Formation Process Research Articles

A Global-Local collaborative approach to quantifying spatial non-stationarity in three-dimensional mineral prospectivity modeling

The three-dimensional (3D) modeling of mineral prospectivity plays a pivotal role in the mineral exploration process, enabling explorers to identify, evaluate, and prioritize deep-seated targets more effectively.Accurately predicting the 3D distribution of mineral prospectivity relies on effectively quantifying correlations to mineralization. The ore formation process is extremely intricate, marked by spatial non-stationary correlations. While state-of-the-art 3D mineral prospectivity modeling methods use machine learning (including deep learning) to capture correlation between geological evidence and mineralization hidden in the geosciences data, limited attention has been given to quantifying the local non-stationary nature in ore formation. This paper proposes a novel method that adapts to local spatial non-stationarity in 3D mineral prospectivity modeling. The approach integrates a prospectively model with a local regression model, creating a global–local collaborative model to quantify spatial non-stationary associations with mineralization. Random Forest (RF) and Reset are employed to construct mineral prospectivity models that quantify the global associations with mineralization. Simultaneously, the geographically weighted regression (GWR) model serves as a local model to capture the local non-stationarity within mineralization association. An Expectation Maximization algorithm is tailored to bridge the gap between global and local models, resulting in an iterative framework that progressively fuses global spatial associations and local non-stationarity related to mineralization. The iterative process generates a mineral perspectivity model that adapts to local non-stationarity in predictive areas. A case study on the Dingjiashan Pb-Zn deposit validates the effectiveness of the proposed method. The results demonstrate that the global–local collaborative mineral perspectivity model significantly boosts prediction accuracy in predictive areas. Moreover, the regression parameters of GWR derived from the model construction process effectively reveal the spatial non-stationary impacts of different ore-controlling factors, thereby improving the interpretability and reliability of predicted mineral prospectivity.

Role of elasticity on polymeric droplet generation and morphology in microfluidic cross-junctions

Recently, our direct numerical simulations [Duan et al., Phys. Fluids 36, 033112 (2024)] showed that fluid elasticity affects the extension length and pinch-off time of the droplet formation process, thus changing the flow pattern. However, the effect of fluid elasticity on the morphology and properties of polymeric droplets is not yet fully understood. In this work, by analyzing the stretched state of the polymer macromolecule and the velocity distribution of the flow process, we find that the increase in fluid elasticity (characterized by the relaxation time) inhibits the contraction of the dispersed phase during droplet pinching and resists the effect of surface tension after droplet generation, which significantly affects the droplet geometry, volume, and generation frequency. The results demonstrate that the length and volume of polymeric droplets increase with the relaxation time of the polymer fluid, while the generation frequency decreases. Meanwhile, the effects of polymer viscosity and the superficial velocity ratio of the continuous to the dispersed phase on the droplets' morphology are investigated. The semi-empirical models for the length, volume, and generation frequency of polymeric droplets are developed for the first time by considering the elastic interaction. The purpose of our work is to provide a better understanding and experimental guidance for controlling the parameters of polymeric droplets with viscoelasticity of different shapes and sizes.

Revealing mechanism of phenol-amine reaction to form humus in compost based on high-resolution liquid chromatography mass spectrometry and spectroscopy

Humus is the stable form of carbon storage in straw compost. The phenol-amine reaction is a pathway for humus formation in straw compost. In this study, two reaction systems, GP group (pyrogallol and glycine) and GCP group (catechol, pyrogallol, and glycine), were constructed in a simulated composting environment and revealed the molecular binding mechanism of the phenol-amine reaction through spectroscopy and mass spectrometry. The results showed that phenolic self-polymerization was faster than phenol-amine reaction. Therefore, the aromatization degree of GP was 27.14 % higher than that of GCP. The phenol-amine reaction first produced fulvic acid, and then formed humus units rich in active functional group structures (i.e., phenolic hydroxyl and carboxyl groups). These units further captured small molecule compounds to form humic acid eventually. This study would provide theoretical support for exploring the humus formation process and the promotion of straw humification by adding phenol or amino acids to compost.

