Carbon-based Research Articles

“Redox switches” of Fe species on zeolite catalysts: Modulating the acidity and the para-xylene yield from methanol

Molecular switches are widely studied in optical devices, computer science, DNA sensor systems, and chiral synthesis; however, their use in heterogeneous catalytic processes is rarely reported. Herein, we report a Fe-based redox switch for tuning the acidity of a ZSM-5-based catalyst in the methanol-to-aromatics reaction. In this reaction, the yield of the target product, para-xylene (PX), is low because various types of acids on the catalyst activate side reactions. Fe oxides and zeolite generate medium-strength Lewis acids, which activate the aromatization of methanol but suppress the dealkylation of xylene. Gradual reduction of Fe oxides during the reaction simultaneously decreases the conversion of methanol, the yield of aromatics, and the yield of PX. The oxidation state of the Fe species and the associated catalytic performance can be regenerated in the air at 550 °C. The redox switches caused regular fluctuation in the catalytic performance and remained stable throughout 16 regeneration cycles (up to 80 h). The employed strategy enabled a PX yield of up to 60% (carbon base) using a SiO₂-coated Zn/P/Fe/ZSM-5 catalyst, which is 3–6 times higher than previously reported values. The result showed a new mode of acidity modulation of the catalyst.

Metaphors of Extractive Capitalism and Fabulation in Nope

This essay argues that Jordan Peele’s Nope (2022) offers metaphor and fabulation as a critique of extractive capitalism and its detrimental consequences on sentient life. Peele visualizes the outcomes of capitalist extraction and accumulation as exemplified in racialized labor exploitation and anthropogenic catastrophe. I examine how the film mobilizes fabulation to explore cinema’s erasure of Blackness from its history as an example of racial extraction. My analysis of extraction extends to the shapeshifting sentient “alien,” nicknamed Jean Jacket, who I contend embodies extractive capitalism via its consumption and expulsion of carbon-based life and indigestible objects. I maintain that Peele uses the trope of the alien-monster as a metaphor to comment on the threat of ecological collapse. I then proceed to study how Nope makes a pointed critique of human misuse of media technologies due to an insatiable avarice for notoriety. Finally, I conclude with a reading of how extractive capitalism forecloses the possibility for humans to establish multispecies empathy and cohabitation.

Genomic Regions and Candidate Genes Affecting Response to Heat Stress with Newcastle Virus Infection in Commercial Layer Chicks Using Chicken 600K Single Nucleotide Polymorphism Array.

Heat stress results in significant economic losses to the poultry industry. Genetics plays an important role in chickens adapting to the warm environment. Physiological parameters such as hematochemical parameters change in response to heat stress in chickens. To explore the genetics of heat stress resilience in chickens, a genome-wide association study (GWAS) was conducted using Hy-Line Brown layer chicks subjected to either high ambient temperature or combined high temperature and Newcastle disease virus infection. Hematochemical parameters were measured during three treatment phases: acute heat stress, chronic heat stress, and chronic heat stress combined with NDV infection. Significant changes in blood parameters were recorded for 11 parameters (sodium (Na+, potassium (K+), ionized calcium (iCa2+), glucose (Glu), pH, carbon dioxide partial pressure (PCO2), oxygen partial pressure (PO2), total carbon dioxide (TCO2), bicarbonate (HCO3), base excess (BE), and oxygen saturation (sO2)) across the three treatments. The GWAS revealed 39 significant SNPs (p < 0.05) for seven parameters, located on Gallus gallus chromosomes (GGA) 1, 3, 4, 6, 11, and 12. The significant genomic regions were further investigated to examine if the genes within the regions were associated with the corresponding traits under heat stress. A candidate gene list including genes in the identified genomic regions that were also differentially expressed in chicken tissues under heat stress was generated. Understanding the correlation between genetic variants and resilience to heat stress is an important step towards improving heat tolerance in poultry.

