Mixing Process Research Articles

The first measurements of carbon isotopic ratios in post-RGB stars: SZ Mon and DF Cyg

ABSTRACT Dusty post-red giant branch (post-RGB) stars are low- and intermediate-mass stars where the RGB evolution was prematurely terminated by a poorly understood binary interaction. These binary stars are considered to be low-luminosity analogues of post-asymptotic giant branch (post-AGB) binary stars. In this study, we investigated the chemical composition of two dusty post-RGB binary stars, SZ Mon and DF Cyg, using multiwavelength spectroscopic data from HERMES/Mercator (optical) and the APOGEE survey (near-infrared). Owing to challenges posed by existing spectral analysis tools for the study of evolved stars with complex atmospheres, we developed E-iSpec: a dedicated spectral analysis tool for evolved stars, to consistently determine atmospheric parameters, elemental abundances, and carbon isotopic ratios. Our abundance analysis revealed that observed depletion patterns and estimated depletion efficiencies resemble those found in post-AGB binary stars. However, the onset of chemical depletion in post-RGB targets occurs at higher condensation temperatures ($T_{\rm turn-off,~post-RGB}\approx 1\, 400$ K), than in most post-AGB stars ($T_{\rm turn-off,~post-AGB}\approx 1\, 100$ K). Additionally, our study resulted in the first estimates of carbon isotopic ratios for post-RGB stars (12C/13CSZ Mon = 8 ± 4, 12C/13CDF Cyg = 12 ± 3). We found that the observationally derived CNO abundances and the carbon isotopic ratios of our post-RGB binary targets are in good agreement with theoretical predictions from the ATON single star evolutionary models involving first dredge-up and moderately deep extra mixing. This agreement emphasizes that in post-RGB binary targets, the observed CNO abundances reflect the chemical composition expected from single star nucleosynthesis (i.e. convective and non-convective mixing processes) occurring during the RGB phase before it is terminated.

Enhanced fluid mixing using a novel multi-stage static pipeline mixer: Numerical simulation and mechanism analysis

Static pipeline mixers play a crucial role in water treatment processes, and their mixing efficiency can be influenced by factors. Innovating mixer design to simultaneously reduce head loss and G-values while maintaining effective mixing across various flow conditions holds practical significance for improving treatment process performance. This study used a combination of numerical simulations and experimental validation to investigate the mixing process of a novel multi-stage static pipeline mixer. The results indicated that within the flow velocity range of 0.2–1.8 m/s, compared to the Kenics mixer, the new multi-stage static pipeline mixers (HOCM and COCM) achieved significant reductions in head loss (89.4 % for HOCM and 52.9 % for COCM) and G-values (67.3 % for HOCM and 31.3 % for COCM). The turbulent kinetic energy intensity of HOCM was much lower than that of COCM and Kenics mixers. Importantly, all mixers reached a state of complete mixing with the coefficient of variation (CoV) less than 0.05. In the HOCM mixer, the 2nd mixing stage was identified as the primary mixing zone, while in the COCM mixer, the 1st mixing stage played a crucial role in mixing. When the mixers achieved a mixing degree of 95 %, the head loss of HOCM and COCM was significantly lower than various types of traditional mixers (Kenics, SMX, SMV, ISG, Inliner Lightnin). This is attributed to the highly efficient mixing effect generated by the clockwise helical flow produced in the 1st and 2nd mixing stages.

The impact of synergistic action of methacrylic acid/zinc oxide/carbon nanotubes on metal Friction and wear

