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In this study, we explore a novel approach to nitrogen oxide (NOx) purification based on the principles of the chemical looping (CL) platform. This technique harnesses the reducing power of natural gas (CH4), instead of ammonia, to eliminate NOxin the flue gas, addressing environmental concerns such as ammonia slip in the state-of-the-art selective catalytic reduction process. The CL scheme involves utilizing nickel oxide (NiO) as the solid oxygen carrier to facilitate oxygen transfer from NOxto CH4in two steps. In the first step (carrier oxidation), NOxin the flue gas reacts with reduced nickel (Ni), transferring its [O] to the carrier, thereby forming NiO. In the subsequent step (carrier reduction), CH4reacts with the lattice oxygen of the oxidized carrier, generating a pure stream of CO2and reducing NiO to Ni. We designed a high-performance carrier by dispersing NiO on an inert support to enhance the carrier’s kinetics and thermal stability. We evaluated various support materials, and among them, alumina (Al2O3) and zirconia (ZrO2) demonstrated significantly superior reactivity. Notably, the Al2O3-supported carrier outperformed the ZrO2-supported carrier in NO purification and CH4reduction and demonstrated stable performance over 10 redox cycles. Furthermore, fixed-bed experiments revealed 100% NO conversion during carrier oxidation, with optimal reaction kinetics achieved at lower space velocities, resulting in an overall high carrier utilization. Importantly, CO2showcased no adverse effects during the NOxpurification step. During the carrier reduction, complete combustion was favored, leading to CH4conversion exceeding 95% and a CO2selectivity of 90% at 400 °C. The CL NOxpurification approach represents a promising strategy for mitigating NOxemissions.

Determining the source and history of hydrothermal fluids are key to better understanding the genesis of lode gold deposits. However, it is difficult to rigorously constrain the fluid history because the fluids typically have a prolonged and complicated history that may obscure the original source signature. We integrate textural characterization, trace element geochemistry, and in situ oxygen isotope analyses of quartz covering three major paragenetic stages of the world-class Dongping lode gold deposit to fingerprint the ore-fluid source and document the deposit’s complex hydrothermal history. Six quartz generations were identified from three paragenetic stages. They consistently display small to large ranges in δ18O values from 13.1 to 0.6‰ (VSMOW), which correspond to calculated δ18O values of 7.4 to –6.0‰ for the quartz-forming fluids. These isotope data are intermediate between the δ18O ranges of magmatic fluids and meteoric water and thus are best interpreted in terms of episodic fluxes of magmatically derived fluids and their subsequent mixing with variable proportions of external meteoric water. Our results highlight the important role of magmatic hydrothermal fluids and their mixing with meteoric water to form the giant Dongping gold deposit. Given the high abundance of quartz that typically spans the entire mineralization process of lode gold deposits, we envisage the versatility and reliability of in situ oxygen isotope analysis of well-characterized quartz in deciphering the origin and complex evolution history of gold-forming fluids.

With increasing environmental concerns because of greenhouse gas (GHG) emissions from conventional sources of energy, a tremendous shift in momentum is observed toward clean combustion sources and carbon-neutral feedstocks. Hydrogen (H2) as a fuel negates carbon emissions during energy generation and hence is gaining attention as a valuable source of energy. The existing processes for producing H2use non-renewable fossil fuels as feedstock. Biogas derived from the decomposition of waste organic matter is a renewable and carbon-neutral feedstock that can be utilized for fossil-free H2generation. In this study, a novel 2-reactor chemical looping water-splitting process (CLWS-2R) is introduced, simulated, and analyzed for the production of H2from biogas. Process simulations are carried out for the CLWS-2R system to achieve optimized process parameters for the desired system operating conditions. The process evaluation parameters of this scheme are compared with three established processes for H2production from biogas, including the 3-reactor chemical looping water-splitting (CLWS-3R), the steam reforming (SR), and the mixed reforming (MR) process. The simulation results from this study indicate that for a biogas feedstock composition of 25% CO2by volume, the CLWS-2R system can achieve the highest cold gas efficiency (CGE: 75%) and the highest effective thermal efficiency (ETE: 71%). The sensitivity analysis on biogas composition indicates that CLWS-2R achieves its highest ETE for biogas with a low CO2content (25–30 vol %), which is almost equivalent to the ETE obtained using MR. For all the remaining biogas compositions with high CO2content, MR achieves the highest ETE.

