Search Results (3,251)

Cameroon, like most countries in sub-Saharan Africa, is grappling with inadequate electricity generation capacity and energy security issues amid an increasing energy demand and the goal to ensure 100% access to electricity and clean cooking for its citizens. The government has identified the uptake of renewable energy technologies (RETs) as instrumental to increasing electricity generation, as well as meeting its Nationally Determined Contributions (NDCs) commitments and overall long-term developmental goals. The nation’s strategies so far have yielded little results due to a combination of factors, ranging from financial to regulatory aspects. This study analyzes the existing renewable energy infrastructure, identifying the motivations and factors that influence the implementation of renewable energy policies and the challenges and barriers faced. It also explores the existing policy frameworks and regulatory mechanisms, provide insights into the policy gaps and suggests enabling mechanisms that will enable a more favorable environment for renewable energy investments and development in Cameroon. Although the policies posited are focused primarily for the energy system of Cameroon, they can be extended to sub-Saharan African countries and in the global context, provided that local conditions are accounted for. Adopting the recommended policy frameworks will stimulate, support and ensure the sustained development and deployment of renewable energy technologies in the nation and in the subregion. Full article

Hexamethyldisiloxane (HMDSO) is an organosilicon compound with a modifiable bandgap, depending on the deposition conditions. This material has many unique properties due to its stability, low toxicity, and strong adhesion, making it useful as a protective barrier against corrosion, moisture, and oxidation. In this work, HMDSO films were deposited on glass substrates by the Plasma Enhanced Chemical Vapor Deposition (PECVD) technique at different deposition times. The optical properties of HMDSO films, such as dielectric permittivity, refractive index, extinction and absorption coefficients, and band gap energy, are inferred from transmission and reflection spectra. As the deposition time increased, the real part of the dielectric constant, the refractive index, and the bandgap energy showed a decrease, dropping from 4.24 to 3.40, from 2.06 to 1.84, and from 2.85 eV to 2.03 eV, respectively. The latter result is determined using classical models such as the O’Leary-Johnson-Lim (‘OJL’) interband transition and the harmonic oscillator model. HMDSO and Silver are used in this study for the fabrication of optical filters using two types of structures, a multiple cavity metal–dielectric (MCMD) and the Fabry–Perot structure. The silver layers are deposited by a sputtering process. The MCMD optical filter shows a higher transmittance of about 30%, but a wide range of wavelengths is transmitted. In contrast, the Fabry–Perot filter showed high contrast but a lower transmittance of about 20%. Full article

The increasing environmental pollution resulting from plastic waste and the need to reuse agro-industrial wastes as a source of discarding has led to the development of innovative biobased products. In the frame of this context, the use of neat polylactic acid (PLA) and its blend with polybutylene succinate (PBS) with or without cellulose nanocrystals (CNCs) extracted from hemp fibers is explored here. This study aimed to assess the biogas production of different biopolymeric films. In parallel, life cycle assessment (LCA) analysis was performed on the same films, focusing on their production phase and potential end-of-life scenarios, regardless of film durability (i.e., single-use packaging) and barrier performance, to counteract possible soil health threats. Specifically, this study considered three specific systems: PLA, PLA_PBS (PLA/PBS blend 80:20 w/w), and PLA_PBS_3CNC (PLA/PBS blend + 3% CNCs) films. The assessment involved a batch anaerobic digestion (AD) process at 52 °C, using digestate obtained from the anaerobic treatment of municipal waste as the inoculum and cellulose as a reference material. The AD process was monitored over about 30 days, revealing that reactors containing cellulose showed inherent biodegradability and enhanced biogas production. On the other hand, biopolymeric films based on PLA and its blends with PBS and CNCs exhibited an inhibitory effect, likely due to their recalcitrant nature, which can limit or delay microbial activity toward biomass degradation and methanogenesis. LCA analysis was performed taking into consideration the complex environmental implications of both including biopolymers in the production of renewable energy and the use of post-composting digestate as an organic fertilizer. Remarkably, the PLA_PBS_3CNC formulation revealed slightly superior performance in terms of biodegradability and biogas production, mainly correlated to the presence of CNCs in the blend. The observed enhanced biodegradability and biogas yield, coupled with the reduced environmental impact, confirm the key role of optimized biopolymeric formulations in mitigating inhibitory effects on AD processes while maximizing, at the same time, the utilization of naturally derived energy sources. Full article

