relativistic Heavy Ion Collider (RHIC), with polarized proton beam in the Blue ring and Au/Al beam in the Yellow ring. The special features of the asymmetric run in 2015 will be introduced. The operation experience will be reviewed as well in the report.
OFFICER AND COMMANDER IN ASYMMETRIC WARFARE OPERATIONS
Directory of Open Access Journals (Sweden)
Giuseppe CAFORIO
2013-01-01
Full Text Available Starting from the data of a field research conducted among soldiers with asymmetric warfare experiences from nine different countries, the author seeks to identify and shed light on the various problems that officers with command responsibilities had to face during their missions. A picture emerges of feelings and experiences relating to their first impression upon arriving in the theatre, relations with local armed forces, relations with the local population and local authorities, relations with NGOs, relations with other armies, the impact of the rules of engagement (ROEs, training and education, and operational experiences. The paper ends with a discussion of the lessons learned.
Asymmetric catalytic aziridination of cyclic enones.
De Vincentiis, Francesco; Bencivenni, Giorgio; Pesciaioli, Fabio; Mazzanti, Andrea; Bartoli, Giuseppe; Galzerano, Patrizia; Melchiorre, Paolo
2010-07-01
The first catalytic method for the asymmetric aziridination of cyclic enones is described. The presented organocatalytic strategy is based on the use of an easily available organocatalyst that is able to convert a wide range of cyclic enones into the desired aziridines with very high enantiomeric purity and good chemical yield. Such a method may very well open up new opportunities to stereoselectively prepare complex chiral molecules that possess an indane moiety, a framework that is found in a large number of bioactive and pharmaceutically important molecules. PMID:20512797
Plasmonic photodetectors based on asymmetric nanogap electrodes
Ge, Junyu; Luo, Manlin; Zou, Wanghui; Peng, Wei; Duan, Huigao
2016-08-01
Hot electrons excited by plasmon resonance in nanostructure can be employed to enhance the properties of photodetectors, even when the photon energy is lower than the bandgap of the semiconductor. However, current research has seldom considered how to realize the efficient collection of hot electrons, which restricts the responsivity of the device. In this paper, a type of plasmonic photodetector based on asymmetric nanogap electrodes is proposed. Owing to this structure, the device achieves responsivities as high as 0.45 and 0.25 mA/W for wavelengths of 1310 and 1550 nm, respectively. These insights can aid the realization of efficient plasmon-enhanced photodetectors for infrared detection.
Governor model for asymmetric deformed nuclei
International Nuclear Information System (INIS)
The governor model is extended to include the asymmetric shape of nuclei which allows a simultaneous analysis of the data for both the ground state and the γ-vibrational bands in deformed even-even nuclei. The rotationally invariant core is assumed to be a spheroid with an axis of symmetry parallel to the axis of rotation. The calculations are carried out under the assumption of no stretching. The static γ-deformation results are compared with the VMI(ARM) and Krutov values, and the calculated energies are in good agreement with the experimental data
Plasma current resonance in asymmetric toroidal systems
Energy Technology Data Exchange (ETDEWEB)
Hazeltine, R. D. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States); Catto, Peter J. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, 167 Albany Street, Cambridge, Massachusetts 02139 (United States)
2015-09-15
The well-known singularity in the magnetic differential equation for plasma current in an asymmetric toroidal confinement system is resolved by including in the pressure tensor corrections stemming from finite Larmor radius. The result provides an estimate of the amplitude of spikes in the parallel current that occur on rational magnetic surfaces. Resolution of the singularity is shown to depend on both the ambipolarity condition—the requirement of zero surface-averaged radial current—and the form of the magnetic differential equation near the rational surface.
Security-Preserving Asymmetric Protocol Encapsulation
Vaudenay, Serge; Phan, Raphael C-W
2007-01-01
Query-response based protocols between a client and a server such as SSL, TLS, SSH are asymmetric in the sense that the querying client and the responding server play different roles, and for which there is a need for two-way linkability between queries and responses within the protocol. We are motivated by the observation that though results exist in other related contexts, no provably secure scheme has been applied to the setting of client-server protocols, which differ from conventional co...
Infinite dimensional mixed economies with asymmetric information
Bhowmik, Anuj
2011-01-01
In this paper, we study asymmetric information economies consisting of both non-negligible and negligible agents and having ordered Banach spaces as their commodity spaces. In answering a question of Herv\\'{e}s-Beloso and Moreno-Garc\\'{i}a, we establish a characterization of Walrasian expectations allocations by the veto power of the grand coalition. It is also shown that when an economy contains only negligible agents a Vind's type theorem on the private core with the exact feasibility can be restored. This solves a problem of Pesce.
