Composition Process Research Articles

Depositional Environment and Ecological Response of Bioconstructions: A Case Study of Southern China (Guizhou Province) in Moscovian-Gzhelian.

From the late Carboniferous to the early Permian, multiple pulses of glaciation and deglaciation have been caused by the LPIA. The Pennsylvanian period experienced phases of recovery, proliferation, and decline, ultimately forming a reef system distinctly different from that of the Mississippian period. During the late Bashkirian to Moscovian, the metazoan reef experienced a limited resurgence, with reef predominantly formed by chaetetid developing in the United States, northern China, and Japan. During the Kasimovian to Gzhelian, the phylloid algal reef dominated the global reef systems. In the late Pennsylvanian, bioconstruction cases and paleoenvironmental proxies in southern Guizhou Province were studied to investigate the composition, recovery, and evolutionary processes of the bioconstructions as well as their response to environmental variations during this period. Several bioconstructions have been reported in the Lumazhai section of Houchang Town, Guizhou Province, southern China, from the Moscovian to the Gzhelian. The upper Carboniferous strata are well-preserved and continuously exposed. The continuous strata, abundant fossils, and diverse bioconstructions provide excellent research materials for exploring the mutual constraints between organisms and their environment. This study identified ten microfacies, whose vertical evolution indicated significant changes in the depositional environment related to relative sea-level fluctuations. Skeletal grains are widely present in these facies. Among them, foraminifera, algae, bryozoans, crinoids, and Tubiphytes are the most common and exhibit distinct distribution characteristics in various environments. Quantitative statistics, CCA and theoretical ecospace have been utilized to examine and interpret environmental impact factors. Quantitative analysis of their relative abundance and distribution patterns provides insights into the complex interactions between organisms and environmental factors. The relative abundances of different organisms and factors controlling their bioconstructions are influenced by relative sea-level changes. CCA analysis reveal that hydrodynamic conditions are the primary influencing factor. Variation trends in average tiering and motility reveal the characteristics of biological communities during environmental changes in phylloid algae and microbial bioconstructions. These bioconstructions are not directly correlated with changes in environmental factors, and the biological communities in phylloid algae mounds and biostromes exhibit similar organism compositions and ecological niches across different environments.

Methylparaben changes the community composition, structure, and assembly processes of free-living bacteria, phytoplankton, and zooplankton

Parabens are common contaminants in river and lake environments. However, few studies have been conducted to determine the effects of parabens on bacteria, phytoplankton, and zooplankton communities in aquatic environments. In this study, the effect of methylparaben (MP) on the diversity and community structure of the aquatic plankton microbiome was investigated by incubating a microcosm with MP at 0.1, 1, 10, and 100 μg/L for 7 days. The results of the Simpson index showed that MP treatment altered the α-diversity of free-living bacteria (FL), phytoplankton, and zooplankton but had no significant effect on the α-diversity of particle-attached bacteria (PA). Further, the relative abundances of the sensitive bacteria Chitinophaga and Vibrionimonas declined after MP addition. Moreover, the relative abundances of Desmodesmus sp. HSJ717 and Scenedesmus armatus, of the phylum Chlorophyta, were significantly lower in the MP treatment group than in the control group. In addition, the relative abundance of Stoeckeria sp. SSMS0806, of the Dinophyta phylum, was higher than that in the control group. MP addition also increased the relative abundance of Arthropoda but decreased the relative abundance of Rotifera and Ciliophora. The β-diversity analysis showed that FL and phytoplankton communities were clustered separately after treatment with different MP concentrations. MP addition changed community assembly mechanisms in the microcosm, including increasing the stochastic processes for FL and the deterministic processes for PA and phytoplankton. Structural equation modeling analysis showed a significant negative relationship between bacteria richness and phytoplankton richness, and a significant positive relationship between phytoplankton (richness and community composition) and zooplankton. Overall, this study emphasizes that MP, at environmental concentrations, can change the diversity and structure of plankton microbial communities, which might have a negative effect on ecological systems.

Hydrogeochemical characteristics and agricultural suitability of shallow groundwater quality in a concentrated coalfield area of Huaibei Plain, China.