Magnetoelastic effect of kimberlite host rocks (Yakutsk diamondiferous province)

The purpose of the research is to conduct petro- and paleomagnetic studies of Early Paleozoic rocks of the carbonate basement of a number of diamond deposits in the Yakutsk diamondiferous province in order to study the changes in petrophysical parameter values in the dynamic influence zone of a kimberlite pipe. It is shown that the formation of kimberlite diatremes accompanied by pulsating explosions shifting upwards brings about thermoelastic stress fields in the kimberlite-bearing medium, which are characterized by epigenetic changes and associated petrophysical heterogeneities (petrophysical anomalies). Petromagnetic heterogeneities of burning and stress are, therefore, some of these petrophysical anomalies, within which kimberlite-bearing rocks have contrastingly changed their original magnetic characteristics under the action of thermodynamic processes. Primarily, petromagnetic anomalies are reflected in the changed nature of the anisotropy of magnetic susceptibility: from sedimentary to dyke geotype. In addition, petromagnetic anomalies of magnetic susceptibility can be accompanied by the formation of metachronous natural residual magnetization vectors in kimberlite host rocks. The dimensions of petromagnetic anomalies (petromagnetic heterogeneities) may significantly exceed the size of the kimberlite pipe itself, which facilitates identification and delineation of the most promising areas. Besides, the magnetoelastic effect can create zones close to the kimberlite bodies that are hardly permeable for relatively viscous, protocrystal-rich mafic magmas. This is the reason for their wedging out along petrophysical barriers that is presented by splitting into thin tongues, formation of trap-free windows and corridors, toroidal shafts with sharply increasing thickness in intrusions, etc. Having relatively elevated values of magnetic and density parameters, such forms of igneous formations will be reflected in the observed geophysical fields. Thus, it is reasonable to consider petromagnetic anomalies as an important petrophysical search criterion for the detection of bedrock kimberlite bodies.

Bedrock regulated climatic controls on the interannual variation of land sink in South-West China karst through soil water availability

South-West China (SWC) is a pivotal region for global greening, recognized as having great carbon sink potential. Multiple evidence underscores the expanding contribution of SWC’s carbon sink to the global carbon sink enhancement. However, our understanding of carbon sink dynamics and the response to climate across bedrock remains limited. In this study, we investigated the divergence in trends in carbon sink across bedrocks, evaluating their respective contributions of bedrocks to the overall carbon sink in SWC. Additionally, we assessed the dominant climatic factors and examined how bedrocks shape the response of carbon sink to climate change. Our results revealed a notable increase in the regional carbon sink, with an average rate of 3.58 TgC/yr from 1981 to 2019. Continuous Carbonate Rocks (CCR) exhibited the highest increased rate of total carbon sequestration (1.57 TgC/yr), surpassing Discontinuous Carbonate Rocks (DCR) by threefold. Non-karst areas contributed the most to both the mean and interannual variations of the overall carbon sink, with CCR exerting the most contribution to the trends. Over time, the contribution of CCR to the overall carbon sink escalated, while the contributions of DCR and non-karst declined. All bedrocks displayed negative correlations between NEP and temperature, with DCR showing higher susceptibility. Non-karst areas experienced adverse impacts from vapor pressure deficit, while CCR benefited from positive soil moisture effects. Our findings implied that bedrock indeed played a critical role in the variations in NEP and the response of NEP to climate change. Bedrock regulated climatic controls on carbon sink through soil water availability as soil water availability is affected by the lithology of basement carbonate. This novel understanding emphasizes the necessity for tailored ecological restoration initiatives that consider the distinctive lithological features of the karst ecosystem, and holds significance for implementing ecologically sound projects in karst regions.

Hypocapnia in women with fibromyalgia.

