Search

[Display omitted] Although photocatalytic H 2 production based on semiconductor materials has a wide potential application, it still facing challenges such as slow reaction kinetics or complex synthesis processes. To meet these challenges, the carbon dots loaded black g-C 3 N 4 (CN-B-CDs) was synthesized by simple calcination method to achieve efficient photothermal-assisted photocatalytic H 2 production. Photothermal imaging experiments confirmed the photothermal effect of CN-B and CDs as dual heat sources to increase the temperature of the composite system, thus improving the effective separation of photo-generated charges. In addition, multiple photocatalytic H 2 production tests exhibited that CN-B-CDs photocatalysts not only have strong stability but also can accommodate a variety of complex water bodies, which displayed the potential for industrial application. This study combined the photothermal effect and the mechanism by which the CDs promote the charge transfer to design a new photocatalytic H 2 production system and provided a new scheme for achieving efficient photothermal-assisted photocatalytic H 2 production using carbon-based materials. [ABSTRACT FROM AUTHOR]

Dormancy has been suggested to be used for metal oxide gas sensors to specifically refer to their response decrease or disappearance after long periods of inactivity at room temperature. In this paper, 1 wt% Pt–SnO 2 composite nanoceramics with especially strong responses to hydrogen–containing atmospheres at room temperature, e.g. a response of 11170 to 1 % H 2 –20 % O 2 –N 2 , were successfully prepared through pressing and sintering. A clear dormancy has been observed for them as their responses decreased seriously with time when they were stored in ambient air at room temperature. Commercial ceramic heating plates (Metal Ceramics Heater, MCH) of 10 mm × 10 mm were attached to bars of 1 wt% Pt–SnO 2 composite nanoceramics. Dormant bars after 12 months of storage were completely regenerated through a heat–treatment of 200 °C for 10 min by attached MCH ceramic heating plates. According to X-ray photoelectron spectroscopy analyses, the formation of hydroxyl groups on SnO 2 in Pt–SnO 2 composite nanoceramics and deposition of impurity gases like H 2 S were proposed responsible for the dormancy, and their removal through mild heat–treatments result in the regeneration. It is suggested that heaters like commercial MCH ceramic heating plates should be included in future room–temperature gas sensors to provide a practicable regeneration from dormancy when needed. [ABSTRACT FROM AUTHOR]

Background: Fire models have used pyrolysis data from oxidising and non-oxidising environments for flaming combustion. In wildland fires pyrolysis, flaming and smouldering combustion typically occur in an oxidising environment (the atmosphere). Aims: Using compositional data analysis methods, determine if the composition of pyrolysis gases measured in non-oxidising and ambient (oxidising) atmospheric conditions were similar. Methods: Permanent gases and tars were measured in a fuel-rich (non-oxidising) environment in a flat flame burner (FFB). Permanent and light hydrocarbon gases were measured for the same fuels heated by a fire flame in ambient atmospheric conditions (oxidising environment). Log-ratio balances of the measured gases common to both environments (CO, CO2, CH4, H2, C6H6O (phenol), and other gases) were examined by principal components analysis (PCA), canonical discriminant analysis (CDA) and permutational multivariate analysis of variance (PERMANOVA). Key results: Mean composition changed between the non-oxidising and ambient atmosphere samples. PCA showed that flat flame burner (FFB) samples were tightly clustered and distinct from the ambient atmosphere samples. CDA found that the difference between environments was defined by the CO-CO2 log-ratio balance. PERMANOVA and pairwise comparisons found FFB samples differed from the ambient atmosphere samples which did not differ from each other. Conclusion: Relative composition of these pyrolysis gases differed between the oxidising and non-oxidising environments. This comparison was one of the first comparisons made between bench-scale and field scale pyrolysis measurements using compositional data analysis. Implications: These results indicate the need for more fundamental research on the early time-dependent pyrolysis of vegetation in the presence of oxygen. Composition of pyrolysis gases measured in non-oxidising and ambient atmospheric conditions has been compared using compositional data analysis. Mean compositions changed between the non-oxidising and ambient atmosphere samples. These results indicate the need for more fundamental research on the early time-dependent pyrolysis of vegetation in the presence of oxygen. [ABSTRACT FROM AUTHOR]

The paper explores the relationship between the shadow economy, corruption, and taxes in 25 high-financial developed countries (HFDCs) and 30 low-financial developed countries (LFDCs) using the PVAR method. The results of the impulse-response function show that the corruption perception index (CPI) has a positive correlation with tax revenue and the shadow economy in HFDCs, while tax revenue and the shadow economy are negatively correlated. In contrast, in LFDCs, the shadow economy has a positive correlation with tax revenue and a negative correlation with the CPI. In addition, the study also suggests that there is no relationship between tax revenue and the CPI. From the above findings, we propose several related policies for each group of countries.

The aging of society is one of the most important trends shaping the social, economic and political life of the 21st century. However, with the increasing number of people of retirement age, the problem of ensuring adequate conditions for a longer life arises. The state influences these conditions through the pension security system, including taxation of pensions. The paper attempts to answer the question whether taxation of remunerations and public pension benefits may have a significant impact on making decisions about choosing a country of work in the common market. For this purpose, Member States have been ranked in terms of two dimensions—the conditions of taxation of wages and the conditions of taxation of retirement benefits. The countries were classified using a multi-criteria comparative analysis and the agglomeration method. The study shows that taxing salaries and pension benefits is of marginal importance from the point of view of an employee’s decision-making. The main factors are the average expenditure on net salaries and the average expenditure on net pension benefits.