Groundwater is one of the chief water sources for agricultural activities in an aggregation of coal mines surrounded by agricultural areas in the Huaibei Plain. However, there have been few reports on whether mining-affected groundwater can be adopted for agricultural irrigation. We attempted to address this question through collecting 71 shallow groundwater samples from 12 coal mining locations. The Piper trilinear chart, the Gibbs diagram, the proportional coefficient of major ions, and principal component analysis were examined to characterize the source, origin, and formation process of groundwater chemical composition. The suitability for agricultural irrigation was evaluated by a final zonation map that establishes a comprehensive weighting model based on analytic hierarchy process and criteria importance though the intercriteria correlation (AHP-CRITIC). The results revealed that the groundwater was classified as marginally alkaline water with a predominant cation of HCO3- and anion of Na+. Total hardness, total dissolved solids, sulfate (SO42-), sodium (Na+), and fluoride (F-) were the primary ions that exceeded the standard. The results also indicated that the dominant hydrochemical facies were Ca-HCO3 and Na-Cl. The dissolution of carbonate, silicate, sulfate minerals, along with cation exchange, were the main natural drivers controlling the hydrogeochemical process of groundwater. The zonation map suggested that 43.17%, 18.85%, and 37.98% of the study area were high, mediate, and low suitability zones, respectively. These results from this study can support policymakers for better managing groundwater associated with a concentration of underground coal mines.

‘Christian notes sound sweetest suffering’: birds, books and textual circulation in Sir John Gibson’s commonplace book (BL Add 37719)

ABSTRACT A growing body of scholarship has worked to recover the vocal dimensions of early modern reading and the effects of aural reading cultures on literary composition. Where these studies have focused on the relationship between the human voice and early modern texts, this article examines how the seventeenth-century royalist prisoner Sir John Gibson deploys early modern ideas about birds and birdsong as he seeks consolation through the material and textual processes of literary composition, manuscript compilation, and epistolary exchange. These efforts are evident in his physical and imaginative construction of his miscellany (BL Add 37719) as possessing bird-like capacities for movement and communication. While Gibson’s miscellany does draw on familiar seventeenth-century ideas about music and the human voice, I argue that his invocations of birds and birdsong produce intriguing and powerful claims for the ways written texts can extend the capabilities of the human voice and body.

A New Paradigm for Semiconductor Manufacturing: Integrated Synthesis, Delivery, and Consumption of Source Chemicals for IC Fabrication

The semiconductor industry is being radically impacted by the placing of greater emphasis on the development of hetero-devices and systems that will act as essential drivers for a wide spectrum of technological applications. The introduction of new materials and their integration with currently used materials are projected to replace integrated circuitry (IC) design and device scaling as the key enablers to the realization of improved device performance and larger density gains. Yet material selection has been constrained by existing fabrication process technology. To date, fabrication processes have dictated material selection by limiting chemical sources or precursors to those that match existing process tools associated with chemically based vapor phase processes and their variants, which in turn limits material compositions in ICs. The processing and integration of new materials compositions and structures will require the introduction of new deposition and etching processes, and manufacturing worthy tool designs and associated protocols that provide new methods for atomic-level control. To this end, a novel manufacturing paradigm is presented comprising a method and system for real-time, closed-loop monitoring and control of synthesis, supply, and consumption of precursors in process intensification techniques including chemical vapor deposition (CVD), atomic layer deposition (ALD), atomic layer etching (ALE), and other IC manufacturing processes. This intelligent automated manufacturing approach is consistent with a central component of the semiconductor industry’s recent adoption of Industry 4.0., including vertical integration of IC manufacturing through robotization, artificial intelligence, and cloud computing. Furthermore, the approach eliminates several redundant steps in the synthesis, handling, and disposal of source precursors and their byproducts for CVD, ALD, ALE and other chemically based manufacturing processes, and thus ultimately lowers the manufacturing cost for both conventional and new IC materials. Further, by eliminating the issues associated with precursor thermal, chemical, and pyrophoric instabilities, this new paradigm enables the deposition of a myriad of new thin-film materials and compositions for IC applications that are practically unattainable with existing precursors. Preliminary and planned demonstration examples for the generation and deposition of highly toxic and unstable source precursors are provided.

Consequences of Local Conspecific Density Effects for Plant Diversity and Community Dynamics.