The purpose of this study was to investigate whether people with fibromyalgia (FM) have dysfunctional breathing by examining acid-base balance and comparing it with healthy controls. Thirty-six women diagnosed with FM and 36 healthy controls matched for age and gender participated in this cross-sectional study. To evaluate acid-base balance, arterial blood was sampled from the radial artery. Carbon dioxide, oxygen, bicarbonate, base excess, pH and lactate were analysed for between-group differences. Blood gas analyses were performed stepwise on each individual to detect acid-base disturbance, which was categorized as primary respiratory and possible compensation indicating chronicity. A three-step approach was employed to evaluate pH, carbon dioxide and bicarbonate in this order. Women with FM had significantly lower carbon dioxide pressure (p = 0.013) and higher lactate (p = 0.038) compared to healthy controls at the group level. There were no significant differences in oxygen pressure, bicarbonate, pH and base excess. Employing a three-step acid-base analysis, 11 individuals in the FM group had a possible renally compensated mild chronic hyperventilation, compared to only 4 among the healthy controls (p = 0.042). In this study, we could identify a subgroup of individuals with FM who may be characterized as mild chronic hyperventilators. The results might point to a plausible dysfunctional breathing in some women with FM.

Norepinephrine versus phenylephrine for managing maternal hypotension during cesarean delivery under spinal anesthesia: a meta-analysis of maternal and neonatal outcomes

Norepinephrine or phenylephrine administration to prevent and treat hypotension during spinal anesthesia for cesarean section has been a significant topic of discussion. This meta-analysis aimed to update existing evidence and provide further insights into neonatal and maternal outcomes associated with norepinephrine and phenylephrine. Review of randomized controlled trials (RCTs) was performed to assess the effectiveness of norepinephrine and phenylephrine in managing maternal hypotension during cesarean delivery under spinal anesthesia. Neonatal umbilical cord blood pH and maternal hypotension were the primary outcomes. Based on the analysis of 26 RCTs with 2984 participants, we found no significant difference between the norepinephrine and phenylephrine groups in umbilical artery pH in neonates (mean difference (MD) 0.00; 95% confidence interval (CI) −0.00 to 0.01, p = 0.20). Neonates Apgar scores did not differ between both groups. Norepinephrine was associated with lower incidences of bradycardia (risk ratio (RR) 0.44; 95% CI 0.37 to 0.51, p &lt; 0.001) and reactive hypertension (RR 0.53; 95% CI 0.39 to 0.72, p &lt; 0.001) in parturient women than phenylephrine. In neither group did umbilical cord blood levels of partial pressure of oxygen (PaO2), partial pressure of carbon dioxide (PaCO2) and base excess (BE) levels of neonates differ significantly, nor did maternal hypotension, nausea or vomiting incidence during delivery. For maternal hypotension after spinal anesthesia, norepinephrine and phenylephrine did not significantly differ in neonatal acidemia. Despite similarities to phenylephrine in managing hypotension and maintaining maternal hemodynamic stability, norepinephrine is a promising alternative.

Iron(III) promoted oxidative annulation of benzylic C-H bonds in (α-amino)arylacetic acids for synthesis of 4-aryl pyrrolo[1,2-a]quinoxalines

Using amino acids for synthesis of heterocycles is a synthetically promising field. However, developing the practical methods for transformations of amino acids into heterocycles is still challenging. Given that alpha amino acids are abundant or easily prepared, herein we report a method for annulation of benzylic C-H bonds in derivatives of 2-phenylglycine with 1-(2-nitroaryl)pyrroles. The reactions proceeded well in the presence of iron(III) acetylacetonate catalyst and potassium carbonate base. Scope of pyrrolo[1,2-a]quinoxalines was studied. Regardless of electronic properties of substituents, the pyrrolo[1,2-a]quinoxaline de-rivatives were successfully isolated, as yields varied from 42% to 52%. Pyrrolo[1,2-a]quinoxalines substituted with heterocycles at C4 positions as pyridine and thiophene were competent substrates. Reaction mechanism was proposed to start with a decar-boxylative/deaminative sequence of 2-phenylglycine to afford benzaldehyde. The iron catalyst was presumed to facilitate the re-duction of 1-(2-nitroaryl)pyrroles to furnish the corresponding aniline. Imine condensation followed by cyclisation and oxidation would yield the pyrrolo[1,2-a]quinoxaline. Our method would offer a convenient tactic to transform abundant alpha amino acids into synthetically useful heterocycles.