Chiral Diamine-catalyzed Asymmetric Aldol Reaction
Institute of Scientific and Technical Information of China (English)
LI Hui; XU Da-zhen; WU Lu-lu; WANG Yong-mei
2012-01-01
A highly efficient catalytic system composed of a simple and commercially available chiral primary diamine (1R,2R)-cyclohexane-1,2-diamine(6) and trifluoroacetic acid(TFA) was employed for asymmetric Aldol reaction in i-PrOH at room temperature.A loading of 10％(molar fraction) catalyst 6 with TFA as a cocatalyst could catalyze the Aldol reactions of various ketones or aldehydes with a series of aromatic aldehydes,furnishing Aldol products in moderate to high yields(up to ＞99％) with enantioselectivities of up to ＞99％ and diastereoselectivities of up to 99:1.
Quantum optics of lossy asymmetric beam splitters.
Uppu, Ravitej; Wolterink, Tom A W; Tentrup, Tristan B H; Pinkse, Pepijn W H
2016-07-25
We theoretically investigate quantum interference of two single photons at a lossy asymmetric beam splitter, the most general passive 2×2 optical circuit. The losses in the circuit result in a non-unitary scattering matrix with a non-trivial set of constraints on the elements of the scattering matrix. Our analysis using the noise operator formalism shows that the loss allows tunability of quantum interference to an extent not possible with a lossless beam splitter. Our theoretical studies support the experimental demonstrations of programmable quantum interference in highly multimodal systems such as opaque scattering media and multimode fibers. PMID:27464096
Long-lived oscillons from asymmetric bubbles
Adib, A B; Almeida, C A S; Adib, Artur B.; Gleiser, Marcelo; Almeida, Carlos A. S.
2002-01-01
The possibility that extremely long-lived, time-dependent, and localized field configurations (``oscillons'') arise during the collapse of asymmetrical bubbles in 2+1 dimensional \\phi^4 models is investigated. It is found that oscillons can develop from a large spectrum of elliptically deformed bubbles. Moreover, it is found that such oscillons are: a) circularly symmetric; and b) stable against small arbitrary radial and angular perturbations. They may thus play an important role in the study of time-dependent nonperturbative configurations in field theory, with applications ranging from nonequilibrium statistical physics to early universe cosmology.
Catalytic asymmetric formal synthesis of beraprost
Kobayashi, Yusuke; Kuramoto, Ryuta
2015-01-01
Summary The first catalytic asymmetric synthesis of the key intermediate for beraprost has been achieved through an enantioselective intramolecular oxa-Michael reaction of an α,β-unsaturated amide mediated by a newly developed benzothiadiazine catalyst. The Weinreb amide moiety and bromo substituent of the Michael adduct were utilized for the C–C bond formations to construct the scaffold. All four contiguous stereocenters of the tricyclic core were controlled via Rh-catalyzed stereoselective C–H insertion and the subsequent reduction from the convex face. PMID:26734111
Sorting with Asymmetric Read and Write Costs
Blelloch, Guy E.; Fineman, Jeremy T.; Gibbons, Phillip B.; Gu, Yan; Shun, Julian
2016-01-01
Emerging memory technologies have a significant gap between the cost, both in time and in energy, of writing to memory versus reading from memory. In this paper we present models and algorithms that account for this difference, with a focus on write-efficient sorting algorithms. First, we consider the PRAM model with asymmetric write cost, and show that sorting can be performed in $O\\left(n\\right)$ writes, $O\\left(n \\log n\\right)$ reads, and logarithmic depth (parallel time). Next, we conside...
Asymmetric Hydrogenation of 3-Substituted Pyridinium Salts.
Renom-Carrasco, Marc; Gajewski, Piotr; Pignataro, Luca; de Vries, Johannes G; Piarulli, Umberto; Gennari, Cesare; Lefort, Laurent
2016-07-01
The use of an equivalent amount of an organic base leads to high enantiomeric excess in the asymmetric hydrogenation of N-benzylated 3-substituted pyridinium salts into the corresponding piperidines. Indeed, in the presence of Et3 N, a Rh-JosiPhos catalyst reduced a range of pyridinium salts with ee values up to 90 %. The role of the base was elucidated with a mechanistic study involving the isolation of the various reaction intermediates and isotopic labeling experiments. Additionally, this study provided some evidence for an enantiodetermining step involving a dihydropyridine intermediate. PMID:27140832
Quantum optics of lossy asymmetric beam splitters
Uppu, Ravitej; Tentrup, Tristan B H; Pinkse, Pepijn W H
2016-01-01
We theoretically investigate quantum interference of two single photons at a lossy asymmetric beam splitter, the most general passive 2$\\times$2 optical circuit. The losses in the circuit result in a non-unitary scattering matrix with a non-trivial set of constraints on the elements of the scattering matrix. Our analysis using the noise operator formalism shows that the loss allows tunability of quantum interference to an extent not possible with a lossless beam splitter. Our theoretical studies support the experimental demonstrations of programmable quantum interference in highly multimodal systems such as opaque scattering media and multimode fibers.
Hydrodynamic attraction and repulsion between asymmetric rotors
International Nuclear Information System (INIS)
At low Reynolds numbers, the hydrodynamic interaction between dumbbells driven by an external rotating field can be attractive or repulsive. Dumbbells of dissimilar asymmetric shape or different coupling to the external field undergo conformational rearrangements that break the time-reversal symmetry. The parameter ranges leading to attraction or repulsion are explored numerically. The results of our simulations suggest that rotating fields may be a useful avenue for the assembly, disassembly and sorting of particles of different shapes, as well as for the study of collective micro-swimmers.
