Carbonic Inclusions Research Articles

The Inclusion Characteristics and Mechanical Properties of M2 High-Speed Steel Treated with a Vacuum Carbon Deoxidation Process

The oxygen content of M2 high-speed steel has not been intentionally controlled in industrial production through secondary refinement in vacuum furnaces. However, a lower oxygen content has a significant effect on the cleanliness, toughness, and addition of rare-earth elements to M2 high-speed steel. The changes in total oxygen content controlled by vacuum carbon deoxidation (VCD) treatment and inclusion evolution were investigated in M2 high-speed steel to understand the effects of carbon on dissolved oxygen and oxides in the carbon–oxygen (C-O) reaction process. Furthermore, the microstructure and properties of M2 high-speed steel caused by vacuum insulation and the role of reducing oxygen content in rare-earth alloying were briefly demonstrated. The results showed that the [O%] decreased from 30 ppm to 3 ppm in a vacuum at holding times above 25 min through the C-O reaction, leading to an inclusion reduction of approximately 70%. In the case of [O%] = 3 ppm in M2 high-speed steel, the addition of rare-earth elements has a greater effect on the inclusion characteristics. Lowering the oxygen content of M2 high-speed steel improves cleanliness and plays a significant role in rare-earth alloying.

Joining of SiC ceramics by iridium: The interfacial phenomena and joint strength

A methodology for joining SiC ceramic parts using iridium foil was devised. The connecting layer was formed via a solid-state reaction at 1350 °C or via a transient liquid phase (TLP) at temperatures exceeding 1417 °C. The microstructure of the connecting layer formed via solid-state reaction exhibits temporal changes. The overall thickness of the layer remains approximately constant over time; however, the thickness of the carbon-free central part, composed of Ir and iridium silicides, decreases with time. The thicknesses of the porous carbon-containing sublayers located on either side of the central region demonstrate an increase. The greatest average flexural strength value was found to be 110 ± 6 MPa. The flexural strength values decrease with an increase in the holding time. This behavior can be attributed to the growth of a porous carbon-containing layer. The connecting layer, obtained via a transient liquid phase, is composed of IrSi and C. The layers on either side of the central dense IrSi part contain a number of pores and carbon inclusions. The SiC/SiC joints formed at 1425 °C and 1500 °C exhibit bending strengths of 66 ± 4 and 29 ± 4 MPa, respectively. These findings illustrate the potential of iridium to join monolithic SiC ceramic parts at relatively low temperatures.

Revealing wear mechanisms of coated shafts in low-speed journal bearings immersed in liquid Lead-Bismuth Eutectic (LBE)

This study investigates wear mechanisms of coated shafts in journal bearings within liquid lead-bismuth eutectic. Shafts were coated with TiAlN, a-C:H, multi-layer TiAlN with sputtered carbon, and chrome plating. Bearings made from sintered iron with carbon inclusions (DEVA 120 and DEVA 121) were tested in LBE at 200 °C and 50 rpm using a dedicated test rig. The a-C:H coatings failed due to tribofilm wear with DEVA 120, while TiAlN coatings failed from fatigue wear with DEVA 120 but succeeded with DEVA 121. Chrome-plated shafts experienced abrasive and adhesive wear with DEVA 121 but survived DEVA 120 due to transfer layer formation. The study highlights the need to understand wear mechanisms and material compatibility to develop durable coatings for harsh environments.

Optimization of strontium removal by Tetraselmis chui grown in bubble column photobioreactors

Green microalgae of the class Chlorodendrophyceae have recently attracted the interest of researchers due to their ability to form micropearls (intracellular inclusions of amorphous calcium carbonate) highly enriched in Sr. The marine species Tetraselmis chui (included in the class Chlorodendrophyceae) shows high uptake of both stable and radioactive Sr isotopes and has been suggested as a potential candidate for the development of new bioremediation tools regarding radioactive 90Sr pollution. In this study, we optimized Sr removal from seawater by growing T. chui in 1-L bubble column photobioreactors (PBRs) with and without CO2 supply. Culturing T. chui in bubble column PBRs greatly improves cell production and Sr removal compared to previous studies. Furthermore, the addition of 10 mL L−1 h−1 CO2 further accelerates T. chui growth and results in better Sr removal rates. This study presents promising results for the development of new bioremediation methods to treat 90Sr pollution.