Authigenic clay mineral constraints on spatiotemporal evolution of restricted, evaporitic conditions during deposition of the Ediacaran Doushantuo Formation

The carbonate-rich shelf facies of the Ediacaran Doushantuo Formation (South China) have produced a broad array of microfossil and isotope proxy records which underpin much of our understanding of environmental change and biospheric evolution during this key time period. Recent reports of locally abundant authigenic, Mg-rich saponite clay in the Yangtze Gorges Area hint at potentially widespread evaporitic conditions in a lagoonal setting. Despite the implications for interpretation of proxy records and the environmental setting of early metazoans, the spatiotemporal extent of restricted, evaporitic conditions across the Yangtze Block remains largely unexplored. Here we use mineralogical and petrographic techniques to document the spatial and stratigraphic distribution of authigenic clay minerals across seven sites, representing a transect from shallow proximal shelf to deep basinal settings. Our results demonstrate the widespread and persistent occurrence of authigenic saponite in proximal shelf settings, whereas talc is identified at more distal shelf sites, consistent with Mg-clay authigenesis in an evaporitic lagoon with spatially variable detrital aluminosilicate input. Slope and basinal sites contain no Mg-clays and are instead characterized by abundant authigenic illite, consistent with an open marine setting. Stratigraphically, illite was found in the basal cap carbonate and uppermost Doushantuo Formation, with Mg-clays only present in the interval in-between, suggesting gradual development of an extensive carbonate rimmed lagoon over the Yangtze shelf that restricted seawater exchange, followed by stronger marine influence due to erosion of the carbonate rim and subsequent marine transgression. We conclude that restricted, evaporitic conditions were much more expansive than previously assumed, potentially providing favorable conditions for the Doushantuo Biota. Further, the widespread presence of authigenic clays across the shelf supports the case for enhanced reverse weathering before the advent of biosilicification.

Machine learning assisted electrochemical sensing technology for the detection of nitrate ions in PM2.5

This study investigates a graphene-modified glassy carbon electrode for detecting nitrate ions in particulate matter (PM2.5). The electrode configuration consists of a glassy carbon base electrode drop-coated with chemically-reduced graphene (CRGN), followed by an optimized nitrate ion-selective membrane (NO3-ISM) layer. Electrochemical impedance spectroscopy demonstrates graphene’s ability to enhance electron transfer by mitigating water layer formation. The nitrate sensor exhibits a linear potentiometric response from 0.1 mM to 0.1 M nitrate and theoretical Nernstian sensitivity. However, chloride interferences are observed. To improve selectivity, a support vector machine model utilizing particle swarm optimization (PSO-SVM) is developed. This machine learning approach shows significantly higher predictive accuracy than univariate calibration, even in mixed nitrate-chloride samples. The combination of the graphene-modified sensor and PSO-SVM algorithm provides an optimized nitrate detection strategy, advancing technologies for air quality monitoring.

Fe3O4@void@C-Schiff-base/Pd yolk-shell nanostructures as an effective and reusable nanocatalyst for Suzuki coupling reaction

This article describes the synthesis of a novel Yolk-Shell structured Magnetic Yolk-Shell Nanomaterials Modified by Functionalized Carbon Shell with Schiff/Palladium Bases (Fe3O4@void@C-Schiff-base/Pd). The designed Fe3O4@void@C-Schiff-base/Pd catalyst was characterized using several techniques such as Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometry (VSM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), thermal gravimetric analysis (TGA), powder X-ray diffraction (PXRD) and Inductively coupled plasma (ICP). The Fe3O4@void@C-Schiff-base/Pd was used as powerful catalyst for preparation Suzuki reaction in short reaction times and high yield in H2O at 60 °C and presence of potassium carbonate base. This nanocatalyst was magnetically recovered and reused several times with keeping its efficiency.

