The unfolding low-carbon transition in the UK electricity system.

The paper explores three periods in the UK electricity consumption-production system since World War II. The first two involved the development of an increasingly centralized, integrated system that provided electricity to meet growing post-war demand. It saw two major changes in governance, first to nationalization, then to privatization and liberalization. The third period started at the turn of the Century, driven by increasing evidence of the impact of fossil fuels on the Earth's climate. The paper focuses on the drivers of change, within the UK and externally, and how they affected governance, technology deployment, and industry structure. It draws on the multi-level perspective and the concepts of governance and technological branching points to inform the analysis of each period. It shows that there is a considerable distance to travel toward a truly sustainable electricity system.

Molecular Additives Improve the Selectivity of CO2 Photoelectrochemical Reduction over Gold Nanoparticles on Gallium Nitride.

Photoelectrochemical CO2 reduction (CO2R) is an appealing solution for converting carbon dioxide into higher-value products. However, CO2R in aqueous electrolytes suffers from poor selectivity due to the competitive hydrogen evolution reaction that is dominant on semiconductor surfaces in aqueous electrolytes. We demonstrate that functionalizing gold/p-type gallium nitride devices with a film derived from diphenyliodonium triflate suppresses hydrogen generation from 90% to 18%. As a result, we observe increases in the Faradaic efficiency and partial current density for carbon monoxide of 50% and 3-fold, respectively. Furthermore, we demonstrate through optical absorption measurements that the molecular film employed herein, regardless of thickness, does not affect the photocathode's light absorption. Altogether, this study provides a rigorous platform for elucidating the catalytic structure-property relationships to enable engineering of active, stable, and selective materials for photoelectrochemical CO2R.

Powering the Future by Iron Sulfide Type Material (FexSy) Based Electrochemical Materials for Water Splitting and Energy Storage Applications: A Review.

Water electrolysis is among the recent alternatives for generating clean fuels (hydrogen). It is an efficient way to produce pure hydrogen at a rapid pace with no unwanted by-products. Effective and cheap water-splitting electrocatalysts with enhanced activity, specificity, and stability are currently widely studied. In this regard, noble metal-free transition metal-based catalysts are of high interest. Iron sulfide (FeS) is one of the essential electrocatalysts for water splitting because of its unique structural and electrochemical features. This article discusses the significance of FeS and its nanocomposites as efficient electrocatalysts for oxygen evolution reaction (OER), hydrogen evolution reaction (HER), oxygen reduction reaction (ORR), and overall water splitting. FeS and its nanocomposites have been studied also for energy storage in the form of electrode materials in supercapacitors and lithium- (LIBs) and sodium-ion batteries (SIBs). The structural and electrochemical characteristics of FeS and its nanocomposites, as well as the synthesis processes, are discussed in this work. This discussion correlates these features with the requirements for electrocatalysts in overall water splitting and its associated reactions. As a result, this study provides a road map for researchers seeking economically viable, environmentally friendly, and efficient electrochemical materials in the fields of green energy production and storage.

Structural Heredity in Catalysis: CO2 Self-Selective CeO2 Nanocrystals for Efficient Photothermal CO2 Hydrogenation to Methane.

The chemical inertness of CO2 molecules makes their adsorption and activation on a catalyst surface one of the key challenges in recycling CO2 into chemical fuels. However, the traditional template synthesis and chemical modification strategies used to tackle this problem face severe structural collapse and modifier deactivation issues during the often-needed post-processing procedure. Herein, a CO2 self-selective hydrothermal growth strategy is proposed for the synthesis of CeO2 octahedral nanocrystals that participate in strong physicochemical interactions with CO2 molecules. The intense affinity for CO2 molecules persists during successive high-temperature treatments required for Ni deposition. This demonstrates the excellent structural heredity of the CO2 self-selective CeO2 nanocrystals, which leads to an outstanding photothermal CH4 productivity exceeding 9 mmol h-1 mcat -2 and an impressive selectivity of >99%. The excellent performance is correlated with the abundant oxygen vacancies and hydroxyl species on the CeO2 surface, which create many frustrated Lewis-pair active sites, and the strong interaction between Ni and CeO2 that promotes the dissociation of H2 molecules and the spillover of H atoms, thereby greatly benefitting the photothermal CO2 methanation reaction. This self-selective hydrothermal growth strategy represents a new pathway for the development of effective catalysts for targeted chemical reactions.