The continuous operation of essential refining equipment, internal mixers, leads to wear on their end faces, resulting in an increased gap between the mixer chamber and the end face. This, in turn, causes material leakage, reducing mixing efficiency and adversely impacting rubber performance. Therefore, investigating metal wear on the mixer's end face during the mixing process is essential. Scholars have introduced dynamic covalent bonds into rubber molecular chains, bestowing self-repairing capabilities upon the materials. This innovation has significant implications for extending rubber lifespan and lowering production costs. It involves adding methacrylic acid (MAA) and excess zinc oxide (ZnO) to construct an ionic crosslinking network, limiting covalent crosslinking of rubber molecules and enabling in-situ polymerization of MAA/ZnO, resulting in self-repairing properties. However, it is crucial to consider corrosive wear induced by MAA's strong acidity on metals. This study combines MAA, ZnO, and multi-walled carbon nanotubes (MWCNTs) through mechanical mixing to create a composite material called zinc methacrylate (ZDMA)/MWCNTs/rubber. The research investigates the in-situ synthesis mechanism of MAA and ZnO and the synergistic mechanism of ZDMA and MWCNTs. The study analyzes the impact of MWCNTs additive amount on the frictional wear of the internal mixer's metal end face. During the mixing process, ZDMA is grafted and polymerized onto rubber's macromolecular chains, forming ionic pairs with strong electrostatic interactions, creating a primarily reversible supramolecular network dominated by ion crosslinking. This ion crosslinking network, along with the three-dimensional mesh structure of MWCNTs, establishes a stable spatial structure within the rubber matrix. The study reveals that increasing the MWCNTs content to 3 phr reduces the aggregation of SiO2 particles and ZDMA granules within the rubber matrix, resulting in reduced friction coefficients, roughness, and wear rates of the metal. However, exceeding 3 phr of MAA content leads to excessive MWCNT aggregation within the rubber matrix, increasing wear rates, roughness, and friction coefficients due to hindrance of rubber macromolecular chain crosslinking and reduced SiO2 particle dispersion within the rubber matrix. These findings provide valuable insights into the dynamics of frictional wear in internal mixers.

Origin of granitoids and coeval mafic microgranular enclaves in the East Kunlun Orogen, northern Tibetan Plateau: Insights from petrography, U-Pb geochronology, geochemical and isotope analyses

Granitoids and coeval mafic microgranular enclaves (MMEs) provide important insights into petrogenesis and crustal evolution. In the eastern sector of the East Kunlun Orogen, the Halazha (HLZ) pluton contains abundant MMEs, recording magma mingling processes. The HLZ pluton comprises quartz diorites and granodiorites, whereas the MMEs have a gabbroic-dioritic composition. This paper provides a detailed description of the petrography and mineralogy of the HLZ pluton and MMEs, and presents new ages and geochemical data. The zircon U–Pb dating results indicate that quartz diorites and granodiorites are ranging from 243 ± 2 Ma to 244.8 ± 1.3 Ma and from 233.3 ± 1.1 Ma to 233.6 ± 1.5 Ma, respectively. The zircon ages of the coeval MMEs are identical to the host rocks, i.e., 244.5 ± 1.1 Ma − 244.5 ± 1.2 Ma, and 233.7 ± 1.3 Ma, respectively. Both quartz diorites and granodiorites contain hornblende, display metaluminous characteristics with average A/CNK values of 0.93 and 0.99, respectively, and thus belong to I-type granite. Both of them are enriched in large-ion lithophile elements such as Rb and Ba and depleted in high-field-strength elements such as Nb and Ta. In addition, they both have low εHf(t) values, ranging from −5.6 to −1.7 and −5.4 to −1.79, respectively. Results suggest that HLZ pluton is derived from magmas formed by the partially melting juvenile mafic lower crust. Quartz diorites experienced hornblende accumulation for its low SiO2 contents. Whereas, the high Sr/Y ratio of granodiorites attributes to the fractional crystallization of apatite. Notably, the crystallization pressure and temperature (average 3.43 kbar and 764 °C) of the hornblende xenocrysts in MMEs is close to it of the hornblende phenocryst in quartz diorite (average 3.68 kbar and 766 °C). This similarity indicates that MMEs in the quartz diorites resulted from magmatic mingling between the mafic magma and the host rock within the deep crust. The hornblende xenocrysts present in MMEs of the granodiorites contain a higher number of inclusions, reveal higher crystallization pressures (average 2.73 kbar) and temperatures (average 825 °C) compared to their host rocks (average 1.35 kbar and 702 °C). These results suggest that MMEs in granodiorites underwent two distinct magmatic mixing processes: the magmatic mixing of mafic magma in the deep crust and then during the upwelling process after this mixed mafic magma entered the granodiorites.