Massless sunset diagrams in finite asymmetric volumes
Niedermayer, F.; Weisz, P.
2016-06-01
This paper discusses the methods and the results used in an accompanying paper describing the matching of effective chiral Lagrangians in dimensional and lattice regularizations. We present methods to compute 2-loop massless sunset diagrams in finite asymmetric volumes in the framework of these regularizations. We also consider 1-loop sums in both regularizations, extending the results of Hasenfratz and Leutwyler for the case of dimensional regularization and we introduce a new method to calculate precisely the expansion coefficients of the 1-loop lattice sums.
Asymmetric Synthesis of Both Enantiomers of Disparlure
Institute of Scientific and Technical Information of China (English)
王志刚; 郑剑峰; 黄培强
2012-01-01
Starting from propargyl alcohol （12）, and on the basis of Zhou＇s modified Sharpless asymmetric epoxidation, the sex pheromone of the Gypsy moth, disparlure （＋）-8 and its enantiomer （-）-8 have been synthesized, each in six steps, with overall yields of 29% for （＋）-8 and 27% for （-）-8 （ee〉98%）. The use of the sequential coupling tactic renders the method flexible, which is applicable to the synthesis of other cis-epoxy pheromones.
Asymmetric coherent transmission for single particle diode and gyroscope
Yang, S; Sun, C P
2009-01-01
We study the single particle scattering process in a coherent multi-site system consisting of a tight-binding ring threaded by an Aharonov-Bohm flux and several attaching leads. The asymmetric behavior of scattering matrix is discovered analytically in the framework of both Bethe Ansatz and Green's function formalism. It is found that, under certain conditions, a three-site electronic system can behave analogous to a perfect semiconductor diode where current flows only in one direction. The general result is also valid for a neutral particle system since the effective magnetic flux may be implemented by a globe rotation. This observation means that the three-site system can serve as an orientation measuring gyroscope due to the approximate linear dependence of the current difference of two output leads on the rotational angular velocity.
Lithium Titanate Confined in Carbon Nanopores for Asymmetric Supercapacitors.
Zhao, Enbo; Qin, Chuanli; Jung, Hong-Ryun; Berdichevsky, Gene; Nese, Alper; Marder, Seth; Yushin, Gleb
2016-04-26
Porous carbons suffer from low specific capacitance, while intercalation-type active materials suffer from limited rate when used in asymmetric supercapacitors. We demonstrate that nanoconfinement of intercalation-type lithium titanate (Li4Ti5O12) nanoparticles in carbon nanopores yielded nanocomposite materials that offer both high ion storage density and rapid ion transport through open and interconnected pore channels. The use of titanate increased both the gravimetric and volumetric capacity of porous carbons by more than an order of magnitude. High electrical conductivity of carbon and the small size of titanate crystals allowed the composite electrodes to achieve characteristic charge and discharge times comparable to that of the electric double-layer capacitors. The proposed composite synthesis methodology is simple, scalable, and applicable for a broad range of active intercalation materials, while the produced composite powders are compatible with commercial electrode fabrication processes. PMID:26950509
Asymmetric Bellow Flexible Pneumatic Actuator for Miniature Robotic Soft Gripper
Directory of Open Access Journals (Sweden)
Ganesha Udupa
2014-01-01
Full Text Available The necessity of the soft gripping devices is increasing day-by-day in medical robotics especially when safe, gentle motions and soft touch are necessary. In this paper, a novel asymmetric bellow flexible pneumatic actuator (AFPA has been designed and fabricated to construct a miniaturised soft gripper that could be used to grip small objects. The model of AFPA is designed using solid works and its bending motion is simulated in Abaqus software for optimisation and compared with experimental results. The actuator is fabricated using compression molding process that includes micromachining of the molds. Experiments conducted show the bending characteristics of the actuator at different pressures. The actuator shows excellent bending performance and the eccentricity in its design supports increased bending or curling motion up to a certain extent compared to normal bellows without eccentricity. The effects of profile shape and eccentricity on the actuator performance are analysed and the results are presented.
CUSP CATASTROPHE MODEL OF INSTABILITY OF PILLAR IN ASYMMETRIC MINING
Institute of Scientific and Technical Information of China (English)
LI Jiang-teng; CAO Ping
2005-01-01
A simplified mechanical model of pillar-hang wall was established in asymmetric mining and instability of the system was discussed by means of potential energy principle and cusp catastrophe theory. The necessary-sufficient condition and the jump value of displacement of pillar and the released energy expressions were derived,which established foundation for quantifying of the instability of system. The results show that instability of the system is related to load and its stiffness distribution. The critical load increases with the increasing relative stiffness, and the system is more stable. On the contrary, the instability of system is likely to occur, and the released energy is larger in instability process, and the harm is more tremendous accordingly.Furthermore, an example was calculated, and the estimated results are in good agreement with the practical experience, which provide basis for mining order and arranging stope.