Covalent Triazine-Based Frameworks with Ru-tda Based Catalyst Anchored via Coordination Bond for Photoinduced Water Oxidation.

Light-induced water splitting (hν-WS) for the production of hydrogen as a solar fuel is considered a promising sustainable strategy for the replacement of fossil fuels. An efficient system for hν-WS involves a photoactive material that, upon shining light, is capable of separating and transferring charges to catalysts for the hydrogen and oxygen evolution processes. Covalent triazine-based frameworks (CTFs) represent an interesting class of 2D organic light-absorbing materials that have recently emerged thanks to their tunable structural, optical and morphological properties. Typically, catalysts (Cat) are metallic nanoparticles generated in situ after photoelectroreduction of metal precursors or directly drop-casted on top of the CTF material to generate Cat-CTF assemblies. In this work, the synthesis, characterization and photocatalytic performance of a novel hybrid material, Ru-CTF, is reported, based on a CTF structure featuring dangling pyridyl groups that allow the Ru-tda (tda is [2,2':6',2'"-terpyridine]-6,6'"-dicarboxylic acid) water oxidation catalyst (WOC) unit to coordinate via covalent bond. The Ru-CTF molecular hybrid material can carry out the light-induced water oxidation reaction efficiently at neutral pH, reaching values of maximum TOF of 17 h-1 and TONs in the range of 220 using sodium persulfate as a sacrificial electron acceptor.

Optimizing Photocatalytic H2 Production by Introduction of Pyrazinyls to WRCs and a New tris-Rhenium Photosensitizer.

The replacement of pyridyl by pyrazinyl in ligands of polypyridyl-based cobalt water reducing catalysts (WRC) shifts reduction potentials anodically. Together with a new, trinuclear ReI photosensitizer, these WRCs show strongly improved photocatalytic performances in turnover numbers (TONs) and maximal H2 evolution rate. Depending on the catalyst structure, up to 65 kTONs at 1 µM WRC concentration were reached. Under electrocatalytic conditions in both DMF and H2O, one of the reported WRCs displays remarkable stability, producing H2 steadily over 21 and 14 d, respectively.

Advancements and Challenges in the Synthesis of Oxymethylene Ethers (OMEs) as Sustainable Transportation Fuels.

The urgent need for sustainable alternatives to fossil fuels in the transportation sector is driving research into novel energy carriers that can meet the high energy density requirements of heavy-duty vehicles without exacerbating the climate change. This concept article examines the synthesis, mechanisms, and challenges associated with oxymethylene ethers (OMEs), a promising class of synthetic fuels potentially derived from carbon dioxide and hydrogen. We highlight the importance of OMEs in the transition towards non-fossil energy sources due to their compatibility with the existing Diesel infrastructure and their cleaner combustion profile. The synthesis mechanisms, including the Schulz-Flory distribution and its implications for OME chain length specificity, and the role of various catalysts and starting materials are discussed in depth. Despite advancements in the field, significant challenges remain, such as overcoming the Schulz-Flory distribution, efficiently managing water as an undesirable byproduct, and improving the overall energy efficiency of the OME synthesis. Addressing these challenges is crucial for OMEs to become a viable alternative fuel, contributing to the reduction of greenhouse gas emissions and the transition to a sustainable energy future in the transportation sector.

Preparation of biochars by conventional pyrolysis of herbal waste and their potential application for adsorption and energy purposes.

The nettle, sage, mint and lemon balm herbs were used for biochars preparation. The physicochemical parameters of obtained materials were related to the lignocellulose composition of the precursors. It has been proved that the content of mineral substance has a significant influence on development of surface area, whereas the amount of hemicellulose affects the content of surface functional groups. It has been also shown that the obtained biochars are characterized by great energy parameters. The higher heating values (HHV) of the carbonaceous materials are comparable to the typical energy sources. The greatest HHV value (20.36 MJ/kg) was characteristic for the biochar obtained by pyrolysis of the lemon balm. In addition, the biochars were used for ionic polymers adsorption from one- and two-components solutions. Despite the adsorbed amounts of macromolecules are not great is has been proved that polyethylenimine and polyacrylic acid have positive influence on their mutual adsorption.

