Theory Of Polarization Research Articles

Theoretically grounded approaches to account for polarization effects in fixed-charge force fields.

Non-polarizable, or fixed-charge, force fields are the workhorses of most molecular simulation studies. They attempt to describe the potential energy surface (PES) of the system by including polarization effects in an implicit way. This has historically been done in a rather empirical and ad hoc manner. Recent theoretical treatments of polarization, however, offer promise for getting the most out of fixed-charge force fields by judicious choice of parameters (most significantly the net charge or dipole moment of the model) and application of post facto polarization corrections. This Perspective describes these polarization theories, namely the "halfway-charge" theory and the molecular dynamics in electronic continuum theory, and shows that they lead to qualitatively (and often, quantitatively) similar predictions. Moreover, they can be reconciled into a unified approach to construct a force field development workflow that can yield non-polarizable models with charge/dipole values that provide an optimal description of the PES. Several applications of this approach are reviewed, and avenues for future research are proposed.

Study of interfacial competitive distribution and synergistic permeation in nanofiltration separation of Salvia divinorum acids from the aqueous extract

The contact between solution and membrane during nanofiltration separation produces the interfacial layer fluid, and the competitive distribution laws of solutes in the interfacial layer are difficult to be analyzed, giving rise to diversified separation results that are challenging to explain using traditional nanofiltration separation theory. Four Salvia divinorum phenolic acid components—sodium salvinorin, protocatechuic aldehyde, rosmarinic acid, and salvianolic acid B—which have gradient relative molecular masses and dissociation constants, were selected as the objects of study. The nanofiltration separation parameters, such as membrane flux and permeation rate of the Salvia divinorum phenolic acids and their variability with the monomer solution under the complex solution environment were systematically analyzed. Based on the correlation between the concentration of the interfacial layer and the initial concentration, membrane flux and mass transfer coefficient in the theory of concentration polarization, the concentration of the interfacial layer of the nanofiltration membrane was calculated. This was combined with the state of association characterized by the distribution of particle sizes in the solution, the research model based on the ‘Associative State-Interfacial Competition-Separation Behavior’ was constructed, and the competitive and synergistic membrane separation regulations of the constituents of salvia phenolic acids were clarified. In acidic solutions, van der Waals forces dominate the interfacial competition, and of the four phenolic acids, salvinorin acid B diffused most easily to the membrane surface, showing that the component with the larger relative molecular mass inhibited the penetration of the smaller component; In alkaline solution, Coulomb force and Van der Waals force together dominate the interfacial competition, and the more acidic sodium salvinorin, etc., would preferentially react with hydroxide. At the same time, combined with the feature that the more molecular states in the particle size distribution of the solution are more likely to form aggregates, it was proven that the dissociation of protocatechuic acid aldehyde was inhibited, and its molecular state was more complete. It was shown that the more acidic sodium salvinorin and others facilitated the less acidic protocatechuic aldehyde to pass through the membrane.

Old wine in new wineskins: Christian nationalism, authoritarianism, and the problem of essentialism in explanations of religiopolitical conflict

AbstractIn 2001, John Levi Martin published a critique of authoritarianism scholarship, arguing that it was marred by fundamental biases of tautology, selective interpretation, and overtheorization of some research subjects but neglect of others. Drawing from this critique, I argue that Christian nationalism scholarship in sociology operates as a variant of authoritarianism research, exhibiting similar claims, strengths, and shortcomings. In a short span of time, the Christian nationalism research agenda has come to dominate the sociological study of religion and enjoyed a high profile in public discourse, presumably due to its relevance to matters of acute political concern. However, this literature interprets empirical results based on unverified assumptions of essentially authoritarian goals and motivations while ignoring plausible alternative explanations. It further neglects respondents who are low on Christian nationalism measures, despite evidence that these respondents play a role in religiopolitical conflict. The result is an essentialist account of Christian nationalism that is politically resonant but theoretically problematic. I propose that these issues can be addressed by a shift away from essentialist and toward social models of belief systems, which offer important advantages: greater consistency with current theories of political polarization, a stronger sociological element, and less susceptibility to researcher bias.