A facile synthetic strategy to simultaneously achieve ultra-wide PL redshift of carbon nanodots and their high selectivity and sensitivity for Mn2+ detection

This paper presents a straightforward synthesis strategy for N, S co-doped carbon nanodots (N, S-CDs), aiming to achieve CDs emitting ultra-wide redshifts while obtaining excellent metal ion detection performance. The N, S-CDs display excellent fluorescence (FL) emission independence regardless of the excitation wavelength or concentration. By introducing a single dopant thiourea, the FL emission of CDs was red-shifted from 445 to 575 nm (∼130 nm). The doped N and S elements are discovered to cause the introduction of defective energy levels and an elevation in oxidation on the surface of CDs, which could potentially be the crucial factor for the ultra-wide redshift of FL emission. Also, it is investigated that solvent engineering is essential for the redshift of the emission peak, which can also be an effective way to synthesize multicolor CDs. Furthermore, the N, S-CDs can be utilized for measuring the water content in methanol solvent based on their solvent effects. Additionally, N, S-CDs have the capability of detecting Mn2+ with high selectivity and sensitivity. The interaction of CDs with Mn2+ resulted in an obvious change in both the UV absorption spectrum and FL lifetime. To put it differently, the reaction mechanism between CDs and Mn2+ probably includes mixed processes of dynamic and static quenching. Zeta potential tests additionally indicate that the FL quenching is strongly correlated with the surface condition of CDs. The outcomes and discoveries offer a fresh and viable method for achieving the simultaneous production of long-wavelength glowing CDs and their analysis and detection of metal ions as fluorescent probes.

The tire–road contact: A mechanical mixing seen as a shear-induced diffusive process

In this paper, the mechanical mixing of road minerals and tire tread rubber is studied experimentally and numerically. A rubber specimen on an experimental set-up is used. SEM observations show that particles on the surface are composed of an intimate mixture of rubber compounds and minerals. A longitudinal section is also observed, showing that the minerals have migrated into the surface. This phenomenon can be seen as a diffusive process driven by shear. To understand the underlying mechanisms, a numerical model is proposed using soft bodies to represent the rubber top layer. A layer of minerals is then sheared onto this surface. The minerals migrate progressively into the rubber, forming a mixed layer of rubber and minerals. The results show also that the mixing mainly depends on the shear rate in the layer containing the minerals. Due to a reinforcing effect of the minerals, velocity is increasingly accommodated in the layer without minerals. As a result, the shear rate in the mixed layer decreases, and therefore the mineral migration. This coupled mechanism explains why the mixing process stops before reaching a homogenized state in the entire domain. To support this analysis, a diffusion coefficient is derived as a function of the shear rate in the mixed layer.

A variable time headway model for mixed car-following process considering multiple front vehicles information in foggy weather

Abstract The aim of this work is to investigate the Fog-related variable time headway (FVTH) model of connected and automated mixed flow considering multi-front vehicles information in a reduced visibility environment for driving safety. The car-following modes of mixed vehicles are analysed and the vehicle ratio for each mode based on Markov chain models is derived, where the number of front vehicles, CAVs penetration rate, and platoon intensity are considered. The combined coupling effect of visibility and driving speed on time headway is explored, and a variable time headway strategy is proposed. Their relationship equations are deduced as the FVTH model. The perturbation method is used to discuss the stability of traffic flow and obtain its stability judgment conditions. The proposed model was validated and the effects were discussed via simulation experiments. The results indicate that the acceleration and deceleration times of vehicles and collision possibility decrease significantly using the proposed method. When penetration rate is 50%, the number of front vehicles is three and platoon intensity is zero, the time to return to a stable state is reduced by 18.9%-30.3% and 24.7%-39.4%, respectively, and Time Exposed Time-to-collision (TET) is reduced by 26.1%-48.9% and 43.7%%-65.4%, respectively, compared with the basic IDM method and IDM method that considers multi-front vehicles information. As visibility decreases, the reduced degree of these indicator values increases. The driving efficiency and safety level can be enhanced.

Deep learning-based pore network generation: Numerical insights into pore geometry effects on microstructural fluid flow behaviors of unconventional resources

Pore-scale transport behaviors and mechanisms of rock reservoirs are still not well understood to increase unconventional resource production. This work mainly focuses on proposing a deep learning-based method to rapidly construct optimal pore network with different pore types, and deeply analyze its effects on pore-scale transport behaviors and mechanisms. The pore-scale variables reservoir evaluation indexes are defined to quantitatively evaluate pore geometry effects on the properties and production of rock reservoirs. The two-phase displacement simulations in pore network are conducted to study microstructural flow behaviors and transport mechanisms. Results suggest that the deep learning-based digital labeling algorithm (DL-DLA) has excellent abilities to rapidly construct pore network with errors less than 5%, compared with the classical algorithms. Square pores and circle throats are suggested as the optimal pore network assembly, considering the fluid phase drainage efficiency and production rate. The microstructural transport mechanisms are concluded as the pore-throat drainage, pore-filling, fluid phase mixing and fluid phase equilibrium processes. The novel theoretical relation between fluid phase drainage and microscopic production indexes provides effective tools to estimate rock reservoir production with errors all less than 10%, which are helpful for the technique developments to increase the production of unconventional resources in rock reservoirs.