Sponge-shaped Au nanoparticles: A stand-alone metallic photocatalyst for driving the light-induced CO2 reduction reaction.

Coinage metal nanoparticles (NPs) enable plasmonic catalysis by generating hot carriers that drive chemical reactions. Making NPs porous enhances the adsorption of reactant molecules. We present a dewetting and dealloying strategy to fabricate porous gold nanoparticles (Au-Sponge) and compare their CO2 photoreduction activity with respect to the conventional gold nanoisland (Au-Island) morphology. Porous gold nanoparticles exhibit an unusually broad and red-shifted plasmon resonance which is in agreement with the results of finite difference time domain (FDTD) simulations. The key insight of this work is that the multi-step reduction of CO2 driven by short-lived hot carriers generated by the d → s interband transition proceeds extremely quickly as evidenced by the generation of methane. A 3.8-fold enhancement in the photocatalytic performance is observed for the Au-Sponge in comparison to the Au-Island. Electrochemical cyclic voltammetry measurements confirm the 2.5-fold increase in the surface area and roughness factor of the Au-Sponge sample due to its porous nature. Our results indicate that the product yield is limited by the amount of surface adsorbates i.e. reactant-limited. Isotope-labeled mass spectrometry using 13CO2 was used to confirm that the reaction product (13CH4) originated from CO2 photoreduction. We present the plasmon-mediated photocatalytic transformation of 4-aminothiophenol (PATP) into p,p'-dimercaptoazobenzene (DMAB) using Au-Sponge and Au-Island samples.

Pollutant Emissions and Oxidative Potentials of Particles from the Indoor Burning of Biomass Pellets.

Residential solid fuel combustion significantly impacts air quality and human health. Pelletized biomass fuels are promoted as a cleaner alternative, particularly for those who cannot afford the high costs of gas/electricity, but their emission characteristics and potential effects remain poorly understood. The present laboratory-based study evaluated pollution emissions from pelletized biomass burning, including CH4 (methane), NMHC (nonmethane hydrocarbon compounds), CO, SO2, NOx, PM2.5 (particulate matter with an aerodynamic diameter ≤2.5 µm), OC (organic carbon), EC (element carbon), PAHs (polycyclic aromatic hydrocarbons), EPFRs (environmentally persistent free radicals), and OP (oxidative potential) of PM2.5, and compared with those from raw biomass burning. For most targets, except for SO2 and NOx, the mass-based emission factors for pelletized biomass were 62-96% lower than those for raw biomass. SO2 and NOx levels were negatively correlated with other air pollutants (p < 0.05). Based on real-world daily consumption data, this study estimated that households using pelletized biomass could achieve significant reductions (51-95%) in emissions of CH4, NMHC, CO, PM2.5, OC, EC, PAHs, and EPFRs compared to those using raw biomass, while the differences in emissions of NOx and SO2 were statistically insignificant. The reduction rate of benzo(a)pyrene-equivalent emissions was only 16%, much lower than the reduction in the total PAH mass (78%). This is primarily attributed to the more PAHs with high toxic potentials, such as dibenz(a,h)anthracene, in the pelletized biomass emissions. Consequently, impacts on human health associated with PAHs might be overestimated if only the mass of total PAHs was counted. The OP of particles from the pellet burning was also significantly lower than that from raw biomass by 96%. The results suggested that pelletized biomass could be a transitional substitution option that can significantly improve air quality and mitigate human exposure.

Relationship of solid fuels use with cognitive function and efficacy of switching to cleaner fuels or using ventilation: A systematic review and meta-analysis.