HST Survey of the Orion Nebula Cluster in ACS/Visible and WFC3/IR Bands. IV. A Bayesian Multiwavelength Study of Stellar Parameters in the Orion Nebula Cluster

We have performed a comprehensive study of the Orion Nebula Cluster (ONC) combining the photometric data obtained by the two Hubble Space Telescope Treasury programs that targeted this region. To consistently analyze the rich data set obtained in a wide variety of filters, we adopted a Bayesian approach to fit the spectral energy distribution of the sources, deriving mass, age, extinction, distance, and accretion for each source in the region. The three-dimensional study of mass distribution for bona fide cluster members shows that mass segregation in the ONC extends to subsolar masses, while the age distribution strongly supports the idea that star formation in the ONC is best described by a major episode of star formation that happened ∼1 Myr ago. For masses ≳0.1 M ⊙, our derived empirical initial mass function (IMF) is in good agreement with a Chabrier system IMF. Both the accretion luminosity (L acc) and mass accretion rates ( Ṁacc ) are best described by broken power-law relations. This suggests that for the majority of young circumstellar disks in this cluster the excess emission may be dominated by X-ray-driven photoevaporation by the central star rather than external photoevaporation. If this is the case, the slopes of the power-law relations may be largely determined by the initial conditions set at the onset of the star formation process, which may be quite similar between regions that eventually form clusters of different sizes.

Study of droplet formation in parallel flow focusing microchannel under electrostatic field control

To achieve efficient preparation of emulsion droplet, this paper uses a two-dimensional mathematical model coupled with a phase field model and an electrostatic field model to calculate the droplet formation in parallel flow focusing multichannel, and analyzes the effect of electric field strength on the droplet formation process. In addition, the effects of different capillary numbers and dispersed phase viscosity on droplet formation were also analyzed. The results show that the emulsion in the channel always generates droplet by dripping regime, and the droplet have the best mono-dispersity. Applying appropriate electric field strength can realize droplet formation frequency and size regulation. Increasing the dispersed phase viscosity increases the breakup thread of the dispersed phase fluid, and the droplet size obtained gradually decreases, the difference in droplet size can be slowed down by applying the electric field. Increasing the electrostatic force leads to a higher droplet deformation rate. The droplet shape classification is plotted using the capillary number (Ca) and electrostatic number (CaE). It is found that the droplet flow pattern in the channel remains a circle only when Ca and CaE are sufficiently small.

Research and development of double layer P-doped laser induced graphene thin film electrode for flexible micro-supercapacitor applications

Laser-induced graphene (LIG) has garnered significant attention for its cost-effectiveness and high efficiency in fabricating flexible micro-energy storage devices. In this study, we devised a simple method to fabricate double layer P-doped LIG electrodes through repetitive laser induction technology for high-performance flexible energy storage applications. Instead of utilizing commercial polyimide (PI) thin film, we optimized the formation process of P-doped PI thin film and achieved a highly flexible double layer P-doped LIG thin film electrode with a uniformly porous structure and the high porosity through repeated laser induction processes. Experimental results demonstrated that the developed double layer P-doped LIG thin film electrode exhibits high porosity, high specific areal capacitance of 180 mF cm-2, and high energy density of 0.025 mWh cm-2. Furthermore, an all-solid-state micro-supercapacitor utilizing hydrogel electrolyte was assembled, demonstrating a high areal capacitance of 62 mF cm-2 and excellent cycling stability with 95% capacitance retention after 6000 charging/discharging cycles. Moreover, the developed all-solid-state micro-supercapacitor successfully powered a light-emitting diode, showcasing its significant potential for practical energy storage applications.

Relocating the “Field” in Theological Field Education

Like higher education as a whole, theological education constitutes a dislocated form of learning, particularly for those who exist beyond the boundaries of euro-normative Christianity. For students who are preparing for religious leadership and ministry, theological field education can be a particularly fraught curricular requirement because it possesses the potential to further dislocate within formational processes. The purpose of this essay is to interrogate these dynamics toward an ethical relocating of the “field” as an embedded, or in situ, experience for students through an attentiveness to lo cotidiano and a practice of critical intersubjectivity.

Axial Spondyloarthritis: an overview of the disease.

