Search results

Gas insulated systems, such as gas insulated lines (GIL), use insulating gas, mostly sulfur hexalfluoride (SF₆), to enable a higher dielectric strength compared to e.g. air. However, under high voltage direct current conditions, charge accumulation and electric field stress may occur, which may lead to partial discharge or system failure. Therefore, numerical simulations are used to design the system and determine the electric field and charge distribution. Although the gas conduction shows a more complex current–voltage characteristic compared to solid insulation, the electric conductivity of the SF₆ gas is set as constant in most works. The purpose of this study is to investigate different approaches to address the conduction in the gas properly for numerical simulations.

In this work, two approaches are investigated to address the conduction in the insulating gas and are compared to each other. One method is an ion-drift-diffusion model, where the conduction in the gas is described by the ion motion in the SF₆ gas. However, this method is computationally expensive. Alternatively, a less complex approach is an electro-thermal model with the application of an electric conductivity model for the SF₆ gas. Measurements show that the electric conductivity in the SF₆ gas has a nonlinear dependency on temperature, electric field and gas pressure. From these measurements, an electric conductivity model was developed. Both methods are compared by simulation results, where different parameters and conditions are considered, to investigate the potential of the electric conductivity model as a computationally less expensive alternative.

The simulation results of both simulation approaches show similar results, proving the electric conductivity for the SF₆ gas as a valid alternative. Using the electro-thermal model approach with the application of the electric conductivity model enables a solution time up to six times faster compared to the ion-drift-diffusion model. The application of the model allows to examine the influence of different parameters such as temperature and gas pressure on the electric field distribution in the GIL, whereas the ion-drift-diffusion model enables to investigate the distribution of homo- and heteropolar charges in the insulation gas.

This work presents numerical simulation models for high voltage direct current GIL, where the conduction in the SF₆ gas is described more precisely compared to a definition of a constant electric conductivity value for the insulation gas. The electric conductivity model for the SF₆ gas allows for consideration of the current–voltage characteristics of the gas, is computationally less expensive compared to an ion-drift diffusion model and needs considerably less solution time.

The purpose of this study is to investigate the role of foreign aid in the Western Balkans countries’ economic growth between 2009 and 2021.

This paper uses a panel data approach to examine the effects of foreign aid on economic growth in the region and incorporates a random-effects model to accommodate the unique cross-country variations and time-specific factors, as well as a pooled OLS and fixed-effects model for a comprehensive, comparative analysis.

The in-depth regression analysis shows that foreign aid has not had a significant impact on the economic growth of the region. Further evidence suggests that trade openness exhibited a significant positive correlation with economic growth, while gross capital formation, although positively associated, did not significantly impact it, indicating the complexity of its role in the region’s economies.

The analysis presented in this study has significant practical implications, particularly for policymakers in the Western Balkans. Given the region’s ambitions for European Union membership and the challenges of high unemployment and inflation, understanding the role of foreign aid is crucial.

This research provides a unique contribution to the field of development economics by examining foreign aid effectiveness within the context of a region often overlooked in the literature. The analysis also offers fresh insights into the complex dynamics of foreign aid and its implications for policy and development strategies.

The heritage and tourist attractiveness of Heritage Cities have aroused interest in establishing mechanisms to enhance their value based on the development of sustainability policies. The socioeconomic and socioenvironmental valuation of these heritage sites has become a necessary tool for decision-making.

Following the recommendations of International Council on Monuments and Sites – ICOMOS, this paper proposes a series of indicators and an exploratory model to define the factors that contribute to their valuation. Following the partial least squares structural equation modelling methodology, information was obtained from 363 intramural residents in the three Heritage Cities that currently have management plans in Spain.

The results show the importance of specifying indicators of sustainable mobility and socioeconomic and socioenvironmental sustainability for an adequate valorisation of heritage sites.

To this end, it is necessary to follow the guidelines of international bodies such as ICOMOS in relation to the management plans.

This study aims to analyze the factors driving Syrian refugees into the informal labor market in Türkiye despite the existence of regulations and programs to facilitate their integration into the formal labor market.

This study presents results from a literature review of secondary sources and primary data collection through semi-structured interviews with key stakeholders and Syrian refugees.

The study shows that the implementation of policies and programs to boost formal employment among refugees has yielded limited results. Many refugees continue to operate within the informal economy. This informality is due to various socio-economic challenges, including anti-refugee sentiments, geographical restrictions and economic crises. The 2023 twin earthquakes have further exacerbated the vulnerable situation of refugees, intensifying the difficulty of achieving self-reliance.

