Conserved Currents Research Articles

Inception of Constructional Submarine Conduit by Asymmetry Generated by Turbidity Current

Submarine conduits are features responsible for transporting clastic debris from continents to the deep ocean. While the architecture of conduits has been extensively studied, the process of their inception remains unclear. This study highlights the possibility that some conduits are initiated by depositional processes involving turbidity currents. Here, we present the results of eight experiments where gravity currents were allowed to develop their own pathways. The simulation tank represented natural scales of continental shelves, slopes, and basins. The initial experiments involved sediment-laden flows with low density (1–10% in volume). In first experiment runs (Series I), sediment deposition occurred primarily on the shelf and slope, resulting in an asymmetric transverse profile. This asymmetry facilitated subsequent conservative currents (1034 to 1070 kg/m3 due to salt dissolution) flowing alongside during the second series, resulting in the formation of a constructive submarine conduit. This feature is analogous to gully formations observed in various locations. This study correlates these findings with gully-like features and proposes a model where non-confined density flows can evolve into confined flows through the construction of asymmetric topography. An evolutionary model is proposed to explain the mechanism, which potentially elucidates the formation of many submarine conduits.

Pierre Bourdieu vis-à-vis Martin Heidegger: the first ‘conservative revolution’

As a philosophy student in 1950s Paris, Pierre Bourdieu experienced a ‘certain fascination’ with the German phenomenologists, Husserl and Heidegger. He later went on in 1975 to write a lengthy article on The Political Ontology of Martin Heidegger, translated into English in 1991. Recently, notable Bourdieusian theorists have emphasised this Heideggerian contribution to Bourdieu’s thought, stressing its significance alongside the classical sociological theorists (Marx, Weber and Durkheim). They thus directly assert or imply its continued importance for the genesis of new social theory. The present article argues against this position and it does so in part by using Bourdieu’s own reflections on Heidegger. Like Theodor Adorno, this analysis rooted Heidegger’s thought in his social position as a lower-class outsider to the patrician German university system. Going beyond Adorno, however, Bourdieu stressed the crises of interwar Germany including the crisis within the country’s academia. Drawing attention to the interwar ‘conservative revolution’ of Carl Schmitt, Oswald Spengler, Erich Jünger, and Fritz Lang, amongst others, Bourdieu delineated Heidegger’s ‘alchemical transformation’ of this conservative current into ‘philosophical form’ to create a symbolic revolution. The article concludes by discussing later scholarship as well as the posthumous publication of Heidegger’s journal, The Black Notebooks. These newly-published sources reveal Heidegger’s coded but virulent antisemitism. In light of these, it is argued that Heideggerian ontology can be used neither for philosophy nor for social theory.

The Response to the Croatian National Struggle in 1848-1849 in the Western Armenian Periodical Press

Key words: Austrian Empire, Hungary, Croatia, national struggle, autonomy, I. Jelacic, “The Arshaluys Araratyan’’, “Hayastan’’ “The Arshaluys Araratyan’’ of Smyrna and “Hayastan’’ of Constantinople, the ideologues of the Armenian national conservative current, commented broadly on the revolutionary and national-liberation struggle taken place in the Austrian Empire in 1848-1849. On the base of the European press news, the Armenian periodicals presented the entire course of the national struggle of the oppressed peoples in the Austrian multinational Empire, as well as the Croats’ struggle. They realized that the national struggle of the Hungarians was directed against the Vienna royal court and aimed to restore their lost state. At the same time the Turkish-Armenian periodicals correctly noticed that the armed Croats were struggling against the Hungarian authorities, desired to be freed from their rule and gain national autonomy within the Austrian Empire. The newspapers “Arshaluys Araratyan’’ and “Hayastan’’ didn’t show any emphatic attitude towards the national struggle of the Croats and presented it mainly from an impartial perspective. Hovhannes Chamurchyan Teroyents, the leader of the Western-Armenian extreme conservatives and editor of “The Hayastan’’, was against any revolutionary movement naming its participants the rioters. He presented the struggle of the Croats simply as a “historiographer”.