The Influence of Partisanship on Assessments of Promise Fulfillment and Accountability

I draw together theories of partisan polarization and motivated reasoning, which suggest that partisanship shapes information processing, and theories of accountability, which argue voters hold elected officials accountable through promise fulfillment. Here, I ask how partisanship influences voter understanding of promise fulfillment and accountability and if voters assess promises through a partisan lens. Two original survey experiments test how respondents react to promise fulfillment on the issues of immigration and human trafficking. I demonstrate that co-partisans differentiate between kept and broken promises, but out-partisans do not. Despite partisan differences, respondents evaluate promise-keeping when asked about accountability but not when asked about approval. Thus, even when voters recognize broken promises, accountability is influenced by partisanship. Immigration, a more polarized issue, is more likely to prime a partisan response than human trafficking, a less polarized issue. Future work must account for partisanship in accountability and what this means for our understanding of fundamental democratic principles.

Green economic efficiency and productivity for sustainable development in China: A ray epsilon-based measure model analysis

Improving green economic efficiency (GEE) and productivity are crucial for China to realize sustainable development goals. However, the economic growth of China has followed an extensive development model with high energy consumption and heavy pollution. This study conducts data envelopment analysis (DEA) to evaluate the GEE of China. First, we introduce the polar coordinates theory in the epsilon-based measure (EBM) model to construct a Ray epsilon-based measure (REBM) model. In addition to the merits of EBM model, the REBM model accounts for the weak disposable relationship between undesirable and desirable outputs. Second, based on REBM model, a REBM-Malmquist-Luenberger (REBM-ML) index is constructed to evaluate the green total factor productivity (GTFP). Finally, we conduct spatial econometric analysis to reveal the dynamic evolution of GTFP. According to the empirical results, the GEE of China is generally low, and the urban agglomerations located at coastal regions own higher GEE. However, the GTFP made progress overall, mainly benefited from the technical progress. Accordingly, in the process of sustainable development, China still faces the challenge of energy saving and emission reduction. The spatial econometric analysis reveals that the GTFP of China existed a significant divergence trend and there was spatial spillover effect between cities, as well as urban agglomerations. Furthermore, we provide policy implications and suggestions for Chinese sustainable development.

Diurnal and semi-diurnal effects of ocean tides on polar motion and UT1: An updated assessment

We revisit the computation of diurnal and semidiurnal effects of the ocean tide on Polar Motion (PM) and UT1 considering the principal waves of the Ocean Tidal Angular Momentum (OTAM) calculated from the FES 2014 ocean tide atlas. We take into account the recent development of polar motion theory, especially the frequency dependence of the transfer functions in (sub-) diurnal bands. The method of calculating the minor waves is also carefully studied and modified: instead of an interpolation based on neighboring waves, we propose a frequency dependent expression obtained by a linear fit to the admittances and phases of principal waves. Compared in time domain with polar motion (PM) and UT1 derived from Very Long Baseline Interferometry (VLBI) observations, our model performs as well as the recent Desai-Sibois model computed from TPXO8 tidal atlas. The impact of diurnal and semi-diurnal oscillations produced by the luni-solar tidal torque on the asymmetric mean mass distribution of the Earth are observed in the corresponding residuals, which is not the case for the older PM/UT1 model recommended in IERS Convention 2010. More generally, we conclude that tidal modelling of sub-daily terms and corresponding empirical developments are consistent to within 23 μas for PM and 3 μs for UT1. In parallel, the effects based on TPXO8 OTAM waves are recalculated according to our method, and present the best agreement with the observations. Our tables, calculated from FES 2014 or TPXO8 OTAM, can be truncated to the 48 or 50 terms with amplitudes above 1 μas for PM or 0.1 μs for UT1 to describe those Earth rotation Parameters in a way consistent with their current observation uncertainties.

