Search results

This study aims to investigate the corrosion inhibitor effect of migrating corrosion inhibitor (MCI) on Q235 steel in high alkaline environment under cathodic polarization.

This study investigated the electrochemical characteristics of Q235 steel with and without MCI by polarization curve and electrochemical impedance spectroscopy. Besides, the surface composition of Q235 steel under different environments was analyzed by X-ray photoelectron spectroscopy. In addition, the migration characteristic of MCI and the adsorption behavior of MCI under cathodic polarization were studied using Raman spectroscopy.

Diethanolamine (DEA) and N, N-dimethylethanolamine (DMEA) can inhibit the increase of Fe(II) in the oxide film of Q235 steel under cathodic polarization. The adsorption stability of DMEA film was higher under cathodic polarization potential, showing a higher corrosion inhibition ability. The corrosion inhibition mechanism of DEA and DMEA under cathodic polarization potential was proposed.

The MCI has a broad application prospect in the repair of damaged reinforced concrete due to its unique migratory characteristics. The interaction between MCIs, rebar and concrete with different compositions has been studied, but the passivation behavior of the steel interface in the presence of both the migrating electric field and corrosion inhibitors has been neglected. And it was investigated in this paper.

The effects of board composition on performance have long been discussed in management research using fractionalization measures. In this study, we propose an alternative measurement approach based on board polarization.

Using an exploratory analysis and applying the polarization measure to German Deutscher Aktienindex (DAX)-, Midcap-DAX (MDAX)- and Small Cap-Index (SDAX)-listed companies, this paper applies the polarization index to examine the relationship between board diversity and performance.

The results show that the polarization concept is well suited to measure principal-agent problems between the members of the management and supervisory boards. We reveal that board polarization is negatively associated with firm performance, as measured by return on investment (ROI).

This exploratory study shows that the measurement of board polarization can be linked to performance differences between companies, which offers promising starting points for further research.

The polarisation of employment is a specific structural change in the labour market when the share of high and low-skilled workers increases and, simultaneously, the share of middle-skilled workers decreases. The chapter analyses the effect of polarisation in Czechia and other Central European countries and describes how employment has changed from the perspective of skills regarding gender. The analysis is based on observing the changes in the share of high, middle and low-skilled workers evaluated on the basis of occupational classification over time. Results imply (with a few exceptions) polarisation of employment across all countries during the period between 1998 and 2021, even if we consider the distinction between males and females. Results confirm that employment polarisation has also become a prevalent phenomenon in Central European countries during the last two decades. Finally, this chapter also summarises the economic motivation for studying polarisation phenomenon.

The global prevalence of social media and its potential to cause polarization are highly debated and impactful. The previous literature often assumes that the ideological bias of any media outlet remains static and exogenous to the polarization process. By studying polarization as a whole from an ecosystem approach, the authors aim to identify policies and strategies that can help mitigate the adverse effects of polarization and promote healthier online discourse.

To investigate online polarization, the authors perform a systematic review and analysis of approximately 400 research articles to explore the connection between cognitive bias and polarization, examining both causal and correlational evidence. The authors extensively evaluate and integrate existing research related to the correlation between online polarization and crucial factors such as public engagement, selective exposure and political democracy. From doing so, the authors then develop a PolarSphere ecosystem that captures and illustrates the process of online polarization formation.

The authors' review uncovers a wide range of associations, including ideological cognition, bias, public participation, misinformation and miscommunication, political democracy, echo chambers and selective exposure, heterogeneity and trust. Although the impact of bias on social media polarization depends on specific environments and internal/external conditions, certain variables exhibit strong associations across multiple contexts. The authors use these observations as a basis from which to construct PolarSphere, an ecosystem of bias-based polarization on social media, to theorize the process of polarization formation.

Based on the PolarSphere ecosystem, the authors argue that it is crucial for governments and civil societies to maintain vigilance and invest in further research to gain a deep comprehension of how cognitive bias affects online polarization, which could lead to ways to eliminate polarization.

Stainless-steel electromagnetic shielding (EMS) fabrics are widely applied as protective materials against electromagnetic interference (EMI). However, these fabrics primarily shield electromagnetic waves through reflection, which can lead to the formation of resonance effects that severely compromise their protective capabilities and potentially cause secondary electromagnetic pollution in the external environment.

In this paper, carbon nanotube fibers are added via spacing method to replace some stainless-steel fibers to impart absorbing properties to stainless-steel EMS fabric. The shielding effectiveness (SE) of the EMS fabrics across various polarization directions is analyzed. Additionally, a spacing arrangement for the carbon nanotube fibers is designed. The EMS fabric with carbon nanotube fibers is manufactured using a semi-automatic sample loom, and its SE is tested using a small window method test box in both vertical and horizontal polarization directions.