Axial Spondyloarthritis (axSpA) is a chronic, inflammatory, immune-mediated rheumatic disease that comprises two subsets, non-radiographic and radiographic axSpA, and belongs to a heterogeneous group of spondyloarthritides (SpA). Over the years, the concept of SpA has evolved significantly, as reflected in the existing classification criteria. Considerable progress has been made in understanding the genetic and immunological basis of axSpA, in studying the processes of chronic inflammation and pathological new bone formation, which are pathognomonic for the disease. As a result, new medication therapies were developed, which bring more effective ways for disease control. This review presents a brief overview of the literature related to these aspects of disease after summarising the available information on the topic that we considered relevant. Specifically, it delves into recent research illuminating the primary pathological processes of enthesitis and associated osteitis in the context of inflammation in axSpA. The exploration extends to discussion of inflammatory pathways, with a particular focus on Th1/Th17-mediated immunity and molecular signaling pathways of syndesmophyte formation. Additionally, the review sheds light on the pivotal role of cytokine dysregulation, highlighting the significance of the IL-23/17 axis and TNF-α in this intricate network of immune responses which is decisive for therapeutic approaches in the disease.

The Politics of Electric Vehicle Subsidies in Indonesia: Actors, Agenda, and Issues

In light of the worldwide determination to address the consequences of climate change, the Indonesian government has established a goal of achieving carbon neutrality by the year 2060. The transportation sector in Indonesia is a significant source of carbon emissions due to its extensive reliance on fossil fuel consumption. In response to this challenge, the Indonesian government has implemented measures to expedite the motor vehicle electrification program by introducing a subsidy policy aimed at facilitating the public’s acquisition of electric vehicles. The formulation of this strategy initiated a sequence of discussions within the public domain. In order to gain a comprehensive understanding of the many actors involved and the process of discourse formation within the discussion, this study has undertaken the collection of 198 stakeholder statements as presented in articles published by national mass media outlets throughout the period spanning from January 2023 to June 2023. This statement mapped with the Discourse Coalition Framework (DCF) theory to find the network of discourse and ideas as the data that was subsequently subjected to analysis utilizing the Discourse Network Analysis. The findings of this study indicate that the discourse surrounding the subsidy program for electric vehicles gave rise to actor network groups that advocated investment and concerns related to environmental sustainability. The author examines the limitations to the interconnections between theoretical frameworks empirical evidence in shaping the discourse surrounding the dynamics of network politics in relation to electric vehicle subsidies in Indonesia.

The determination of the features of the process of mixture formation of hydrogen burner

The determination of the features of the process of mixture formation of hydrogen burner

An empirical view of the extended atmosphere and inner envelope of the asymptotic giant branch star R Doradus

Context. The mass loss experienced on the asymptotic giant branch (AGB) at the end of the lives of low- and intermediate-mass stars is widely accepted to rely on radiation pressure acting on newly formed dust grains. Dust formation happens in the extended atmospheres of these stars, where the density, velocity, and temperature distributions are strongly affected by convection, stellar pulsation, and heating and cooling processes. The interaction between these processes and how that affects dust formation and growth is complex. Hence, characterising the extended atmospheres empirically is paramount to advance our understanding of the dust formation and wind-driving processes. Aims. We aim to determine the density, temperature, and velocity distributions of the gas in the extended atmosphere of the AGB star R Dor. Methods. We acquired observations using ALMA towards R Dor to study the gas through molecular line absorption and emission. We modelled the observed 12CO v = 0, J = 2 − 1, v = 1, J = 2 − 1, and 3 − 2 and 13CO v = 0, J = 3 − 2 lines using the 3D radiative transfer code LIME to determine the density, temperature, and velocity distributions up to a distance of four times the radius of the star at sub-millimetre wavelengths. Results. The high angular resolution of the sub-millimetre maps allows for even the stellar photosphere to be spatially resolved. By analysing the absorption against the star, we infer that the innermost layer in the near-side hemisphere is mostly falling towards the star, while gas in the layer above that seems to be mostly outflowing. Interestingly, the high angular resolution of the ALMA Band 7 observations reveal that the velocity field of the gas seen against the star is not homogenous across the stellar disc. The gas temperature and density distributions have to be very steep close to the star to fit the observed emission and absorption, but they become shallower for radii larger than ∼1.6 times the stellar sub-millimetre radius. While the gas mass in the innermost region is hundreds of times larger than the mass lost on average by R Dor per pulsation cycle, the gas densities just above this region are consistent with those expected based on the mass-loss rate and expansion velocity of the large-scale outflow. Our fits to the line profiles require the velocity distribution on the far side of the envelope to be mirrored, on average, with respect to that on the near side. Using a sharp absorption feature seen in the CO v = 0, J = 2 − 1 line, we constrained the standard deviation of the stochastic velocity distribution in the large-scale outflow to be ≲0.4 km s−1. We characterised two blobs detected in the CO v = 0, J = 2 − 1 line and found densities substantially larger than those of the surrounding gas. The two blobs also display expansion velocities that are high relative to that of the large-scale outflow. Monitoring the evolution of these blobs will lead to a better understanding of the role of these structures in the mass-loss process of R Dor.