The study’s drawbacks include a small sample size. This implies that the sample is not representative; therefore, results may lack generalizability.

The study’s findings could stimulate greater engagement in public policy, facilitate the management of public perceptions regarding refugees and provide support to the private sector, all to enhance the integration of Syrian refugees into the formal labor market.

This study addresses crucial areas previously unexplored, including the impact of economic and natural disaster crises on the labor market integration of refugees. To the best of the author’s knowledge, by investigating these factors for the first time, this study offers novel insights into their influence on refugees’ labor market integration.

The ionization of the air surrounding the phase conductor in high-voltage transmission lines results in a phenomenon known as the Corona effect. To avoid this, Corona rings are used to dampen the electric field imposed on the insulator. The purpose of this study is to present a fast and intelligent surrogate model for determination of the electric field imposed on the surface of a 120 kV composite insulator, in presence of the Corona ring.

Usually, the structural design parameters of the Corona ring are selected through an optimization procedure combined with some numerical simulations such as finite element method (FEM). These methods are slow and computationally expensive and thus, extremely reducing the speed of optimization problems. In this paper, a novel surrogate model was proposed that could calculate the maximum electric field imposed on a ceramic insulator in a 120 kV line. The surrogate model was created based on the different scenarios of height, radius and inner radius of the Corona ring, as the inputs of the model, while the maximum electric field on the body of the insulator was considered as the output.

The proposed model was based on artificial intelligence techniques that have high accuracy and low computational time. Three methods were used here to develop the AI-based surrogate model, namely, Cascade forward neural network (CFNN), support vector regression and K-nearest neighbors regression. The results indicated that the CFNN has the highest accuracy among these methods with 99.81% R-squared and only 0.045468 root mean squared error while the testing time is less than 10 ms.

To the best of the authors’ knowledge, for the first time, a surrogate method is proposed for the prediction of the maximum electric field imposed on the high voltage insulators in the presence Corona ring which is faster than any conventional finite element method.

Groups of students were enrolled in a course that sought to produce a three-phase theoretical model over three semesters.

A design project to comprehensively address school violence was launched at a university in eastern Pennsylvania.

This article updates the recent and most critical finding of the project by illuminating specific implications of the importance of teacher training and the development toward competence in recognition of children who are emotionally and psychologically injured through proactive measures such as screening for emotional and psychological well-being.

Although the model has not been tested, screening to identify those in need of emotional support and training to support teachers is clear. Screening and training offer important opportunities to help learners build skills toward resilience to soften the effects of trauma.

A view of the “whole child” with regard to academic success could further foster social and emotional development.

Early intervention can prevent the onset of symptoms associated with posttraumatic stress and related disorders. This effort alone may significantly reduce the uncomfortable incidences and perhaps ultimate prevention of the violence that is perpetuated among children.

Preliminary research supports a continued conversation regarding effective tools to find children emotionally and psychologically at-risk, which allows teachers an opportunity for timely emotional and psychological interventions.

Several types of vaccines were manufactured by different companies to control and stop the spread of COVID-19. This study aimed to identify the postvaccination side effects of the three different vaccines (Pfizer, AstraZeneca and Sinopharm) among the Iraqi population in Baghdad, Iraq.

A prospective cross-sectional study was conducted in Baghdad, Iraq from May 2021 to March 2022. An online-based questionnaire was used to collect the data through social media, i.e. WhatsApp, Messenger and Google Classroom. A total of 737 vaccinated participants using a snowball sampling methodology were used in this study.

Among the study population, 328 (44.50%) were males and 409 (55.50%) were females. The highest age group that participated was 18–30 years (79.10%) followed by 31–40 years (12.10%), 41–50 years (4.20%), 51–60 years (2.40%) and 60 = years (2.20%). However, 58.8% of the participants received Pfizer-BioNTech, 23.7% received the AstraZeneca-Oxford vaccine and 17.5% received Sinopharm. Out of the total participants, 56.60% showed postvaccination side-effects such as fever, headache, fatigue and dizziness, while 33% showed no side-effects and 10.40% were not sure. Pfizer-BioNTech and AstraZeneca-Oxford vaccines were the most vaccines prevalent of side-effects.

The majority of the side reactions associated with the AstraZeneca and Pfizer vaccines were manageable and self-limiting, including fever, fatigue, headache, joint pain and dizziness, compared to the Sinopharm vaccines, which reported lower postside effects.

The objective of this study is to investigate the impact of the COVID-19 pandemic on the consumer payment behavior in Italy by correlating financial literacy with digital payment awareness, examining media anxiety and financial security, and including a gender analysis.