Room Temperature Synthesis of Tellurium by Solution Atomic Layer Deposition.

This study demonstrates the deposition of tellurium (Te) on silicon/silicon nitride substrates using solution atomic layer deposition (sALD) at ambient temperature. The process employs tellurium tetrachloride (TeCl4) and bis(triethylsilyl)-telluride ((TES)2Te) as precursors, with toluene as the solvent. Growth parameters were optimized through systematic variation of the pulse and purge times. Morphological characterization via scanning and transmission electron microscopy revealed needle-like crystallites, while X-ray diffractometry confirmed the crystalline nature of the deposited Te. Increasing the number of deposition cycles resulted in larger Te crystallites and enhanced substrate surface coverage. A thin amorphous carbon shell surrounding the crystallites and carbon inclusions was observed, likely originating from the organic solvent. X-ray photoemission spectroscopy analysis indicated high-purity Te films with minimal surface oxidation. The small chlorine signal suggested a near-complete precursor reaction and the efficient purging of byproducts. This novel sALD approach presents a promising method for depositing Te on various surfaces under mild conditions.

A maghemite (γ-Fe2O3) incorporated activated carbon photocatalytic nanocomposite fabricated via Co-precipitation utilized against degradation of methyl orange

The γ−Fe2O3/ACP has been synthesized in different ratios by facile co-precipitation method to degrade the methyl orange dye. In order to check the stability and potential of photo activated catalyst, UV, PL, SEM, XRD, EDX, FTIR and Zeta Potential are discussed here. The bandgap has been reduced from 2.06 eV to 1.86eV. Here, 1:3 γ−Fe2O3/ACP sample showed maximum reduced bandgap of 1.86 eV. The PL spectroscopy showed that 1:3 sample has less intensity, which in turn have 94 % photo degradation of methyl orange dye in 180min. The 1:3 sample showed 87 % degradation of methyl blue dye at 125mins light irradiation and proved as an optimal concentration of ACP in maghemite at pH of 11. The inclusion of carbon into maghemite enhances the overall properties by reducing the charge recombination rate. No impurity has been found in the final synthesized samples confirmed through EDX. The XRD and SEM revealed that size of crystallites and particle size increases, which confirms that bandgap is reduced. While trapping techniques and recycling techniques has been employed on the optimal concentration sample to check its stability towards degradation of methyl orange (MO) dye. The photo catalysis through such nanocomposite is not reported before. The 1:3 sample showed promising potential towards pollutants degradation in waste water treatment.

Effect of sp2-Hybridized Carbon Inclusions in Diamond Films on the Sensor Performance Toward Synchrotron Radiation

Effect of sp2-Hybridized Carbon Inclusions in Diamond Films on the Sensor Performance Toward Synchrotron Radiation

Self-healing carbon fiber/epoxy laminates with particulate interlayers of a low-melting-point alloy

In order to prolong the service life of fiber-reinforced polymer composites, the implementation of self-healing ability with the micro-encapsulated healing agent has been extensively studied. However, such microcapsule-based self-healing composites typically suffer from degraded mechanical properties due to the liquid-phase inclusions, thereby limiting their proliferation. Here, a low-melting-point alloy is utilized as the particulate inclusions of carbon fiber/epoxy laminated composites. Field's Metal particles (melting point: 62 °C) are distributed between woven carbon fiber preforms followed by the resin impregnation to realize laminated composites with a Field's Metal-enhanced interlayer(s). The resulting laminated composites demonstrate the autonomic repair of interlaminar failure with a 40 % of healing efficiency. Most of all, the mechanical properties of these self-healing laminated composites are comparable to the conventional laminated composites attributed to the rigid inclusions that can be compressed to increase the fiber volume. Since the Field's Metal particle inclusions can bestow polymer composites with self-healing ability and the potential increase in mechanical properties, Field's Metal-enhanced fiber-reinforced polymer composites are expected to unlock the practical utility of self-healing composites.