Coal is an essential primary energy source in modern industry. An important pathway of coal utilization is to gasify coal into syngas, which is then used for downstream production of numerous chemicals such as methanol and liquid fuels. Despite its wide applications, conventional coal gasification still faces challenges such as the use of a costly air separation unit and limited syngas H2/CO ratio. Chemical looping gasification technology is a promising alternative to replace conventional coal gasification with increased thermal efficiency and higher level of process intensification. This study presents the process analysis of chemical looping coal gasification and its integration with downstream production of dimethyl ether (DME) to reveal the advantages of the chemical looping scheme compared to conventional gasification schemes. This study discusses the simulation strategies to maintain adiabatic operation in the chemical looping system. The operating parameters of the chemical looping system are adjusted to achieve the maximum cold gas efficiency in one case study, while the operating parameters of the chemical looping system are adjusted to achieve the maximum effective thermal efficiency in another case study. These two chemical looping cases involve the integration of the chemical looping system with the DME synthesis in a process that considers overall process material and heat flows and power consumption and generation. An exergy analysis is also conducted for these two integrated chemical looping cases, revealing that they both can achieve around 10% increase in exergy efficiency over the conventional gasification system.

Climate change poses unprecedented challenges, demanding efforts toward innovative solutions. Amid these efforts, chemical looping stands out as a promising strategy, attracting attention for its CO2capture prowess and versatile applications. The chemical looping approach involves fragmenting a single reaction, often a redox reaction, into multiple subreactions facilitated by a carrier, frequently a metal oxide. This innovative method enables diverse chemical transformations while inherently segregating products, enhancing process flexibility, and fostering autothermal properties. An intriguing facet of this novel technique lies in its capacity for CO2utilization in processes like dry reforming and gasification of carbon-based feeds such as natural gas and biomass. Central to the success of chemical looping technology is a profound understanding of the intricacies of redox chemistry within these processes. Notably, nanoscaled oxygen carriers have proven effective, characterized by their extensive surface area and customizable structure. These carriers hold substantial promise, enabling reactions under milder conditions.

The effect of calcium silicate hydrate (C-S-H) on chloride (Cl−) binding and steel corrosion in simulated concrete pore solution (SCPS) was evaluated. The results showed that Cl−absorbed by C-S-H conformed to Freundlich isotherm for 0.1–1.0 M of Cl−. When C-S-H reached equilibrium in saturated Ca(OH)2solution, its degree of polymerization increased. The high pH is unfavorable for the absorption of Cl−by C-S-H, but favorable for the passivation of steel. The synthetic C-S-H powder contains NO3−, which prolongs the passivation time of steel, but the presence of silicate is favorable for the formation of a passivation film with good corrosion resistance. The addition of C-S-H promoted the chloride threshold value of steel corrosion and delayed the corrosion development process.

• The C-BiOCl/Bi 2 S 3 (C-BOC/BS) composites are successfully prepared. • C-BOC/BS show good photoelectrochemical (PEC) and photocatalytic (PC) properties. • The optimized 5C-BOC/5BS composite is used as a PEC sensor for Cr(VI) detection. • Efficient Cr(VI) removal is achieved via adsorption and PC reduction by 5C-BOC/5BS. Novel C-BiOCl/Bi 2 S 3 composites are prepared by hydrothermal C doping in BiOCl and in-situ growth of Bi 2 S 3 on C-BiOCl. Compared with BiOCl, C-BiOCl has a larger exposed surface area and can effectively absorb visible light. The construction of a heterojunction in C-BiOCl/Bi 2 S 3 further promotes the separation and transfer of photogenerated carriers. With improved photoelectric properties, the optimized 5C-BiOCl/5Bi 2 S 3 is applied as a dual-functional composite for photoelectrochemical (PEC) detection and photocatalytic (PC) reduction of Cr(VI). The 5C-BiOCl/5Bi 2 S 3 shows a linear range of 0.02–80 μM for PEC cathodic detection of Cr(VI) with a detection limit of 0.01628 μM. Additionally, 99.5% of Cr(VI) can be removed via absorption and PC reduction by 5C-BiOCl/5Bi 2 S 3 , with the reduction rate constant (k) 336 times higher than that of BiOCl. [ABSTRACT FROM AUTHOR]

