Search Results (69)

With the rapid industrialization, excessive reliance on fossil fuels has resulted in energy crises and environmental pollution, driving the search for sustainable alternatives. Biomass-derived resources have emerged as promising candidates to replace fossil-based feedstocks. Among these, furfural (FF) serves as a key platform molecule that can be catalytically hydrogenated to various high-value chemicals, with furfuryl alcohol (FA) representing one of the most valuable products. Currently, Cr-based catalysts remain predominant for the selective hydrogenation of FF to FA. However, the severe environmental toxicity of Cr necessitates urgent development of alternative Cr-free catalytic systems. This study systematically reviews recent advances in FF hydrogenation to FA, providing an in-depth discussion of reaction mechanisms, including adsorption configurations, solvent effects, and side reactions, as well as a comprehensive analysis of structure–activity relationships, involving active metal, support, promoter, and preparation methods. Furthermore, we evaluate the application of the advanced characterization techniques for monitoring the reaction processes. Finally, we propose the future research directions: (1) designing efficient and stable non-noble metal catalysts and (2) elucidating reaction mechanisms via the combined in situ characterization and theoretical calculations. These efforts would facilitate the academic understanding and industrial implementation of the FF-to-FA conversion process. Full article

The electrochemical oxidation of biomass-derived 5-hydroxymethylfurfural (HMF) coupled with water electrolysis for green hydrogen production is a promising strategy to address energy crises and environmental pollution. Despite the suitable adsorption energy for HMF due to their partially filled d-band electronic structures, Ni- or Co-based oxides/hydroxides still face challenges in insufficient activity and stability. In this study, a porous heterogeneous nickel cobalt oxide/hydroxide growth on nickel foam (NF), which is defined as NF@NiCo-H/O, was developed via immersion in concentrated alkali solution. Compared with the single-component NiCo oxides, the NF@NiCo-H/O catalyst exhibits a lower application potential of only 1.317 V, 1.395 V, and 1.443 V to achieve current densities of 20, 50, and 100 mA cm⁻², respectively, in an alkaline solution containing HMF. Additionally, it demonstrates rapid reaction kinetics with a Tafel slope of 27.6 mV dec⁻¹ and excellent cycling stability. Importantly, the presence of more high-valent Ni³⁺-O species on the catalyst surface contributes to its exceptional selectivity for 2,5-furandicarboxylic acid (86.7%), Faradaic efficiency (93.1%), and conversion rate (94.4%). This catalyst provides some theoretical guidance for the development of biomass electrooxidation catalysts for sustainable energy and chemical production. Full article

The 7 October 2023 attack by Hamas on Israeli civilians and Israel’s ensuing assault in Gaza caused immense public upheaval in Berlin, home of Europe’s largest Palestinian diaspora. This article shows how Palestinian families intergenerationally navigate the ensuing losses, protests and school unrests, which took place not just in response to the devastation in Gaza and the West Bank, but also to Germany’s unwavering support for Israel, while suppressing pro-Palestinian voices. For the families, this intensification of the protracted Israeli–Palestinian conflict deepened a state of chronic crises based on traumas, longstanding insecurity and increasing xenophobia in Germany. Drawing from 11 years of ethnographic research in Berlin–Neukölln, I show how events since 7 October drastically changed the neighborhood’s ethos, forcing a communal front of silence. The silence was a reaction to fears of being misrepresented in the media and threats of deportation and school expulsions. Examining prevailing sociopolitical influences, and what happens within families and between generations, I illustrate how families became more insular in their mourning and grief yet found ways to navigate their political views intergenerationally. My argument scrutinizes sociopolitical processes leading to increased polarization and highlights the importance of schools as safe spaces for identity formation and contemplation. Full article

The current environmental pollution and energy crises are global concerns that must be addressed. Considering this background, three perovskites (YMnO₃, Co-doped YMnO₃, and Sn-doped YMnO₃) were synthesized via a sol–gel method and characterized by XRD, SEM, and EDX. Their water-splitting electrocatalytic activity was evaluated in a strongly alkaline medium. The highest activity was observed during hydrogen evolution reaction (HER) experiments on a glassy carbon electrode coated with a catalyst ink containing the Co-doped material. Initially, the HER overpotential value at −10 mA/cm² was 0.59 V, and the Tafel slope was 115 mV/dec. Following a chronoamperometric stability test, the overpotential became 0.46 V and the Tafel slope 119 mV/dec. The higher HER activity of the modified electrode is ascribed to a higher number of catalytic sites exposed to the electrolyte solution and the presence of Carbon Black. The photocatalytic activity of the perovskites was investigated as well, using different experimental conditions and simulated solar irradiation. The results show that the photocatalytic activity can be improved by doping, and the highest removal efficiency is achieved in the presence of the Co-doped YMnO₃ when ~60% of 17α-ethynylestradiol is degraded. Furthermore, the initial pH has no favorable effect on the degradation efficiency. The reusability of Co-doped YMnO₃ was also tested and minimal activity loss was found after three photocatalytic cycles. Full article