Efficient exploration of electronic and dielectric properties using advanced first-principles analysis grounded in modern theory of polarization: Application to PbTiO3

Efficient exploration of electronic and dielectric properties using advanced first-principles analysis grounded in modern theory of polarization: Application to PbTiO₃

Customer engagement, moral identity and oppositional brand loyalty in virtual communities

PurposeOppositional brand loyalty poses a challenge to the management of virtual communities. This study aims to categorize these loyalty behaviors into positive (willingness to pay a price premium and brand evangelism) and negative (schadenfreude and anti-brand actions) dimensions. It then explores how customer engagement and moral identity influence these dimensions in the context of brand competition.Design/methodology/approachStructural equation modeling was conducted to analyze the main and moderating effects, using survey data obtained from 498 valid responses out of a total of 636 responses from Xiaomi's virtual communities.FindingsThe results indicate that customer engagement significantly influences all four dimensions of oppositional brand loyalty. The relationship between customer engagement and brand evangelism is notably stronger among customers with a strong moral identity. Conversely, the effects of customer engagement on schadenfreude and anti-brand actions are attenuated for these customers.Originality/valueAnchored in theories of brand tribalism, social identity and brand polarization, this study bifurcates oppositional brand loyalty into directions of preference and antagonism, empirically showcasing moral identity's moderating effect. It contributes to the literature on antagonistic loyalty and moral identity, offering strategic insights for companies to navigate schadenfreude and anti-brand actions in online communities.

Polish borders: media polarization and the representation of the refugee crises at the borders with Belarus (2021) and Ukraine (2022)

RESEARCH OBJECTIVE: This paper examines how specific media outlets (Polityka, Sieci) have portrayed the crises on Poland’s borders with Belarus and Ukraine. It focuses on refugees during the period of border crossings by capturing reactions, emotions, and decisions highlighted in the media during that period. Utilizing media polarization theory, the authors analyse similarities and differences in selected media outlets’ coverage of the crises. THE RESEARCH PROBLEM AND METHODS: The following research questions were asked: What is the media portrayal of the refugees on the Belarus and the Ukrainian borders? Does the structural level of MP (media polarization) impact the behavioural level? The authors conducted qualitative media content analysis, following Pisarek’s (1983) research process and Mayring’s (2014) Inductive Category. THE PROCESS OF ARGUMENTATION: The theory of media polarization is presented, followed by an analysis of the literature examining this phenomenon in the context of the refugee crises at Poland’s borders with Belarus and Poland. Qualitative content analysis of over 100 articles published in two strategically selected structurally polarized weeklies was carried out using the nVIVO software. RESEARCH RESULTS: The structural level of media polarization is reflected in the behavioural one. This study reveals that the main thematic focus is the refugees at the Belarusian border, who are described via political, social, and religious themes. The crisis at the Ukrainian border also exhibits polarizing elements, primarily centring on evaluating or criticizing the authorities and addressing or ignoring uncomfortable and problematic issues that emerge in connection to these refugees CONCLUSIONS, INNOVATIONS AND RECOMMENDATION: This study constitutes a significant contribution to the theory of media polarization, addressing it also in relation to issues of diversity, tolerance, inclusivity, and humanitarianism.

Nonuniqueness in defining the polarization: Nonlocal surface charges and the electrostatic, energetic, and transport perspectives