Abstract Background Retinopathy of Prematurity (ROP) is a proliferative retinal vascular disease occurring in the retina of premature infants and is the main cause of childhood blindness. Nowadays anti-VEGF and retinal photocoagulation are mainstream treatments for ROP, but they develop a variety of complications. Hydrogen (H2) is widely considered as a useful neuroprotective and antioxidative therapeutic method for hypoxic-ischemic disease without toxic effects. However, whether H2 provides physiological angiogenesis promotion, neovascularization suppression and glial protection in the progression of ROP is largely unknown.This study aims to investigate the effects of H2 on retinal angiogenesis, neovascularization and neuroglial dysfunction in the retinas of oxygen-induced retinopathy (OIR) mice. Methods In this study, mice that were seven days old and either wild-type (WT) or Nrf2-deficient (Nrf2−/−) were exposed to 75% oxygen for 5 days and then returned to normal air conditions. Different stages of hydrogen gas (H2) inhalation were administered. Vascular obliteration, neovascularization, and blood vessel leakage were analyzed and compared. To count the number of neovascularization endothelial nuclei, routine HE staining of retinal sections was conducted. Immunohistochemistry was performed using DyLight 594 labeled GSL I-isolectin B4 (IB4), as well as primary antibodies against proliferating cell nuclear antigen (PCNA), glial fibrillary acidic protein (GFAP), and Iba-1. Western blots were used to measure the expression of NF-E2-related factor 2 (Nrf2), vascular endothelial growth factor (VEGF), Notch1, Dll4, and HIF-1α. Additionally, the expression of target genes such as NQO1, HO-1, Notch1, Hey1, Hey2, and Dll4 was measured. Human umbilical vein endothelial cells (HUVECs) treated with H2 under hypoxia were used as an in vitro model. RT-PCR was used to evaluate the mRNA expression of Nrf2, Notch/Dll4, and the target genes. The expression of reactive oxygen species (ROS) was observed using immunofluorescence staining. Results Our results indicate that 3–4% H2 does not disturb retinal physiological angiogenesis, but ameliorates vaso-obliteration and neovascularization in OIR mice. Moreover, H2 prevents the decreased density and reverses the morphologic and functional changes in retinal astrocytes caused by oxygen-induced injury. In addition, H2 inhalation reduces microglial activation, especially in the area of neovascularization in OIR mice. H2 plays a protective role in vascular regeneration by promoting Nrf2 activation and suppressing the Dll4-induced Notch signaling pathway in vivo. Also, H2 promotes the proliferation of HUVECs under hypoxia by negatively regulating the Dll4/Notch pathway and reducing ROS levels through Nrf2 pathway aligning with our findings in vivo.Moreover, the retinal oxygen-sensing mechanisms (HIF-1α/VEGF) are also involved in hydrogen-mediated retinal revascularization and neovascularization suppression. Conclusions Collectively, our results indicate that H2 could be a promising therapeutic agent for POR treatment and that its beneficial effect in human ROP might involve the activation of the Nrf2-Notch axis as well as HIF-1α/VEGF pathways. Graphical Abstract

Lithium tantalate (LiTaO3) perovskite finds wide use in pyroelectric detectors, optical waveguides and piezoelectric transducers, stemming from its good mechanical and chemical stability and optical transparency. Herein, we present a method for synthesis of LiTaO3 nanoparticles using a scalable Flame Spray Pyrolysis (FSP) technology, that allows the formation of LiTaO3 nanomaterials in a single step. Raman, XRD and TEM studies allow for comprehension of the formation mechanism of the LiTaO3 nanophases, with particular emphasis on the penetration of Li atoms into the Ta-oxide lattice. We show that, control of the High-Temperature Particle Residence Time (HTPRT) in the FSP flame, is the key-parameter that allows successful penetration of the -otherwise amorphous- Li phase into the Ta2O5 nanophase. In this way, via control of the HTPRT in the FSP process, we synthesized a series of nanostructured LiTaO3 particles of varying phase composition from {amorphous Li/Ta2O5/LiTaO3} to {pure LiTaO3, 15–25 nm}. Finally, the photophysical activity of the FSP-made LiTaO3 was validated for photocatalytic H2 production from H2O. These data are discussed in conjunction with the role of the phase composition of the LiTaO3 nanoparticles. More generally, the present work allows a better understanding of the mechanism of ABO3 perovskite formation that requires the incorporation of two cations, A and B, into the nanolattice. [ABSTRACT FROM AUTHOR]

As an important gas signaling molecule, hydrogen sulfide (H2S) affects multiple organ systems, including the nervous, cardiovascular, digestive, and genitourinary, reproductive systems. In particular, H2S not only regulates female reproductive function but also holds great promise in the treatment of male reproductive diseases and disorders, such as erectile dysfunction, prostate cancer, varicocele, and infertility. In this review, we summarize the relationship between H2S and male reproductive organs, including the penis, testis, prostate, vas deferens, and epididymis. As lower urinary tract symptoms have a significant impact on penile erection disorders, we also address the potential ameliorative effects of H2S in erectile dysfunction resulting from bladder disease. Additionally, we discuss the regulatory role of H2S in cavernous smooth muscle relaxation, which involves the NO/cGMP pathway, the RhoA/Rho-kinase pathway, and K+ channel activation. Recently, various compounds that can alleviate erectile dysfunction have been reported to be at least partly dependent on H2S. Therefore, understanding the role of H2S in the male reproductive system may help develop novel strategies for the clinical treatment of male reproductive system diseases. [ABSTRACT FROM AUTHOR]

The deactivation of active sites caused by high-temperature sintering and the deposition of a large amount of carbon are the main difficulties in the reforming of methane using Ni-based catalysts. La, as a promoter, has an ameliorating effect on the defects of Ni-based catalysts. In this article, the mechanism of action of Ni-based catalysts with the introduction of the rare-earth metal additive La was reviewed, and the effects of La on the methane-reforming performance of Ni-based catalysts were examined. The physical properties, alkalinity, and activity of Ni-based catalysts can be enhanced by the use of the auxiliary agent La, which promotes the conversion of CH4 and CO2 as well as the selectivity towards H2 and CO formation in the reforming of methane. The reason why the Ni-based catalysts could maintain long-term stability in the presence of La was discussed. Furthermore, the current state of research on the introduction of different amounts of La in the reforming of methane at home and abroad was analyzed. It was found that 2–5 wt.% La is the most optimal quantity for improving the catalyst activity and stability, as well as the CO2 chemisorption. The limitations and directions for future research in the reforming of methane were discussed. [ABSTRACT FROM AUTHOR]