The rising chemical demand and its associated concern of climate change have put an impetus on converting diverse domestic sources to valuable products in a decarbonized manner. Lignocellulosic biomass, a viable feedstock, is garnering significant attention as a sustainable alternative to fossil fuels. However, challenges in handling biomass feed variability and effectively processing its char and tar contents have hampered its commercial deployment. However, the chemical looping-based biomass-to-syngas (BTS) technology being developed by The Ohio State University is among the most promising technologies for industrial biomass reforming. It utilizes proprietary iron oxide particles in a cocurrent moving-bed reactor, leveraging the flow dynamics to transform biomass to syngas, and has been proven to be more efficient than conventional processes. However, this cocurrent system suffers from a thermodynamic barrier, inhibiting the syngas yield. To overcome this barrier, a novel chemical looping cross-current system is developed and investigated through detailed thermodynamic ASPEN studies after accounting for practical constraints. The barrier in the cocurrent system can be attributed to the equilibrium between exiting syngas and solid streams, which limits the oxidation of oxygen carriers. The cross-current reactor system overcomes this issue by shifting the exit of the syngas stream to the middle of the reactor, thus not allowing the exiting syngas and solid streams to be in equilibrium and creating a cocurrent section above the syngas exit and a countercurrent section below it. Thermodynamic simulations conducted under autothermal conditions reveal that the cocurrent and cross-current systems perform similarly with steam and CO2co-injection. However, under an isothermal condition, which is now feasible with cheaper and sustainable heating methods, the cross-current system achieves ∼34% higher syngas yield over the cocurrent system (∼0.074 in cross-current compared to ∼0.055 in cocurrent) for both steam and CO2co-injection. The findings from this study justify the scale-up of the cross-current system and provide system-level insights into biomass valorization.

To accelerate the performance estimation in neural architecture search, recently proposed algorithms adopt surrogate models to predict the performance of neural architectures instead of training the network from scratch. However, it is time-consuming to collect sufficient labeled architectures for surrogate model training. To enhance the capability of surrogate models using a small amount of training data, we propose a surrogate-assisted evolutionary algorithm with network embedding for neural architecture search (SAENAS-NE). Here, an unsupervised learning method is used to generate meaningful representation of each architecture and the architectures with more similar structures are closer in the embedding space, which considerably benefits the training of surrogate models. In addition, a new environmental selection based on a reference population is designed to keep diversity of the population in each generation and an infill criterion for handling the trade-off between convergence and model uncertainty is proposed for re-evaluation. Experimental results on three different NASBench and DARTS search space illustrate that network embedding makes the surrogate model achieve comparable or superior performance. The superiority of our proposed method SAENAS-NE over other state-of-the-art neural architecture algorithm has been verified in the experiments.

We present a novel low-temperature chemical looping combustion scheme for simultaneous natural gas conversion into a sequestration-ready CO2stream and NOxpurification. The scheme employs nickel oxide (NiO) supported on ZrO2as the oxygen carrier. In the process, CH4reduces the oxidized carrier to Ni/ZrO2in a co-current moving bed reactor, which is then oxidized back to NiO/ZrO2by the NOx-laden flue gas in a fluidized bed reactor, completing the oxygen carrier loop. Thermodynamic studies demonstrate that the presence of CO2does not significantly affect NOxpurification performance at different flue gas flow rates. The operating temperatures of the reactors are selected based on NOx-temperature programmed oxidation (TPO) and CH4-temperature programmed reduction (TPR) experiments. Results show that the process can optimally operate at temperatures close to the combustion plants’ flue gas temperature of 400–500 °C, reducing the need for hot utilities. The study conducts comprehensive isothermal and autothermal analyses of the process to evaluate the effects of temperature and carrier flow rate on CH4conversion, CO2selectivity, carbon deposition, and NOxconversion. For the autothermal analysis, the CH4reactor operates adiabatically, while the NOxreactor operates isothermally. Comparative studies with the conventional NOxselective catalytic reduction (SCR) process indicate an exergy efficiency and effective thermal efficiency (ETE) improvement of 9 and 18 percentage points, respectively. The findings suggest that this low-temperature chemical looping process is a promising solution for flue gas NOxtreatment, utilizing cheaper natural gas as the reductant and eliminating environmental concerns, such as ammonia or urea slippage. Overall, this study contributes to the development of more efficient and sustainable methods for reducing NOxemissions.

The powder thermal diffusion alloying method is an important method to fabricate intermetallic coatings on magnesium alloy substrates. The diffusion source, the diffusion time and the diffusion temperature are key parameters for a diffusion alloying process. While the effective time of an active diffusion source at the diffusion temperature is still unclear. Clarification of the effective time of a diffusion source is important, as the diffusion source could be utilized effectively and economically only if the effective time of the active diffusion source is known. Here, the effective time of a diffusion source at 400 °C was investigated. Results show that, the effective time of the diffusion source which contains 10 g ZnO and 1 g NH4Cl is around 150 h at 400 °C. For a more compact diffusion source, the effective time is relatively shorter. Then, chemical reactions in the diffusion source at elevated temperature were analyzed. The failure of the diffusion source is related to the reduction in the number of active metal ions, while an ineffective diffusion source can be reactivated by addition of new halide powder. These results could deepen the understanding of the role of the diffusion source in a powder thermal diffusion alloying process and indicate a limit under which the diffusion source could be utilized effectively.