Ionic crystals, ranging from dielectrics to solid electrolytes to complex oxides, play a central role in the development of modern technologies for energy storage, sensing, actuation, and other functional applications. Mesoscale descriptions of these crystals are based on the continuum polarization density field to represent the effective physics of charge distribution at the scale of the atomic lattice. However, a long-standing difficulty is that the classical electrostatic definition of the macroscopic polarization — as the dipole or first moment of the charge density in a unit cell — is not unique; rather, it is sensitive to translations of the unit cell in an infinite periodic system. This unphysical non-uniqueness has been shown to arise from starting directly with an infinite system — wherein the boundaries are ill-defined — rather than starting with a finite body and taking appropriate limits. This limit process shows that the electrostatic description requires not only the bulk polarization density, but also the surface charge density, as the effective macroscopic descriptors; that is, a nonlocal effective description. Other approaches to resolve this difficulty include the popular modern theory of polarization that completely sets aside the polarization as a fundamental quantity in favor of the change in polarization from an arbitrary reference value and then relates the change in polarization to the transport of charge (the “transport” definition); or, in the spirit of classical continuum mechanics, to define the polarization as the energy-conjugate to the electric field (the “energetic” definition).This work examines the relation between the classical electrostatic definition of polarization, and the transport and energy-conjugate definitions of polarization. We show the following: (1) The transport of charge does not correspond to the change in polarization in general; instead, one requires additional simplifying assumptions on the electrostatic definition of polarization for these approaches to give rise to the same macroscopic electric fields. Thus, the electrostatic definition encompasses the transport definition as a special case. (2) The energy-conjugate definition has both bulk and surface contributions; while traditional approaches neglect the surface contribution, we find that accounting for the nonlocal surface contributions is essential to be consistent with the classical definition and obtain the correct macroscopic electric fields.

Navigating pandemic waves: Consensus, polarisation and pluralism in the Finnish parliament during COVID-19

This article studies how the COVID crisis affected polarisation, politicisation and consensus in Finnish parliamentary discourse, a case in which we expect pluralist political institutions and culture to mitigate polarisation. In addition to the empirical contribution, we add to the theory of polarisation by drawing from Chantal Mouffe’s theory of plural democracy to argue that the opposite of polarisation may take the form of a depoliticised consensus or a pluralism of legitimate positions (‘agonism’). Furthermore, we apply Norman and Isabela Fairclough’s political discourse analysis to studying polarisation qualitatively, arguing that scrutiny of argumentative premises enables assessment of how profound certain political conflicts are. Studying 485 parliamentary speeches given in 2020–2021, we argue that a morally charged consensus imperative with nationalistic overtones quickly developed in Spring 2020, and pluralism gradually re-emerged later. The article highlights that while polarisation can threaten democracy, so can moralisation and enforced consensus.

Revisiting polar paradox: antioxidant activity in bulk oil using selected phenol lipids.

The purpose of this work was to re-evaluate the polar paradox theory (PPT) that explains the relationships between the efficacy of antioxidants, their polarity, and their environments. In this study, ascorbic acid (AA), ascorbyl palmitate (AP), gallic acid (GA), gallyl palmitate (GP), Trolox (TR), α-tocopherol (TO), resveratrol (R), and resveratryl palmitate (RP) were employed to assess conjugated dienoic acid (CDA), the p-anisidine value (p-AV), headspace oxygen content, and hexanal formation in a bulk oil system. TR, TO, R, and RP showed better antioxidant activities in CDA and p-AV and higher headspace oxygen content than AA, AP, GA, and GP. AA showed lower hexanal formation than AP, whereas GP, TO, and RP had better antioxidant activity than their derivatives. These findings suggest that the PPT might be useful to explain the oxidation that occurs at the air-oil interface/association colloids but applying it to other assays might not appropriate.

Effect of grain size on the dielectric and magnetic properties of YFeO3 ceramics densified by microwave sintering and spark plasma sintering from powders synthesized via reverse chemical co-precipitation