Background: Allergic rhinitis (AR) is an allergic reaction dominated by the Th2 immune response in the nasal mucosa. The bacterial infection process affects the balance between Th1 and Th2 immune responses, and the level of exposure to environmental flora is closely related to the development of AR. Hydrogen (H2) is a medical molecule with anti-inflammatory and antioxidant properties. This study aimed to explore the possible mechanism of action of H2 on AR through its ability to regulate the balance of nasal flora. Methods: Serum eosinophil count (EOS), immunoglobulin E (IgE) concentration, visual analog scale (VAS), total nasal symptom score (TNSS), and rhinoconjunctivitis quality of life questionnaire (RQLQ) were observed before and after hydrogen inhalation in AR patients. Skin prick test (SPT) was used to determine allergen sensitisation. Community composition and relative abundance of nasal flora were examined before and after hydrogen inhalation and in normal subjects using 16S rRNA gene sequencing. Results: There were no adverse reactions during and after hydrogen inhalation in AR patients, with a favorable safety profile and significant improvements in VAS, TNSS, EOS, and IgE (P

Gas-phase hydrogen combustion is ubiquitous in industrial processes, and the associated surface kinetics on heat-resistant alloys plays a crucial role in designing efficient low-carbon technologies. We conducted new temperature programmed reduction experiments to determine the reducibility of materials following an oxidation cycle. These experiments were modeled using a thermoconsistent multi-site microkinetic model for H2 heterogeneous oxidation on Inconels, which was validated against literature experiments. This competitive adsorption model considers iron bulk content, hydrogen spillover and subsurface oxygen migration on hydrogen surface oxidation kinetics. New X-ray diffraction experiments confirmed the postulated crystallographic structures in the Inconel samples, suggesting their presence on the surface scale. The phenomenological model was coupled with several state-of-the-art gas-phase oxidation mechanisms to assess gas/surface reactions interaction as a function of material and temperature. The results reveal a complex interaction in which surface removes H radicals from the gas-phase, while the Bradford (H2+OH) reaction converts OH into H2O, promoting water adsorption on Inconel. This interaction was found to give rise to gas-phase thermokinetic oscillations. The model predicts a non-monotonous effect of reactor area-to-volume ratio on reactivity and emphasizes the impact of Inconel composition on product selectivity. Overall, the multi-site model provides new insight into the contrasting reactivities among active sites, bridging the gap between material science and heterogeneous combustion modeling.

Transition metal dichalcogenides (TMDs), particularly monolayer TMDs with direct bandgap properties, are key to advancing optoelectronic device technology. WSe2 stands out due to its adjustable carrier transport, making it a prime candidate for optoelectronic applications. This study explores monolayer WSe2 synthesis via H2-assisted CVD, focusing on how carrier gas flow rate affects WSe2 quality. A comprehensive characterization of monolayer WSe2 was conducted using OM (optical microscope), Raman spectroscopy, PL spectroscopy, AFM, SEM, XPS, HRTEM, and XRD. It was found that H2 incorporation and flow rate critically influence WSe2's growth and structural integrity, with low flow rates favoring precursor concentration for product formation and high rates causing disintegration of existing structures. This research accentuates the significance of fine-tuning the carrier gas flow rate for optimizing monolayer WSe2 synthesis, offering insights for fabricating monolayer TMDs like WS2, MoSe2, and MoS2, and facilitating their broader integration into optoelectronic devices. [ABSTRACT FROM AUTHOR]

This paper presents a theoretical analysis of the selected properties of HCNG fuel calculations and a literature review of the other fuels that allow the storage of ecologically produced hydrogen. Hydrogen has the most significant CO2 reduction potential of all known fuels. However, its transmission in pure form is still problematic, and its use as a component of fuels modified by it has now become an issue of interest for researchers. Many types of hydrogen-enriched fuels have been invented. However, this article will describe the reasons why HCNG may be the hydrogen-enriched fuel of the future and why internal combustion (IC) piston engines working on two types of fuel could be the future method of using it. CO2 emissions are currently a serious problem in protecting the Earth's natural climate. However, secondarily, power grid stabilization with a large share of electricity production from renewable energy sources must be stabilized with very flexible sources—as flexible as multi-fuel IC engines. Their use is becoming an essential element of the electricity power systems of Western countries, and there is a chance to use fuels with zero or close to zero CO2 emissions, like e-fuels and HCNG. Dual-fuel engines have become an effective way of using these types of fuels efficiently; therefore, in this article, the parameters of hydrogen-enriched fuel selected in terms of relevance to the use of IC engines are considered. Inaccuracies found in the literature analysis are discussed, and the essential properties of HCNG and its advantages over other hydrogen-rich fuels are summarized in terms of its use in dual-fuel (DF) IC engines. [ABSTRACT FROM AUTHOR]

Nodular heterotopia (NH)–related drug‐resistant epilepsy is challenging due to the deep location of the NH and the complexity of the underlying epileptogenic network. Using ictal stereo‐electroencephalography (SEEG) and functional connectivity (FC) analyses in 14 patients with NH‐related drug‐resistant epilepsy, we aimed to determine the leading structure during seizures. For this purpose, we compared node IN and OUT strength between bipolar channels inside the heterotopia and inside gray matter, at the group level and at the individual level. At seizure onset, the channels within NH belonging to the epileptogenic and/or propagation network showed higher node OUT‐strength than the channels within the gray matter (p =.03), with higher node OUT‐strength than node IN‐strength (p =.03). These results are in favor of a "leading" role of NH during seizure onset when involved in the epileptogenic‐ or propagation‐zone network (50% of patients). However, when looking at the individual level, no significant difference between NH and gray matter was found, except for one patient (in two of three seizures). This result confirms the heterogeneity and the complexity of the epileptogenic network organization in NH and the need for SEEG exploration to characterize more precisely patient‐specific epileptogenic network organization. [ABSTRACT FROM AUTHOR]

Despite the increasing attention on energy poverty due to its health implications, the South African story is yet to be told, while pathways of influence have received little empirical investigation in the extant literature. This study examines how energy poverty affects mental distress in post-apartheid South Africa and explores gender and locational heterogeneities in outcomes as well as potential pathways. We use five years of longitudinal data extracted from the National Income Dynamics Survey (NIDS). We employ the Lewbel instrumental variable method to resolve endogeneity and apply causal mediation analysis to identify potential channels of effect. The findings suggest that energy poverty is associated with an increase in mental distress. This outcome is consistent across different estimation methods and conceptualisations of energy poverty. The deteriorating effect of energy poverty on mental distress is more pronounced among females and rural residents. We further establish that experiences of persistent cough and chest pains/tightness serve as potential pathways in the link between energy poverty and mental distress. We encourage the South African government to increase budgetary allocations to the free basic electricity policy and provide connection subsidies to poor households, which have the potential to alleviate energy poverty and reduce mental distress as a result.

