Search

The ever-growing carbon-based economy has led to alarming increases in greenhouse gas (GHG) emissions, particularly methane (CH4) and carbon dioxide (CO2). These emissions accelerate global warming, pollution and environmental challenges. Methane Dry Reforming (DRM) offers a promising technology to address this issue by converting CH4and CO2into a valuable syngas (CO + H2) mixture, which is a valuable fuel and a building block for many important chemical reactions (Fischer-Tropsch process). However, finding affordable and environmentally friendly catalysts for large-scale applications remains a critical hurdle. This study delves into the development of stable nickel-zirconia catalysts prepared via impregnation method. The weight percentage of nickel and zirconia was varied to optimize the catalyst's activity by controlling deactivation phenomenon that is a major challenge at higher temperatures during DRM. Various characterization techniques (XRD, FT-IR, SEM-EDX, TGA, TEM and BET) were employed to evaluate synthesized catalysts physio-chemical properties. Additionally, catalytic performance was assessed at temperatures ranging from 550 to 750 °C and a gas hourly space velocity (GHSV) of 72,000 mL/h.gcat. Among tested catalysts, 15% Ni/ZrO2displayed remarkable conversion values for both CH4(62.9%) and CO2(64.9%). Importantly, it exhibited significantly lower weight loss (ca. 15.42%) compared to other variants, indicating better resilience against coke deposition. This enhanced stability can be attributed to synergistic interplay between nickel and zirconia support, effectively suppressing carbon formation. These findings demonstrate potential of 15% Ni/ZrO2as a promising catalyst for experimental DRM application. With the obvious high activity and stability, 15% Ni/ZrO2candidate serves as an eco-friendly candidate for greenhouse gas conversion into green fuel energy, contributing to a sustainable economy and clean environment.

Early embryonic development arrest (EEDA) is a unique form of early spontaneous abortion in pregnant women, which is previously suggested to be associated with metabolic abnormalities. Noninvasive biomarkers would significantly improve its diagnosis and clinical outcome. Here, we performed a targeted metabolomics study in plasma from EEDA patients (n= 27) and normal pregnant women (NPW, n= 27) using liquid chromatography coupled with mass spectrometry (LC–MS) to identify potential diagnostic marker metabolites. Our results showed significantly different plasma metabolic profiles between EEDA patients and NPW. Particularly, EEDA patients showed significant alterations in amino acid, carbohydrate, and vitamin metabolism, which were characterized by 21 significantly increased metabolites and five decreased metabolites in plasma. Further receiver operating characteristic analysis showed that an optimal combination of S-methyl-5′-thioadenosine, kynurenine, leucine, and malate could be used as a panel of metabolites for EEDA diagnosis. The area under the curve of the metabolite panel was 0.941, suggesting a better performance than any single metabolite for the diagnosis of EEDA. In summary, our study identifies a panel of differential metabolites in plasma that could act as potential biomarkers for the diagnosis of EEDA in clinical settings.

•A delayed coker from a refinery in Egypt is revamped using Pinch Analysis.•Graphical representation of exchangers analyzes violations to Pinch principles.•Revamping study shows 11 % energy savings, 13 % cut in CO2and 3.4 MM$ profit.

•A novel coupled thermo-hydro-mechanical-chemical (THMC) model is developed using the finite volume method (FVM).•FVM and the extended finite volume method (XFVM) are integrated based on the embedded discrete fracture model (EDFM).•The influence of key parameters on heat production is revealed under THMC coupling conditions.