BACKGROUND: A growing number of studies have examined the relation between solid fuels use and cognitive function in the mid-elderly, but results are inconsistent. Therefore, a systematic review and meta-analysis was carried out to evaluate their relevance and the efficacy of switching to cleaner fuels or using ventilation. METHOD: We used PubMed, Web of Science, and Cochrane Library databases to identify 17 studies in which the primary outcome variable was cognitive function decline or cognitive disorders, and the exposure measure was solid fuels use. The final search date of August 31, 2023. The effect size of odds ratio (OR), regression coefficient (ß), and 95% confidence interval (CI) were pooled. Heterogeneity and the possibility of publication bias were assessed by using the Q-statistic and Begg's test, respectively. RESULT: Among the 17 included papers, the study participants were ≥45 years old. Eleven studies assessed the relationship between solid fuels use and cognitive function decline [number of studies (n) = 11, ß = -0.144; I2 = 97.7%]. Five studies assessed the relationship between solid fuels use and cognitive disorders (n = 5, OR = 1.229; I2 = 41.1%). Switching from using solid fuels to clean fuels could reduce the risk of cognitive function decline as compared to those who remained on using solid fuels (n = 2; ß = 0.710; I2 = 82.4%). Among participants using solid fuels, who cooked without on ventilated stoves were correlated with an enhanced risk of cognitive disorders as compared to participants who cooked with ventilated stoves (n = 2; OR = 1.358; I2 = 44.7%). CONCLUSION: Our meta-analysis showed a negative relationship between solid fuels use with cognitive function, and a positive relationship with cognitive disorders. Cleaner fuels, using ventilation, improved cookstoves can reduce the adverse health hazards of solid fuels use.

Progress and challenges in valorisation of biomass waste from ornamental trees pruning through pyrolysis processes. Prospects in the bioenergy sector.

Nowadays, the scarcity of energy resources is promoting the search for alternative energy sources, boosting interest in the use of forest lignocellulosic residue in the energy sector. In this study, the focus is on the energy recovery from two lignocellulosic residues originated during the pruning of ornamental trees (Horse Chestnut, CI, and False Acacia, FA). Both conventional and flash pyrolysis techniques were applied. The experimental pyrolysis variables were obtained from the study of the thermal behaviour of the pruning residues in thermogravimetric analysis. It was carried out under 5 heating rates and kinetic parameters were estimated using Flynn-Wall-Ozawa method. Results denoted higher maximum mass loss rate values for the same release temperature regions under FA experiments. Also, FA samples had lower final residues for the processes. However, activation energy values were so close for both species. FA was also linked to the faster reactions according frequency factor outcomes. Conventional pyrolysis of pruning residues was carried out in a horizontal oven of original design at a heating rate of 25 °C/min, at 750 °C and 60 min of permanence at that temperature; flash pyrolysis was tested in that oven at 750 and 850 °C. In these pyrolysis processes, three fractions were obtained: bio-char, bio-oil and gas. The physicochemical attributes of the bio-chars suggested their potential utility as biofuels (28.4-29.8 MJ/kg), adsorbent precursors or soil additives. Conventional pyrolysis bio-oils had a dominant monoaromatic hydrocarbons nature, with phenols being the most abundant (≥60%), while flash bio-oils contain mainly polycyclic aromatic hydrocarbons. Conventional pyrolysis gases contained up to 60 vol% of CO2; flash pyrolysis gases had high combustible gas content (CO, CH4, H2) and a low CO2 content (<25 vol%). As a result, their calorific value (18.06 MJ/kg) exhibited a threefold increase compared to the gas produced through conventional pyrolysis (6.04 MJ/kg).

Recent advances in liquid fuel production from plastic waste via pyrolysis: Emphasis on polyolefins and polystyrene.

The management of plastic waste (PW) has become an indispensable worldwide issue because of the enhanced accumulation and environmental impacts of these waste materials. Thermo-catalytic pyrolysis has been proposed as an emerging technology for the valorization of PW into value-added liquid fuels. This review provides a comprehensive investigation of the latest advances in thermo-catalytic pyrolysis of PW for liquid fuel generation, by emphasizing polyethylene, polypropylene, and polystyrene. To this end, the current strategies of PW management are summarized. The various parameters affecting the thermal pyrolysis of PW (e.g., temperature, residence time, heating rate, pyrolysis medium, and plastic type) are discussed, highlighting their significant influence on feed reactivity, product yield, and carbon number distribution of the pyrolysis process. Optimizing these parameters in the pyrolysis process can ensure highly efficient energy recovery from PW. In comparison with non-catalytic PW pyrolysis, catalytic pyrolysis of PW is considered by discussing mechanisms, reaction pathways, and the performance of various catalysts. It is established that the introduction of either acid or base catalysts shifts PW pyrolysis from the conventional free radical mechanism towards the carbonium ion mechanism, altering its kinetics and pathways. This review also provides an overview of PW pyrolysis practicality for scaling up by describing techno-economic challenges and opportunities, environmental considerations, and presenting future outlooks in this field. Overall, via investigation of the recent research findings, this paper offers valuable insights into the potential of thermo-catalytic pyrolysis as an emerging strategy for PW management and the production of liquid fuels, while also highlighting avenues for further exploration and development.