Sulfur hexafluoride (SF6) is the most widely used gas insulation dielectric in power system, Currently, SF6 degradation technology based on non-thermal plasma faces issues with high content of difficult-to-treat byproducts like SO2F2. This study proposes improving the SF6 destruction and removal efficiency (DRE) through tandem DBD degradation and investigates the impact of adding H2 on the tandem DBD degradation of SF6 and its decomposition products. The results show that under conditions of 2% initial SF6 concentration, 1.5% H2, 150 mL/min gas flow rate, and 80W input power, the DRE in the first-stage tube is 73.2%, reaching 78.02% in the second-stage tube, and the DRE of SF6 in the dual-stage tandem reaches as high as 82.82%. In terms of decomposition products, there is no difference in the types of products formed in the two reaction tubes when H2 is added, and the main products are SO2F2, SO2, SOF2, and SOF4. The addition of H2 will inhibit the formation of S-O-F gas products, improves DRE and significantly regulates the distribution of degradation products, reducing the amount of SO2F2 generated in the second-stage tube and making SO2 the main product. Adding H2 with a concentration of 2.5 % can avoid the formation of SO2F2 in the second-stage tube. This study provides guidance for efficient SF6 degradation and product control.

The paper examines the convergence of tax systems in Central and Eastern European countries (CEECs) over the period 1995–2018. Due to the increasing impact of tax competition, we have focused on income taxes, in particular, corporate ones. We have identified the factors that influence the taxation system and trends in income taxation in the CEECs by adapting the hidden Markov model approach. We find that many CEECs have reduced income taxation in the analysis period, mainly by lowering tax rates. Corporate income taxes have also decreased in many CEECs in the same period; however, the reverse has been observed too. Both convergence and divergence have been identified among the CEECs over the period considered. The speed of these processes based on the used variables varied depending on both exogenous and endogenous factors. These factors have been diagnosed as being specific to the periods of tax reforms, i.e., before and after accession to the European Union (EU) and the global financial crisis.

Hydrogen (H2) is a clean energy carrier widely used in oil refineries, fertilizers, chemicals, and steel manufacturing. Presently, the majority of H2 is produced from either steam methane reforming of natural gas or coal gasification; however, these technologies result in a massive amount of CO2 emission. Alternatively, the use of photocatalysts for producing H2 via water splitting is an eco‐friendly and sustainable approach, among which the selection of highly efficient, stable, and cheap photocatalysts is the key. In this review, Znln2S4‐based photocatalysts are thoroughly described in terms of the fundamentals and thermodynamics of water splitting, fabrication methods, and different heterostructure photocatalytic systems. After this, recent developments in the large‐scale implementation of photocatalytic reactors are discussed. Finally, a summary of future research directions and major conclusions is provided. With proper modification, such as heterojunction systems and the selection of proper fabrication methods, Znln2S4‐based photocatalysts could be superior materials for water splitting. In short, this review article could offer meaningful and useful insights and guidance for the development of Znln2S4‐based photocatalysts in water splitting for producing H2 under visible light. [ABSTRACT FROM AUTHOR]

The research effort in the microcombustor field has recently increased due to the demand for high-performance systems in microelectromechanical and micro power generation devices. To address rising concerns about pollutants from fossil sources, zero-carbon fuels such as hydrogen (H2) and ammonia (NH3) have been considered as an alternative in microcombustion processes. In a microcombustor, the surface area-to-volume ratio is much higher compared to conventional combustion systems, resulting in faster heat transfer rates and more intense combustion reactions. However, achieving efficient mixing of fuel and an oxidizer in a microcombustor can be challenging due to its small size, particularly for highly reactive fuels like H2. For NH3, challenges in microcombustion involve a low reactive, high ignition temperature (923 K vs. 793 K of H2) and high concentration of NOx combustion products. Therefore, studying the performance of these fuels in microcombustors is important for developing clean energy technologies. In this paper, to explore features of non-premixed NH3/air and H2/air combustion in micro-scale combustors, an Ansys Fluent numerical investigation was conducted on a Y-shaped microcombustor. Results show that for combustion with H2, stationary flames can be achieved even at lower equivalence ratios. Additionally, the pollutants generated from H2 in the flame are generally twice those of NH3. The overall efficiency of the microcombustor is two times greater for NH3 conditions than for H2 conditions. [ABSTRACT FROM AUTHOR]

Here Pt loaded SnO 2 –Co 3 O 4 composite was fabricated using a hydrothermal method and was applied to gas sensing for the first time. The structure, morphology, surface and gas sensing property of the sensing composites were respectively studied by XRD, SEM, HRTEM (Mapping), BET, XPS and electrochemical workstation. The gas sensing results showed that the response value of 1%Pt loaded SnO 2 /5%Co 3 O 4 to hydrogen gas was 57.9, which was 9.6 times of pristine SnO 2. And the response time of 1%Pt-loaded SnO 2 /5%Co 3 O 4 to hydrogen was 12 s, which was much faster than that of pristine SnO 2. The material also exhibited other excellent sensing performance such as selectivity for detecting H 2 gas. Based on the experiments, the improved H 2 sensing properties was due to synergistic effect of the spillover effect of Pt element and the formation of p-n junction. This work will provide valid method to fabricate SnO 2 -based gas sensing materials for real application to detect target gas. • Pt loaded SnO 2 –Co 3 O 4 was fabricated and applied to gas sensor for the first time. • The response of 1%Pt loaded SnO 2 /5%Co 3 O 4 to 100 ppm H 2 reached 57.9. • The synergistic effect of Pt and Co elements are discussed. • The average size of 1%Pt loaded SnO 2 /5%Co 3 O 4 composite is only 6 nm. (Debye length). • The sensor has excellent sensing selectivity to H 2 against the tested interfering gases. [ABSTRACT FROM AUTHOR]