PENGEMBANGAN MEDIA BERBASIS KOMPUTER UNTUK PEMBELAJARAN KIMIA KELAS XI PADA SEKOLAH MENENGAH ATAS

Difficulty learning abstract consepts in material forms of the molecule based on the theory of electron domain and molecular hybridization in the formation of simple covalent coumpounds involving electron is verry small in size. With conventional learning to use the media shaped balloons and images/charta make their experience misconceptions. Make use of computer assisted animations media adobeflash program. The program is able to help students discover and explore the concepts of learning materials to animate the process of formation of the molecules of the compound geometry. The program is easy to obtain and can be used on all computers. Material forms of molecules according to VSEPR theory (valence shell electron pair repulsion) and Hybridization theory contained in the computer based media is aimed at helping students learn to achieve mastery of core competencies which are already contained in the syllabus set by time. Products are developed in accordance with the educational technology area abstract include students in determining the geometry of the steps forming the molecules of the compound. The stages are carried out in the development of media, namely: design learning, create computer based animation media, validate products with product testing. Advice of expert material/content, media expert, design expert, and data from trials of the target group to be enter performance improvement products. Based on the results of the expert validation and testing of the target group can be concluded that the computer –based instructional media products on the molecular forms of material at Senior High School chemistry in particular at ninth grade IPA (Natural Sciences). With regard to these results the school, especially Senior High School 8 Batanghari media products in order to incorporate this learning into the school website that can be accessed by the wider media users for further development. Keyword: Development, Computer based Media, Molecular Forms.

Differences in medically assisted reproduction use by sexual identity and partnership: a prospective cohort of cisgender women.

Differences in medically assisted reproduction use by sexual identity and partnership: a prospective cohort of cisgender women.

The Preparing Background of Kipchak Written Language with Armenian Letters

The Turkish language, one of the ancient languages in the world, has continually evolved and expanded across various geographical regions, establishing diverse historical and contemporary branches through the creation of written languages based on numerous alphabets. The formation processes of these branches of the Turkish language, which emerged gradually over time, are directly related to their ethnological structures, religious and social lifestyles, interactions in the ethno-linguistic field, geographical settlements, political situations and economic conditions. The Turkish language, which advanced as a unified written language between the 8th and 13th centuries, within the Eastern Turkish written tradition, began to diversify from the 13th century onwards, a trend that persisted into the subsequent centuries. Today, the historical and contemporary aspects of the Turkish language, encompassing over 20 written variants, should be examined by subjecting it to studies with an interdisciplinary approach.. Additionally, determining the background factors that led to the emergence of these written languages will enable a correct interpretation of the language’s evolutionary phases. This study aims to unveil the developmental trajectory of the Kipchak written language, which emerged in Eastern Europe during the 16th and 17th centuries through the use of Armenian letters. Determinations and evaluations will be conducted to explore the underlying factors that facilitated the emergence of this written language.

TBHP: A Sustainable Alternative For Carbon‐Oxygen Bond Formation

AbstractOver past few decades, synthetic chemists are working tirelessly for the development of environmentally benign and economically competent carbon‐oxygen bond formation processes. Various oxidizing reagents and catalysts are being used to serve this purpose. Among all, t‐butyl hydrogen peroxide (TBHP) has emerged as a greener and economically viable oxygen source, radical initiator and precursor of t‐BuO⋅ and t‐BuOO⋅ radicals. It has been extensively utilized as a reagent for the synthesis of epoxides, ketones, secondary alcohols, heterocyclic rings like benzofurans, isoquinoline and many more. The present review will unfold the recent advancements made in the field of TBHP‐promoted C−O bond formation.