Selective Replacement of Cholesterol with Cationic Amphiphilic Drugs Enables the Design of Lipid Nanoparticles with Improved RNA Delivery.

The delivery of RNA across biological barriers can be achieved by encapsulation in lipid nanoparticles (LNPs). Cationic amphiphilic drugs (CADs) are pharmacologically diverse compounds with ionizable lipid-like features. In this work, we applied CADs as a fifth component of state-of-the-art LNPs via microfluidic mixing. Improved cytosolic delivery of both siRNA and mRNA was achieved by partly replacing the cholesterol fraction of LNPs with CADs. The LNPs could cross the mucus layer in a mucus-producing air-liquid interface model of human primary bronchial epithelial cells following nebulization. Moreover, CAD-LNPs demonstrated improved epithelial and endothelial targeting following intranasal administration in mice, without a marked pro-inflammatory signature. Importantly, quantification of the CAD-LNP molar composition, as demonstrated for nortriptyline, revealed a gradual leakage of the CAD from the formulation during LNP dialysis. Altogether, these data suggest that the addition of a CAD prior to the rapid mixing process might have an impact on the composition, structure, and performance of LNPs.

Design and construction of a single orifice oscillatory flow reactor for the continuous production of biodiesel from sunflower oil

Biodiesel, a renewable energy replacing fossil fuels, exhibits eco-friendly traits with beneficial lubrication properties. This research aims to design and construct a single-orifice oscillatory flow reactor to reduce the reaction time, improve the mixing process, and increase efficiency. The response surface method was used for the analysis of independent parameters like molar ratio (1:6–1:12), temperature (30–50 °C), reactor length (1–3 m), and catalyst concentration (0.75%-1.25%) on yield as the dependent variable. Elevated temperature up to 50 °C enhances conversion from 61.91% to 69.51%, peaking at 65.43% by 60 °C, adjusting the molar ratio to 1:9 boosts biodiesel conversion from 58.70% to 69.51%, dropping by 4% at 1:12 ratio. Catalyst concentration at 1% heightens conversion from 48.82% to 69.51%, but at 1.25%, it falls to 57.26%. Increasing reactor length to 2 m yields a 20% boost, while at 3 m, conversion drops by 4%. Optimal conditions, at 40 °C, 1:9 ratio, 1% catalyst, and 3 m reactor, resulted in a 91.98% conversion percentage. Experimental verification at the suggested point yields an 89% conversion, aligning acceptably with the model’s prediction. Biodiesel meets EN 14214 standards, positioning it as a viable diesel fuel alternative.

Innovative laser-assisted glass bending approaches using a near-infrared continuous wave laser

Limited research has been conducted on laser glass bending, with only a few studies to date. In 2008, a CO2 continuous-wave (CW) laser experiment achieved a maximum bending angle of 24° for a 10 mm wide and 150 µm thick glass sheet. However, challenges persisted in bending thicker and wider glass sheets while reducing permanent material accumulation along the bending axis. In this study, we present a novel approach using a near-infrared CW laser operating at a wavelength of 1070 nm and with a maximum power of 500 W, successfully bending glass with varying thicknesses and widths. Notably, we achieved bending angles of 30°, 60°, and even 90° on soda-lime glass (550 µm thick) and borosilicate glass (1000 µm thick). By integrating an inventive laser bending configuration alongside a complementary scanning strategy, we effectively overcame the challenge of persistent material accumulation during plastic deformation along the bending axis. This advancement enabled us to directly bend 1 mm thick, 13 mm wide borosilicate glass, resulting in a minimal thickness increase of approximately 10 % at a 30-degree bending angle. Furthermore, this approach optimally utilizes laser energy, requiring less than one-third of the laser power typically utilized by existing configurations. Remarkably, we achieved an impressive expansion in the bendable glass width, reaching 25 mm, by implementing a configuration with dual-beam mix processing. This study advances the potential applicability of laser glass bending technology, increasing its possibilities for industries such as manufacturing, optics, and electronics that require curved glass applications.