To maintain a global zero-emission policy and a high standard of living, new energy systems with higher system efficiency and net zero-emission productions need to be designed and deployed. This paper describes a novel integrated system between a direct-fired supercritical carbon dioxide (sCO2) power system with hydrogen and oxygen for zero-emission power generation and storage. sCO2 power cycles offer higher thermodynamic efficiencies than conventional gas-fired Brayton cycles. Heat is added to the system from the combustion of hydrogen and oxygen. The system consists of an electrolyzer unit and two cryogenic storage systems for hydrogen and oxygen. The proposed system is designed as a medium/long-term battery that can use excess electricity from the grid to produce hydrogen (electrolyzer) and supply to the grid (hydrogen combustion) in times of higher demand. Nitrous oxide emissions are mitigated by oxy-combustion and water separation from the post-combustion products allows for a closed-loop water cycle. The optimization of cycle parameters suggests a turbine inlet temperature of 1473 K and a pressure of 30 MPa for a specific net power output of 348 kJ/kg electrical. This results in an H2-sCO2 direct-fired power cycle efficiency of around 53 % with an overall system round-trip efficiency of up to 35 %.

Although widely used for energy production, fossil fuels pose a challenge in the fight against climate change. They are used in various sectors, with construction accounting for 40% of total energy demand.. To address this issue, the article looks at alternative technologies and fuels that can effectively reduce our dependence on fossil fuel-based energy, reduce our carbon footprint, and make existing buildings more self-sufficient. Hydrogen-powered fuel cells have the potential to completely transform energy production in buildings, generating energy on-site and reducing the carbon footprint of existing constructions. This article compares four commercial fuel cell options (SOFC and PEMFC) based on their technical, regulatory, and economic viability. Moreover, the selected equipments, suitable for domestic use and scalable, will be evaluated for their integration into an existing building to provide a proportion and knowledge of space. In conclusion, Equipment B (PEMFC) was chosen for installation after carefully considering the spatial and technical requirements that had to be met. The low maintenance costs of Equipment B played a crucial role, and the use of disruptive technology was in line with the case study strategy. Some parameters, such as space, ventilation, and temperature, are future fuel cell policy benchmarks. The comparison of PEMFC shows a developing competitive sector applicable to our building.

A collector-generator (C-G) cell used for the in-situ detection of H2 generated through electrochemical catalysis was described. The cell was mainly assembled with two fluorine-doped tin oxide (FTO) electrodes deposited with Pt nanoparticles, the magnitude of the current generated by the electrocatalytic oxidation of H2 at the collector was used for quantitative analysis of H2 generated at the generator. When the generator potential was set at −0.5 ∼ −0.6 V vs. Ag/AgCl and the collector potential at 0.4 ∼ 0.5 V vs. Ag/AgCl, the total Faradaic efficiency of the C-G cell could stabilize about 70%, the detection limit was about 45 μmol/L and the sensitivity was about 1 mA/55 μmol L−1. This dual working electrode technology could provide a convenient and rapid method for H2 determination and evaluate the performance of H2 generation catalysts that assembled on the semiconductor thin-films.

This study delved into the thermodynamic optimization of a geothermal system integrated with a fuel cell unit for energy storage during peak consumption. An innovative system was devised to simultaneously produce cooling, electricity, hydrogen, and freshwater by combining an absorption chiller, reverse osmosis, PEM Electrolyzer, and two double Organic Rankine Cycles. To assess the impact of local weather conditions, case studies were conducted in the cities of Hong Kong (China), Bandar Abbas (Iran), Tepic (Mexico), and Melbourne (Australia). Computational modeling employed EES software, and optimization using Response Surface Methodology aimed to enhance system performance and minimize costs. The geothermal system was engineered to meet the electricity demands of residential households during peak consumption. The optimal results demonstrated that the proposed geothermal system, in its most efficient configuration, could achieve an exergy efficiency of 73.17 % and an energy efficiency of 25.25 % while operating at a cost rate of 74.36 $/h. An economic analysis revealed that among the system components, ORC1 unit and PEME incurred the highest costs. Additionally, the PEME, evaporator, and absorption chiller were identified as the main contributors to exergy destruction. The total exergy destruction rate of the proposed geothermal system is 1840.7 kWh and the total cost rate of the system is 51.73 $/h. Lastly, the assessment of the suggested geothermal system across the studied cities indicated that it performed most effectively in Melbourne, Australia. The results of the study of the production capacity in the four study cities showed that Melbourne has the highest production rate with a rate of 14,573 MWh, Tepic with a rate of 13,425 MWh, and Hong Kong with a rate of 13,174 MWh. The lowest annual rate with the amount of 12,784 MWh belongs to the city of Bandar Abbas. The environmental results showed that by producing 14,573 megawatts of electricity in the city of Melbourne, it is possible to expand 14 hectares of green space per year. Also, prevented the reduction of carbon dioxide emissions by 2972.8 tonsCO2/MWh at 71,349.4 $/tonsCO2. The analysis of the production power of the system showed that the electricity needs of 1533 people can be provided for one year by starting the geothermal system in Melbourne City.

Lithium tantalate (LiTaO3) perovskite finds wide use in pyroelectric detectors, optical waveguides and piezoelectric transducers, stemming from its good mechanical and chemical stability and optical transparency. Herein, we present a method for synthesis of LiTaO3 nanoparticles using a scalable Flame Spray Pyrolysis (FSP) technology, that allows the formation of LiTaO3 nanomaterials in a single step. Raman, XRD and TEM studies allow for comprehension of the formation mechanism of the LiTaO3 nanophases, with particular emphasis on the penetration of Li atoms into the Ta-oxide lattice. We show that, control of the High-Temperature Particle Residence Time (HTPRT) in the FSP flame, is the key-parameter that allows successful penetration of the -otherwise amorphous- Li phase into the Ta2O5 nanophase. In this way, via control of the HTPRT in the FSP process, we synthesized a series of nanostructured LiTaO3 particles of varying phase composition from {amorphous Li/Ta2O5/LiTaO3} to {pure LiTaO3, 15–25 nm}. Finally, the photophysical activity of the FSP-made LiTaO3 was validated for photocatalytic H2 production from H2O. These data are discussed in conjunction with the role of the phase composition of the LiTaO3 nanoparticles. More generally, the present work allows a better understanding of the mechanism of ABO3 perovskite formation that requires the incorporation of two cations, A and B, into the nanolattice.