Cloud response to co-condensation of water and organic vapors over the boreal forest

Abstract. Accounting for the condensation of organic vapors along with water vapor (co-condensation) has been shown in adiabatic cloud parcel model (CPM) simulations to enhance the number of aerosol particles that activate to form cloud droplets. The boreal forest is an important source of biogenic organic vapors, but the role of these vapors in co-condensation has not been systematically investigated. In this work, the environmental conditions under which strong co-condensation-driven cloud droplet number enhancements would be expected over the boreal biome are identified. Recent measurement technology, specifically the Filter Inlet for Gases and AEROsols (FIGAERO) coupled to an iodide-adduct chemical ionization mass spectrometer (I-CIMS), is utilized to construct volatility distributions of the boreal atmospheric organics. Then, a suite of CPM simulations initialized with a comprehensive set of concurrent aerosol observations collected in the boreal forest of Finland during spring 2014 is performed. The degree to which co-condensation impacts droplet formation in the model is shown to be dependent on the initialization of temperature, relative humidity, updraft velocity, aerosol size distribution, organic vapor concentration, and the volatility distribution. The predicted median enhancements in cloud droplet number concentration (CDNC) due to accounting for the co-condensation of water and organics fall on average between 16 % and 22 %. This corresponds to activating particles 10–16 nm smaller in dry diameter that would otherwise remain as interstitial aerosol. The highest CDNC enhancements (ΔCDNC) are predicted in the presence of a nascent ultrafine aerosol mode with a geometric mean diameter of ∼ 40 nm and no clear Hoppel minimum, indicative of pristine environments with a source of ultrafine particles (e.g., via new particle formation processes). Such aerosol size distributions are observed 30 %–40 % of the time in the studied boreal forest environment in spring and fall when new particle formation frequency is the highest. To evaluate the frequencies with which such distributions are experienced by an Earth system model over the whole boreal biome, 5 years of UK Earth System Model (UKESM1) simulations are further used. The frequencies are substantially lower than those observed at the boreal forest measurement site (< 6 % of the time), and the positive values, peaking in spring, are modeled only over Fennoscandia and the western parts of Siberia. Overall, the similarities in the size distributions between observed and modeled (UKESM1) are limited, which would limit the ability of this model, or any model with a similar aerosol representation, to project the climate relevance of co-condensation over the boreal forest. For the critical aerosol size distribution regime, ΔCDNC is shown to be sensitive to the concentrations of semi-volatile and some intermediate-volatility organic compounds (SVOCs and IVOCs), especially when the overall particle surface area is low. The magnitudes of ΔCDNC remain less affected by the more volatile vapors such as formic acid and extremely low- and low-volatility organic compounds (ELVOCs and LVOCs). The reasons for this are that most volatile organic vapors condense inefficiently due to their high volatility below the cloud base, and the concentrations of LVOCs and ELVOCs are too low to gain significant concentrations of soluble mass to reduce the critical supersaturations enough for droplet activation to occur. A reduction in the critical supersaturation caused by organic condensation emerges as the main driver of the modeled ΔCDNC. The results highlight the potential significance of co-condensation in pristine boreal environments close to sources of fresh ultrafine particles. For accurate predictions of co-condensation effects on CDNC, also in larger-scale models, an accurate representation of the aerosol size distribution is critical. Further studies targeted at finding observational evidence and constraints for co-condensation in the field are encouraged.

Evaluation and associated mechanism of mitigating Cr depletion by vanadium in modified 9Cr-1Mo steel: Experiment and phase-field modelling