Failure analysis of low carbon steel pipeline for district heating and cooling systems: Case studies

In this study, we investigated the failure modes of three low carbon steel pipelines used in district heating and cooling systems. Unlike thermal fatigue and external damage, which are typical causes of pipe failure in district heating and cooling systems, we observed unusual failure cases attributed to corrosion. Microscopic analysis, potentiodynamic polarization tests, and zero resistance ammeter measurements were conducted to analyze the root cause of failure. For the pipe elbow, stress analysis was performed using the finite element method. In the district heating system, fibrous inhomogeneous inclusions accelerated corrosion penetration in the pipeline. For the case of entrapped fibrous ceramic inclusions in pipe (350A), pore clusters formed by the inclusions acted as pathways for corrosion penetration. For the case of entrapped fibrous carbon inclusions in pipe (450A), corrosion penetration of pipeline due to galvanic effects occurred. In the district cooling system, bulging and plastic fracture were observed at the pipe elbow (250A), attributed to the freezing pressure exerted by water on the locally corroded weld joint.

Navigating the personal carbon inclusion scheme: An evolutionary game theory approach to low-carbon behaviors among socio-economic groups

In response to the challenges posed by climate change, China has launched the Personal Carbon Inclusion (PCI) scheme to encourage individuals to transition towards low-carbon lifestyles. This study investigates the behaviors of participants within the PCI scheme using a tripartite evolutionary game model, encompassing high-income and low-income individuals, as well as the PCI platform itself. The research analyzes participants' strategies, examines the evolutionary stability of different strategies, and assesses the robustness of equilibrium points within the game dynamics. Key findings reveal: (1) High-income participants tend to be less willing to adopt low-carbon behaviors compared to low-income participants. (2) The PCI platform displays limited proactive engagement in promoting low-carbon policies. (3) Factors, particularly the cost and pricing mechanisms of low-carbon actions, significantly impact the evolutionary progression of the system. Moreover, practical recommendations are provided to enhance the effectiveness of PCI schemes.

Petrology, phase equilibria modelling, and fluid inclusion study of mafic granulites from Bhavani Suture Zone, Southern India

We report new petrology, mineral chemistry, P–T conditions, and fluid inclusion data on mafic granulites from the Mettupalayam region along the Bhavani Suture Zone, Southern Granulite Terrane, India. Phase equilibria modelling of mafic granulites yielded peak P–T conditions of 780–860 °C and 7.6–10.1 kbar followed by a near isothermal decompression along a clockwise P–T path. The trapped fluid inclusions in the peak metamorphic minerals display a melting temperature range from −57.4 °C to −56.6 °C, close to the triple-point temperature of pure CO2. The primary inclusions homogenized at −18.9 °C to +0.2 °C, corresponding to density values of 0.93–1.03 g/cm3. Homogenization of the secondary inclusions occurred within the range from −6.3 to +18.1 °C, corresponding to low CO2 densities of 0.79–0.96 g/cm3. From the textural characteristics of the high-density primary carbonic fluid inclusions, we interpret these inclusions as the CO2-rich syn-metamorphic fluid present during the high-grade metamorphism. The secondary fluids characterised by lower densities have undergone re-equilibration during the exhumation stage (decompression) from the peak granulite-facies metamorphism along a clockwise P–T trajectory. This interpretation is consistent with the occurrence of hornblende + plagioclase symplectite around the porphyroblastic garnet, suggesting decompression. We infer that the high-density CO2 was the dominant syn-metamorphic fluid components present during the granulite-facies metamorphism in the Mettupalayam region. Such carbonic fluids, possibly derived by degassing from carbonates or mantle sources, probably played a significant role in stabilizing high-grade mineral assemblages along this collisional suture zone.