H9N2 avian influenza virus (AIV) has widely circulated in poultry worldwide and sporadic infections in humans and mammals. During our surveillance of chicken from 2019 to 2021 in Shandong Province, China, we isolated 11 H9N2 AIVs. Phylogenetic analyses showed that the eight gene segments of the 11 isolates were closely related to several sublineages of Eurasian lineage: BJ/94-like clades (HA and NA genes), G1-like clades (PB2 and M genes), and SH/F/98-like clades (PB1, PA, NP and NS genes). The isolates showed mutation sites that preferentially bind to human-like receptors (HA) and mammalian fitness sites (PB2, PB1 and PA), as well as mutations in antigen and drug resistance sites. Moreover, studies with mice revealed four isolates with varying levels of pathogenicity. The average antibody titer of the H9N2 AIVs was 8.60 log2. Based on our results, the epidemiological surveillance of H9N2 AIVs should be strengthened.

Oxymethylene ethers (OMEs) have been studied as possible additives or replacements for diesel fuels. Typically, studies have considered only methyl-terminated OMEs. Recent structure–property relationship models suggest that extended-alkyl OMEs may provide improvements to many of the properties of methyl-terminated OMEs that make them less suitable as diesel fuel blendstocks. In this work, we describe the synthesis and characterization of 16 different OMEs with methyl-, ethyl-, propyl-, butyl-, isopropyl-, and isobutyl-terminating alkyl groups with varying oxymethylene chain lengths. Indicated cetane number, lower heating value, flash point, density, viscosity, vapor pressure, and oxidative stability are tested via ASTM standard methods. Additionally, water solubility, boiling point, seal material compatibility, and sooting propensity (via the yield sooting index) are measured for these fuels. For diesel compatibility, all tested OMEs except smaller methyl and ethyl OMEs and the branched isopropyl OME meet cetane number requirements. Extending the alkyl end group increases the heating value, but all OMEs, due to their oxygen content, have heating values less than diesel. Despite this, all OMEs show significant reductions in soot production per unit heating value. Only the heaviest OMEs meet diesel viscosity requirements, and most are higher density than diesel. OMEs with larger alkyl groups show the highest stability under accelerated auto-oxidation conditions. Increases in alkyl group length cause order of magnitude reduction in water solubility, from hundreds of g/L for methyl terminated OMEs to hundreds of mg/L for butyl terminated OMEs. Limited seal material testing indicates that PEEK polymers are unaffected by OMEs, and while extended alkyl groups may improve compatibility with FKM (Viton), other common elastomers (NBR, silicone) remain incompatible with all tested OMEs. Overall, it is found that methyl-terminated OMEs exhibit the most potential for soot reduction, but OMEs with larger propyl- and butyl-terminating alkyl groups show improved compatibility with existing diesel systems.

The climate models of the Intergovernmental Panel on Climate Change list black carbon (BC) as an important contributor to global warming based on its radiative forcing (RF) impact. Examining closely these models, it becomes apparent that they might underpredict significantly the direct RFfor BC, largely due to their assumed spherical BC morphology. Specifically, the light absorption and direct RFof BC agglomerates are enhanced by light scattering between their constituent primary particles as determined by the Rayleigh–Debye–Gans theory interfaced with discrete dipole approximation and recent relations for the refractive index and lensing effect. The light absorption of BC is enhanced by about 20% by the multiple light scattering between BC primary particles regardless of the compactness of their agglomerates. The resulting light absorption agrees very well with the observed absorption aerosol optical depth of BC. ECHAM-HAM simulations accounting for the realistic BC morphology and its coatings reveal high direct RF= 3–5 W/m2in East, South Asia, sub-Sahara, western Africa, and the Arabian peninsula. These results are in agreement with satellite and AERONET observations of RFand indicate a regional climate warming contribution by 0.75–1.25 °C, solely due to BC emissions.

Oxymethylene dimethyl ethers (OMEn) produced over novel Ru supported hierarchical zeolite beta catalyst can be utilized as a fuel in a conceptual circular carbon cycle using Direct Air Capture and green hydrogen as the feedstock.