Research on ''green tax'' has seen significant development as societies prioritize addressing environmental degradation and climate change. This paper retrieved 20,685 SCOPUS documents, focusing on 1502 from 2015 to 2022. The study provides an overview of research, trends, and future directions. Researchers have explored green tax's effectiveness in reducing pollution, impact on economic growth, and potential to incentivize sustainable practices. Future directions may involve innovative tax design, analyzing distributional effects, assessing international cooperation, promoting clean technologies, and using green tax revenues for environmental initiatives. This evolving research offers valuable insights for policymakers striving for sustainable development.

[Display omitted] Hydrogen generation by photocatalysis is one of the most effective approaches to rationally utilize solar energy. In this work, we designed a biphasic photothermal-photocatalytic system. Spherical g-C 3 N 4 (HCN) was grown on the carbonized wood (CW) by a one-step hydrothermal method. The carbonization layer in carbonized wood/spherical g-C 3 N 4 (CW-HCN) system was able to further enhance the photothermal conversion of water steam production by improving the absorption of solar radiation. In addition, the temperature was increased due to photothermal effect, which was beneficial for H 2 evolution reaction. Moreover, the carbonized layer could act as a reservoir for photogenerated electrons on g-C 3 N 4 , which could accelerate the charge separation. Benefiting from all above-mentioned merits, the H 2 evolution rate of CW-HCN system under simulated sunlight reached 2700.18 μmol/m2/h, which was 42.23 times higher than that of pristine g-C 3 N 4 powder directly dispersed in water. In addition, the CW-HCN system exhibited broad applicability, maintaining the H 2 evolution activity of 2013.29 μmol/m2/h with seawater as water resource. This work provided a new strategy for highly efficient H 2 evolution. [ABSTRACT FROM AUTHOR]

The perspective of natural hydrogen as a clear, carbon-free, and renewable energy source appears very promising. There have been many studies reporting significant concentrations of natural hydrogen in different countries. However, natural hydrogen is being extracted to generate electricity only in Mali. This issue originates from the fact that global attention has not been dedicated yet to the progression and promotion of the natural hydrogen field. Therefore, being in the beginning stage, natural hydrogen science needs further investigation, especially in exploration techniques and exploitation technologies. The main incentive of this work is to analyze the latest advances and challenges pertinent to the natural hydrogen industry. The focus is on elaborating geological origins, ground exposure types, extraction techniques, previous detections of natural hydrogen, exploration methods, and underground hydrogen storage (UHS). Thus, the research strives to shed light on the current status of the natural hydrogen field, chiefly from the geoscience perspective. The data collated in this review can be used as a useful reference for the scientists, engineers, and policymakers involved in this emerging renewable energy source. [ABSTRACT FROM AUTHOR]

With the global sustainable development goals, it has become imperative for developing countries, especially sub-Saharan African countries, to think inward on ways to increase domestically mobilized revenue. The recovery of the global economy within the last few years has increased foreign assistance inflow into African countries. However, the direction of its impact on domestic mobilized revenue is unclear. This study revisited the relationship between foreign aid and domestic mobilized revenues for 32 sub-Saharan African countries using a more recent and novel dataset on tax revenue. We employed instrumental fixed effect Quantile regression, a novel technique in aid and tax revenue literature. The study's findings show that the impact of foreign aid varies across tax revenue distribution. We found a negative and significant effect in countries with high tax effort. While the effect is insignificant in countries with low tax effort, sub-Saharan African countries, especially those with low tax revenue, need to use foreign aid to strengthen their tax administration and adopt modern tax revenue collection technologies. As a result, sub-Saharan African countries should request advanced countries or donors to provide technical support in tax revenue mobilization. [ABSTRACT FROM AUTHOR]

Abstract In this work, we report that hydrogen (H2) doped in n-type a-Si:H thin films strongly influences the electronic correlation in increasing the conversion output power of solar cells. Type n a-Si:H thin films were grown using PECVD on ITO substrates with various H2-doping, to obtain various thin films for solar-cell applications. N-type a-Si:H thin films were prepared, and then characterized using ellipsometric spectroscopy, atomic force microscopy, Fourier transform infrared spectroscopy, and transmission electron microscopy. The addition of doped-H2 to the thin layer shows a decrease in optical conductivity, while the energy gap in the thin layer shows a significant increase in the a-Si:H-type thin layer. Our results show that H2 doping plays a very important role in the electronic structure, which is indicated by the significant energy gap difference. On the other hand, the bond structure of each H2-doped thin film showed a change from amorphous to nanocrystalline structures which were evenly distributed in each H2-doped bonding. Overall, we believe that the addition of doped-H2 to our findings could help increase the power conversion output of the solar cell due to the modification of the electronic structure.

The deactivation of active sites caused by high-temperature sintering and the deposition of a large amount of carbon are the main difficulties in the reforming of methane using Ni-based catalysts. La, as a promoter, has an ameliorating effect on the defects of Ni-based catalysts. In this article, the mechanism of action of Ni-based catalysts with the introduction of the rare-earth metal additive La was reviewed, and the effects of La on the methane-reforming performance of Ni-based catalysts were examined. The physical properties, alkalinity, and activity of Ni-based catalysts can be enhanced by the use of the auxiliary agent La, which promotes the conversion of CH4 and CO2 as well as the selectivity towards H2 and CO formation in the reforming of methane. The reason why the Ni-based catalysts could maintain long-term stability in the presence of La was discussed. Furthermore, the current state of research on the introduction of different amounts of La in the reforming of methane at home and abroad was analyzed. It was found that 2–5 wt.% La is the most optimal quantity for improving the catalyst activity and stability, as well as the CO2 chemisorption. The limitations and directions for future research in the reforming of methane were discussed.

Transition metal dichalcogenides (TMDs), particularly monolayer TMDs with direct bandgap properties, are key to advancing optoelectronic device technology. WSe2 stands out due to its adjustable carrier transport, making it a prime candidate for optoelectronic applications. This study explores monolayer WSe2 synthesis via H2-assisted CVD, focusing on how carrier gas flow rate affects WSe2 quality. A comprehensive characterization of monolayer WSe2 was conducted using OM (optical microscope), Raman spectroscopy, PL spectroscopy, AFM, SEM, XPS, HRTEM, and XRD. It was found that H2 incorporation and flow rate critically influence WSe2’s growth and structural integrity, with low flow rates favoring precursor concentration for product formation and high rates causing disintegration of existing structures. This research accentuates the significance of fine-tuning the carrier gas flow rate for optimizing monolayer WSe2 synthesis, offering insights for fabricating monolayer TMDs like WS2, MoSe2, and MoS2, and facilitating their broader integration into optoelectronic devices.