Conspecific density dependence (CDD) in plant populations is widespread, most likely caused by local-scale biotic interactions, and has potentially important implications for biodiversity, community composition, and ecosystem processes. However, progress in this important area of ecology has been hindered by differing viewpoints on CDD across subfields in ecology, lack of synthesis across CDD-related frameworks, and misunderstandings about how empirical measurements of local CDD fit within the context of broader ecological theories on community assembly and diversity maintenance. Here, we propose a conceptual synthesis of local-scale CDD and its causes, including species-specific antagonistic and mutualistic interactions. First, we compare and clarify different uses of CDD and related concepts across subfields within ecology. We suggest the use of local stabilizing/destabilizing CDD to refer to the scenario where local conspecific density effects are more negative/positive than heterospecific effects. Second, we discuss different mechanisms for local stabilizing and destabilizing CDD, how those mechanisms are interrelated, and how they cut across several fields of study within ecology. Third, we place local stabilizing/destabilizing CDD within the context of broader ecological theories and discuss implications and challenges related to scaling up the effects of local CDD on populations, communities, and metacommunities. The ultimate goal of this synthesis is to provide a conceptual roadmap for researchers studying local CDD and its implications for population and community dynamics.

Impacts of Soil Compaction and Phosphorus Levels on the Dynamics of Phosphate-Solubilizing and Nitrogen-Fixing Bacteria in the Peanut Rhizosphere

Soil properties, including soil compaction and the nutrient content, influence the composition and functions of rhizosphere microbial communities. There is limited information on how soil compaction and phosphorus application affect phosphate-solubilizing (PSB) and nitrogen-fixing bacteria (NFB). This study aimed to examine the responses of PSB and NFB in the rhizosphere of peanut (Arachis hypogaea L.) plants under varying soil compaction and phosphorus application levels. To address this, pot experiments were conducted to assess the composition and assembly processes of rhizosphere PSB and NFB in peanut cultivar Hua Yu 22 under two soil compaction levels (T1, 1.25 g/cm3 compaction, and T2, 1.00 g/cm3 compaction) and two phosphorus (P) levels (P0, no P applied, and P1, 1.2 mM P/kg soil applied). The results showed that PSB community shifts were closely correlated with the content of soil available phosphorus, soil acid phosphatase activity, soil nitrogenase activity, and soil compaction. Additionally, the content of soil available phosphorus and soil compaction were correlated with changes in operational taxonomic units of NFB. A network analysis revealed that the complexities of PSB were significantly higher than those of NFB. A stronger negative relationship was identified among NFB communities. The assembly of PSB communities was primarily driven by drift processes, whereas NFB communities were influenced by a combination of homogenizing selection and drift. Both PSB and NFB community compositions were significantly affected by phosphorus limitations and soil compaction. These findings enhance our understanding of the impacts of soil compaction and phosphorus application on PSB and NFB communities, with implications for optimizing peanut crop production. Our results will provide reference for crop cultivation in compacted and low-phosphorus soils. The important phosphate-solubilizing and nitrogen-fixing bacteria screened in the interaction network in this study will become candidate microbial agents for alleviating soil compaction and low phosphorus levels.

Effect of additional Al sources on early-age strength of fly ash-based geopolymer containing calcium carbide residue and Glauber’s salt as activators

Alkali-activated materials are more environmentally friendly than cementitious composites and are used in the construction and building sector. However, their intrinsic low early strength under ambient temperatures hinders their practical applicability. More research is needed on the possibilities of increasing early strength at ambient temperatures. In this study, aluminum sulfate (AS) was used as an additional aluminum source to improve the early-age properties of fly ash (FA)-based geopolymers incorporating calcium carbide residue (CCR) and Glauber’s salt (GS) as activators. XRD, TG, SEM, ICP and isothermal calorimetry analyses were carried out to characterize the phase composition, microstructure and hydration process of the prepared materials. The results showed that the 1d strength of AS1-CCR10 was increased by 260.7 % compared with the control material, and the effect on the late strength was negligible. The relative content of AFt increased by 2.97 %, creating a more compact microstructure. During the extraction process, insufficient dissolved Al3+ in the composite led to a decrease in initial strength. In the hydration process, the induction period of AS1-CCR10 was advanced by 40.92 % and that of t50 was advanced by 57.74 %, which accelerated the early reaction rate. However, the Krstulovic-Dabic model could not accurately describe the initial stage of the hydration reaction of composite materials. This study is helpful to broaden the utilization of geopolymer composites and provide a theoretical basis for the preparation and reaction mechanism of alkali-activated materials.