Nature and Typology of Different Types of Soviet Conservatism

The paper poses the problem of Soviet conservatism. What protective forces and mechanisms were inherent in the Soviet system? Since any society should have its own conservative tendencies, one can also talk about elements of conservatism in the Soviet society, culture and ideology. Nevertheless, refl ections on this problem lead to an epistemological diff iculty. In what sense can we talk about Soviet conservatism in general? After all, the defi ning worldview of the Soviet period was Marxist ideology, which was radically revolutionary and progressive. Even the word “conservative” was then perceived in a decisively negative way. Nevertheless, it is noted that in the late Soviet society it was possible to be a Soviet conservative, wishing for the preservation of the USSR but disapproving of communism and Marxism. The paper states that Soviet conservatism cannot be described as a single entity. In diff erent epochs, diff erent types of Soviet conservatism can be distinguished that struggled with each other and contradicted each other. In addition, the distinction between them is a bit of conditional, because all of them were permeated by the revolutionary-progressive elements of the dominant ideology or stood out against a background of the latter. The paper outlines an approximate general typology of Soviet conservatism: cultural-humanistic Soviet conservatism, pro-Leninist Soviet conservatism, Stalinist Soviet conservatism, pro-Stalinist Soviet conservatism, situational Brezhnev conservatism, and Soviet conservatism of non-Soviet authors and thinkers. It states that the USSR was largely brought to the collapse by the defectiveness and insuff iciency of its conditionally conservative, protective forces and principles. It is only with a very high degree of conditionality that one can talk about the phenomenon of Soviet conservatism, understanding it as a set of transformed, unnatural, and contradictory conservative and quasi-conservative ideological currents that do not add up to a single whole.

Precursory patterns to vortex nucleation in stirred Bose-Einstein condensates

Within the Gross-Pitaevskii theory, we study precursory pattern formations to the nucleation of vortex dipoles in a two-dimensional Bose-Einstein condensate stirred by a Gaussian potential. We introduce a smooth superfluid vorticity field and its conservative current, which capture very well the gradual process of vortex nucleation as a mechanism of topological singularities acquiring smooth cores. This is characterized by the localization of the superfluid vorticity into core regions which harbor the phase slips. For more impenetrable obstacles, we find that there are additional phase slips that do not acquire cores, thus remaining pinned as ghost vortices to the potential. We show that the vortex kinematics is slaved to the superfluid vorticity current, which determines not only the onset of nucleation but also the shedding dynamics.

Vortical effects in Dirac fluids with vector, chiral and helical charges

Helicity of free massless Dirac fermions is a conserved, Lorentz-invariant quantity at the level of the classical equations of motion. For a generic ensemble consisting of particles and antiparticles, the helical and chiral charges are different conserved quantities. The flow of helicity can be modelled by the helicity current, which is again conserved in the absence of interactions. Similar to the axial vortical effect which generates an axial (chiral) current, the helicity current is induced by vorticity in a finite temperature medium with vector (electrical) charge imbalance via the helical vortical effects, leading to new nondissipative transport phenomena. These phenomena lead to the appearance of a new hydrodynamic excitation, the helical vortical wave. Our results suggest the existence of a new type of triangle anomalies in QED which involve the helicity currents in addition to the standard vector and axial currents. Further exploiting the conservation of the helical current, we show that a finite helical chemical potential may be used to characterise thermodynamic ensembles of fermions similarly to, but independently of, the vector charge and chirality. We derive the pressure P for fermions at finite vector, axial and helical chemical potentials and show that the quantities arising in anomalous transport, including various vortical and circular conductivities and the shear-stress coefficients, can be obtained by differentiation of P with respect to the appropriate chemical potentials. Finally, we calculate the helicity relaxation time in the quark-gluon plasma above the crossover and show that it is similar to that for the axial charge.