The mediating effect of sleep quality on solid cooking fuel use and psychological distress among rural older adults: evidence from Shandong, China.

BACKGROUND: Exposure to indoor air pollution from solid cooking fuel use may increase mental disorders risk through pathways such as oroxidative stress, neuroinflammation, or cerebrovascular damage. However, few studies have explored the underlying mechanism between solid cooking fuel use and psychological distress. The present study aims to investigate the mediating role of sleep quality on the relationship between solid cooking fuel use and psychological distress among older adults in rural Shandong, China. METHODS: This study used the cross-sectional data from the second follow-up survey of the Shandong Rural Elderly Health Cohort (SREHC). A total of 3,240 rural older adults were included in the analysis. Logistic regression and the Karlson, Holm, and Breen (KHB) mediation analyses were performed to investigate the relationship between solid cooking fuel use and psychological distress, as well as the mediating role of sleep quality in this association. RESULTS: This study found that solid cooking fuel use was significantly and positively associated with psychological distress among older adults in rural Shandong, China (OR = 1.38, 95% CI: 1.12,1.70). Mediation analysis revealed that sleep quality mediated the association between solid cooking fuel use and psychological distress among older adults (ß = 0.06, P = 0.011). The mediation effect accounted for 16.18% of the total effect. CONCLUSIONS: Our study showed that solid cooking fuel use was associated with psychological distress among rural older adults, and sleep quality mediated this association. Interventions should focus on addressing cooking fuel types and poor sleep quality to reduce psychological distress. In the future, more aggressive environmental protection policies would be needed to lessen the adverse effects of indoor air pollution on the health of older adults in rural China.

Associations between cooking fuel use, its transitions, and worsening sensory impairments among Chinese middle-aged and older adults: a cohort study.

BACKGROUND: This study aimed to explore the associations between household air pollution (HAP), measured by cooking fuel use, sensory impairments (SI), and their transitions in Chinese middle-aged and older adults. METHODS: Participants were recruited from the 2011 China Health and Retirement Longitudinal Study (CHARLS) and were subsequently followed up until 2018. Data on SI were collected by self-reported hearing and vision impairments, which were divided into three categories: non-SI, single SI (hearing or vision impairment), and dual SI (DSI). Cooking fuels, including solid and clean fuels, are proxies for HAP. The transitions of cooking fuels and SI refer to the switching of the fuel type or SI status from baseline to follow-up. Cox proportional hazard regression models were used to explore associations, and hazard ratios (HRs) and 95% confidence intervals (CI) were used to evaluate the strength of the association. RESULTS: The prevalence of non-SI, single SI, and DSI was 59.6%, 31.8%, and 8.6%, respectively, among the 15,643 participants at baseline in this study. Over a median follow-up of 7.0 years, 5,223 worsening SI transitions were observed. In the fully adjusted model, solid fuel use for cooking was associated with a higher risk of worsening SI transitions, including from non-SI to single SI (HR = 1.08, 95% CI = 1.01-1.16) and from non-SI to DSI (HR = 1.26, 95% CI = 1.09-1.47), but not from single SI to DSI. In addition, compared to those who always used solid fuels, participants who switched from solid to clean fuel for cooking appeared to have attenuated the risk of worsening SI transitions. The statistical significance of the associations remained in the set of sensitivity analyses. CONCLUSION: Solid fuel use was associated with higher risks of worsening SI transitions, while converting the type of cooking fuel from solid to clean fuels may reduce the risk of worsening SI transitions. Our study suggests that tailored clean fuel interventions, especially in developing countries, should be implemented to prevent sensory impairments and hence reduce the burden of sensory impairment-related disability.

Cooking fuel use and respiratory health of women and children in rural Ballabgarh, Haryana.