ABSTRACTThe presence of cervical lymph node metastases has been considered as the most important adverse prognostic factor for patients with laryngeal squamous cell carcinoma (LSCC). However, the underlying mechanisms remain to be fully revealed. In this study, we explored the expression profile of Foxhead box D1(FOXD1), its association with epithelial-to-mesenchymal transition (EMT), and its downstream targets in LSCC. Bioinformatic analysis was performed based on the LSCC subset of The Cancer Genome Atlas-Head and Neck Squamous Cell Carcinoma (TCGA-HSNC) and Chromatin immunoprecipitation (ChIP)-seq data from Cistrome Data Browser. LSCC cell lines AMC-HN-8 and TU212 were used for in vitrostudies. Results showed that FOXD1upregulation was associated with poor prognosis of LSCC. FOXD1knockdown reduced N-cadherin and Vimentin expression but increased E-cadherin expression in AMC-HN-8 cells. Its overexpression showed opposite effects in TU212 cells. FOXD1 could bind to the promoter of ZNF532and activate its transcription. ZNF532overexpression enhanced the invasion of both AMC-HN-8 and TU212 cells. In comparison, its knockdown significantly impaired their invasion. ZNF532knockdown nearly abrogated the alterations of EMT markers caused by FOXD1overexpression. Its overexpression largely rescued the phenotypes caused by FOXD1knockdown. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that ZNF532correlated genes are largely enriched in extracellular matrix regulations. LSCC patients with high ZNF532expression (top 50%) had a significantly worse progression-free survival. In summary, this study confirmed that FOXD1 promotes partial-EMT of LSCC cells via transcriptionally activating the expression of ZNF532.

ABSTRACTIncreasing evidence suggests that dysregulated miRNA expression can lead to the tumorigenesis of osteosarcoma (OS). Nevertheless, the potential role of miR-23b-3p in OS is unclear and remains to be explored. Microarray analysis was performed to identify key genes involved in OS. Reverse transcription quantitative polymerase chain reaction and Western blotting were used to examine miR-23b-3p expression, ventricular zone expressed PH domain-containing 1 (VEPH1) transcript (as well as other transcripts as indicated), and phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway-related protein expression. A luciferase reporter gene assay was performed to confirm the regulatory relationship between VEPH1 mRNA and miR-23b-3p. Cell viability was evaluated using the Cell Counting Kit-8 assay, cell growth was assessed using the bromodeoxyuridine enzyme-linked immunosorbent assay, and cell migration was tested using a wound healing assay. We found significant upregulation of miR-23b-3p in OS, which prominently promoted the viability, proliferation, and migration of OS cells. Additionally, VEPH1 was found to be a target of miR-23b-3p and its expression was decreased in OS. Lastly, VEPH1 alleviated the promotion effect of miR-23b-3p on the malignancy phenotypes of OS cells via the PI3K/AKT signaling pathway. Thus, miR-23b-3p augmented the viability, proliferation, and migration of OS cells by directly targeting and downregulating VEPH1, which inhibited the activation of the PI3K/AKT signaling pathway.

A novel process scheme for energy production from coal with in situsulfur capture, known as the coal-direct chemical looping process with sulfur removal (CDCL-SR), is proposed in this study. The proposed process utilizes multimetal oxide comprising the oxides of copper and calcium supported on inert SiC as the oxygen carrier to combust coal and simultaneously produce separate streams of CO2and SO2, thus eliminating the need for downstream processing units. The computational software ASPEN Plus has been utilized to carry out detailed reactor simulations along with a thorough thermodynamic analysis of the process. The reactor modeling results indicate that the moving bed reducer can effectively convert all the carbon present in coal into CO2while capturing sulfur in the form of calcium sulfide in the reduced oxygen carrier. The reduced oxygen carrier can in turn be oxidized using steam to produce pure SO2stream that can be readily utilized. Process simulation results indicate that the proposed CDCL-SR process has thermal and exergy efficiencies of 86 and 51%, respectively, significantly higher than both the conventional pulverized coal Rankine cycle and Fe-based CDCL processes.

Geopolymers can effectively deal with construction waste disposal problems, achieving resource recycling and higher strength than normal cement concrete. However, natural defects make geopolymer concrete difficult to apply in actual construction. This paper aims to make up for the natural defects of geopolymers while maintaining environmentally friendly materials. The low-calcium fly ash and blast furnace refining slag powder are used as raw materials, sodium silicate and sodium hydroxide are used as alkali activators, and chopped natural fibers are added as reinforcing materials to prepare natural fiber reinforced low-calcium fly ash and blast furnace refining slag base. Polymeric composites were used to investigate the effects of different natural fibers on the workability, compressive strength, tensile strength, water absorption, shrinkage and microstructure of geopolymer composites.

This document takes saline soil in Binzhou as the research object using smelter slag as the soil stabilizer to solid saline soil in Binzhou, which has been proved achieving good performance of saline soil solidification. The results show that the soil solidification developed indoors can be used in combination with low-dose lime to achieve good performance in solidification of saline soil. The 7d strength is relatively higher than that of both ordinary lime stabilized soil and lime-fly ash stabilized soil, which completely meet the unconfined compressive strength requirements of the base layer in the current technical specifications. The soil stabilizer can improve the unconfined compressive strength of the saline soil, especially the post-14-day strength, and improve the immersion compressive strength and water stability of the cured saline soil. As the dosage of curing agent gets higher than seven percent, the 28d strength change of cured soil is no longer significant. The test result demonstrates that the dosage of curing agent should be less than seven percent.