Under mild conditions, the effective conversion of carbon dioxide (CO₂) into formic acid (HCOOH) and carbon monoxide (CO) represents a promising avenue for mitigating greenhouse gas emissions and addressing energy crises. In this work, we analyzed the electro-catalytic activities of six metals (Ti, Fe, Ni, Cu, Zn, and Cr) anchored on monolayer molybdenum telluride (TM@MoTe₂) for the CO₂ reduction reaction (CO₂RR) from CO₂ to HCOOH and CO. Compared to the reversible hydrogen electrode, the limiting potential for HCOOH production on Ni@MoTe₂ is only about −0.38 V, and it is only about −0.20 V for the CO production on Cu@MoTe₂. The limiting potential is concerned with the free energies of *OCHO and *COOH. Both the CO₂RRs suppress the competing hydrogen evolution reaction (HER) and exhibit good selectivity for the desired reaction products. These features enable the efficient conversion of CO₂ into HCOOH on Ni@MoTe₂ or CO on Cu@MoTe₂. Our calculations could provide valuable insights for the design and synthesis of high-performance catalysts based on MoTe₂. Full article

WO₃ has attracted great attention in the field of catalysts due to its excellent photocatalytic performance. However, the difficulty in recycling and low reuse percentage of nano WO₃ limit its application. This paper used the hydrothermal method to prepare an Fe₃O₄@SiO₂@WO₃ core–shell nanocatalyst. Its composition and structure were characterized by various techniques including XRD, FT-IR, and Raman analyses, which confirmed the successful preparation of a core–shell-structured catalyst with a strong response to an external magnetic field. In the degradation experiment of rhodamine B solution (RhB), the composite catalyst with a WO₃ doping amount of 0.8 g and catalyst dosage amount of 30 mg had the best catalytic degradation effect on 10 ppm RhB, with a degradation efficiency of 99.80%. Due to its high transparency and ion conductivity, SiO₂ did not affect the performance of the composite catalyst, but could effectively reduce the corrosion of WO₃ by the reaction solution. The presence of a SiO₂ interlayer prevented any deterioration in the catalytic efficiency of WO₃ nanocrystal shells and the chemical and thermal stability of Fe₃O₄ nuclei. By applying an external magnetic field, this nanocatalyst can be easily recovered from the solution. These features not only maximize the value of this new material, but also provide sustainable solutions for environmental protection, energy crises, and health issues. Full article

The cryptocurrency market, known for its inherent volatility, has been significantly influenced by external shocks, particularly during periods of global crises such as the COVID-19 pandemic and the Russia–Ukraine war. This study investigates the volatility of the top seven cryptocurrencies by market capitalization—Bitcoin (BTC), Ethereum (ETH), Tether (USDT), Binance Coin (BNB), USD Coin (USDC), XRP, and Cardano (ADA)—from 1 January 2020 to 1 September 2024, employing a range of GARCH models (GARCH, EGARCH, TGARCH, and DCC-GARCH). This research aims to examine the persistence of leverage effects, volatility asymmetry, and the impact of past price fluctuations on future volatility, with a particular focus on how these dynamics were shaped by the pandemic and geopolitical tensions. The findings reveal that past price fluctuations had a limited impact on future volatility for most cryptocurrencies, although leverage effects became evident during market anomalies. Stablecoins (USDC and USDT) showed a distinct volatility pattern, reflecting their peg to the US Dollar, while platform-associated BNB demonstrated unique volatility characteristics. The results underscore the market’s sensitivity to price movements, highlighting the varying reactions of investor profiles across different cryptocurrencies. These insights contribute to understanding volatility transmission within the cryptocurrency market during times of crisis and offer important implications for market participants, particularly in the context of risk management strategies. Full article