Laminar mixing of Newtonian and non‐Newtonian fluids in SMX static mixer

AbstractThis report is focused on understanding the mixing performance of Newtonian and non‐Newtonian fluids in an SMX static mixer through computational fluid dynamics (CFD) study in Simcenter STAR‐CCM+. For this, the standard SMX mixer with four mixer elements of radius 26 mm was chosen. The aspect ratio (L/D) was taken as 1. The model constructed was compared using pressure drop ratio values available in literature. First, the design was validated for Newtonian fluid, then for shear‐thinning fluid (non‐Newtonian). Mixing patterns produced through particle tracking approach revealed how blending improved as the fluid moved downstream and interacted with increasing number of mixer elements. A sensitivity study was undertaken to investigate the effect of particle injection mechanism on the mixing process. Two injection methods, vertical and horizontal, were explored to check the influence of injection position on mixing. The results indicate that for the given configuration irrespective of the injection location, at least four mixing elements are needed to achieve good mixing for both Newtonian and shear‐thinning fluids investigated in this study. Statistical reports were used to quantify mixing to understand the mixing behaviour for Newtonian and non‐Newtonian fluids with change in Reynolds number. At high Reynolds number, non‐Newtonian fluids exhibited better mixing abilities. Further, efforts were taken to optimize the various design parameters to produce the most optimum solution with a single mixer element for Newtonian fluid.

Effect of health rights accessibility on the urban integration of minority rural migrants in China: a cross-sectional study

BackgroundAccessing health rights is an integral component of people’s aspirations for a better life. Existing discussions and evaluations regarding the accessibility of health rights for minority rural migrants are insufficient. In comparison to objective health conditions, inequalities in health rights lead to chronic and long-term depletion of human capital among minority rural migrants. This study aimed to assess the overall impact, heterogeneity effects, and mechanisms of health rights accessibility on the urban integration of minority rural migrants.MethodsBased on the 2017 China Migrants Dynamic Survey Data (CMDS), this study employs OLS models, 2SLS models, conditional mixed process (CMP) methods, and omitted variable tests to estimate the impact of health rights accessibility on the urban integration of minority rural migrants. Additionally, from the perspectives of migration scope and illness experience, this study explored the heterogeneity in the relationship between health rights accessibility and urban integration. Finally, using the Karlson–Holm–Breen (KHB) model, this study dissects the mechanisms through which health rights accessibility influences the urban integration of minority rural migrants.ResultsHealth rights accessibility significantly enhances the urban integration of minority rural migrants. Moreover, compared to minority rural migrants who move across provinces and who have no history of illness, those who migrate within the same province and who have experienced illness are more sensitive to the positive impact of health rights accessibility. However, the enhancing effect of health rights accessibility does not significantly differ between the new and old generations of minority rural migrants. Furthermore, health rights accessibility can indirectly improve the urban integration of minority rural migrants by elevating health levels, improving health habits, and reinforcing health behaviors. Among these, the indirect effects mediated by health habits are more pronounced.ConclusionThe research conclusions underscore the issue of health accessibility and urban integration among minority rural migrants, providing a reexamination and clarification of the policy effects of health rights in promoting the urban integration of minority rural migrants. Relevant policy design should commence with improving the health rights of minority rural migrants, enhancing their health integration capabilities, and effectively boosting their ability to integrate into urban life.

The Dynamic Spatial Structure of Flocks.

Studies of collective motion have heretofore been dominated by a thermodynamic perspective in which the emergent "flocked" phases are analyzed in terms of their time-averaged orientational and spatial properties. Studies that attempt to scrutinize the dynamical processes that spontaneously drive the formation of these flocks from initially random configurations are far more rare, perhaps owing to the fact that said processes occur far from the eventual long-time steady state of the system and thus lie outside the scope of traditional statistical mechanics. For systems whose dynamics are simulated numerically, the nonstationary distribution of system configurations can be sampled at different time points, and the time evolution of the average structural properties of the system can be quantified. In this paper, we employ this strategy to characterize the spatial dynamics of the standard Vicsek flocking model using two correlation functions common to condensed matter physics. We demonstrate, for modest system sizes with 800 to 2000 agents, that the self-assembly dynamics can be characterized by three distinct and disparate time scales that we associate with the corresponding physical processes of clustering (compaction), relaxing (expansion), and mixing (rearrangement). We further show that the behavior of these correlation functions can be used to reliably distinguish between phenomenologically similar models with different underlying interactions and, in some cases, even provide a direct measurement of key model parameters.