Analytic structure of the Landau gauge quark propagator from Padé analysis

The analytic structure of the two flavorful QCD lattice Landau gauge quark propagator is investigated with Pad\'e approximants applied to its vector and scalar form factors. No poles at complex momentum are observed for the propagator. Moreover, there is clear evidence of a pole at real on-axis negative Euclidean momentum, i.e., for a Minkowski type of momentum. This pole occurs at Euclidean momenta $p\ensuremath{\sim}\ensuremath{-}300\text{ }\text{ }\mathrm{MeV}$ and it reproduces typical quark mass values used in phenomenological effective quark models. The Pad\'e approximant analysis also gives hints on the presence of a branch cut. Our results also show a clear correlation between the position of this pole, understood as an effective quark mass, and the pion mass that is compatible with partial conservation of the axial current. Slightly differences between the poles for the two quark form factors are observed which can be viewed either as a limitation of the method or as a suggestion that the quark propagator has no spectral representation.

Polarization phenomena in the reaction e++e−→N+N¯+π0 in the framework of the nonresonant mechanism

The dependence of the nucleon polarization in the reaction ${e}^{+}+{e}^{\ensuremath{-}}\ensuremath{\rightarrow}N+\overline{N}+{\ensuremath{\pi}}^{0}$ over different invariant variables is derived for the nonresonant mechanism. The nucleon polarization is expressed in terms of six invariant complex amplitudes, assuming the conservation of the hadron electromagnetic currents and the P invariance of the hadron electromagnetic interaction. An inclusive experimental setup when the proton (or the antiproton) and the pion are detected in coincidence is considered. Numerical estimations are performed for the so-called normal polarization in the energy range from threshold up to $s=16\text{ }\text{ }{\mathrm{GeV}}^{2}$, using selected parametrizations of the nucleon electromagnetic form factors in frame of a formalism derived in a previous work for the calculation of the unpolarized differential cross section.

Poisson gauge models and Seiberg-Witten map

The semiclassical limit of full non-commutative gauge theory is known as Poisson gauge theory. In this work we revise the construction of Poisson gauge theory paying attention to the geometric meaning of the structures involved and advance in the direction of a further development of the proposed formalism, including the derivation of Noether identities and conservation of currents. For any linear non-commutativity, Θab(x) = {f}_c^{ab} xc, with {f}_c^{ab} being structure constants of a Lie algebra, an explicit form of the gauge Lagrangian is proposed. In particular a universal solution for the matrix ρ defining the field strength and the covariant derivative is found. The previously known examples of κ-Minkowski, λ-Minkowski and rotationally invariant non-commutativity are recovered from the general formula. The arbitrariness in the construction of Poisson gauge models is addressed in terms of Seiberg-Witten maps, i.e., invertible field redefinitions mapping gauge orbits onto gauge orbits.

Contact interaction analysis of octet baryon axial-vector and pseudoscalar form factors

Octet baryon axial, induced pseudoscalar, and pseudoscalar form factors are computed using a symmetry-preserving treatment of a vector$\,\times\,$vector contact interaction (SCI), thereby unifying them with an array of other baryon properties and analogous treatments of semileptonic decays of pseudoscalar mesons. The baryons are treated as quark--plus--interacting-diquark bound states, whose structure is obtained by solving a Poincar\'e-covariant Faddeev equation. The approach is marked by algebraic simplicity, involves no free parameters, and since it is symmetry preserving, all consequences of partial conservation of the axial current are manifest. It is found that SCI results are consistent with only small violations of SU$(3)$-flavour symmetry, an outcome which may be understood as a dynamical consequence of emergent hadron mass. The spin-flavour structure of the Poincar\'e-covariant baryon wave functions is expressed in the presence of both flavour-antitriplet scalar diquarks and flavour-sextet axialvector diquarks and plays a key role in determining all form factors. Considering neutral axial currents, SCI predictions for the flavour separation of octet baryon axial charges and, therefrom, values for the associated SU$(3)$ singlet, triplet, and octet axial charges are obtained. The results indicate that at the hadron scale, $\zeta_{\cal H}$, valence degrees-of-freedom carry roughly 50% of an octet baryon's total spin. Since there are no other degrees-of-freedom at $\zeta_{\cal H}$, the remainder may be associated with quark+diquark orbital angular momentum.