Copyright of Journal of Engineering (17264073) is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this work, we report that hydrogen (H2) doped in n-type a-Si:H thin films strongly influences the electronic correlation in increasing the conversion output power of solar cells. Type n a-Si:H thin films were grown using PECVD on ITO substrates with various H2-doping, to obtain various thin films for solar-cell applications. N-type a-Si:H thin films were prepared, and then characterized using ellipsometric spectroscopy, atomic force microscopy, Fourier transform infrared spectroscopy, and transmission electron microscopy. The addition of doped-H2 to the thin layer shows a decrease in optical conductivity, while the energy gap in the thin layer shows a significant increase in the a-Si:H-type thin layer. Our results show that H2 doping plays a very important role in the electronic structure, which is indicated by the significant energy gap difference. On the other hand, the bond structure of each H2-doped thin film showed a change from amorphous to nanocrystalline structures which were evenly distributed in each H2-doped bonding. Overall, we believe that the addition of doped-H2 to our findings could help increase the power conversion output of the solar cell due to the modification of the electronic structure. [ABSTRACT FROM AUTHOR]

The transformation from traditional iron- and steelmaking technologies to green H2-based new technologies will require an improvement in the quality and purity of iron ore burden materials. Iron ore pellets are essential inputs for producing direct reduced iron (DRI), but the conventional binders, used in iron ore pelletizing, introduce gangue oxides to the DRI and consequently increase the slag generation and energy consumption in the steelmaking unit. Partial and/or full replacement of the traditional binders with novel organic binders would significantly contribute to improving the process efficiency, particularly in the next-generation H2-based direct reduction technology. This study illustrates the feasibility of pelletizing magnetite iron ore concentrate using four organic binders: KemPel, Alcotac CS, Alcotac FE16, and CMC, in comparison to bentonite as a reference. The study explores the influence of binder type, binder dosage, and moisture content on the characteristics and properties of the pellets. The efficiency of binders was characterized by the moisture content, drop number test, cold compression strength, and H2 reduction of pellets. For dry pellets, CMS was superior among other binders including bentonite in developing dry strength. After firing, the pellets produced by the partial replacement of bentonite with 0.1 wt.% KemPel demonstrate a performance nearly identical to the reference pellets. While the complete replacement of bentonite with organic binder shows a lower performance of fired pellets compared to the reference, it may still be suitable for use in DR shaft furnaces. The cold-bonded pellets demonstrate a superior reduction rate compared to fired pellets. [ABSTRACT FROM AUTHOR]

Hydrogen (H2) is a renewable energy source that has the potential to reduce greenhouse gas emissions. However, H2 is also highly flammable and explosive, requiring sensitive and safe sensors for its detection. This work presents the synthesis and characterization of WO3/graphene binary and WO3/graphene/Pd (WG-Pd) ternary nanocomposites with varying graphene and Pd contents using the microwave-assisted hydrothermal method. The excellent catalytic efficacy of Pd nanoparticles facilitated the disintegration of hydrogen molecules into hydrogen atoms with heightened activity, consequently improving the gas-sensing properties of the material. Furthermore, the incorporation of graphene, possessing high conductivity, serves to augment the mobility of charge carriers within the ternary materials, thereby expediting the response/recovery rates of gas sensors. Both graphene and Pd nanoparticles, with work functions distinct from WO3, engender the formation of a heterojunction at the interface of these diverse materials. This enhances the efficacy of electron–hole pair separation and further amplifies the gas-sensing performance of the ternary materials. Consequently, the WG-Pd based sensors exhibited the best gas-sensing performance when compared to anther materials, such as a wide range of hydrogen concentrations (0.05–4 vol.%), a short response time and a good selectivity below 100 °C, even at room temperature. This result indicates that WG-Pd ternary materials are a promising room-temperature hydrogen-sensing materials for H2 detection. [ABSTRACT FROM AUTHOR]

Abstract Background Postoperative pain is a serious clinical problem with a poorly understood mechanism, and lacks effective treatment. Hydrogen (H2) can reduce neuroinflammation; therefore, we hypothesize that H2 may alleviate postoperative pain, and aimed to investigate the underlying mechanism. Methods Mice were used to establish a postoperative pain model using plantar incision surgery. Mechanical allodynia was measured using the von Frey test. Cell signaling was assayed using gelatin zymography, western blotting, immunohistochemistry, and immunofluorescence staining. Animals or BV-2 cells were received with/without ASK1 and Trx1 inhibitors to investigate the effects of H2 on microglia. Results Plantar incision surgery increased MMP-9 activity and ASK1 phosphorylation in the spinal cord of mice. MMP-9 knockout and the ASK1 inhibitor, NQDI-1, attenuated postoperative pain. H2 increased the expression of Trx1 in the spinal cord and in BV-2 cells. H2 treatment mimicked NQDI1 in decreasing the phosphorylation of ASK1, p38 and JNK. It also reduced MMP-9 activity, downregulated pro-IL-1β maturation and IBA-1 expression in the spinal cord of mice, and ameliorated postoperative pain. The protective effects of H2 were abolished by the Trx1 inhibitor, PX12. In vitro, in BV-2 cells, H2 also mimicked NQDI1 in inhibiting the phosphorylation of ASK1, p38, and JNK, and also reduced MMP-9 activity and decreased IBA-1 expression induced by LPS. The Trx1 inhibitor, PX12, abolished the protective effects of H2 in BV-2 cells. Conclusions For the first time, the results of our study confirm that H2 can be used as a therapeutic agent to alleviate postoperative pain through the Trx1/ASK1/MMP9 signaling pathway. MMP-9 and ASK1 may be the target molecules for relieving postoperative pain.