Studies of the phase composition and ultrafine structure of the initial domestic raw materials of proppants

The results of the study of intracrystalline electric and magnetic fields in samples on 57Fe nuclei by the ultrafine method of the Mossbauer effect are considered. The source of gamma radiation was 57Co in the chromium matrix. The spectra of the samples were measured on 57Fe nuclei using the MS1104Em spectrometer in the mode of constant accelerations at room temperature for absorption. The crystal structure, phase composition, and electronic states of individual components of the proppants are given. The measurements were carried out on the d8 Advance universal complex (Bruker, Germany). The data of parameters recorded on detectors of secondary energy characteristics of X-rays corresponding to K, L, M, N and O levels of electronic transitions using computer processing of elemental compositions and their ratios in samples are analyzed. The data of X-ray studies of the composition of fly ash are presented, determining its potential application in various industries, including the production of proppants. The results of the analysis of the chemical composition of bauxite samples obtained by X-ray diffraction analysis are presented. The silicon modulus (µSi) has been determined, which is the ratio of Al2O3 to SiO2 to characterize the quality of bauxite. The main components of bauxite were Al2O3 (aluminum oxide) and SiO2 (silicon dioxide). A significant content of Fe2O3 (iron oxide) was also noted, which is 24-33 wt. % for bauxite.

Study of Aging Characteristics for Metalized HTPB Based Composite Solid Propellants Stored in Ambient Conditions

The aging of any propellant is defined as the change in the physical, chemical, and performance parameters of solid rocket propellants. The propellant’s service life and aging properties are important parameters of the study, especially for missiles and other defense applications. Hydroxyl-terminated polybutadiene (HTPB) based composite solid propellants with ammonium perchlorate (AP) are the most prominently used propellants in the operations of solid rocket motors in the defense and space sectors. Thus, studying this composite solid propellant is of essential when determining ambient service life. Performance parameters studied in this research are burn rate under high-pressure conditions in Crawford bomb setup, Thermogravimetric Analysis, and Fourier Transform Infrared Spectroscopy (FTIR). SEM and X-ray diffraction (XRD) analysis of the aged sample were also conducted to ascertain the chemical composition and morphological changes in the samples. Naturally aged propellant strands manufactured in different years have been compared with freshly prepared ones to establish a trend for deriving conclusions. The results from different analysis techniques, FTIR, XRD, and FESEM, depicted that oxidation of metals happens while aging of propellant due to atmospheric moisture, and the metal oxides prominently affect the propellant chemical composition and decomposition process of the propellant samples. The ballistic properties of the aluminium added samples showed an increment in burn rate. In contrast, the bimetal addition of aluminium and magnesium combined as an additive decreased the ballistic burn rate.

Distinct influences of altitude on microbiome and antibiotic resistome assembly in a glacial river ecosystem of Mount Everest

The profound influences of altitude on aquatic microbiome were well documented. However, differences in the responses of different life domains (bacteria, microeukaryotes, viruses) and antibiotics resistance genes (ARGs) in glacier river ecosystems to altitude remain unknown. Here, we employed shotgun metagenomic and amplicon sequencing to characterize the altitudinal variations of microbiome and ARGs in the Rongbu River, Mount Everest. Our results indicated the relative influences of stochastic processes on microbiome and ARGs assembly in water and sediment were in the following order: microeukaryotes < ARGs < viruses < bacteria. Moreover, distinct assembly patterns of the microbiome and ARGs were found in response to differences in altitude, the latter of which shift from deterministic to stochastic processes with increasing differences in altitude. Partial least squares path modeling revealed that mobile genetic elements (MGEs) and viral β-diversity were the major factors influencing the ARG abundances. Taken together, our work revealed that altitude-caused environmental changes led to significant changes in the composition and assembly processes of the microbiome and ARGs, while ARGs had a unique response pattern to altitude. Our findings provide novel insights into the impacts of altitude on the biogeographic distribution of microbiome and ARGs, and the associated driving forces in glacier river ecosystems.