In this work, Functional Data Analysis (FDA) is used to detect behavioral patterns in the Bolsa de Valores de Colombia (BVC) in reaction to the global crises caused by COVID-19 and the war in Ukraine. The oil price fluctuation curve is considered a covariate. The FDA’s distinctive ability is to represent stock values as smooth curves that evolve over time and provide new insights into the dynamics of the BVC. The methodology makes use of functional multivariate techniques applied to the smoothed curves of the closing prices of the main stocks of the BVC. The results show that the correlations of the oil curve with the average market curve change from almost null or low in the global period to extremely significant in time windows immediately after the beginnings of COVID-19 and the war in Ukraine, respectively. On the other hand, the velocity curves, which are used to evaluate the stock market volatility, show a pattern of synchronization of companies in the crisis periods. Furthermore, in these crisis periods, the companies in BVC showed a high synchronization with the Brent crude oil price. In conclusion, this work shows the usefulness of the FDA as a complement to time series analysis in the study of stock markets. The results of this research could be of interest to academic researchers, financial analysts, or institutions. Full article

This study investigates the public relations (PR) challenges faced by the airline industry during the COVID-19 pandemic, with Spirit Airlines as a focal case. Using a mixed-methods approach, this study analyzes a dataset of 344 LinkedIn online reviews and digital reactions to an incident where a family was removed from a Spirit Airlines flight after their two-year-old child refused to wear a mask. The case study highlights the complex PR challenges airlines face in balancing public health protocols with customer relations during health crises. Through thematic and sentiment analyses, this research identifies gaps in traditional crisis communication models, advocating for empathetic, transparent strategies that align with pandemic-related sensitivities. It underscores the need for specialized staff training to effectively manage such crises. The findings suggest that conventional PR strategies fall short in addressing the multifaceted nature of pandemic-induced crises, calling for a shift towards human-centered communication and robust stakeholder management. This study contributes to the discourse on crisis communication in the airline industry, offering actionable insights for balancing public health responsibilities with customer satisfaction. It calls for a reevaluation of established crisis communication frameworks, urging future research to explore more inclusive and adaptive PR practices in response to health emergencies. Full article

Geothermal energy exploitation has emerged as a critical solution to combat global climate crises, such as reducing CO₂ emissions and climate warming. Scaling is the process of mineral precipitation in fluid pathways and geothermal equipment. It is known to significantly hamper geothermal energy production by decreasing the rates of heat extraction. Numerous research efforts are dedicated to characterising dissolution and precipitation processes, not only to provide know-how for further and safer developments in geothermal energy, but also to adapt such findings to the ever emerging field of geothermal energy recovery. This paper presents an overview of experiments—performed under variable pressure and temperature conditions—with a focus on scaling. We assess the different factors that influence disequilibrium reactions in carbonate rocks, the different experimental setups, and their application to the field. The influence of experimental variables (such as temperature and pressure) on mineral dissolution and precipitation is discussed, and the main learning points from experiments are compared and contrasted. We address techniques for preventing and controlling scaling in geothermal wells based on a comprehensive analysis of experimental studies in carbonate rocks. We propose that the intelligent combination of fieldwork, numerical approaches, and laboratory experience provides a foundation for the success of future work in this field. Full article

Photocatalysis has attracted more and more attention as a possible solution to environmental, water, and energy crises. Although some photocatalytic materials have already proven to perform well, there are still some problems that should be solved for the broad commercialization of photocatalysis-based technologies. Among them, cheap and easy recycling, as well as stability issues, should be addressed. Accordingly, the application of gels, either as a photocatalytic material or as its support, might be a good solution. In this review, various propositions of gel-based photocatalysts have been presented and discussed. Moreover, an easy nanoarchitecture design of gel-based structures enables fundamental studies, e.g., on mechanism clarifications. It might be concluded that gels with their unique properties, i.e., low density, high specific surface area, great porosity, and low-cost preparation, are highly prospective for solar-energy-based reactions, water treatment, photodynamic cancer therapies, and fundamental research. Full article