Tectonic-magmatic-hydrothermal interactions in a hot dry rock geothermal system: The role of the transfer and normal faults in the Acoculco caldera (Mexico)

In the Acoculco caldera (hot dry rock system) two geothermal boreholes were planned to intersect fracture systems in the carbonate basement. Even though the caldera is located in an area of active deformation with high rainfall, a scarce permeability was recognized. To shed light on this apparent mismatch, we investigate the area by integrating a structural and kinematic dataset on faults and fractures with the volcanological data. The results highlighted two main coeval fault systems, NW- and NE striking respectively, and two associated minor N-S and E-W striking sets, affecting the area of the Acoculco caldera and controlling its volcanic evolution. The kinematic analysis on fault-slip surfaces demonstrated that the NW-striking faults are characterized by two superposed movements: the first comprises right strike-slip to right lateral oblique-slip, while the second is dominantly normal. In contrast, the NE-striking structures display only dominantly normal movements. We explain the kinematic evolution by two recurring events, determined by the interplay between regional extension and uplift: when a crustal extension was dominant in the region (first kinematic event), the NW- and NE-trending structures played the role of transfer and normal faults, respectively; in contrast, when uplift predominated (second kinematic event) both the pre-existing NW- and NE-striking faults acted with normal movements. The location of eruptive centers is controlled by the permeability along the regional faults and their step-over zones. A closer analysis carried out in the surroundings of the geothermal boreholes suggests that deformation migrated northwards, and that fractures are sealed in this sector of Acoculco, thus strongly reducing permeability. In this view, the most promising areas for potential permeability at depth might occur northwards, beyond of the Acoculco caldera, and along the NW-trending structures. In conclusion, the fault kinematics is influenced by periods of increased partial melting of the lithosphere, the latter determining anomalous heat flux and uplift. This process interacts with the fluid pathways that are in turn controlled by the tectonic segmentation, and this is a new model to explain the tectonic-magmatic and hydrothermal interaction of this region.

Enhancement electrochemical properties of supercapacitors using hybrid CuO/Ag/rGO based nanoporous composite as electrode materials

Utilizing clean and renewable energy sources requires the development of effective, reliable, and reasonably priced electrodes for supercapacitors. Herein, a simple, cheap, and fast synthesis method was developed to synthesize CuO/Ag/RGO(S1) as electrode material for Supercapacitors. Also, the effect of adding different proportions of silica nanoparticles S2A (1CuO/1Ag/1RGO/0.5SiNp), S2B (1CuO/1Ag/1RGO/1SiNp), and S4 (1CuO/1Ag/1RGO/1.5 SiNp) on the electrochemical properties of the composite was also investigated. Among the four synthesized composites, composite S1, due to its porous structure, has better electrochemical parameters than the other three composites. Also, the correct combination of a metal base (CuO, Ag) and carbon base (Reduced graphene oxide) materials with the accurate synthesis method and the use of proper precursors (F127, Ag(NO3), Cu(NO3)2) made the S1 composite have an ideal electrochemical result(Specific capacitance: 936 F g−1, energy density: 130 Wh kg−1, power density: 500 W kg−1, cycle stability: 90% rate capability: 88%) Compared to the pure state of each of these materials and other similar hybrid compounds. The reason for such ideal electrochemical results, which distinguishes this project from other similar projects, is the synergistic effect of the combination of CuO, Ag, and RGO, along with the hierarchical porosity obtained in the correct synthesis method. In our opinion, CuO/Ag/RGO maybe a viable choice for electrocatalytic and energy storage applications that require distinct electrochemical performances.

Proses Transesterifikasi Biodiesel Menggunakan Katalis Sodium Methoxide Dan Katalis Berbasis Karbon Aktif Dari Tempurung Kelapa Yang Diimpregnasi NaOH

Biodiesel is one of the renewable energies that can be obtained by converting triglycerides into methyl esters by transesterification process. Used cooking oil is heated with anhydrous methanol which is added with an acid catalyst or base catalyst. The catalyst has a role as a substance to reduce the activation energy of fatty acids in used cooking oil to increase the reaction rate. In this study, Sodium methoxidealkaline catalyst and NaOH-impregnated activated carbon base catalyst were used. Activated carbon catalyst using variation of concentration of activated carbon 1N, 2N, 3N, 4N, and 5N for 18 hours, 21 hours, and 24 hours and the use of sodium methoxidecatalyst with variation of oil: methanol ratio 1:3, 1:6, 1:9, 1:12, 1:15. The results showed that the biodiesel yield using carbon catalyst was 98.2%, 2% w/w catalyst with oil: methanol ratio 1:12 at 60℃ for 120 minutes. The best result of biodiesel using sodium methoxidecatalyst is 87.65%, catalyst 1.25% w/w with ratio 1:12, temperature 60℃ for 120 minutes. Keyword :  Active Carbon, Biodiesel, Catalyst, Sodium Methoxide, Transesterification