The Cambridge “Gang” Meets Iranian Intellectual History: Reimagining Conservatism In Context

The Iranian humanities publication Farhang Emrooz (Today's Culture) published a series of articles on the Cambridge school of intellectual history in May 2016. The journal's colloquium, while hardly the only intervention on the Cambridge school by Iranian scholars, constitutes perhaps the most sophisticated exploration to date of the relationship between the school and Iranian intellectual history. It also excavates what Professor Ḥātam Qāderī defines as conservative currents of historiography in England and Iran. How, this article asks, is Cambridge-style history presented as a conservative approach and what might the school's Iranian reception tell us about the purpose of such a presentation? Furthermore, how do Qāderī and his peers attempt to reform Iranian historiography by diverging from other historiographical currents in Iran?

General Analysis of the Reaction e^+ + e^- → N + Ñ + π^0

The general analysis of the reaction , in the case of longitudinally polarized electron beam, has been performed in the one-photon-nnihilation approximation, accounting for the polarization states of the final nucleon. This analysis is useful for the description of the continuum (non-resonant) and resonant (with different possible vector mesons or excited baryons in the intermediate virtual states of the Feynman diagrams) contributions. The conservation of the hadron electromagnetic currents and P-invariance of the hadron electromagnetic interaction were used to express the matrix element in terms of the six complex independent invariant amplitudes. The general structure of the hadronic tensor for the case of unpolarized final hadrons and polarized nucleon has been derived. The spin-independent part of the hadronic tensor is determined by five structure functions and the spin-dependent one by 13 structure functions. The transversal, longitudinal and normal components of the nucleon polarization four-vector are expressed by means of the four-vectors of the particle momenta. The five independent invariant variables which describe the reaction have been introduced. The limits of the changing of these variables have been considered. The kinematical double invariant variables regions are given in the figure. The kinematics, suitable to study the invariant mass distributions, is investigated.

Contribution of the nonresonant mechanism to the double and single differential distributions over the invariant variables in the reaction e++e−→N+N¯+π0

The general analysis of the differential cross section and various polarization observables is performed for the process ${e}^{+}+{e}^{\ensuremath{-}}\ensuremath{\rightarrow}N+\overline{N}+{\ensuremath{\pi}}^{0}$ assuming that the annihilation occurs through the exchange of one virtual photon. The dependence of the differential distributions over invariant variables is derived for the reaction ${e}^{+}+{e}^{\ensuremath{-}}\ensuremath{\rightarrow}N+\overline{N}+{\ensuremath{\pi}}^{0}$ in the so-called nonresonant mechanism, applying the conservation of the hadron electromagnetic currents and the P-invariance of the hadron electromagnetic interaction. The detection in an exclusive experimental setup where the nucleon (or antinucleon) and pion are detected in coincidence is considered. A number of single and double differential distributions have been calculated analytically and numerical estimates are given for the $p\overline{p}{\ensuremath{\pi}}^{0}$ and $n\overline{n}{\ensuremath{\pi}}^{0}$ channels, in the Born (nonresonant) approximation, in the energy range from threshold up to $s=16\text{ }\text{ }{\mathrm{GeV}}^{2}$.

Universal nature of rapid evolution of conservative gravity and turbidity currents perturbed from their self-similar state

We explore the nature of gravity and conservative turbidity currents perturbed from their self-similar state and, in particular, we elucidate the cyclic sequence that universally arise in these rapidly-varying regimes. This sequence comprises four states determined by the bulk Richardson number and the acceleration/deceleration of the flow, and its universal nature is supported by six highly resolved direct and large eddy simulations. We study the details of this complex nonmonotonic rapid evolution and explore the how and why of this unique behavior.