Background: Eosinophilic esophagitis (EoE) is a rare, chronic immune-mediated disorder with limited treatment options. Despite the U.S. Food and Drug Administration (FDA) approval of dupilumab for EoE, other monoclonal antibodies remain unapproved and are used off-label with limited evidence on their efficacy and safety. This systematic review rigorously and comprehensively evaluates the evidence for monoclonal antibody therapies used off-label to treat EoE. Methods: We conducted a systematic review across PubMed, EMBASE, Cochrane Central, and ClinicalTrials.gov, assessing the efficacy and safety of off-label monoclonal antibodies in EoE through clinical outcomes and the FDA Adverse Event Reporting System (FAERS) data. Results: Among ten monoclonal antibodies reviewed, mepolizumab that targets IL-5 showed the most promise with a moderate recommendation based on Level 2 evidence. Others like omalizumab (anti-IgE), dectrekumab (anti-IL-13), and reslizumab (anti-IL-5) showed limited utility. Safety evaluations via the FAERS database revealed significant adverse drug reactions, including serious events like asthmatic crises, pneumonia, and adrenal insufficiency for mepolizumab and reslizumab, as well as chronic obstructive pulmonary disease and gastroenteritis for omalizumab. Dectrekumab’s safety profile remains unclear due to a lack of data. Conclusions: While mepolizumab demonstrates potential as an off-label treatment, none of the antibodies reviewed have FDA approval for EoE. Clinicians should consider the balance between local and systemic effects and exercise caution, closely monitoring for adverse effects, particularly in patients with respiratory comorbidities. Continued research is crucial to establish a more robust evidence base for these therapies. Full article

The coronavirus crisis hit both the world and national economies hard. By using a structural equation modelling (SEM) approach and microlevel data from the Community Innovation Survey (CIS2020) on a representative sample of 6437 Norwegian firms comprising a set of COVID-19-related questions, this paper explores the role of firms’ innovation capabilities and strategic agility in times of crises. Our main hypothesis is that these two concepts are interrelated. More specifically, this paper investigates the ‘push’ and ‘pull’-mechanisms of the pandemic on firms’ innovation strategies, as well as which firms were most agile, adapted quickly, introduced innovation due to the COVID-19 crisis rapidly and became more effective with respect to their pre-crisis innovation capabilities. The results indicate that both mechanisms were active during the coronavirus crisis, and most of the firms carried out strategic reactions and changed their business operations on along-term basis. However, the results for innovation output and efficiency improvements vary significantly. “Process developers”, “active R&D doers” and “radical innovators” (the firms that are persistent innovators with the highest score on performing in-house R&D continuously and on innovating in the pre-crisis period) are found to be most agile during the pandemic. They had both introduced innovation and improved their efficiency in quick response to COVID-19. However, firms with low innovation capabilities demonstrated poorer performance during the crisis. These results imply that pre-existing innovation capabilities are important for firms’ strategic flexibility during crises and their ability to respond to changes quickly and efficiently. Full article

Social media data are increasingly used to assess public opinion dynamics and develop sustainable regional tourism policies. This study explored the changes in travel patterns and preferences in Gangwon Province before, during, and after the implementation of social distancing measures during the COVID-19 pandemic. Five hundred and twenty-six YouTube videos related to travel in Gangwon Province were collected using NodeXL, and content and statistical analyses were conducted on travel regions, main activities, and viewers’ reactions. The main findings indicated that as the intensity of social distancing measures increased, the activity of YouTube video creators also increased, particularly in the East Coast region, compared with other locations such as mountains, rivers, and traditional markets. Viewer engagement was the highest during the implementation of social distancing, showing a considerable interest in beach travel. These results have significant implications for planning safe travel during crises such as COVID-19 and for local governments to promote a responsible travel environment. Full article

This study examined the emotional reactions and coping resources of Bedouin teenagers (ages 12–18) following the events of 7 October 2023 and the subsequent Iron Swords War between Israel and Hamas forces in Gaza. This study focused on the relationships between subjective exposure, personal sense of coherence, community resilience, and the use of different coping strategies, on the one hand, and anxiety, anger, and psychological distress, on the other. During 2024, 762 participants completed the study questionnaire, which addressed the different study variables. The findings revealed significant differences between the boys and the girls. Specifically, the girls reported higher levels of subjective exposure and emotional reactions. Personal sense of coherence was found to be a significant protective factor. In contrast, the use of nonproductive coping strategies increased distress. This study underscores the need for intervention programs tailored for this society and by gender, as well as training for educational professionals, to help them to identify and treat emotional reactions to stress in ways that take into consideration the Bedouin cultural context. This study enhances our understanding of how Bedouin teenagers cope with stressful situations and crises. Full article