The global need to reduce energy demand has led European governments to accelerate their endeavors to achieve their targets regarding nearly zero-energy buildings. Despite the implementation of funding initiatives for the energy upgrading of buildings in EU member states and other European countries, research has shown that the absorption rates of the offered funds remain low. This research aims to assess the significance of the barriers to improving the energy efficiency of Greece’s building stock. This is achieved by ranking the identified barriers using the best-worst method (BWM). The innovation provided by this study is that the data obtained are based on the experience of three categories of stakeholders, including professionals in the field, i.e., engineers and skilled workers, and homeowners. The results show that all three groups are discouraged from performing the energy upgrading of buildings due to economic barriers but also technological barriers related to a lack of training in the use of and slow development of related new technologies. Full article

In the UK, SMEs account for 99.9% of the business population, with from 43% to 53% of UK business emissions coming from SMEs. However, SMEs face specific barriers in relation to net zero targets, such as a lack of knowledge about strategies to achieve net zero targets. Despite the ongoing lack of a formal decarbonisation plan for SMEs, various types of projects have been designed to help SMEs to move towards the UK’s net zero target. The Eastern New Energy (ENE) project received funding from the European Regional Development Fund (ERDF) to support SMEs across significant economic areas of the UK, namely the East of England, to help address the barriers that prevent SMEs from decarbonising. The project provided a range of measures, including raising their level of knowledge and providing technical support to help with SME decarbonisation. Following the completion of our targeted support activities, semi-structured interviews (n = 21) were conducted with SME beneficiaries to evaluate the effectiveness of the support with the ambition of providing some policy recommendations based on understanding how national and strategic support can be effective for a diverse, often unconnected ecosystem of businesses. The findings from the interviews indicated that engagement in the ENE project had positive impacts on the SMEs’ understanding of net zero, or how to start their journey towards decarbonisation by identifying their source of emissions and learning how to calculate them. However, accounting for emissions from Scope 3 activities, transition costs and building restrictions were the main barriers that undermined the ENE recommendations. Our research concludes that in designing engagement projects and support, one needs to acknowledge such restrictions and barriers, which requires government interventions to cover all aspects of the SME decarbonisation journey, from nuanced and responsive policy making to developing bespoke knowledge transfer and supporting low-carbon material provision that can support a decarbonised marketplace. Full article

This review provides a detailed analysis of zero waste (ZW) initiatives, focusing on national policies, strategies, and case studies aimed at minimising municipal solid waste (MSW). It evaluates the environmental, social, and economic impacts of waste and explores the transition from conventional landfill reliance to sustainable waste management practices. Key ZW approaches, including circular economy frameworks and extended producer responsibility (EPR), are examined through case studies from countries such as China, Germany, and the United States. The review highlights advancements in waste-to-energy (WTE) technologies, the development of zero waste cities, and the critical role of policies in achieving significant MSW reduction. Additionally, it identifies key challenges such as infrastructure gaps and regulatory weaknesses and offers practical solutions to overcome these barriers. This study serves as a valuable resource for policymakers aiming to implement effective waste reduction strategies and enhance sustainable waste management systems globally. Full article

The pairs of Cu₂O/CuO and CoO/Co₃O₄ as the carriers of transferring oxygen and storing heat are essential for the recently emerged high-temperature thermochemical energy storage (TCES) system. Reported research results of Cu₂O and CoO oxidation kinetics show that the reaction rate near equilibrium decreases with the temperature, which leads to the negative activation energy obtained using the Arrhenius equation and apparent kinetics models. This study develops a first-principle-based theoretical model to analyze the Cu₂O and CoO oxidation kinetics. In this model, the density functional theory (DFT) is adopted to determine the reaction pathways and to obtain the energy barriers of elementary reactions; then, the DFT results are introduced into the transition state theory (TST) to calculate the reaction rate constants; finally, a rate equation is developed to describe both the surface elemental reactions and the lattice oxygen concentration in a grain. The reaction mechanism obtained from DFT and kinetic rate constants obtained from TST are directly implemented into the rate equation to predict the oxidation kinetics of Cu₂O without fitting experimental data. The accuracy of the developed theory is validated by experimental data obtained from the thermogravimetric analyzer (TGA). Comparing the developed theory with the traditional apparent models, the reasons why the latter cannot appropriately predict the true oxidation characteristics are explained. The reaction rate is jointly controlled by thermodynamics (reaction driving force) and kinetics (reaction rate constant). Without considering the effect of the reaction driving force, the negative apparent activation energy of Cu₂O oxidation is obtained. However, for CoO oxidation, the negative apparent activation energy is still obtained although the effect of the reaction driving force is considered. According to the DFT results, the activation energy of the overall CoO oxidation reaction is negative, but the energy barriers of the elementary reactions are positive. Moreover, according to the first-principle-based rate equation theory, the pre-exponential factor in the kinetic model is dependent on the partition function ratio and decreases with the temperature for the Cu₂O and CoO oxidation near equilibrium, which results in the apparent activation energy being slightly lower than the actual value. Full article