YFeO3 (YFO) ceramics were synthesized by reverse co-precipitation at different pH values followed by microwave sintering (MS) and spark plasma sintering (SPS) techniques. Also, the effect of the grain size on the magnetic and dielectric properties of the sintered ceramics was examined using various characterization methods. Moreover, FESEM micrographs showed that the particle size of the calcined samples has declined by increasing the pH value. Furthermore, the magnetization curves exhibited weak ferromagnetic behavior in the pre-sintered powder samples. Besides, the Ms value was enhanced from 1.26emu/g to 2.3emu/g by an increase in pH from 8.5 to 10.5 owing to reducing the particle size and subsequently raising the amount of uncompensated surface spins. Furthermore, the powder samples showed an increase in the Hc and Mr values from 15Oe to 28Oe and 0.127emu/g to 0.296emu/g, respectively, with a reduction in particle size from 0.632 μm to 0.272 μm. Additionally, the specimens processed through the sintering techniques demonstrated a remarkable reduction in magnetic characteristics. Therefore, a decrease in magnetic saturation values from 2.3emu/g to 0.43emu/g for the MS sample and to 0.17emu/g for the SPS specimen was attributed to a marked reduction in the amount of free surfaces and subsequently uncompensated surface spins. At last, the observed dielectric characteristics of all the sintered pellets had a common dielectric behavior. This signifies that by increasing the frequency the ε′ and tanδ decline at lower frequencies and become frequency-independent at higher frequencies based upon the Maxwell-Wagner polarization theory. On the other hand, the ε′ value for the SPS sample produced at pH = 10.5 underwent a decline of 2.5 times at the low frequency of 200 Hz compared to the MS one due to the significant decrement of the grain boundaries on account of the coarsening of grains.

Tailoring the dielectric properties of bentonite for advanced capacitor Applications: The role of ruthenium and strontium incorporation

This study utilized incipient wetness impregnation to synthesize bentonite materials and to enhance their physical characteristics with ruthenium (Ru) and strontium (Sr) ions. The atomic composition of the materials was confirm confirmed via the analysis of the EDX measurements. X-ray crystallography indicates that the materials have almost similar diffraction peak profiles, and that the addition of Sr increases the crystallinity of the bentonite grains. Dielectric and electrical properties, measured between 25 °C and 55 °C at frequencies of 1 kHz −1 MHz, revealed that the real and imaginary impedances increased upon the introduction of 5 % Ru and 5 % Sr, possibly due to Ru and Sr segregation into the grain boundaries, increasing the resistance of the bentonite granular structure. For all materials, the observed saturation of the real electric modulus at high frequencies, and the reduction of the permittivity with increasing frequency, may be explained by the Maxwell-Wagner interfacial polarization and Koop's empirical theory. This trend is more pronounced for the bentonite with Sr, highlighting the essence of the present work for engineering interfacial polarisation applications associated with supercapacitors and batteries.

Electric Polarization from a Many-Body Neural Network Ansatz.

Abinitio calculation of dielectric response with high-accuracy electronic structure methods is a long-standing problem, for which mean-field approaches are widely used and electron correlations are mostly treated via approximated functionals. Here we employ a neural network wave function ansatz combined with quantum MonteCarlo method to incorporate correlations into polarization calculations. On a variety of systems, including isolated atoms, one-dimensional chains, two-dimensional slabs, and three-dimensional cubes, the calculated results outperform conventional density functional theory and are consistent with the most accurate calculations and experimental data. Furthermore, we have studied the out-of-plane dielectric constant of bilayer graphene using our method and reestablished its thickness dependence. Overall, this approach provides a powerful tool to accurately describe electron correlation in the modern theory of polarization.

Probing 3D Magnetic Fields Using Thermal Dust Polarization and Grain Alignment Theory

Magnetic fields are ubiquitous in the Universe and are thought to play an important role in various astrophysical processes. Polarization of thermal emission from dust grains aligned with the magnetic field is widely used to measure the 2D magnetic field projected onto the plane of the sky, but its component along the line of sight is not yet constrained. Here, we introduce a new method to infer 3D magnetic fields using thermal dust polarization and grain alignment physics. We first develop a physical model of thermal dust polarization using the modern grain alignment theory based on the magnetically enhanced radiative torque alignment theory. We then test this model with synthetic observations of magnetohydrodynamic simulations of a filamentary cloud with our updated POLARIS code. Combining the tested physical polarization model with synthetic polarization, we show that the B-field inclination angles can be accurately constrained by the polarization degree from synthetic observations. Compared to the true 3D magnetic fields, our method based on grain alignment physics is more accurate than the previous methods that assume uniform grain alignment. This new technique paves the way for tracing 3D B-fields using thermal dust polarization and grain alignment theory and for constraining dust properties and grain alignment physics.