Sodium borohydride (SBH) hydrolysis in the presence of cheap and efficient catalysts has been proposed as a safe and efficient method for generating clean hydrogen energy for use in portable applications. In this work, we synthesized bimetallic NiPd nanoparticles (NPs) supported on poly(vinylidene fluoride-co-hexafluoropropylene) nanofibers (PVDF-HFP NFs) via the electrospinning approach and reported an in-situ reduction procedure of the NPs being prepared by alloying Ni and Pd with varying Pd percentages. The physicochemical characterization provided evidence for the development of a NiPd@PVDF-HFP NFs membrane. The bimetallic hybrid NF membranes exhibited higher H2 production as compared to Ni@PVDF-HFP and Pd@PVDF-HFP counterparts. This may be due to the synergistic effect of binary components. The bimetallic Ni1−xPdx(x = 0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3)@PVDF-HFP nanofiber membranes exhibit composition-dependent catalysis, in which Ni75Pd25@PVDF-HFP NF membranes demonstrate the best catalytic activity. The full H2 generation volumes (118 mL) were obtained at a temperature of 298 K and times 16, 22, 34 and 42 min for 250, 200, 150, and 100 mg dosages of Ni75Pd25@PVDF-HFP, respectively, in the presence of 1 mmol SBH. Hydrolysis utilizing Ni75Pd25@PVDF-HFP was shown to be first order with respect to Ni75Pd25@PVDF-HFP amount and zero order with respect to the [NaBH4] in a kinetics study. The reaction time of H2 production was reduced as the reaction temperature increased, with 118 mL of H2 being produced in 14, 20, 32 and 42 min at 328, 318, 308 and 298 K, respectively. The values of the three thermodynamic parameters, activation energy, enthalpy, and entropy, were determined toward being 31.43 kJ mol−1, 28.82 kJ mol−1, and 0.057 kJ mol−1 K−1, respectively. It is simple to separate and reuse the synthesized membrane, which facilitates their implementation in H2 energy systems. [ABSTRACT FROM AUTHOR]

This paper discusses using H2 and H∞ robust control approaches for designing control systems. These approaches are applied to elementary control system designs, and their respective implementation and pros and cons are introduced. The H∞ control synthesis mainly enforces closed-loop stability, covering some physical constraints and limitations. While noise rejection and disturbance attenuation are more naturally expressed in performance optimization, which can represent the H2 control synthesis problem. The paper also applies these two methodologies to multi-plant systems to study the stability and performance of the designed controllers. Simulation results show that the H2 controller tracks a desirable closed-loop performance, while the H∞ controller guarantees robust stability for the closed-loop system. The validation of the techniques is demonstrated through the robust and performance gamma index, where the H∞ controller achieved a robust gamma index of 0.8591, indicating good robustness and the H2 controller achieved a performance gamma index of 2.1972, indicating a desirable performance. The robust control toolbox of MATLAB is used for simulation purposes. Overall, the paper shows that selecting a suitable, robust control strategy is crucial for designing effective control systems, and the H2 and H∞ robust control approaches are viable options for achieving this goal.

Rice is one of the major food crops which is being most explored for continuous improvement to feed the growing population. In view of this, forty-three rice landraces and varieties from Tamil Nadu were subjected to variability and principal component analyses with fifteen quantitative traits and eight qualitative traits. For the variability parameters a higher PCV, GCV with high heritability and genetic advance was observed for all the traits. This indicated the presence of additive gene action and effective selection could be carried out for all traits in future breeding programs. Subsequently, from the principal component analysis five reliable PC’s with eigen values greater than one was attained. PC1 explained a total variability of 28.53% followed by PC2 which exhibited 16.99% of the variability. The major positive contributions towards the variability across PC’s were established by days to 50% flowering, plant height, flag leaf length, culm length, days to maturity, leaf width, panicle length, number of tillers, number of productive tillers, seedling height and grain width. Among all, Sornamasuri and JGL were found to be desirable for yield attributing traits from the PCA biplots and these genotypes could be evaluated for their similar performance in other breeding programs for utilization. Further among all qualitative traits, grain colour and leaf blade colour were observed to be variable among the landraces and they could be utilised as key morphological markers for identifying true to type varieties in future.

The research effort in the microcombustor field has recently increased due to the demand for high-performance systems in microelectromechanical and micro power generation devices. To address rising concerns about pollutants from fossil sources, zero-carbon fuels such as hydrogen (H2) and ammonia (NH3) have been considered as an alternative in microcombustion processes. In a microcombustor, the surface area-to-volume ratio is much higher compared to conventional combustion systems, resulting in faster heat transfer rates and more intense combustion reactions. However, achieving efficient mixing of fuel and an oxidizer in a microcombustor can be challenging due to its small size, particularly for highly reactive fuels like H2. For NH3, challenges in microcombustion involve a low reactive, high ignition temperature (923 K vs. 793 K of H2) and high concentration of NOx combustion products. Therefore, studying the performance of these fuels in microcombustors is important for developing clean energy technologies. In this paper, to explore features of non-premixed NH3/air and H2/air combustion in micro-scale combustors, an Ansys Fluent numerical investigation was conducted on a Y-shaped microcombustor. Results show that for combustion with H2, stationary flames can be achieved even at lower equivalence ratios. Additionally, the pollutants generated from H2 in the flame are generally twice those of NH3. The overall efficiency of the microcombustor is two times greater for NH3 conditions than for H2 conditions.

An appropriate pyrolysis temperature is required to achieve the best-quality oil and gas products via kerogen pyrolysis for the application of the in situ shale exploitation technology. In this study, the oil and gas products obtained at different pyrolysis temperatures via the oil shale pyrolysis process were analyzed using gas chromatography (GC). The results show that as the pyrolysis temperature increases, the content of hydrocarbon gases first increases and then decreases. Meanwhile, the H2 content in nonhydrocarbon gases gradually increases and reaches 64.07% at 550 °C. In addition, when the pyrolysis temperature is > 400 °C, the content of light components in shale oil rapidly increases. Further, when the pyrolysis temperature exceeds 500 °C, the content of light components in shale oil exceeds 42%. Finally, the H2 content obtained from oil shale pyrolysis by injecting water vapor is approximately eight times higher than that obtained from direct dry distillation. Additionally, the shale oil quality under water vapor action is better than that under direct dry distillation. The kerogen pyrolysis is performed in the H2-rich environment and shale oil is prone to hydrogenation reaction.