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The study analyzes the variability over time of the Snow Line Altitude (SLA) and its correspondence with the Equilibrium Line Altitude (ELA) in four glaciers of the Southern Patagonian Icefield (SPI): Perito Moreno, Upsala, Viedma and De los Tres. Using Google Earth Engine and Landsat satellite imagery, an automated algorithm based on the Otsu image segmentation method was developed to analyze the 1985–2023 time series to obtain the Snow Cover Ratio (SCR) and subsequently estimate the SLA using the ALOS World 3D DSM. The study employed the near infrared (NIR) and shortwave infrared (SWIR) bands of Landsat images, with the SCR and subsequently the SLA determined using only the NIR band, as well as a band ratio between the NIR/SWIR bands. The results indicated that the Viedma glacier showed a statistically significant positive trend in SLA elevation, while the other three glaciers showed a stationary behavior with high variability. The SLA calculated using the NIR/SWIR bands tended to be higher compared to the NIR band calculation, especially for the Viedma and Upsala glaciers. Comparisons with previous studies (De Angelis, 2014; Popovnin et al., 1999) and recent glaciological measurements from the Inventario Nacional de Glaciares (2015–2022) showed that the SLA derived from the NIR bands aligned more closely with the aforementioned works.

This paper aims to contribute to the field of knowledge surrounding Education for Sustainable Development (ESD) curricula with a view to filling a gap in ESD literature by identifying features that may help ESD course designers. The study asks the questions: what is taught in ESD courses in higher education? and what content do students say they like? Working within the constructivist tradition, this study involved two groups of participants: 13 ESD design/delivery participants from six universities based in five countries (Group One) and 737 ESD students (Group Two) from three of those universities. The overarching methodology of comparative analysis was used to address the research questions. Data collection included course learning materials, participant questionnaires, one-on-one interviews, focus groups, and feedback on teaching. Group One data was analysed using comparative/descriptive analysis and reflexive thematic analysis was used for Group Two data. The methods were complementary to de/reconstruct data for comparability of features. NVivo software was employed to acquire results which are presented visually using tables and concept maps. The study identifies common content taught in stand-alone ESD courses and makes recommendations for course modelling based on Group One data contributions and what content Group Two say they like. The recommendations are presented as seven categories of consolidated curricular themes including science and sustainability based, contextually relevant, and futures hope. Consideration is given to student internal/external motivational domains and possible connection to curricular themes. Recommendations are practical and flexible, not prescriptive. The original contribution to knowledge lies in suggestions for ESD course content.

The Kingdom of Saudi Arabia is experiencing a surge in electricity demand, with power generation increasing 4 times in 25 years from 1990 to 2014. Despite the abundant primary renewable energy sources, the country has overlooked them in the past in national energy policies. However, in recent years, renewable energy has become a part of the Kingdom of Saudi Arabia’s energy conservation policy due to climate changes, technological progress, economies of scale, and increased competitiveness in supply chains. The Saudi government has created the King Abdullah City for Atomic and Renewable Energy (KACARE) to develop national strategies for effectively utilizing renewable and nuclear energy. This paper reviews the current state of the art of the renewable energy technologies available on the market and evaluates the installation of renewable energy plants near Saudi Arabia’s East Coast for a new town, focusing on technical rather than economic aspects. The paper provides a wide review of the possible technical solutions to exploit the producibility of different renewable sources, considering the challenging climate conditions typical of desert areas. The analysis of a real case study shows a high availability of wind and solar irradiance that allow a net energy production of 354 and 129 GWh, respectively. In addition, the comparison between a typical ground-mounted photovoltaic (PV) system and an emerging floating PV reveals that for the same installed power, occupied area, and environmental conditions, the latter has a 4% greater performance ratio due to the cooling effect of water.

Abstract In this study, the implementation of different corona discharge models in a transient program for overhead multiconductor lines based on the implicit Crank‐Nicolson Finite Difference Time Domain method is presented. Among different corona models available in the literature, two empirical models (Gary's and Suliciu's models) and a physics‐based model (Malik's model) are discussed, which are broadly used in EMT programs, and their predictions under fast‐front lightning surges and slow‐front switching impulses are assessed. The authors critically review the dynamic capacitance approach in terms of numerical accuracy, when dealing with slowly varying voltages, and applicability, regarding dispersive models assuming a non‐instantaneous charge‐voltage relation. The alternative voltage‐controlled generator approach is proposed, which is successfully included in the implicit Crank‐Nicolson scheme. One of the objectives of this study is to show how different corona models may predict overvoltages with huge discrepancies, depending on the transient waveform and the propagation distance, despite the similarity of the q‐v hysteresis curves. More evident discrepancies between models under fast‐front voltage waves are reported, rather than for switching impulses. The consistency of these results in terms of the models' features and q‐v curves is analysed, highlighting the necessity for new engineering tools for corona simulation of general predictive capability.