Conservation of currents in reduced full-F electromagnetic kinetic and fluid models

In this paper, we present an analysis of the conservation of currents in a full-F electromagnetic gyro-kinetic model in the long-wavelength limit. This equation corresponds to what is usually called the ‘vorticity equation’, which is not strictly correct as it cannot be formulated as the curl of a velocity equation. In the paper, we will therefore use the term ‘current conservation equation’ instead. Our results are relevant to reduced plasma descriptions like gyro-kinetic, drift-kinetic, gyro-fluid and drift-fluid models for tokamaks and stellarators. The equation describes the change of the polarization charge density (often called ‘vorticity’) in terms of the polarization stress due to the flow, external sources and three currents: the parallel current, the curvature current and a current related to the magnetic field fluctuations. We compare this equation with previous drift- and gyro-fluid equations and find general agreement, except in the vorticity source terms where previous drift-fluid models fail to capture the heating and density sources. We discuss the role of currents in the dynamics of diamagnetic and flow shear. The possible connection between these currents with phenomena observed in experiments that influence the radial electric field in the edge of tokamak plasmas, like resonant magnetic perturbations, and different magnetic field configurations and shapes, is presented.

Global Youth in A Local Area: Hybridisation of Identity among Young Muslims in Yogyakarta Interfaith Community

This article investigates the hybrid portraits of identity among young Muslims who are members of the Young Interfaith Peacemaker Community (YIPC) in Yogyakarta. Several inquiries have articulated that Indonesian youth tend to be dragged into ‘conservative turn’ and extremism ideology. However, in this qualitative research we have found the different faces of young Muslims and, in fact, the behavior and religious expression of nowadays youth are not singular and that simple. By using an interpretive phenomenological approach—and through observation, interviews, and documentation particularly from informants—we formulate an argument that young Muslims in the Yogyakarta interfaith community represent a form of multi-identity amalgamation (hybrid). As part of a globally networked society in a local area, they choose to take a dissimilar path from conservative currents and extremist tendencies and then decide to narrate inclusive values, tolerance, and peace education. These snapshots depict a fusion of their thought or horizon (micro-individual) with the community atmosphere (meso-community) and the reality (macro-social politics) around them—which be called Horizontverschmelzung in Hans-Georg Gadamer’s concept. This could be discovered from a sequence of socio-religious behaviour and expressions among youth who are active in the interfaith community in Yogyakarta.

Hydrostatic vs. non-hydrostatic modelling of density currents developing two dimensionally on steep and mild slopes

Salinity and turbidity currents developing two dimensionally on steep and mild slopes are simulated numerically. An application of the process-based model Delft3D-Flow is presented that is able to capture the dynamics of subaqueous dense underflows by solving the two dimensional over the vertical (2DV) Reynolds-averaged Navier–Stokes equations under hydrostatic (H) and non-hydrostatic (NH) pressure assumptions. The development of conservative density currents that plunge in fresh water as a result of an upstream input of denser salty water and turbidity currents flowing down a fixed sandy bed with uniform slope are thoroughly investigated. Down-slope evolution of the modelled density currents is characterised by water entrainment coefficients that fall within the range of laboratory data. Vertical profiles of both velocity and excess density conform with previous experimental measurements. NH solutions, differently from their H counterparts, are shown to capture in detail time-dependent stages of dense undercurrents, such as the dynamics of their fronts, the passage of their heads as well as the development of Kelvin–Helmholtz (KH) instabilities at their interfaces with the ambient fluid resulting in the velocity pulsing of their bodies. Nonetheless, the H application of Delft3D-Flow predicts fairly well the steady state of salty and turbid undercurrents, thus representing a computationally cost-effective alternative for the modelling of field-scale density currents.