Book review - Post Carbon Inclusion: Transition Built on Justice

Book review - Post Carbon Inclusion: Transition Built on Justice

The effect of land use and land cover on soil carbon storage in the Yellow River Delta, China: Implications for wetland restoration and adaptive management

Gaining a comprehensive understanding of the effect of land use/land cover (LULC) and soil depth on soil carbon storage, through the manipulation of external carbon input and turnover processes, is crucial for accurate predictions of regional soil carbon storage. Numerous research investigations have been conducted to examine the impact of LULC on the storage and cycling of carbon in the surface soils of coastal wetlands. Nevertheless, there remains a dearth of understanding concerning the implications of this phenomenon on subterranean soils, a crucial factor in discerning the capacity for carbon sequestration in coastal wetlands and implementing measures for their preservation. The study focused on the Yellow River Delta (YRD) in China, which serves as a representative model system. It aimed to assess the impact of LULC as well as soil depth on carbon storage. This was achieved by a combination of remote sensing interpretation and field samplings. The findings of the study indicate that there was an increase in soil organic carbon storage with both the area covered and the depth of the soil across the four different land use types, namely forest, grass, tidal flat, and cultivated land. Cultivated land was identified as the predominant LULC type, encompassing 41.73% of the entire YRD. Furthermore, it accounted for a substantial carbon storage of 76.08%. In comparison to soil layers at depths of 0–20 cm and 20–40 cm, 40–60 cm was discovered to have the maximum carbon storage, accounting for 42.29% of total carbon storage. Furthermore, one of the main factors influencing carbon storage is salinity, which shows a negative association with carbon storage. Moreover, the aforementioned findings underscore the significance of the conjoined physical and chemical properties induced by LULC in influencing the dynamics of soil carbon. This suggests that the inclusion of deep soil carbon in the estimation and restoration of soil carbon storage is necessary. This inclusion will support the realization of the United Nations' “Toward Zero Carbon” effort and facilitate the implementation of China's national carbon neutrality objectives.

Physicochemical analysis of Catonyx cuvieri (Mammalia, Xenarthra) remains from the Pleistocene of Paraguay

The fossil-diagenetic characteristics, such as mineralogical aspects present in the ribs of Catonyx cuvieri (Lund, 1839) (Mammalia, Xenarthra), were analyzed in this work. These analyzed remains come from the Risso Cave, San Lazaro's District, Concepción Department, Paraguay. The vibrational response was studied using Raman and Fourier transform infrared (FTIR) and the mineralogy and elemental compositions were examined using multiple characterizations techniques. The main functional groups belong to the mineral part of the bone, and specific functional groups were associated with organic components. The characterization indicated that material was composed of apatites and the original mineral structure was affected by partial ionic substitutions, probably due to the interaction of the fossil with the environment. A Gaussian deconvolution model (GM) was used to identify the individual overlapping bands in the regions of interest in the spectra. A diagenesis pathway for the fossil involved the inclusion of calcium carbonate on the surface of the bone due to the accumulation of moisture, which allowed the recrystallization of hydroxyapatite and the precipitation of calcite in the pores and silicates of the bone. It’s worth mentioning that this work is the first in the ground sloths C. cuvieri in South America. In addition, the material here constitutes the most complete fossil record of a member of the Pleistocene megafaunal of Paraguay.

LiMn0.8Fe0.2PO4 as a promising cathode material in solid-state lithium batteries: Structural and electrical characterization

In this study, the synthesis, structural characterization, and electrical property analysis of LiMn0.8Fe0.2PO4 (LM8F) and its carbon-composite variant (LM8F-10%C) as potential cathode materials for solid-state lithium batteries were reported. Employing high-energy ball milling (HEBM) followed by calcination, LM8F was synthesized using ammonium dihydrogen phosphate, lithium carbonate, manganese(II) acetate tetra-hydrate, and iron(III) phosphate as precursors. The introduction of glucose as a carbon source aimed at the formation of a carbon-coated composite to enhance the electrical conductivity of the material. Structural and morphological characteristics of the synthesized materials were elucidated through X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FeSEM). The XRD results confirmed the olivine and orthorhombic structure of the synthesized material, highlighting its suitability for use as a cathode in solid-state lithium batteries. Electrical properties were assessed using an LCR meter to examine the impact of carbon coating on electrochemical performance. The findings demonstrated that the inclusion of carbon significantly improved the electrical conductivity, potentially leading to enhanced battery performance. This work contributes to the development of high-performance cathode materials for solid-state lithium batteries, paving the way for future advancements in energy storage technologies.