According to the experimental data and electromagnetic theory analysis, it is determined that when the spacing between the carbon nanotube fibers is less than a specific distance, the SE of the stainless-steel EMS fabric significantly improves. The fabric exhibits stable absorbing properties within the tested frequency range, effectively addressing the issue of secondary damage that arises from relying solely on reflective shielding. Conversely, as the spacing between the carbon nanotube fibers exceeds this distance, the SE diminishes. Notably, the SE in the vertical polarization direction is substantially higher than that in the horizontal polarization direction at the same frequency.

This study provides a new path for the development of high-performance EMS fabrics with good wave-absorption characteristics and SE.

Once a corporate crisis is entangled with a social issue, how consumers make sense of the crisis can be impacted by issue-based opinion polarization. This study investigates the underlying mechanisms as consumers go through this process. This study also examines whether corporate social advocacy (CSA) can be an effective crisis-response strategy for mitigating reputational loss.

Theoretical inquiries were empirically tested using an online experiment (N = 792). The experiment set the context in China, in a working-overtime-issue-related crisis. It had a 2 (online exposure: anti-issue opinion vs. pro-issue opinion) × 2 (CSA: absence vs. presence) between-subject design with a continuous variable (pre-existing issue attitudes) measured before the manipulation.

This study found that pre-existing issue attitudes can be directly and indirectly associated with corporate reputation, for the issue attitudes influence how consumers attribute crisis blame. Such a direct effect of pre-existing issue attitudes varies depending on which polarized opinion consumers were exposed to on social media. This study also found CSA to be a robust crisis response strategy, through multiple mechanisms, in protecting the corporate reputation.

Scholars are scarcely aware of the threats that issue-based opinion polarization poses to corporate reputation. This study serves as an early attempt to provide theoretical explanations. In addition to this, this study extends the current conceptual understandings of CSA during corporate crises that involve social issues while adding fresh insights into the established typology of crisis-response strategies.

In this paper, the authors aim to study the effect of hydrogen on the pitting corrosion behavior of Incoloy 825, a commonly used material for heat exchanger tubes in hydrogenated heat exchangers.

The pitting initiation and propagation behaviors were investigated by electrochemical and chemical immersion experiments and observed and analyzed by scanning electron microscope and energy dispersive spectrometer methods.

The results show that hydrogen significantly affects the electrochemical behavior of Incoloy 825; the self-corrosion potential decreased from −197 mV before hydrogen charging to −263 mV, −270 mV and −657 mV after hydrogen charging, and the corrosion current density increased from 0.049 µA/cm² before hydrogen charging to 2.490 µA/cm², 2.560 µA/cm² and 2.780 µA/cm² after hydrogen charging. The pitting susceptibility of the material increases.

Hydrogen is enriched on the precipitate, and the pitting corrosion also initiates at that location. The synergistic effect of hydrogen and precipitate destroys the passive film on the metal surface and promotes pitting initiation.

In the face of increasing political polarization worldwide, this study explores whether people create biased perceptions of political knowledge and how this affects their selection and evaluation of political content on YouTube.

For this study, an online experiment was conducted with 441 panels of South Korean respondents. In the first phase, participants answered 10 questions designed to capture their level of objective political knowledge, and for each question, they indicated whether they had responded to that question correctly as a means of measuring their subjective political knowledge. In the second phase, two types of YouTube thumbnails were presented to represent progressive and conservative claims on two controversial political issues, and participants rated and selected the content they would like to see.

Participants with low political knowledge perceived their knowledge as more than it really was. In contrast, participants with high political knowledge perceived their political knowledge as less than it really was. This biased perception of political knowledge influences respondents' choice and evaluation of political YouTube channel videos.

At a time when political polarization is increasing around the world, this study sought to explore how perceptions of political knowledge differ from actual political knowledge by applying the Dunning-Kruger effect. The authors also used political YouTube channels, whose role in forming public opinion and political influence is rapidly growing, to study the behavior and attitudes of a group of Korean respondents in the media according to their actual and perceived level of political literacy.

This paper aims to propose a single element, dual feed, polarisation diversity antenna. The proposed antenna operates from 2.9 to 10.6 GHz for covering the entire ultra-wideband (UWB) frequency range. The antenna is designed for usage in massive multiple input multiple output (MIMO) and closed packaging applications.

The size of the antenna is 24 × 24 × 1.6 mm³. The radiating element of the antenna is derived from the Sierpinski–Knopp (SK) fractal geometry for miniaturization of the antenna size. The antenna has a single reflecting stub placed between the two orthogonal feeds, to improve isolation.

The proposed antenna system exhibits S₁₁ < −10 dB, S₂₁ < −15 dB and stable radiation characteristics in the entire operating region. It also offers an envelope correlation coefficient < 0.01, a diversity gain > 9.9 dB and a capacity loss < 0.4 bps/Hz. The simulated and measured outputs were compared and results were found to be in similarity.

The proposed UWB-MIMO antenna has significant size reduction through usage of SK fractal geometry for radiating element. The antenna uses a single radiating element with dual feed. The stub is between the antenna elements which provide a compact and miniaturized MIMO solution for high density packaging applications. The UWB-MIMO antenna provides an isolation better than −20 dB in the entire UWB operating band.