Unsteady Multiphase Simulation of Oleo-Pneumatic Shock Absorber Flow

The internal flow in oleo-pneumatic shock absorbers is a complex multiphysics problem combining the interaction between highly unsteady turbulent flow and multiphase mixing, among other effects. The aim is to present a validated simulation methodology that facilitates shock absorber performance prediction by capturing the dominant internal flow physics. This is achieved by simulating a drop test of approximately 1 tonne with an initial contact vertical speed of 2.7 m/s, corresponding to a light jet. The flow field solver is ANSYS Fluent, using an unsteady two-dimensional axisymmetric multiphase setup with a time-varying inlet velocity boundary condition corresponding to the stroke rate of the shock absorber piston. The stroke rate is calculated using a two-equation dynamic system model of the shock absorber under the applied loading. The simulation is validated against experimental measurements of the total force on the shock absorber during the stroke, in addition to standard physical checks. The flow field analysis focuses on multiphase mixing and its influence on the turbulent free shear layer and recirculating flow. A mixing index approach is suggested to facilitate systematically quantifying the mixing process and identifying the distinct stages of the interaction. It is found that gas–oil interaction has a significant impact on the flow development in the shock absorber’s upper chamber, where strong mixing leads to a periodic stream of small gas bubbles being fed into the jet’s shear layer from larger bubbles in recirculation zones, most notably in the corner between the orifice plate and outer shock absorber wall.

Effect of Mixing Intensity on Electrochemical Performance of Oxide/Sulfide Composite Electrolytes

Despite the variety of solid electrolytes available, no single solid electrolyte has been found that meets all the requirements of the successor technology of lithium-ion batteries in an optimum way. However, composite hybrid electrolytes that combine the desired properties such as high ionic conductivity or stability against lithium are promising. The addition of conductive oxide fillers to sulfide solid electrolytes has been reported to increase ionic conductivity and improve stability relative to the individual electrolytes, but the influence of the mixing process to create composite electrolytes has not been investigated. Here, we investigate Li3PS4 (LPS) and Li7La3Zr2O12 (LLZO) composite electrolytes using electrochemical impedance spectroscopy and distribution of relaxation times. The distinction between sulfide bulk and grain boundary polarization processes is possible with the methods used at temperatures below 10 °C. We propose lithium transport through the space-charge layer within the sulfide electrolyte, which increases the conductivity. With increasing mixing intensities in a high-energy ball mill, we show an overlay of the enhanced lithium-ion transport with the structural change of the sulfide matrix component, which increases the ionic conductivity of LPS from 4.1 × 10−5 S cm−1 to 1.7 × 10−4 S cm−1.

Study on mixing characteristics of viscoplastic fluid in a rigid-flexible impeller stirred tank

Abstract The rigid-flexible impeller (RF impeller) was used in the mixing process of viscoplastic fluid, and the mixing performance of RF impeller was explored by using numerical simulation and experimental analysis. Results indicated that RF impeller could reduce the power consumption (P) and demonstrate the advantage of energy-saving compared with Rushton turbine (RT). RF impeller demonstrated a more pronounced force coupling effect between the impeller and surrounding fluid, and exhibited superior adaptability in the flow field compared with RT. Meanwhile, the utilization of RF impeller can effectively enhance the expansion of high velocity region, expand the cavern zone, and decrease the mixing efficiency number while maintaining constant P compared with RT, and the size of high velocity region and cavern zone could be increased with an increase in impeller speed. Moreover, the cavern structure was obtained through the visualization experiment, and the results were similar to that in the simulation. The findings suggested that incorporating rigid-flexible combination structure design of impeller blades could effectively expand the cavern zone, reduce the stagnant zone, and enhance the mixing efficiency in the viscoplastic fluid mixing process.