BMPR2encodes the bone morphogenetic protein receptor type 2. Most of heritable pulmonary arterial hypertension is caused by mutations of BMPR2.Pulmonary arterial hypertension is characterized by increased pulmonary vascular resistance and sustained elevation of mean pulmonary arterial pressure. Here we sought to identify novel mutations in a family with pulmonary arterial hypertension. Whole-exome sequencing obtained variants data from the patient's blood Genomic DNA who was diagnosed with pulmonary arterial hypertension. Sanger sequencing was used to confirm potential causative variants in the patient. A novel frame-shift mutation in BMPR2(NM_001204:c.453dupA, p.I152Nfs*29) was identified in the patient with pulmonary arterial hypertension, she also had subclinical hypothyroidism and hyperuricemia. This frame-shift mutation will cause the BMPR2 protein loss of function, leading to the obstruction of BMPs signaling pathway, further affect the growth, proliferation and differentiation of vascular cells. Our study expands the spectrum of BMPR2mutations and enriches the clinical features.

Multiple osteochondromas (MO) is an autosomal dominant hereditary disorder, which typically manifests as skeletal dysplasia, mainly involving long bones and knees, ankles, elbows, wrists, shoulders, and pelvis. Previous studies have demonstrated that mutations in exostosin glycosyl transferase-1 (EXT1) and exostosin glycosyl transferase-2 (EXT2) were the main cause of MO. In this study, we enrolled 2 families with MO. Sanger sequencing revealed 2 novel frameshift mutations – c.1432_1433insCCCCCCT; p.Lys479Profs*44 and c.1431_1431delC; p.S478PfsX10 – in the EXT1gene detected in 2 families, respectively. Both novel mutations, located in the conserved domain of EXT1 and predicted to be disease causing by informatics programs, were absent in our 200 control cohorts and other public databases. Our study expanded the spectrum of EXT1mutations and contributed to genetic diagnosis and counseling of patients with MO.

The transformation of CO2to chemicals and fuels offers a means of CO2utilization while mitigating the global carbon footprint. An attractive strategy involves the CO2reforming of methane with oxygen carriers. In this strategy, methane is used as the reducing agent to provide hydrogen for CO2reduction. This study aims to investigate the reactivity of the ilmenite-based oxygen carrier undergoing a redox reaction for CO2reduction coupled with methane reforming and the underlying mechanism using combined experimental study and density functional theory calculations. The enhanced activity for the methane conversion and CO2reduction with FeTiO3was revealed under the CH4/CO2ratio of >8.75 with CO2conversion of >95%. The mechanistic probe indicated that the oxygen vacancies and hydrogen atoms from the successive dissociation of CH4are crucial for CO2activation and reduction. In the dominant formate pathway, the CO2molecule is hydrogenated to the HCOO* intermediate species and then decomposes to CO via the C–O and C–H cleavage at the oxygen vacancy site with a low barrier of 62.5 kJ/mol. These results shed light on the fundamental understanding of hydrogen-assisted CO2reduction over ilmenite-based oxygen carries and open up future research on potential strategies to improve CO2utilization for redox reactions.

The global market size for acetic acid is expected to increase at a high compounded annual growth rate over the next few years due to an increased demand from the end-users such as the automobile, furniture, and construction industries. One of the key factors driving the acetic acid production is methanol formation, which in turn depends on syngas generation. The process simulation and reactor modeling study presented here explores the use of a novel petcoke-to-syngas process for acetic acid production where the petcoke is subjected to chemical looping gasification (CLG) using calcium ferrite (Ca2Fe2O5) as the oxygen carrier. The underlying thermodynamics of petcoke partial oxidation are studied through the assessment of parameters such as the syngas purity, carbon deposition, and S# (an indicator of the syngas quality) using computational simulations carried out in Aspen. The effect of natural gas and steam co-injection along with petcoke has also been studied while also focusing on regeneration of the reduced carrier using steam and CO2. As sulfur is an integral part of the petcoke stream, its interaction with the oxygen carrier has also been analyzed and a process configuration is reported that allows the production of a sulfur-free syngas stream. Process simulations reveal an increase in the exergy efficiency of syngas production, syngas yield per mol of carbon, and acetic acid yield per mol of carbon by 32% points, 50, and 14%, respectively, using the Ca2Fe2O5-assisted CLG process as opposed to the conventional petcoke gasification route, thus rendering acetic acid production using the CLG route economically attractive.