Modification of LiMn0·6Fe0·4PO4 lithium-ion battery cathode materials with a fluorine-doped carbon coating

In this study, glucose and NH4F were utilized as sources of carbon and fluorine, respectively, for the synthesis of LiMn0·6Fe0·4PO4 (LMFP) nanoscales. These nanoscales were subsequently modified with varying levels of fluorine-doped carbon through co-precipitation and mechanical ball milling processes. The LMFP, incorporating carbon and varying levels of fluoride ions, exhibit higher specific discharge capacities at 0.2 Cand electrochemical characteristics compared to the original LMFP coated solely with carbon. The inclusion of fluorine-doped carbon in the composite material creates numerous pathways for expeditious electron transfer. Moreover, the partial formation of metal fluoride at the interface between the surface of LMFP and the layer of carbon coating doped with fluorine enhances the reduction in the charge-transfer resistance. The modified ferromanganese phosphate cathode material reveals an outstanding discharge capacity displaying a reversible discharge specific capacity value of 131.73 mA h g−1 at 10C and 154.6 mA h g−1 at 0.2C, due to its unique structure.

Assessing Carbon Sequestration Potential in State-Owned Plantation Forests in China and Exploring Feasibility for Carbon Offset Projects

In the pursuit of carbon neutrality, state-owned forests are prime candidates for carbon offset projects due to their unique tenure and management characteristics. Employing methodologies endorsed by the International Panel on Climate Change and logistic growth curves, this study assesses the carbon stocks and sequestration potential of established state-owned plantation forests across 31 Chinese provinces from 2023 to 2060, encompassing seven forestry industry groups. This study projects that by 2060, these forests will amass a carbon stock of 558.25 MtC, with the highest stock in Northeast China (122.09 MtC) and the lowest in Northwest China (32.27 MtC), notably showing the highest growth rate at 91.15%. Over the forecast period, they are expected to accumulate a carbon sink of 637.07 MtCO2e, translating to an average annual carbon sink of 17.22 MtCO2e and an average annual carbon sink per unit of 1.41 tons of CO2 per hectare per year. Additionally, state-owned forests have the potential to offset approximately 0.15%–0.17% of annual carbon emissions, aligning with international climate goals. However, it is essential to note that the conversion of these carbon sinks into tradable carbon credits is subject to specific methodology requirements. Therefore, the future development of carbon offset projects in China’s state-owned forests should consider the advancement of carbon market mechanisms, including the Chinese Certified Emission Reduction and the introduction of a carbon inclusion mechanism and natural forest methodology, to fully realize their potential contributions to carbon neutrality. In summary, these findings offer valuable insights for shaping the future of carbon offset initiatives within China’s state-owned forests.

Dark pottery from the early Iron Age in southern Veneto, Italy: The provenance issue under the adoption of specific technological procedures