A class of finite element methods with averaging techniques for solving the three-dimensional drift-diffusion model in semiconductor device simulations

Obtaining a satisfactory numerical solution of the classical three-dimensional drift-diffusion (DD) model, widely used in semiconductor device simulations, is still challenging nowadays, especially when the convection dominates the diffusion. In this work, we propose a series of finite element schemes with different types of averaging techniques to discretize the three-dimensional continuity equations. Our methods are based on the classical finite element framework, quite different from those mixed finite element/volume methods that also employ inverse averaging techniques. At first, the Slotboom variables are employed to transform the continuity equations into self-adjoint second-order elliptic equations with exponentially behaved coefficients. Then four averaging techniques, denoted with A1-A4, are introduced to approximate the exponential coefficient with its average on every tetrahedral element of the grid. The first scheme calculates the harmonic average of the exponential coefficient on a whole tetrahedron, and the other three schemes calculate the average of the exponential coefficient on each edge of a tetrahedral element. Our methods can avoid the spurious non-physical numerical oscillations and guarantee the conservation of the computed terminal currents with a terminal current evaluation approach. In fact, these methods not only maintain numerical stability but also overcome the disadvantages of some stabilization methods that cannot guarantee the conservation of the terminal currents, such as the streamline-upwind Petrov-Galerkin (SUPG) method. Moreover, the derivation of these discretization methods does not need the dual Voronoi grid as that of the finite volume Scharfetter-Gummel (FVSG) method or other mixed finite element/volume methods with inverse averaging techniques, which greatly reduces the complexity of parallel implementations of our methods. Simulations on two realistic three-dimensional semiconductor devices are carried out to test the accuracy and stability of our methods. According to numerical results, we conclude that scheme A4 can produce more accurate numerical solutions than the other three schemes, especially when the bias applied on the electrode is high. Numerical results also show that the scheme A4 is more robust than the Zlámal finite element method [1] in high-bias cases, and it also performs better than the FVSG method and a tetrahedral mixed finite element method [2] on poor-quality grids. Scheme A4 is also employed to study rich physical properties of the n-channel MOSFET.

Spór polityczny między PiS i PO wokół modelu integracji europejskiej

The dispute over the model of European integration and around the proposals for reform and change of the European Union, which appear time and again, has become one of the main axes of conflict in Polish politics. The aim of this article is to analyse the political views of the two main actors in this dispute – Law and Justice (conservative current) and Civic Platform of the Republic of Poland (liberal current). Representatives of both ideological currents, despite significant axiological differences, were in favour of European integration. While the Law and Justice party presented a Eurorealist stance, the views of PO politicians can be described as Euro-enthusiastic. Sharp disagreements arose when the scope and extent of European integration and the model of the EU needed to be clarified, which de facto boiled down to a debate around the role and significance of the nation-state in international relations. The theoretical layer of political thought is particularly exposed in the study, as the acceptance of a realist or liberal paradigm of international relations by the parties studied was tantamount to support for a particular model of the European Union. It also seemed crucial to examine the relevance and importance of political values such as the state and its sovereignty, collective identity or security and their relationship to the desired vision of the EU.

The off-shell recursion for gravity and the classical double copy for currents

We construct the off-shell recursion for gravity and the graviton current for the perturbative double field theory (DFT). We first formulate the perturbative DFT, which is equivalent but simpler to perturbative general relativity, to all-orders in fluctuations of generalised metric. The perturbative action and equations of motion (EoM) are derived to arbitrary order for pure gravity case. We then derive the graviton off-shell recursion, the gravity counterpart of the Berends-Giele recursion in Yang-Mills theory, through the so-called perturbiner method using the EoM of the perturbative DFT. We solve the recursion iteratively and obtain the graviton off-shell currents explicitly. We then discuss the classical double copy for the off-shell currents. We present the current KLT relation for gravity by extending the result proposed by Mizera and Skrzypek for the non-gravitational effective field theories. The relation represents graviton currents by squaring gluon currents with the KLT kernel up to gauge transformation and regular terms that do not have any pole. Finally we discuss the off-shell conservation of currents for nonlinear gauge choices.