Consumers’ attitudes toward cashless payments were investigated using an online survey conducted from November 2021 to February 2022 on a sample of 836 Italian citizens by considering the behavioral characteristics and aspects of financial literacy. Structural equation modeling (SEM) was used to test the hypotheses and to determine whether the model was invariant by gender.

The analysis showed that the fear of contracting COVID-19 and the level of financial literacy had a direct influence on the payment behavior of Italians, which was completely different in its weighting. Fear due to the spread of news regarding the pandemic in the media indirectly influenced consumers’ noncash attitude. The preliminary results of the gender multigroup analysis showed that cashless payment was the same in the male and female subpopulations.

This research is noteworthy because of its interconnected examination. It examined the effects of the COVID-19 pandemic on people’s payment choices, assessed their knowledge, and considered the influence of media-induced anxiety. By combining these factors, the study offered an analysis from a gender perspective, providing understanding of how financial behaviors were shaped during the pandemic.

The purpose of this study is to look into the hygroscopic and tribo-mechanical properties of a polypropylene/polyamide-6 (PP/PA6) blend and a PP/PA6/Boron sesquioxide composite.

The hygroscopic behaviour of the PP/PA6 blend and PP/PA6/Boron sesquioxide composite was studied using a water contact angle goniometer in this study. To validate the hygroscopic behaviour of the blend and composite, water contact angles and surface energy of the materials were investigated. Tensile strength and hardness tests were used to determine mechanical characteristics, and tribological experiments on a pin-on-disc tribometer were used to demonstrate the friction and wear rates of dry and water-conditioned blends and composites. The melting temperature of dry and water-conditioned composites was determined using DSC analysis.

The hygroscopic effect of the PP/PA6 blend was found to be minimal in the experiment, while it was relatively dominating in the PP/PA6/Boron sesquioxide composite. Tensile strength was found to be somewhat lower in blend and composite compared to virgin PP, whereas hardness was found to be higher in both blend and composite. The composite’s tribological testing findings were fairly outstanding, with the coefficient of friction (COF) and wear rates significantly reduced due to boron sesquioxide reinforcement. The reaction between boron sesquioxide and water molecules produced boric acid, which increased the tribological characteristics of the composite even further. Following 30 days of water conditioning, the weight of the blend increased by 3.64% and the weight of the composite increased by 6.45% as compared to the dry materials. After water conditioning, tensile strength reduced by 0.8% for the blend and 14.16% for the composite. Hardness was determined to be the same in the dry state and after water-conditioning for blend but dropped 1% for composite. As compared to blend, the COF and wear resistance of composite were 15.52% and 25.16% higher, respectively. After absorbing some water, the results increased to 28.57% and 34.9%, respectively.

The mechanical and thermal behaviour of polymer composites (particularly polyamide composites) vary depending on the surrounding environment. Tests were carried out to explore the effect of water treatment on the tribo-mechanical and thermal characteristics of PP/PA6/Boron sesquioxide composite. Water treatment caused polyamides to bind with water molecules, resulting in voids in the material. The interaction between boron sesquioxide and water molecules produced boric acid, which increased the tribological characteristics of the composite.

Recent literature in the field of knowledge management (e.g. Nonaka and Takeuchi, 2021) asks for new, future-oriented approaches to strategy that allow us to deal with an increasingly complex world. Thus, this paper aims to build an approach to exploit aesthetics (human’s sensory perceptions and their felt meanings) to sense an organizations purpose and realize it by means of organizational strategy.

Conceptual paper, providing a new perspective on the perception of Organizational Purpose. The abductive argument follows Weick’s notion of Disciplined Imagination (Weick, 1989).

The main argument of this paper is that aesthetics contribute to the identification of organizational purpose. Thus, aesthetic perceptions can inform strategy to implement a stakeholders’ sense of purpose into strategy.

The argument presented is grounded in recent literature on the concepts of purpose and aesthetics and abductive in nature. Thus, empirical research to validate the argument would be beneficial and worthwhile to be undertaken.

The paper presents the idea to integrate the sense of organizational purpose into a corporate strategy to address stakeholders’ value expectations and build more sustainable organizations. By emphasizing aesthetics, the study takes a stand for the inclusion of nonrational knowledge in organizational decision-making.

As far as the author’s knowledge goes, the concepts of aesthetics and organizational purpose have not theoretically been connected to each other. However, due to the implicit nature of purpose, aesthetics may serve as the matching knowledge tool to work with organizational purpose.