Test sequencing for binary systems is a nondeterministic polynomial-complete problem, where greedy algorithms have been proposed to find the solution. The traditional greedy algorithms only extract a single kind of information from the D-matrix to search the optimal test sequence, so their application scope is limited. In this study, two novel greedy algorithms that combine the weight index for fault detection with the information entropy are introduced for this problem, which are defined as the Mix1 algorithm and the Mix2 algorithm. First, the application scope for the traditional greedy algorithms is demonstrated in detail by stochastic simulation experiments. Second, two new heuristic formulas are presented, and their scale factors are determined. Third, an example is used to show how the two new algorithms work, and four real-world D-matrices are employed to validate their universality and stability. Finally, the application scope of the Mix1 and Mix2 algorithms is determined based on stochastic simulation experiments, and the two greedy algorithms are also used to improve a multistep look-ahead heuristic algorithm. The Mix1 and Mix2 algorithms can obtain good results in a reasonable time and have a wide application scope, which also can be used to improve the multistep look-ahead heuristic algorithm.

Production of various value-added chemicals through natural gas conversion with syngas as an intermediate is becoming increasingly popular because of the abundance of natural gas and maturation of syngas-producing technologies. Chemical looping reforming is one such technology that is envisioned as a substitute to the existing syngas production processes such as steam methane reforming, autothermal reforming, and partial oxidation of natural gas (POX) because of its superior thermodynamic capabilities and less parasitic energy requirements. The proposed work makes use of CuO-modified Ca2Fe2O5-based oxygen carriers for syngas production through chemical looping, where the system performance is subjected to thermodynamic scrutiny. The main objective of the proposed work is to assess the change in syngas production capability and other process parameters because of reduced endothermicity of the process through CuO incorporation. Thermodynamic simulations are carried out to assess the system performance at various operating temperatures, pressures, and lattice oxygen availability. Parameters such as the effective thermal efficiency, cold gas efficiency, and exergy efficiency are calculated to evaluate the performance of oxygen carriers with varying compositions of CuO. These parameters are measured for two process configurations: isothermal and thermoneutral. An overall process simulation is further carried out to gain a deeper perspective of the changes occurring in the chemical-looping system because of CuO modification of the oxygen carrier.

Loss of function of arginine vasopressin receptor 2 (AVPR2) may affect the recognition and binding of arginine vasopressin (AVP) which, in turn, may prevent the activation of Gs/adenylate cyclase and reduce the reabsorption of water by renal tubules and combined tubes. Finally, the organism may suffer from nephrogenic diabetes insipidus (NDI), a kind of kidney disorder featured by polyuria and polydipsia, due to a break of water homeostasis. In this study, we enrolled a Chinese family with polyuria and polydipsia. The proband presented abnormal fluid intake and excessive urine output. A water deprivation and AVP stimulation test further indicated that this patient had NDI. By sequencing known causative genes for diabetes insipidus, we identified a novel mutation in AVPR2(c.547G>A; p.V183M) in the family. This mutation, located in a conserved site of AVPR2 and predicted to be disease-causing by informatics programs, was absent in our 200 controls and other public databases. Our study not only further confirms the clinical diagnosis, but also expands the spectrum ofAVPR2mutations and contributes to genetic diagnosis and counseling of patients with NDI.

Syngas production is highly critical to the manufacturing of many value-added products, and its economic prospects can be increased through the enhancement of fuel conversion and the syngas yield. This study explores the thermodynamic characteristics of syngas production through chemical looping reforming (CLR) of natural gas using dicalcium ferrite (Ca2Fe2O5) as the oxygen carrier in a cocurrent moving-bed reactor. The effects of temperature, pressure, and steam addition are studied for both isothermal and adiabatic conditions. A natural gas conversion of 99.78% and a yield of 2.86 mol of syngas/mol of natural gas are obtained for CLR as compared to 95.97% and 2.70, respectively, for autothermal reforming (ATR). A fluidized bed and a countercurrent moving bed are employed for the regeneration of reduced solids using air and a steam/CO2mixture, respectively, thereby achieving operational flexibility. The syngas yield increases by ∼41% using the steam/CO2mixture, whereas a high-purity H2is obtained from the oxidation of reduced solids in pure steam. The process analyses indicate an increase in the effective thermal efficiency from 86.4% to 92.2% and the exergy efficiency from 79.5% to 85.3% on using the Ca2Fe2O5-based CLR over ATR, rendering the syngas production using CLR economically attractive.