BACKGROUND: Household air pollution arising from combustion of unclean fuels during cooking activities causes serious respiratory health effects. This study investigated patterns of household cooking fuel use and its effect on respiratory health status of women and children. METHODS: A cross-sectional study was conducted in rural households of Ballabgarh, Haryana during December 2019 to January 2020 among 18-45 years old women and their children having age between 6 and 59 months. A total of 450 households were selected using simple random sampling. Cooking fuel use was categorised as unclean (Wood, dung cakes, crop residues) and clean (LPG and electricity). The classification of mixed fuel use (predominantly unclean or clean) was based upon duration of unclean fuel use ≥ 2.5 h per day. The clinical history and physical examination was done using a semi-structured questionnaire. Assessment of respiratory health status of women participants was done using peak expiratory flow meter and presence of pneumonia in children was evaluated as per Integrated Management of Neonatal and Childhood Illnesses (IMNCI) guidelines. RESULTS: Overall use of unclean cooking fuels was predominant in 59.6% of households and 71.8% of households had mixed fuel use. Only clean fuel use was in 11.3% of households. Nasal stuffiness, breathing difficulty and cough were observed among 13.1%, 10.5% and 8.5% among women while the common respiratory symptoms in children were cough (27.8%) and runny nose (22.9%). As compared to clean fuels, women using unclean fuels were more likely to have any respiratory symptom (aOR 3.0, 95% CI: 1.5-6.0) and impaired pulmonary functions (adjusted OR 1.9, 95% CI: 1.2-2.9). Cooking fuel use was not associated with respiratory symptoms and presence of pneumonia in children living in the households. CONCLUSION: Cooking with unclean fuel continues to be prevalent in the households of rural Ballabgarh and adversely affects the respiratory health of women indicating strengthening of initiatives promoting clean fuel use.

Switching indoor fuels and the incidence of physical-psychological-cognitive multimorbidity: A prospective cohort study.

BACKGROUND: In developing countries, including China, solid-fuel-based heating and cooking is common. For older people, the multimorbidity prevalence is exceptionally high. Nevertheless, studies on the associations of indoor solid fuels use, especially switching fuels types, on multimorbidity in middle-aged and older people is scarce. METHODS: Data from five waves of the China Health and Retirement Longitudinal Study were used in this study. Indoor fuels were classified as solid or clean fuels. Physical-psychological-cognitive multimorbidity (PPC-multimorbidity) was defined as the simultaneous presence of three disease types (physical illness, psychological disorders, cognitive impairment). Using Cox proportional risk models, hazard ratios (HRs) and 95 % confidence intervals (95 % CI) were calculated to investigate the associations of heating- and cooking-related baseline indoor fuels and switching indoor fuels with PPC-multimorbidity incidence. RESULTS: In the heating (n=3121, mean age=56.55 years, male proportion=54.25 %) and cooking (n=3574, mean age=56.67 years, male proportion=52.94 %) analyses, 75.07 % and 45.64 % of the participants used solid fuels at baseline, and 564 (18.07 %) and 613 (17.15 %) PPC-multimorbidity cases were diagnosed during follow-up, respectively. Participants with baseline heating- and cooking-based solid fuels use had greater PPC-multimorbidity incidences [HRs (95 % CIs): 1.23 (0.98, 1.55) and 1.44 (1.21, 1.73)], respectively. Additionally, combined baseline heating- and cooking-based solid fuels use was associated with even greater PPC-multimorbidity incidence [HR (95 % CI): 1.55 (1.18, 2.04)]. Persistent solid fuels use obviously increased the PPC-multimorbidity incidence [HRs (95 % CIs): 2.43 (1.67, 3.55) for heating and 2.63 (2.03, 3.40) for cooking]. Moreover, switching from solid to clean fuels was associated with a significantly decreased PPC-multimorbidity incidence [HRs (95 % CIs): 0.27 (0.20, 0.35) for heating and 0.36 (0.28, 0.46) for cooking]. CONCLUSIONS: Long-term solid-fuels use is associated with an increased PPC-multimorbidity incidence, and switching to cleaner fuels is associated with a decreased PPC-multimorbidity incidence in adults aged ≥45 years.

Spectral Investigations of Fluorescence Tracers in Automotive and Aviation Fuels under Cryogenic Conditions.