Mechanical properties of pyrolysis carbon black in rubber compound application

Waste tire pyrolysis is a thermal decomposition process that converts waste tires into liquid fuel which also produce by product material such as producer gas, pyrolysis carbon black (CBp), and steel wire. Nowadays, carbon black produced by pyrolysis is being employed as a low-grade carbon base fuel. The technical feasibility of using CBp as a substitute for commercial carbon black N330 in styrene-butadiene rubber (SBR) was investigated in the study. The researcher also looked at how the composition ratio of CBp and N330 affected the mechanical characteristics of rubber in comparison to the outcomes of pure carbon black N330. It was discovered that the low composition ratio of 20% CBp and 80% N330 (R-2) had comparable Mooney viscosity to that of N330 carbon black, as well as the highest torque (MH) and torque increment (ΔM) values, but increased CBp content led to increased rubber viscosity and decreased cure time due to sulfur residues CBp was inferior to N330 in its effect on reinforcement. With an increase in CBp content, the tensile strength, shear strength, and elongation at break of SBR vulcanizates decreased considerably, while the hardness increased. Consequently, the CBp value evaluated for hardness applications provides significant manufacturing cost savings.

Synthesis of carbon microsphere-supported nano-zero-valent iron sulfide for enhanced removal of Cr(VI) and p-nitrophenol complex contamination in peroxymonosulfate system

Carbon microspheres supported sulfurized nano zero-valent iron (CMS@S-nFe0) was successfully prepared. The interaction impact of different dosages on the removal of Cr(VI) and p-nitrophenol (PNP) complex contamination was explored by response surface method (RSM). The results showed both the C group and Fe2+ on the surface of carbon microspheres could be used as activators of peroxymonosulfate (PMS) decomposition, and •OH and SO4•- could be produced to promote the oxidative degradation of PNP. Among them, SO4•- was the main reactive oxygen species. The presence of PNP could further promote the reduction of Cr(VI). Besides, loading nFe0 and FeS compounds on the carbon base could significantly reduce the production of free iron ions, which could effectively remove Cr(VI) and PNP from polluted water. In terms of treatment results, CMS@S- nFe0 was a promising material for wastewater treatment because of its excellent performance in adsorption of heavy metals and degradation of organic pollutants.

Association of carbon monoxide poisonings and carboxyhemoglobin levels with COVID-19 and clinical severity.

Coronavirus disease 2019 (COVID-19), which recently spread throughout the entire world, is still a significant health issue. Additionally, the most common cause of risky poisoning in emergency services is carbon monoxide (CO) poisoning. Both disorders seem to merit more research as they have an impact on all bodily systems via the lungs. To determine how arterial blood gas and carboxyhemoglobin (COHb) levels affect the clinical and prognostic results of individuals requiring emergency treatment who have both COVID-19 and CO poisoning. Between January 2018 and December 2021, 479 CO-poisoning patients participated in this single-center, retrospective study. Patients were primarily divided into two groups for analysis: Pre-pandemic and pandemic periods. Additionally, the pandemic era was divided into categories based on the presence of COVID-19 and, if present, the clinical severity of the infection. The hospital information system was used to extract patient demographic, clinical, arterial blood gas, COVID-19 polymerase chain reaction, and other laboratory data. The mean age of the 479 patients was 54.93 ± 11.51 years, and 187 (39%) were female. 226 (47%) patients were in the pandemic group and 143 (30%) of them had a history of COVID-19. While the mean potential of hydrogen (pH) in arterial blood gas of all patients was 7.28 ± 0.15, it was 7.35 ± 0.10 in the pre-pandemic group and 7.05 ± 0.16 in the severe group during the pandemic period (P < 0.001). COHb was 23.98 ± 4.19% in the outpatients and 45.26% ± 3.19% in the mortality group (P < 0.001). Partial arterial oxygen pressure (PaO2) was 89.63 ± 7.62 mmHg in the pre-pandemic group, and 79.50 ± 7.18 mmHg in the severe group during the pandemic period (P < 0.001). Despite the fact that mortality occurred in 35 (7%) of all cases, pandemic cases accounted for 30 of these deaths (85.7%) (P <0.001). The association between COHb, troponin, lactate, partial arterial pressure of carbon dioxide, HCO3, calcium, glucose, age, pH, PaO2, potassium, sodium, and base excess levels in the pre-pandemic and pandemic groups was statistically significant in univariate linear analysis. Air exchange barrier disruption caused by COVID-19 may have pulmonary consequences. In patients with a history of pandemic COVID-19, clinical results and survival are considerably unfavorable in cases of CO poisoning.