The methane-to-syngas (MTS) chemical looping process is an advanced methane reforming technology for the production of high purity syngas. The developed MTS process utilizes metal oxide oxygen carriers in a cocurrent moving bed reactor to partially oxidize the methane such that the resulting syngas stream is undiluted by nitrogen in air or H2from overconversion and directly suitable for downstream processing. The oxygen carriers are regenerated with air in a separate fluidized bed reactor producing a spent air stream separate from the product syngas, circumventing the need for cryogenic air separation units. In this work, a 15 kWthsubpilot unit is designed and operated in a continuous manner to experimentally confirm the viability of the MTS process. Reactor design considerations and methodology are discussed in detail. An iron–titanium composite oxygen carrier is used as the oxygen carrier for its ability to achieve high methane conversion while regulating the product syngas to the partial oxidation products, CO and H2. Syngas is produced with an H2/CO ratio of ∼2, and a purity of ∼97% is produced with methane conversion exceeding 99%. The coinjection of methane with H2and/or H2O is explored for the purpose of H2utilization and flexible H2/CO ratios, allowing the MTS process to produce syngas for a variety of downstream processes without reactor modification. The results indicate that syngas with H2/CO ratios ranging from 1.19 to 2.50 with high methane conversion and syngas purity can be produced with coinjection. No evidence of carbon deposition on the oxygen carrier is revealed, and the oxygen carrier retained structural integrity after subjection to reaction and circulation in the subpilot unit.

Chemical looping is an advanced material and energy conversion technology that can achieve both high-level process intensification and efficiency. To analyze chemical looping processes, it is essential to include process conditions that are realistic and comparable to those that are expected in industrial systems. Relevant variations in these conditions as occurred in bench versus industrial-scale systems include isothermal versus adiabatic operation of the reactors and local versus global process heat integration. Naturally, the types of reactors employed dictate how the reactor operation is to be conducted from the heat integration viewpoint in the overall process arrangement. As an example, in industrial applications, a fluidized bed reactor is operated near uniform temperature conditions. A fixed bed or a moving bed reactor, on the other hand, is typically operated adiabatically, and thus under the autothermal operation, the nonisothermal condition prevails, leading to different strategies for process simulations and heat integration requirements. This study presents the chemical looping process simulation based on a moving bed reactor used as a reducer for two H2generation process configurations under autothermal operating conditions. The two process configurations are represented by the two-reactor (reducer–combustor followed by the water–gas shift reaction) and the three-reactor (reducer–oxidizer–combustor with water splitting for H2generation in the oxidizer) chemical looping systems with each configuration producing H2in a different operating scheme. The simulation results are compared with the conventional steam methane reforming (SMR) system as a baseline case to underscore the attractiveness of the chemical looping configurations. Specifically, for each configuration, the parametric study under the adiabatic conditions is used to optimize the operating conditions that can satisfy the heat balance requirements and can achieve a maximum H2yield. The exergy analysis indicates that the two-reactor chemical looping and three-reactor chemical looping systems can achieve, respectively, a 4.0 and 11.4% increase in relative percentage in the overall process exergy efficiency over the conventional steam methane reforming system.

Oxygen chemistry plays a pivotal role in numerous chemical reactions. In particular, selective cleavage of C–H bonds by metal oxo species is highly desirable in dehydrogenation of light alkanes. However, high selectivity of alkene is usually hampered through consecutive oxygenation reactions in a conventional oxidative dehydrogenation (ODH) scheme. Herein, we show that dual-functional Mo–V–O mixed oxides selectively convert propane to propylene via an alternative chemical looping oxidative dehydrogenation (CL-ODH) approach. At 500 °C, we obtain 89% propylene selectivity at 36% propane conversion over 100 dehydrogenation–regeneration cycles. We attribute such high propylene yield—which exceeds that of previously reported ODH catalysts—to the involvement and precise modulation of bulk lattice oxygen via atomic-scale doping of Mo and show that increasing the binding energy of V–O bonds is critical to enhance the selectivity of propylene. This work provides the fundamental understanding of metal–oxygen chemistry and a promising strategy for alkane dehydrogenation.

A three-dimensional ECVT sensing technique is applied to imaging complex slugging phenomena of a gas–solid fluidized bed under ambient and elevated temperature conditions. The study indicates that the time interval between rising slugs decreases with an increase in the gas velocity, reaching a nearly steady time interval value of about 1 s between two slugs when the gas velocity is ∼1.7 m/s above the minimum fluidization velocity. The fluidized bed behaves as a bubbling fluidized bed at low gas velocities. In slugging regime, the slug rise velocity increases with the gas velocity. A mechanistic analysis of forces around the dense phase solid particles suggests that the relationship between the slug rise velocity and the gas velocity for the square-nosed slugging bed is not strictly linear and is highly related to the interparticle forces, internal friction of particles, and gas velocity in addition to the wall stress.