Metabolomics is a powerful and essential technology for profiling metabolic phenotypes and exploring metabolic reprogramming, which enables the identification of biomarkers and provides mechanistic insights into physiology and disease. However, its applications are still limited by the technical challenges particularly in its detection sensitivity for the analysis of biological samples with limited amount, necessitating the development of highly sensitive approaches. Here, we developed a highly sensitive liquid chromatography tandem mass spectrometry method based on a 3-nitrophenylhydrazine (3-NPH) derivatization strategy that simultaneously targets carbonyl, carboxyl, and phosphoryl groups for targeted metabolomic analysis (HSDccp-TM) in biological samples. By testing 130 endogenous metabolites including organic acids, amino acids, carbohydrates, nucleotides, carnitines, and vitamins, we showed that the derivatization strategy resulted in significantly improved detection sensitivity and chromatographic separation capability. Metabolic profiling of merely 60 oocytes and 5000 hematopoietic stem cells primarily isolated from mice demonstrated that this method enabled routine metabolomic analysis in trace amounts of biospecimens. Moreover, the derivatization strategy bypassed the tediousness of inferring the MS fragmentation patterns and simplified the complexity of monitoring ion pairs of metabolites, which greatly facilitated the metabolic flux analysis (MFA) for glycolysis, the tricarboxylic acid (TCA) cycle, and pentose phosphate pathway (PPP) in cell cultures. In summary, the novel 3-NPH derivatization-based method with high sensitivity, good chromatographic separation, and broad coverage showed great potential in promoting metabolomics and MFA, especially in trace amounts of biospecimens.

Following the rapidly increasing global demand for natural gas, many countries are launching projects to expand gas pipeline networks (GPNs). As a result, more cyclic GPNs are under construction with more rigorous physical constraints required, bringing new challenges to GPN optimization. This paper proposes a novel nonconvex mixed-integer nonlinear programming (MINLP) formulation for operational optimization of the cyclic GPN with simultaneous consideration of thermal hydraulics and flow direction reversibility, which has not been explored in the literature. To solve the proposed MINLP model, a three-level decomposition algorithm is proposed to generate an approximate solution, from which the flow direction is extracted and used to fix all discrete variables in the original MINLP model to construct two-stage NLP models. The NLP models are then solved to improve solution feasibility and quality. The computational results show that the proposed approach outweighs several state-of-the-art commercial MINLP solvers with better solutions and shorter computational time.

The specific interactions between protein and metabolites (PMIs) are closely related to many cellular processes and play a vital role in signal transduction and regulating material and energy metabolism. However, most of the available analytical strategies for PMIs involve chemical modification of metabolites or immobilization of protein, which has restricted current PMIs study mainly to lipid–protein and hydrophobic metabolites. In this work, a label-free online kinetic size exclusion chromatography-mass spectrometry (KSEC-MS) method combined with untargeted metabolomics was developed to define PMIs in a complex system. The metabolite mixture and target protein were injected into the SEC column sequentially without preincubation, and the separation results of KSEC were monitored by global metabolite profiling with mass spectrometry. The potential ligands in the metabolite mixture can be discovered if their migration patterns were affected by the target protein and the variation was positively correlated with the concentration of target protein. To verify this approach, carbonic anhydrase was first selected as a test protein, and acetazolamide as its known inhibitor was successfully defined. Furthermore, human serum albumin (HSA) as the common transport carrier of metabolites was selected as a target protein to demonstrate the usefulness of this approach. Multiple endogenous ligands of HSA were simultaneously defined from the extracted metabolites of human serum; most of them are polar metabolites rather than nonpolar lipids. This approach can provide a novel way for mapping and identifying unknown PMIs in a complex system, especially for polar metabolites–protein interactions.

AbstractPPARγ is an isoform of peroxisome proliferator-activated receptor (PPAR) belonging to a super family of nuclear receptors and is a primary target of the effective drug to treat the type II diabetes. The experiments found that Lyso-phosphatidylcholines (LPC) could bind to PPARγ, but the binding modes remain unknown. We used the Molecular Docking and Molecular Dynamic (MD) simulations to study the binding of four LPC ligands (LPC16:0, LPC18:0, LPC18:1-1 and LPC18:1-2) to PPARγ. The two-step MD simulations were employed to determine the final binding modes. The 20 ns MD simulations for four final LPC-PPARγ complexes were performed to analyze their structures, the binding key residues, and agonism activities. The results reveal that three LPC ligands (LPC16:0, LPC18:0 and LPC18:1-1) bind to Arm II and III regions of the Ligand Binding Domain (LBD) pocket, whereas they do not interact with Tyr473 of Helix 12 (H12). In contrast, LPC18:1-2 can form the hydrogen bonds with Tyr473 and bind into Arm I and II regions. Comparing with the paradigm systems of the full agonist (Rosiglitazone–PPARγ) and the partial agonist (MRL24–PPARγ), our results indicate that LPC16:0, LPC18:0 and LPC18:1-1 could be the potential partial agonists and LPC18:1-2 could be a full agonist. The in-depth analysis of the residue fluctuations and structure alignment confirm the present prediction of the LPC agonism activities.Communicated by Ramaswamy H. Sarma