Molecular cages have promising host–guest properties for drug delivery applications. Specifically, guest⊂cage complexes can be used for the on-command release of encapsulated guest molecules in response to specific stimuli. This research explores both the dynamic and constrictive binding guest⊂cage systems for drug encapsulation and release in biological environments. In dynamic systems, the guest rapidly passes in-and-out through the portals of the cage, enabling drug delivery in vitro but facing limitations in vivo due to dilution effects that result in guest release. These challenges are addressed by constrictive binding systems, where the guest is trapped in a “gate-closed” state within the cage. In these systems, the on-command release is triggered by a “gate opening” event, which lowers the guest–out energy barrier. A full guest release is achieved when the gate opening reduces the cage–guest affinity, making constrictive binding systems more effective for controlled drug delivery. As a result, this study shows that guest⊂cage complexes have suitable properties for drug delivery in biological contexts. Full article

Product appreciation is defined as valuing and sustaining the use of a functional, energy-efficient product. This study adopted a user perspective to understand the circular behavior of product appreciation and explore the factors influencing it. Employing a qualitative exploratory approach, in-depth, cross-language (English and Arabic) interviews were conducted with participants from different nationalities. The collected data were then subjected to an adapted and augmented version of reflexive thematic analysis, allowing for a thorough examination of the underlying motivations and barriers to product appreciation. Our analysis revealed 60 motivation factors and 30 barrier factors. More importantly, six motivation themes emerged: attachment due to sentimental value, user satisfaction, holistic positive engagement, product ingenuity and enduring value, economic mindfulness, and retention and status quo tendency. In contrast, four barrier themes were identified: changes in user preferences, user dissatisfaction, craving newness, and free upgrades. This study accentuates the delineation of the newly identified circular behavior of product appreciation and highlights its significance in extending product life cycles and slowing resource loops. The findings provide valuable insights for designers, researchers, business strategists, and policymakers aiming to foster sustainable consumption and production patterns through product design, sustainable value propositions, and extended producer responsibility policies. Furthermore, the proposed adapted version of the reflexive thematic analysis method is expected to be a significant contribution to the qualitative research literature. Full article

Gliomas are the most common primary brain tumors, representing approximately 28% of all central nervous system tumors. These tumors are characterized by rapid progression and show a median survival of approximately 18 months. The therapeutic options consist of surgical resection followed by radiotherapy and chemotherapy. Despite the multidisciplinary approach and the biomolecular role of targeted therapies, the median progression-free survival is approximately 6–8 months. The incomplete tumor compliance with treatment is due to several factors such as the presence of the blood–brain barrier, the numerous pathways involved in tumor transformation, and the presence of intra-tumoral mutations. Among these, the interaction between the mutations of genes involved in tumor bio-energetic metabolism and the functional response of the tumor has become the protagonist of numerous studies. In this scenario, the main role is played by mitochondria, cellular organelles delimited by a double membrane and containing their own DNA (mtDNA), which participates in numerous cellular processes such as the regulation of cellular metabolism, cellular proliferation, and apoptosis and is also the main source of cellular energy production. Therefore, it is understood that the mitochondrion, specifically its functional alteration, is a leading figure in tumor transformation, including brain tumors. The acquisition of mutations in the mitochondrial DNA of tumor cells and the subsequent identification of the so-called mitochondria-related genes (MRGs), both functional (mutation of Complex I) and structural (mutations of Complex III/IV), have been seen to play an important role in metabolic reprogramming with increased proliferation, resistance to apoptosis, and the progression of tumorigenesis. This demonstrates that these mitochondrial alterations could have a role not only in the intrinsic tumor biology but also in the extrinsic one associated with the therapeutic response. We aim to summarize the main mitochondrial dysfunction interactions present in gliomas and how they might impact prognosis. Full article

This paper presents a critical review of Lithuania’s climate change mitigation policies within the energy sector, focusing on their alignment with Sustainable Development Goals (SDGs). This study highlights the significance of energy efficiency, renewable energy, and energy security in Lithuania’s efforts to reduce greenhouse gas emissions and transition to a sustainable energy system. The review analyzes the selected research literature that studies Lithuania’s efforts to adapt and fulfill EU energy directives and national goals, emphasizing the impacts of these policies on various sectors, including residential, transport, and industry. The methodology includes a comprehensive analysis of the existing literature and semi-structured interviews with stakeholders regarding their perceptions of the current state and future directions of Lithuania’s energy policies. Findings indicate substantial progress in renewable energy adoption and energy efficiency improvements, contributing to SDG 7 (Affordable and Clean Energy) and SDG 13 (Climate Action). However, challenges such as high costs, underdeveloped financing mechanisms, and limited public awareness hinder further advancements. This paper suggests that future policies should focus on overcoming these barriers, enhancing public engagement, and integrating technological innovations to achieve more significant energy savings and GHG reductions. Recommendations for policy improvements and further research directions are also discussed. Full article