Abstract The transmission of an electromagnetic field produced by a current loop of finite radius through a coaxial circular aperture in a perfectly conducting plate is evaluated through a rapidly convergent formulation in an exact form. By applying the equivalence principle, the problem is first formulated in the Hankel transform domain, obtaining a set of dual integral equations in which the equivalent surface magnetic current density defined on the aperture is not known. The set of dual integral equations is regularised in a second‐kind Fredholm integral equation by applying the Abel integral‐transform technique. The solution is achieved by expanding the unknown in a set of orthogonal basis functions that correctly reproduce the behaviour of the equivalent magnetic current at the edge of the aperture. Finally, under particular assumptions, a low‐frequency solution is extracted in a closed form. Numerical results are reported to validate the accuracy and efficiency of the proposed formulations.

This paper explores out-of-school suspensions and expulsions among Black females, who have often been ignored in the extant educational research literature. More specifically, the authors explore the question of whether Black females have been overrepresented in out-of-school suspensions and expulsions in New Jersey public schools. Using data from the Civil Rights Data Collection (CRDC), the authors found that Black females in New Jersey have in fact been overrepresented in both, out-of-school suspensions and expulsions. The extent of that overrepresentation of Black females has not only worsened over time but could also be considered graver in New Jersey than in the rest of the United States. The authors additionally contend that these school push-outs increase the likelihood that Black girls will enter the school-to-criminal justice pipeline. After discussing the study findings in detail, the authors provide several recommendations that are designed to help better comprehend and address the various discipline-related issues impacting Black girls in the New Jersey public school system and that could potentially have broader implications for all of the nation's schools.

The study analyzes the variability over time of the Snow Line Altitude (SLA) and its correspondence with the Equilibrium Line Altitude (ELA) in four glaciers of the Southern Patagonian Icefield (SPI): Perito Moreno, Upsala, Viedma and De los Tres. Using Google Earth Engine and Landsat satellite imagery, an automated algorithm based on the Otsu image segmentation method was developed to analyze the 1985–2023 time series to obtain the Snow Cover Ratio (SCR) and subsequently estimate the SLA using the ALOS World 3D DSM. The study employed the near infrared (NIR) and shortwave infrared (SWIR) bands of Landsat images, with the SCR and subsequently the SLA determined using only the NIR band, as well as a band ratio between the NIR/SWIR bands. The results indicated that the Viedma glacier showed a statistically significant positive trend in SLA elevation, while the other three glaciers showed a stationary behavior with high variability. The SLA calculated using the NIR/SWIR bands tended to be higher compared to the NIR band calculation, especially for the Viedma and Upsala glaciers. Comparisons with previous studies (De Angelis, 2014; Popovnin et al., 1999) and recent glaciological measurements from the Inventario Nacional de Glaciares (2015–2022) showed that the SLA derived from the NIR bands aligned more closely with the aforementioned works. [ABSTRACT FROM AUTHOR]

Detecting and understanding historical changes in the frequency of geo-climatic hazards (G-CHs) is crucial for the quantification of current hazards and project them into the future. Here we focus in the eastern subtropical Andes (32–33∘ S), using meteorological data and a century-long inventory of 553 G-CHs triggered by rainfall or snowfall. We first analyse their spatio-temporal distributions and the role of climate variability in the year-to-year changes in the number of days per season with G-CHs. Precipitation is positively correlated with the number of G-CHs across the region and year-round; mean temperature is negatively correlated with snowfall-driven hazards in the western (higher) half of the study region during winter and with rainfall-driven hazards in the eastern zone during summer. The trends of the G-CH frequency since the mid-20th century were calculated, paying attention to their non-systematic monitoring. The G-CH series for the different triggers, zones and seasons were generally stationary. Nonetheless, there is a small positive trend in rainfall-driven G-CHs in the eastern zone during summer, congruent with a rainfall increase there. We also found a decrease in snowfall-driven G-CHs in the western zone from the late 1990s onwards, most likely due to a reduction in winter precipitation rather than to an increase in temperature.