Integrating marine renewable energy (MRE) with conventional energy sources and logically constructing island energy systems is crucial for alleviating island energy supply challenges and helping coastal energy systems achieve a sustainable, low-carbon transition. In this study, the status of marine energy utilisation technologies is reviewed, with a focus on advancements in energy conversion equipment, grid integration, and energy storage. The economic feasibility and environmental sustainability of marine energy systems are comparatively analysed to enhance the development and utilisation of marine energy technology while reducing the economic cost of power generation. Suitable equipment is highlighted for islands, with efficient energy generation strategies proposed to achieve cleaner, localised, and cost-effective island integrated energy system (IIES) design. Island energy facilities vary, and integrated development is crucial for building new energy systems. Based on the types and resources of island energy, IIESs are constructed for hierarchical energy utilisation and multi-energy coupling, coordinating resources to achieve source–grid–load–storage integration. The optimisation of IIESs is reviewed, with a focus on modelling methods, intelligent algorithm development, and system simulation. This study differs from previous research as it considers the integration of marine energy into existing systems to achieve comprehensive integration of multiple energy sources. Additionally, optimisation and solution methods for IIES models are summarised. To integrate complex, multivariable energy systems and create stable and predictable outputs, marine energy and load forecasting methods are explored. Overall, this study supports the advancement of marine energy utilisation, focusing on its progressive integration into island energy systems as the efficiency of marine energy improves. This work aims to inspire the development of new functions and modules based on existing system optimisation and forecasting techniques.

•Provide significant insights into flow patterns and bubble behaviors under microgravity.•Reveal the heat transfer mechanisms of flow boiling under microgravity.•Illustrate the effect of microgravity diminishes under high heat flux.•The influence of microgravity can be neglected when exceeding a critical velocity.

•Particle deposition is studied using dynamic mesh and double deposition methods.•Film cooling and deposition thickness are compared at different inclination angles.•The optimum blowing ratio is 1.0 for the leading edge under 60° inclination angle.•Film cooling for 60° inclination reduces by 6.28 % at blowing ratio from 1.0 to 2.0.•Leading edge for 60° inclination has the least deposition at blowing ratio of 2.0.

•The published papers in Special Issue PIT are reviewed.•The conference series PRES is described.•The statistical data of the conference PRES-2022 are presented.•Integration and intensification of thermal processes in papers of SI are described.

•Temperature Zone Diagram Method (TZDM) is developed to give specific heat transfer process.•Mathematical programming model is established to solve TZDM for obtaining better heat transfer results.•Energy optimization model of the entire natural gas purification plant is established based on temperature zone division diagram.•TZDM has good adaptability and can accurately give heat transfer position and heat transfer flux, and has great advantages in energy optimization of chemical plants with complex heat transfer networks.

•A HOPLIRE method is proposed for reconstructing the two-phase interface.•HOPLIRE method has the advantage of the implementation procedure simplicity.•HOPLIRE method has high accuracy in reconstructing the two-phase interface.

This is the first Virtual Special Issue (VSI) of Cleaner Energy Systems. It contains research articles originating from some of the papers presented at the 16th Conference on Sustainable Development of Energy, Water and Environmental Systems (SDEWES), which was held both onsite and online in Dubrovnik, Croatia, from 10 to 15 October 2021, related to the scope of Cleaner Energy Systems. The main target of this VSI, which is in line with the conference goals, is to cover topics that focus on preventing the generation of waste while increasing efficiencies in the use of energy, water, resources, and human capital. The articles in this VSI present extended developments as follow-ups from the conference papers. The treated topics are central to making energy systems cleaner – heat transfer and heat exchanger efficiency, Heat Integration and District Heating, policies for promoting the use of renewable energy, and energy efficiency of buildings.

•An extension of the Heat Integration to achieve energy saving for a process.•A method for retrofitting an existing natural gas purification process.•Heat exchanger networks and tower operating variables are optimised for energy.•A two-stage method integrated the PSO and an SRTGD-based model solving algorithm.•A case study is given to demonstrate the developed method.