This study investigated spectral laser-induced fluorescence signals of dyes in fuels for automotive and aerospace applications under low temperatures and cryogenic conditions down to 183 K. For this purpose, a fluorescence chamber was developed based on cooling with liquid nitrogen. The design enabled a minimal inner chamber temperature of 153 K. Furthermore, the applicability of two-color LIF for liquid thermometry was evaluated under these conditions. The temperature determination was based on the temperature-sensitive fluorescence intensity ratio of the special dyes doped into the fuels determined in suitable spectral regions, which represented common bandpass filters. For this purpose, the fluorescence signals of the dye doped into the gasoline and jet fuel surrogate isooctane were tested as well as blends of isooctane and the ethanol biofuels E20 (comprising 80 vol.% isooctane and 20 vol.% ethanol), E40, and E100. Additionally, a realistic multi-component fuel Jet A-1 mixed with a suitable fluorescence dye was investigated. E100 was doped with Eosin-Y, and the remaining fuels were doped with Nile red. Temperature-dependent spectral LIF intensities were recorded in the range of 183 K-293 K, which simulate extreme environments for aerospace and automotive applications. Frozen fuel-dye mixtures cause significant extinction effects and prevent sufficient signal detection at low and cryogenic temperatures, defining the detection limit. A temperature decrease led to a spectral shift in the emission peaks of E100 doped with Eosin-Y toward shorter wavelengths, while the spectra of mixtures doped with Nile red were shifted toward longer wavelengths. The suggested bandpass filters produced the temperature-sensitive intensity ratio (the average over the temperature interval) of the dyes with the largest sensitivity for Jet A-1 (5.2%/K), followed by E100 (4.95%/K), E40 (4.07%/K), E20 (3.23%/K), and isooctane (3.07%/K), even at cryogenic temperatures.

Developing customized fuel models for shrub and bracken communities in Galicia (NW Spain).

Geospatial fire behaviour and fire hazard simulators, fire effects models and smoke emission software commonly use standard fuel models in order to simplify data collection and the inclusion of complex fuel scenarios. These fuel models are often mapped using remotely sensed data. However, given the great complexity of fuelbeds, with properties that vary widely in both time and space, the use of these standard fuel models can greatly limit accurate fuel mapping. This affects fuel hazard assessment, fuel reduction treatment plans, fire management decision-making and evaluation of the environmental impact of wildfire. In this study, we developed unique customized fire behaviour fuel models for shrub and bracken communities, by using k-medoids clustering analysis based on both fuel structural characteristics and potential fire behaviour. We used an original database of 722 destructive sample plots in nine different shrub and bracken communities covering the entire distribution area in Galicia (NW Spain), one of the regions in Europe most affected by forest fires. Measurements of cover, height and fuel fractions loads differentiated by size and vegetative state (live or dead) were used to estimate the potential rate of fire spread with five different models including fireline intensity, heat per unit area and the flame length for each sampling site and considering extreme environmental conditions. The optimal number of clusters was established by combining practical knowledge about the shrubland communities under study and their associated fire behaviour, with maximization of the mean value of the silhouette variable and minimization of the within-cluster sum of squares. The structural characteristics of the medoids derived from the analysis were associated with each of the proposed customized fuel models. Finally, a simple dichotomous classification based only on shrub height was developed to enable construction of spatially explicit fuel model maps based on remotely sensed data. Thus, the methodology applied allows generation of a more realistic representation of fuel distribution in the landscape, based on fuel structure measurements of natural regional ecosystems rather than on the use of standard models. We believe that the proposed methodology is generally applicable to communities composed of other shrub and fern species in different biogeographical regions.

Evaluating the roles of energy innovation, fossil fuel costs and environmental compliance towards energy transition in advanced industrial economies.

Given the dire state of climate change, investigating key elements that impact the energy transition process and help monitor progress in greenhouse gas emissions to achieve environmental sustainability is of critical importance. The current study explores the association between energy transition, compliance with environmental agreements, fossil fuels costs, environmental technologies, economic growth, and environmental degradation in G20 economies from 1995 to 2019. Our findings from extensive econometric analysis reveal that economic growth, environmental innovation, renewable energy, and environmental compliance facilitate while fossil fuels and environmental degradation hinder the energy transition process. Our findings conclude that developed countries must focus on alternate energy resources to overcome environmental challenges and subsidize renewable energy and environmental technologies to replace fossil fuels with green energy resources methodologically. Further, policy measures have been discussed in detail in the study.