Nanotubular hafnia arrays hold significant promise for advanced opto- and nanoelectronic applications. However, the known studies concern mostly the luminescent properties of doped HfO₂-based nanostructures, while the optical properties of nominally pure hafnia with optically active centers of intrinsic origin are far from being sufficiently investigated. In this work, for the first time we have conducted research on the wide-range temperature effects in the photoluminescence processes of anion-defective hafnia nanotubes with an amorphous and monoclinic structure, synthesized by the electrochemical oxidation method. It is shown that the spectral parameters, such as the position of the maximum and half-width of the band, remain almost unchanged in the range of 7–296 K. The experimental data obtained for the photoluminescence temperature quenching are quantitatively analyzed under the assumption made for two independent channels of non-radiative relaxation of excitations with calculating the appropriate energies of activation barriers—9 and 39 meV for amorphous hafnia nanotubes, 15 and 141 meV for monoclinic ones. The similar temperature behavior of photoluminescence spectra indicates close values of short-range order parameters in the local atomic surrounding of the active emission centers in hafnium dioxide with amorphous and monoclinic structure. Anion vacancies $V_O^{-}$ and $V_O^{2-}$ appeared in the positions of three-coordinated oxygen and could be the main contributors to the spectral features of emission response and observed thermally stimulated processes. The recognized and clarified mechanisms occurring during thermal quenching of photoluminescence could be useful for the development of light-emitting devices and thermo-optical sensors with functional media based on oxygen-deficient hafnia nanotubes. Full article

With the increasing global emphasis on green energy and sustainable development goals, the electrocatalytic oxygen evolution reaction (OER) is gradually becoming a crucial focus in research on water oxidation for hydrogen generation. However, its complicated reaction processes associated with its high energy barrier severely limit the efficiency of energy conversion. Recently, layered double hydroxide (LDH) has been considered as one of the most promising catalysts in alkaline media. Nonetheless, lacking a deep insight into the kinetic process of the electrocatalytic OER process is detrimental to the further optimization of LDH catalysts. Therefore, monitoring the catalytic reaction kinetic process via surface-sensitive in situ spectroscopy is especially important. In particular, the in situ Raman technique is capable of providing fingerprint information for surface species and intermediates in the operating environment. From the perspective of Raman spectroscopy, this paper provides an exhaustive overview of research progress in in situ Raman for the characterization of the catalytic mechanism of LDH catalysts, providing theoretical guidance for designing LDH materials. Finally, we present an incisive discussion on the challenges of the electrocatalytic in situ Raman technique and its future development trend. Full article

The aim of this research was to investigate the social conditions of the implementation of energy cooperatives in Poland as a demand-side policy tool to reduce carbon emissions. Qualitative empirical research was conducted, including interviews with members and leaders of energy cooperatives as well as experts, to assess the effectiveness of new legal regulations concerning energy cooperatives. This study shows that the negative historic connotations with cooperatives do not impede the readiness of Poles to create energy cooperatives. They are open to innovation and are willing to cooperate for energy stability, which seems to be the most important factor determining involvement in energy cooperatives. The results also highlight significant barriers for the development of energy cooperatives, such as regulatory constraints and a lack of true incentives. Energy cooperatives have the potential to popularize renewable energy sources in Poland, but their growth requires better adaptation of legal regulations and greater political support. Full article

The transport sector, and especially the increase in individual vehicle ownership, contribute significantly to air pollution. The transition to electric vehicles (EVs) is seen as a sustainable alternative to reduce emissions of polluting gases. However, in Brazil, the EV market has not yet reached a significant size. Given this scenario, this study aims to analyze the factors that influence the decision to buy EVs in Brazil, highlighting personal, psychological, economic, performance, and environmental variables and barriers. The aim is also to develop a model with guidelines that can help stakeholders. The quantitative stage of the study involved a survey of 514 respondents. The data were analyzed using statistical methods, including structural equation modeling (SEM), which allowed for a deeper investigation of the proposed hypotheses. The survey findings reveal that, in the Brazilian context, performance factors—such as autonomy, availability of recharging infrastructure, and maintenance—are the main drivers influencing EV purchase decisions. Environmental factors, including energy reuse, pollution reduction, and minimizing environmental impacts, have also gained significant importance. Economic factors are crucial, particularly concerning cost–benefit perceptions. The differences between Brazil and other regions highlight the importance of accounting for cultural and economic variations when analyzing consumer behavior towards EVs. Full article