Siam folk tune “Lanna” for string orchestra

This article discusses the compositional materials and process of “Lanna” for string orchestra based on folk tunes from Northern Thailand (Lanna). The composition comprises 6 movements for a duration of 50 minutes. The composer carefully selected folk tunes and rendered a balance between the borrowed ones and the newly composed materials through the careful mix of musical elements, including keys, melodies, rhythmic patterns, idioms, and re-created the sound to imitate the performance techniques of the original instruments. Certain Western compositional techniques were adapted to fit the original melodies in order to retain the identity of the work and provide a balanced blend of the original Eastern and the new Western melodies, thereby creating a new perspective of sound as well as an inspiration for other composers to continue crafting music in this genre. Traditional Lanna tunes, including Fon Phang, Pan Fai, Noi Chai Ya, and Lao Duang Dokmai are presented partly in multi movements to convey traditional melodies. Imitations of certain singing and playing techniques are also transcribed via selections of instruments in the ensemble, especially the violin solo, to portray both the authentic Lanna atmosphere and the blend of the two cultures.

Whole rock lithogeochemical analysis of the Mount Read Volcanics: a new tool for geochemical exploration

The Mount Read Volcanics (MRV) of western Tasmania is a belt of Middle to Late Cambrian submarine volcanics and volcaniclastics and one of the major base and precious metal provinces within Australia. Exploration success in the MRV has been in decline in recent years due to a variety of challenges including intensely altered rocks with complex stratigraphy and lithofacies variation, and a lack of accessible outcrop. As a result, local and regional mapping of the MRV is often restricted to Group-level stratigraphy, rendering geological mapping ineffective for identifying decametre-scale mine stratigraphy. Surface rock chip and drill hole samples were collected and analysed using commercially available geochemical assays to create a regional geochemical dataset of the MRV, covering the entire province and all major stratigraphic units. From these data, a lithogeochemical methodology was developed, utilizing Ti/Nb and V/Sc systematics that effectively characterizes the samples according to composition and magmatic processes. This method is shown to be robust to biases due to alteration and lithofacies, eliminating the need for highly selective sampling or extensive data filtering. To demonstrate the utility of this method in an exploration context, data from the K-lens of the Rosebery polymetallic volcanic-hosted massive sulfide (VHMS) deposit was used as a case study. Using Ti/Nb–V/Sc systematics, a rock composition classification was developed that allowed for discrimination of the footwall, hanging wall and host stratigraphy of the Rosebery mine sequence. A geochemical fingerprint for the footwall stratigraphy to mineralization was developed, and by correlating this signature to the regional unclassified samples, geochemical analogues for the Rosebery footwall were readily identified. This approach rapidly reduces the exploration search space and provides valuable information for future mineral exploration. The methodology is applicable in other terrains; however, appropriate orientation studies are required to investigate potential biases due to lithofacies, alteration and mineralogical variability.

HUMAN THOUGHT PROCESS ON HOTEL ADVERTISEMENTS:

Conceptual Blending (CB) is a framework within Cognitive Linguistics to create meaning construction that determines brain cognitive functions upon reading hotel advertisements which the study aimed to illustrate and elaborate. The study utilized advancement theory of CB by applying intertextuality concept to create multiple meanings done from prior studies. The study also utilized qualitative method to analyze a poster from ANA Intercontinental Manza Beach Resort through applying non-participant observation, purposive sampling, and triangulation theory methods. To analyze the data, the concepts of data collection, data condensation, data display and data conclusion were used. The study found that the processes of composition, completion, and elaboration within blended space of CB built the meaning construction within human brain. Composition stage created arrays of features from composing features within input spaces that build up new concepts within completion stage. The completion stage then created new concepts based on cultural knowledge combining all the features composed within composition process and the meanings were broaden by elaboration stage which cleared out what the new concepts actually meant for. These processes created the emergent structure which carries novelty meanings from the analysis. In this stage, the meaning has been completely concluded from all the elaborated meaning happening on prior stages.