Deciphering the Way Ratai geothermal system, Lampung, Indonesia: A comprehensive geochemical and isotopic analysis

This study investigates the geochemistry and isotopic characteristics of geothermal manifestations in the Way Ratai geothermal field, Lampung, Indonesia, to elucidate the system's fluid flow, reservoir temperature, and the origins of its thermal waters. Fourteen samples were collected from Way Ratai, with three additional from Jatimulyo and four from Natar. The major ion contents and stable isotope ratios (δ18O and δD) were examined. The Way Ratai hot springs are classified as chloride-type waters based on the Cl-SO4-HCO3 concentration ratios, whereas the Natar and Jatimulyo hot springs are characterized as bicarbonate-type waters. The estimated reservoir temperature for the Way Ratai system ranges from approximately 174 °C to 210 °C, with a depth between 600 and 1000 m. Isotopic analysis indicates that the thermal waters at Way Ratai predominantly originate from meteoric sources. The recharge area for the Way Ratai geothermal fluid is estimated to be at an elevation of 1200 m above sea level, corresponding precisely to the location of Mt. Ratai. Through geochemical and isotopic analysis, it is inferred that the hot springs at Natar and Jatimulyo are connected to the Way Ratai reservoir, having undergone mixing and dilution processes. This research is integral to effective exploration and development strategies in the region, offering key insights into the potential of the Way Ratai geothermal field. The detailed geochemical and isotopic analyses contribute to a deeper understanding of the geothermal systems in the area and their viability for sustainable energy exploitation.

Modelling the centrifugal mixing process of minced meat to optimise the production of chopped meat semi-finished products

One of the most important problems in ensuring the quality of mincemeat preparation in the production of sausages is the effective structuring of components and mixing of their ingredients. To solve this problem, researchers added a multifunctional admixture based on whey protein in the process of centrifugal mixing of the components, which determined the composition of the factor space of the investigated process. Based on the results of the research, the effective content of whey protein, sodium alginate, and soy fiber in the developed recipe was proven, which showed high characteristics in terms of fat-retaining and moisture-retaining ability, digestibility, pH level – activity, and other parameters. The developed formulation made it possible to improve the general indicator of the balance of amino acids in the product and increase the functional-technological and quality parameters of the developed products. The physical and mechanical characteristics of the obtained meat product were evaluated based on the results of physical and mathematical modelling. Modelling was carried out using Federman-on-Buckingham's second similarity theory and the "dimension theory" method, which allows the processing of the obtained experimental data in the form of a criterion equation, which was compiled using Froude, Euler, and Sherwood criteria. The purpose of this study was to obtain dependencies between such process factors as product density, the coefficient of dynamic viscosity of the technological medium, the ultimate shear stress, the change in the concentration of the main impurities of lactic acid in the raw material, the value of the diffusion coefficient and the coefficient of mass transfer in the loading mass, the weight of one load of products, the angular frequency of rotation of the screws of the minced meat mixer, the radius of the rotating working bodies, the characteristic size of the products after grinding. Using the complex criterion equation and the developed program, we find a recommended set of operating mode parameters for preparing minced meat under the conditions of centrifugal influence on the mixing process and the action of the specified factors.

Textures and Chemistry of Crystal Cargo of the Pleiades Volcanic Field, Antarctica: Potential Influence of Ice Load in Modulating the Plumbing System

Abstract The Pleiades Volcanic Field (PVF) of northern Victoria Land (Antarctica) is made up of a dozen scoria cones whose erupted products present an unusually complete evolutionary trend from alkali-basalt to trachyte. With the aim of reconstructing the evolution of the PVF plumbing system, we have investigated the petrography and chemistry of main mineral phases using scanning electron microscopy (SEM-EDS) coupled with major element analyses using an electron probe microanalyser (EPMA-WDS). We further focussed on clinopyroxene phenocrysts obtaining a more detailed characterization by means of trace laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) element analyses coupled with machine learning thermobarometry. The results indicate that fractional crystallization and magma mixing are the major processes determining the development of the complete evolution trend. While fractional crystallization is a persistently active process in all parts of the plumbing system, mixing among differently evolved magma batches pertaining to the same association is responsible for the formation of intermediate compositions in the differentiation lineage at a specific pressure range (0.4–0.5 GPa). These processes are compatible with significant residence time of magmas at depth, resulting in multiple episodes of magma mixing, as testified by resorption and overgrowth textures in phenocryst assemblage occurring under isobaric conditions. The prolonged residence time likely increased the efficiency of the mixing process, leading to the formation of magmas with intermediate composition. In turn, the build-up of volatiles during the magma differentiation at depth could have favoured the eruption of these (variably differentiated) magmas. Considering that the PVF is situated in a glacial region, a process forcing long magma residence time can be envisaged associated with increased ice loading during glacial stages. This study specifically considers the ice fluctuations in the last 100 ka, theorizing the possibility of a climate-controlled volcano plumbing system.