The growing partisan politicization of non-political online spaces: A mixed-method analysis of news app reviews on Google Play between 2009 and 2022

Drawing on theories of identity politics and partisan polarization, we explored the politicization of Google Play’s news app reviews—an explicitly non-political domain. Using a mixed-methods approach, Analysis of Topic Model Networks (ANTMNs), combining topic modeling, network analysis, community detection, and theory-driven qualitative reading, we analyzed 759,143 reviews from 2009 to 2022 across 46 news apps. Three themes emerged: Technical, Content Quality, and Political. The political discourse in reviews has intensified over the years, with notable spikes around election periods. Accusations of bias were found to correlate most strongly with lower app ratings. The findings provide alarming empirical evidence for the politicization of non-political spaces, such as the app reviews section on app stores. With identity politics on the rise, this study sheds light on the importance of considering non-political online spaces for the study of political discourse.

Thermodynamic analysis of a dual-pressure evaporation high-temperature heat pump with low GWP zeotropic mixtures for steam generation

High-temperature heat pumps (HTHPs) have gained attention due to their economic and environmental benefits in utilizing industrial waste heat for steam generation. This study focuses on improving the HTHPs’ performance by employing two-stage separation and dual-pressure evaporation technology in the auto-cascade heat pump cycle. Additionally, binary zeotropic refrigerant mixtures with low-GWP are selected using the polar perturbed-chain statistical associated fluid theory (PC-SAFT) equation of state. The findings indicate that the R1234ze(E)&R1233zd(E) refrigerant mixture outperforms other potential alternatives, exhibiting a thermodynamic effectiveness 0.85%–1.86% higher than the benchmark mixture, R134a&R245fa. The improved cycle demonstrates significant enhancements, achieving a 45.17% increase in heat source utilization efficiency and a 24.48% improvement in COP compared to the basic auto-cascade cycle. Effective temperature matching between refrigerant mixtures and heat sources/sinks is guaranteed in the improved cycle. Moreover, a parameter analysis reveals that increasing the subcooling degree of the cascaded heat exchanger and the separation dryness fraction at separator 2 enables improvements in both COP and heat source utilization efficiency. These findings provide valuable insights into the design of steam generation heat pumps and the selection of refrigerant mixtures.

Full-field solution from an oblique shock to estimate ground motion from blasting

The full-field solution (FFS) of the seismic radiation from a blasthole is refined with the use of a source function consistent with the shock physics on the detonation shock/rock interface. This source function accounts for the directionality of the flow in the detonation front, that is curved under the influence of the confining rock, inducing on it an oblique shock mostly on axial direction, contrary to current models that consider a radial source. The interaction of the explosive/confiner system is solved with the oblique shock local polar theory. From this analysis, pressure (p) versus deflection angle (Θ) polar curves are constructed and plotted in the p-Θ plane. The intersection of the explosive and confiner polar curves corresponds to the possible shock matching solution across the explosive/rock interface, which leads to a shock incident angle. A code has been written in MATLAB to perform the shock polar analysis. The resulting detonation front angle of the explosive with the confiner is considered to build a combined radial/axial source. For this, the displacement potentials for the axial component of the source are formulated and incorporated to the solution. Experimental data from quarry blasting are used to illustrate the application of the FFS model and the calibration of results in terms of attenuation coefficients. The effect of introducing the radial/axial combined source is also discussed.

Cajal, the neuronal theory and the idea of brain plasticity.

This paper reviews the importance of Cajal's neuronal theory (the Neuron Doctrine) and the origin and importance of the idea of brain plasticity that emerges from this theory. We first comment on the main Cajal's discoveries that gave rise and confirmed his Neuron Doctrine: the improvement of staining techniques, his approach to morphological laws, the concepts of dynamic polarisation, neurogenesis and neurotrophic theory, his first discoveries of the nerve cell as an independent cell, his research on degeneration and regeneration and his fight against reticularism. Second, we review Cajal's ideas on brain plasticity and the years in which they were published, to finally focus on the debate on the origin of the term plasticity and its conceptual meaning, and the originality of Cajal's proposal compared to those of other authors of the time.