The 9Cr-1Mo steel is extensively utilized in nuclear heat exchangers due to its exceptional corrosion resistance properties. The Chromium (Cr) element plays a pivotal role in enhancing the corrosion resistance. The Cr accumulates at grain boundaries (GBs) where defects and mismatches are located during long-term usage, leading to the depletion of Cr within the grain interior. This results in the Cr-rich carbide precipitates form along GBs, with a corresponding the depletion zone residing in the adjacent regions. In this study, we employed aberration-corrected high-resolution electron microscopy in high-angle annular dark field microscopy (HAADF) mode, equipped with energy dispersive spectroscopy (EDS), to analyse carbides formation along GBs and obtain elemental distribution information. Our investigation reveals that the Cr-rich carbide promotes the formation of chromium-depletion zone (CDZ) by consuming the surrounding Cr in the matrix, and the presence of vanadium-rich carbide inhibits the formation of (CDZ) from atomic scale.A phase-field modelling approach is employed to investigate the diffusive formation process in a polycrystalline system. Our modelling results are consistent with experimental observations. Cr preferentially diffuses towards grain boundaries (GBs) and accumulates, facilitating the formation of Cr-rich phases by consuming adjacent Cr in the surrounding region. The bilateral region of GBs serves as a source for supplying Cr to these newly formed phases while depleting Cr content, ultimately leading to the development of CDZ.By employing experimental techniques and phase-field method, this research provides valuable insights into the role of Cr, carbide precipitates, influence of vanadium, and CDZ formation.

A Contrastive Analysis of Word Formation Processes in Interrogating Widespread Democratic Decay and Breakdown in some West African Countries

In contemporary times democracy is threatened across West African states like never before. Democracy is under increasing assault from the elected leaders and their cronies. A noticeable, subtle, stifling strangulation of democratic structures and substance leads to the erosion of democracy in more than a few West African countries and a total breakdown of democracy through coups in others. Despite the attempts by the ECOWAS and AU to discourage democratic breakdown in Africa, military intervention continues to truncate democracies in many African countries. This paper interrogated the root-causes of the prevalence of democratic breakdown in West African countries and the factors sustaining military interventions in the region. Building upon earlier scholarly work on democratic breakdown and deploying the doctrinal research methodology, the researcher analysed the resurgence of and effects of military intervention and truncation of democratic practices in West Africa. The findings of this research showed that military intervention is edging West African countries to the precipice and there have been more than a few complete democratic breakdowns in West African countries in recent times. In conclusion, the researcher offers suggestions on how democratic breakdown can be arrested in the West African region and/or reduce its occurrence by advocacy, enthronement of good governance, citizenship participation, application of the rule of law, and upholding of constitutional provisions.

Transforming mountain agriculture in China: Linking smallholder family production and moderate-scale agriculture

Transforming mountain agriculture in China involves integrating smallholder family production and moderate-scale agricultural operations. This process enhances agricultural efficiency, alleviates poverty, and combats hunger in mountainous regions, thus contributing to sustainable development goals. This study developed a conceptual framework to transform mountain agriculture based on the theory of spatial-behavior interaction. The aim was to elucidate the inherent mechanisms and formation processes. The validity of this framework was confirmed by analyzing two representative cases. Additionally, the study distilled the experiences of mountain agriculture transformation in China and established a Chinese model. The study found that spatial constraints in mountainous areas are no longer the predominant limiting factors in transforming mountain agriculture. The transformation should consider the compatibility between the transformation approach and the local agricultural production history, the structure of agricultural production subjects, and the distribution of agricultural production benefits. Linking smallholder family production and moderate-scale agriculture shows strong feasibility in mountainous regions. This study provides valuable insights into transforming mountain agriculture in other mountainous regions worldwide, particularly in developing countries.

Numerical Modeling and Simulation of the Nonisothermal Double Quench Phase Separation Process for the Production of Polymeric Membranes Using Polystyrene‐Cyclohexanol Polymer Solution

AbstractThe double quench phase separation is a simplified type of continuous cooling process that is widely seen in industrial processes for polymeric membrane formation. Uncommon quenching conditions can lead to the creation of novel membrane microstructures. This study aims to theoretically investigate the impact of nonisothermality on the morphology formation during the double‐quench thermally‐induced phase separation process. First, quench is employed during different stages of phase separation to observe the possibility of secondary morphology formation. Next, two initial quench temperatures are selected, one shallow and the other deep. The initial solution temperature and the secondary quench temperature are kept constant to inspect the impact of the initial quench temperature on the structure formation. Lastly, the results of the secondary quench are compared with and without employing the enthalpy of demixing. Results verified that the stage of phase separation, the initial and secondary quench temperatures, cooling rate, and the secondary quench composition are the most important parameters in the the nonisothermal double quench phase separation process. The morphology should be well‐developed in order for the secondary structure formation. In addition, it is shown that heat generation during demixing in the primary and secondary quenches significantly influences the secondary morphology formation.