One of the earliest known settlements of Pre-Roman Padua, Veneto Region (north-eastern Italy) was located in the very centre of the present-day city. The archaeological excavations revealed structures related to craft activities (metallurgical and pottery workshops) and residential areas datable from the late 9th to the 1st century BCE. A large pyrotechnic structure formed by an earthen block densely filled and covered by broken ceramic vessels was found, bringing to light the earliest foundry of the Pre-Roman Padua known to date. Many potsherds found in the site correspond to a regional ceramic class that included coarse and fine wares mainly composed of very dark ceramic bodies. A multi-analytical study based on macroscopic and petrographic descriptions as well as mineralogical, geochemical and microstructural analyses, was carried out in order to state the technological choices adopted for producing these dark vessels and the provenance of the raw materials. A poorly manufacturing was adopted to produce the common pottery, resulting coarse wares uneven textured, while the fine wares were produced by adopting the purification of the base clays and/or the tempering of the clay pastes. Common geo-resources were used, consisting in illitic-chloritic clays rich in quartz and feldspars, the firing regime conditions covered a range of maximum temperatures (normally under 850 °C) and the temper was constituted by silicate (chiefly quartzite, rhyolite and trachyte rock fragments) and/or carbonate (calcite and/or dolomite) inclusions, that were added after having been grounded and/or sieved. The specific mineral and lithic markers of provenance identified in the sherds confirmed the correspondence of this pottery with a local production. However, the specific technological choices that were carried out must be taking into consideration, since the purification removed the larger grains originally present in the base clays and the tempering influenced the chemical composition of the sherds. The different degree of purification of the base clays and the differential tempering procedures that were accomplished point out the adoption of very specific recipes to produce the fine wares, suggesting the correspondence of this local ceramic class with diverse sub-productions and the high level of specialization achieved by the potters in southern Veneto during the Early Iron Age.

Mathematical modelling for predicting performance and emissions of a diesel engine fuelled with palm kernel biodiesel–diesel-diethyl carbonate fuel blends

The search for environmentally friendly and sustainable alternatives to conventional diesel fuels has prompted investigations into blends of biodiesel and oxygenated additives like diethyl carbonate. This study focuses on developing mathematical models to predict the performance and emissions of a single-cylinder diesel engine running on palm kernel biodiesel blended with varying proportions of diethyl carbonate. Response Surface Methodology with a general factorial design was employed to create mathematical models for brake thermal efficiency, brake-specific fuel consumption, hydrocarbon, carbon monoxide, and oxides of nitrogen emissions. The two input variables were engine load (five levels) and diethyl carbonate percentage in the fuel blend (five levels). Second-order models were developed, and model fit was evaluated using analysis of variance (ANOVA) at 95% confidence. The developed RSM models showed excellent fit with high R-squared values close to unity, satisfying the model adequacy criteria. ANOVA revealed the models to be statistically significant predictors of the response variables based on load and diethyl carbonate percentage. The optimum operating condition for best performance and emissions balance was found to be 71% load and 10% diethyl carbonate inclusion. The study emphasises the importance of alternative fuels in mitigating environmental pollution and reducing dependence on fossil fuels.

Gas-phase Condensation of Carbonated Silicate Grains

Reports on the detection of carbonates in planetary nebulae (PNe) and protostars have suggested the existence of a mechanism that produces these compounds in stellar winds and outflows. A subsequent laboratory study has reported a possible mechanism by presenting the non-thermodynamic-equilibrium (TE), gas-phase condensation of amorphous silicate grains with amorphous calcium carbonate inclusions. The authors concluded that water vapor was necessary for the formation of the carbonates. We present a laboratory study with pulsed laser ablation of a MgSi target in O2 and CO2 gases and report, in the absence of water vapor, the non-TE, gas-phase condensation of amorphous carbonated magnesium silicate dust. It consists of amorphous silicate grains with the formula MgSiO3, which comprise carbonate groups homogeneously dispersed in their structure. The IR spectra of the grains show the characteristic bands of amorphous silicates and two bands at ∼6.3 and ∼7.0 μm, which we assign to the carbonate groups. The silicate bands are not significantly affected at an estimated Si:C ratio of 9:1–9:2. Such grains could form in winds and outflows of evolved stars and PNe if C atoms are present during silicate condensation. Additionally, we find that Lyα radiation dissociates the carbonate groups at the surface of the carbonated silicate grains and we estimate the corresponding photodissociation cross section of (0.04 ± 0.02) ×10−16 cm2. Therefore, photodissociation would limit the formation of carbonate groups on grains in winds and outflows of stars emitting vacuum ultraviolet photons, and the carbonates observed in protostars have not formed by gas-phase condensation.