The electromagnetic interaction between a circular disk with finite conductivity and finite thickness and a coaxial circular loop of constant current is addressed here. The finite conductivity and thickness of the material disk lead to the adoption of suitable generalized boundary conditions, and the problem is thereby reduced to the solution of two sets of dual integral equations in the Hankel transform domain. Such equations are then solved by expanding the spectral unknowns in Neumann series of Bessel functions. An alternative formulation that is valid for purely conductive screens with no magnetic properties, which is computationally much faster, is proposed as well. The magnetic shielding effectiveness of the structure is studied in detail, pointing out its dependencies and possible critical situations.

Islands are facing significant challenges in meeting their energy needs in a sustainable, affordable, and reliable way. Traditionally, the primary source of electricity on the islands has been imported diesel fuel, with high financial costs for most utilities. In this context, even replacing part of the traditional production with renewable energy source can reduce costs and improve the quality of life of islanders. However, integrating large amounts of renewable energy production into existing grids introduces many concerns regarding feasibility, economic analysis, and technical implementation. From this point of view, machine learning and deep learning techniques are efficient tools to mitigate these problems. Their potential results are beneficial considering isolated grids of small islands which are not connected to the national grid. In this paper, a study of the Italian island of Ponza is carried out. The isolation leads to several challenges, such as the high cost related to the transport, installation, and maintenance of renewable energy sources in a small area with several constraints and their intermittent power production, which requires the use of storage systems for dispatching purposes. The proposed study aims to identify future developments of the electricity grid by considering the deployment of both renewable energy sources and energy storage systems. Furthermore, future scenarios are depicted through the use of autoregressive and deep learning techniques to give an idea about the economic costs of both energy demand and supply.

Anion exchange membranes (AEM) have gained attention recently as a promising candidate for low-cost water electrolysis systems to produce hydrogen, linked with renewable energy resources as a sustainable alternative to fossil fuels. The development of potential materials for producing and analyzing AEM is an imperative step towards commercialization and plays a competitive role in the hydrogen production industry. In this article, we developed a composite anion exchange membrane prepared by activating a commercial support structure (Celgard® 3401) with a commercially available functional group (Fumion® FAA-3) through a phase-inversion process. Fourier-transform infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) analysis demonstrated the phase-inversion procedure as an effective methodology. Furthermore, the cell performance test result (with Celgard/Fumion) was very promising and even better in comparison with a commercial membrane commonly applied in alkaline electrolysis (Fumasep). We also developed a testing procedure for membrane performance evaluation during electrolysis which is very critical considering the effect of CO2 absorption on membrane conductivity.

In recent years, the explosion of renewable energy sources, the increase in the demand for electrical energy, and several improvements in related technologies have fostered research in many relevant areas of interest [...]

Within the policy framework of the energy union strategy started in 2015, the European Union (EU) finalized the “Clean Energy for all Europeans Package” (CEP) in 2019 [...]

The ongoing energy crisis and the rising prices of fossil fuels have accelerated the need for a renewable energy transition [...]

Over the past decade, decarbonization and environmental issues have taken a key role in worldwide politics [...]

Fast-front transients play an important role in the insulation design of any power system. When a stroke hits the shield wire or the tower of high-voltage overhead power lines, flashover may occur either along the span or across tower insulators, depending on the relevant voltages and insulation strength. As a result, backflashover may take place from the tower structure to the phase conductor whenever a huge impulse current flows along the tower towards considerably high footing impedances. For these reasons, tower modeling for transients studies is an important step in the insulation design, and also for lower voltage applications, where indirect lightning effects may play a predominant role. However, after decades of research on tower modeling, starting from the 1930s with the first model proposed by Jordan, no consensus has been reached neither on a widely accepted tower model nor on the quantitative effect of the tower models on insulation design. Moreover, the fundamental mechanisms at the base of the transient response of towers and the definition of some fundamental parameters have not been totally clarified yet. The aim of this review is to present the available tower models developed through the years in the power community, focussing mainly on lumped/distributed circuit models, and to help the reader to obtain a deeper understanding of them.