Mulching drive changes in soil microbial community assembly processes and networks across aggregate fractions

Soil microbial community assembly processes and networks in croplands have been widely explored; however, their dynamics and how they regulate winter wheat yield across distinct soil aggregate fractions under the combined effects of mulching and soil horizons have not been comprehensively understood. Therefore, based on a 9-y field experiment, the responses of soil bacterial and fungal community assembly processes and interkingdom association networks to mulching were specifically investigated at the soil aggregation level. Soil properties and microbial biomass were separated into distinct mulching in the topsoil (0–10 cm), and soil water content was considered the most critical factor. The soil bacterial community was affected mainly by mulching and soil horizon compared with the fungal community in microaggregates (<0.25 mm). Notably, the bacterial community displayed more robust stochastic processes than the fungal one, and microbial interkingdom association networks were more complex and stable in micro-than macroaggregates. Soil potential carbon mineralization, pH, and total nitrogen were the dominant properties regulating winter wheat grain yield in combination with microbial community composition, assembly processes, and networks in each soil aggregate class. Wheat yield decreased under straw mulching and was mainly regulated by bacterial community composition and assembly processes. Thus, this study enhanced our understanding of the regulations for wheat yield, which could facilitate soil microbial community management at the aggregation level for sustainable crop production in mulching conservation agroecosystems.

Effect of Ni and Nb concentration on microstructural evolution in a 20Cr ferritic alloy strengthened by Ni16Nb6Si7-G phase

The effects of Nb and Ni contents on the precipitation of the Ni16Nb6Si7-G phase and the resulting hardening behavior in Fe–20Cr ferritic alloys were systematically investigated using micro-hardness, electron microscopy, and atom probe techniques. The results demonstrate that an optimal Nb content of ∼0.75 wt. % promotes the precipitation of the Ni16Nb6Si7-G phase, leading to a maximum micro-hardness of approximately 430 H V when aged at 560 °C for 24 h. Excess Nb content (>0.75 wt. %) introduces the Fe2Nb-Laves phase at grain boundaries and within the grains, which competes with the G-phase for precipitation. Conversely, an increase in Ni content effectively raises the dissolution temperature of the Ni16Nb6Si7-G phase to approximately 850 °C. The austenite phase begins to form when the Ni content exceeds 4 wt. %. Finally, the strengthening effect of the Ni16Nb6Si7-G phase and its underlying competition precipitation with the Fe2Nb-Laves phase as well as the possible benefit of inducing austenite phase was discussed in the context of developing 20Cr ferritic alloys with high strength and good ductility. These findings provide valuable insights into the influence of Nb and Ni contents on the microstructural evolution and mechanical properties of the newly developed 20Cr alloy, which may be helpful in guiding the design of high performance ferritic alloys by optimizing composition and heat treatment processes.

Diverse biological communities promote SOM molecular diversity and compositional transformations during natural fallow stage in paddy fields

Monoculture cultivation patterns in agro-ecosystems only provide less varied soil organic matter (SOM) molecules of plant origin. Whether and how the natural fallow stage between cultivation seasons facilitates the restoration of SOM molecular diversity and mitigates the adverse impacts of constant cropping pattern is elusive. Here, we utilized FT-ICR-MS, UHPLC-MS/MS, and high-throughput sequencing to investigate the biological change processes in SOM molecular composition under cultivation and fallow status in a long-farmed paddy field. Our study showed that SOM molecular diversity increased by 45.70%–85.36% in fallow stage compared to rice cultivation season. SOM molecular diversity was positively correlated with bacterial diversity and root exudate molecular diversity, and negatively correlated with fungal diversity. Notably, root exudate molecular diversity accounted for 48.48% of the variation in SOM molecular diversity. The increased SOM molecular diversity in fallow stage was attributed more to the diverse plant-produced molecules than the microbe-consumed molecules. Plant species turnover resulted in the conversion of root exudate components to Organoheterocyclic compounds and Organic acids/derivatives from rice planting stage to fallow stage. Recruited microbes were dominated by Basidiomycita, Ascomycota, Acidobacteria, Chloroflexi and Proteobacteria, resulting in the transformation from carbohydrates, lipid-like SOM molecules to lipid-like and lignin-like SOM molecules. Both field and microcosm experiments confirmed that root exudates are the main source of SOM molecules, and are influenced by the soil microbial community. This study provides solid evidence that fallow status in agro-ecosystems provides explosion of biodiversity and counteracts the negative effects of long-term monoculture cultivation on SOM diversity.Graphical

A Line-Search-Based Algorithm for Multiphase Flash Calculations with CO2-Hydrocarbon System.