Mineralization and Skarn Formation Associated with Alkaline Magma Chambers Emplaced in a Limestone Basement: A Review

The emplacement of shallow magma chambers within a carbonate basement is a typical feature of many volcanic systems around the world. The accompanying formation of exoskarns, endoskarns, cumulates, exsolved fluids and differentiated melts at the interface between the magma chamber and carbonate host-rock is well documented through mineralogical and geochemical studies of ejected skarns and cumulates and through fluid and melt inclusion studies. This review presents the current knowledge on the interaction of alkaline magma chambers with carbonate-bearing host-rocks, with a focus on the geochemical evolution and mineralization at the outer margins of the magma chamber and the accessory mineral phases at Somma-Vesuvius, Colli Albani and Merapi volcanic systems. Furthermore, we discuss how this interaction and its products, especially the CO2 released during the thermometamorphic decarbonation of the carbonate host-rock, impacts the eruptive behavior in all three systems.

High-entropy oxide/phase-inverted carbon for enhanced lithium–sulfur batteries

The high theoretical charge-storage capacity and low cost of the lithium–sulfur battery cathode make it a promising next-generation energy-storage system. The development of high-loading sulfur cathodes has become a trend for addressing the low sulfur-loading capability and high polysulfide-diffusion instability of lithium–sulfur batteries. In this study, we investigate the feasibility of material and component designs to develop a high-loading sulfur cathode with improved polysulfide retention and conversion. Through the phase-inversion (PI) method, we fabricate a cathode substrate with a hierarchical configuration from large open pores, small interconnecting pores, and to a compacted conductive carbon base. The hierarchical porous configuration allows for high sulfur accommodation and polysulfide absorption. Moreover, the carbon backbone is decorated with a (CrMnFeNiMg)3O4 high-entropy oxide (HEO) nanoceramic, which imparts the substrate with a strong chemical polysulfide adsorption ability, to improve the electrochemical stability of the cell and enable electrochemical catalysis of sulfide nucleation during cell cycling. The porous conductive substrate allows for the fabrication of an HEO/PI carbon sulfur cathode with high sulfur loading and content of 6–10 mg cm−2 and 50 wt%, respectively (considering the total mass of the cathode). The high-loading cathode also achieves excellent electrochemical performance, with a high charge-storage capacity of 903 mA∙h g−1, long cycle life of 200 cycles, high areal capacity of 7.24 mA∙h cm−2, and energy density of 14.12 mW∙h cm−2.

Iodine-mediated domino cyclization of hydrazides for one-pot synthesis of 1,3,4-oxadiazoles via oxidative bond cleavage of vinyl azide

An iodine and base-promoted domino cyclization has been disclosed for one-pot synthesis of 1,3,4-oxadiazoles via oxidative cleavage of C(sp2)-N and C(sp2)-C bonds. Herein, the use of potassium carbonate base was found to be crucial reagents in this oxidative cyclization and deacylation through selective bonds cleavage, affording mono and disubstituted 1,3,4-oxadiazoles respectively. The domino process provides a variety of substrate scope with moderate to good yields and is highly functional group compatible. Moreover, an important drug molecule fenadiazole was derived following the present procedure.