Multiphase flash calculations are pivotal in compositional simulation, necessitating a robust and efficient computational algorithm. In this work, we have developed a line-search-based algorithm framework for stability analysis and multiphase flash calculations. This algorithm is rooted in the modified Newton step and line-search method. The modified Newton step, derived from modified Cholesky factorization, ensures a descent direction, while the line search determines the degree of decrease. This combination facilitates convergence even in challenging regions for phase stability analysis and multiphase flash calculations, exhibiting superlinear convergence speed. Unlike traditional approaches that rely on successive substitution iteration and may resort to Newton iteration only if the Hessian matrix is positive definite, our algorithm incorporates modification via modified Cholesky factorization upon encountering a nonpositive definite Hessian matrix. We tested our algorithm with several classical fluids, demonstrating its efficiency and robustness. Furthermore, we assessed the algorithm's performance by computing the pressure-composition diagram for the CO2-hydrocarbon system, where all calculations achieved rapid convergence without failure. This newly developed algorithm for phase stability analysis and multiphase flash calculations represents a significant advancement for compositional or chemical process simulations.

Strength stability at high temperatures for additively manufactured alumina forming austenitic alloy

Several fast-spectrum nuclear reactors designed to generate high power (∼450 MWe) rely on forced convection of media such as supercritical CO2, sodium, or liquid lead to cool the nuclear core, operating at temperatures up to 600 °C. Cost-effective, high-strength Fe-based alumina forming austenitic (AFA) alloys are a promising candidate for the fabrication of critical nuclear components. This study investigated laser powder bed fusion (LPBF) processing of an AFA alloy composition optimized for improved creep resistance. Electron microscopy revealed an elongated grain structure along the build direction with a fine sub-grain cellular structure decorated with (Cr,Fe,Nb)23C6 carbide precipitates at the intercellular boundaries. At temperatures of 20–900 °C, the LPBF alloy's superior tensile properties compared to its arc-melted counterpart and other advanced steels (e.g., SS316) were attributed to the distribution of nano-sized carbide precipitates, whereas the high ductility was attributed to the LPBF alloy's elongated grain structure.

Characteristics of stachyose-induced effects on gut microbiota and microbial metabolites in vitro associated with obesity in children.

Childhood obesity presents a serious health concern associated with gut microbiota alterations. Dietary interventions targeting the gut microbiota have emerged as promising strategies for managing obesity in children. This study aimed to elucidate the impact of stachyose (STS) supplementation on the gut microbiota composition and metabolic processes in obese children. Fecal samples were collected from 40 obese children (20 boys and 20 girls) aged between 6 and 15 and in vitro fermentation was conducted with or without the addition of STS, respectively, followed by 16S rRNA amplicon sequencing and analysis of short-chain fatty acids (SCFAs) and gases. Notably, our results revealed that STS supplementation led to significant alterations in gut microbiota composition, including an increase in the abundance of beneficial bacteria such as Bifidobacterium and Faecalibacterium, and a decrease in harmful bacteria including Escherichia-Shigella, Parabacteroides, Eggerthella, and Flavonifractor. Moreover, STS supplementation resulted in changes in SCFAs production, with significant increases in acetate levels and reductions in propionate and propionate, while simultaneously reducing the generation of gases such as H2S, H2, and NH3. The Area Under the Curve (AUC)-Random Forest algorithm and PICRUSt 2 were employed to identify valuable biomarkers and predict associations between the gut microbiota, metabolites, and metabolic pathways. The results not only contribute to the elucidation of STS's modulatory effects on gut microbiota but also underscore its potential in shaping metabolic activities within the gastrointestinal environment. Furthermore, our study underscores the significance of personalized nutrition interventions, particularly utilizing STS supplementation, in the management of childhood obesity through targeted modulation of gut microbial ecology and metabolic function.