Homogeneous Process Research Articles

Stochastic model of seed dispersal with homogeneous and non-homogeneous Poisson processes under habitat reduction conditions.

This study presents a stochastic model of seed dispersal based on a branching random walk (BRW) framework, incorporating both homogeneous and non-homogeneous Poisson point processes (PPP). Building on the model introduced by Coletti et al. (2023), we examine the effects of habitat reduction on seed dispersal dynamics. We analyze the phase transition behavior of the BRW model under varying conditions of habitat fragmentation, focusing on how these conditions influence the critical dispersal rate. Specifically, we study a BRW on the real line with a non-homogeneous PPP driven by a log-normal density, constrained between spatial barriers. Our simulations localize the critical dispersal rate with respect to barrier positions and compare this dependence between homogeneous and non-homogeneous models.

IMPROVEMENT OF THE HOMOGENIZER HEAD DESIGN

Summary. An analysis of the equipment used for the homogenization of milk raw materials was carried out. Technologies for obtaining homogenized milk are considered. Disadvantages of existing technological processes have been identified. The areas of improvement of homogenization processes are defined and the need for the development of equipment for their implementation is substantiated. The research methods of the homogenization process are substantiated, a description of the studied raw materials is given, and the design of the homogenizer head is proposed. The influence of the geometric parameters of the modernized homogenizer head on the efficiency of the homogenization process was determined, and the optimal parameters were determined experimentally. As a result of the conducted research, it can be concluded that the homogenization process is very important for the production of pharmaceutical emulsions. The calculation and modeling of the homogenizing head of the valve homogenizer was carried out. In order to carry out two-stage homogenization, it was proposed to modernize the homogenizing head. the previous design is inferior to the modernized one in terms of homogenization of food liquids.

Impact of Thermal Energy on Water and Ethylene Glycol (50:50)-Based Rotating Hybrid Nanofluid Past A Riga Surface with Radiation, Homogeneous and Heterogeneous Reactions

Hybrid nanofluid is crucial in improving the efficiency of heat transmission in thermal engineering applications, particularly the cooling of electrical equipment, heat exchangers, fuel cells, printing machines, etc. This study sought to investigate the augmentation of heat and mass transmission by the use of a rotating hybrid nanofluid consisting of a mixture of gold and silver nanoparticles suspended in water and ethylene glycol (50:50) past a heated Riga surface with velocity slip and suction. The energy equation is constructed using nonlinear radiation and heat consumption. The impact of both homogeneous and heterogeneous processes on the hybrid nanofluid is also explored. The governing mathematical model begins with partial differential equations that are converted into ordinary differential equations using a suitable conversion technique. The results of numerical computations are recorded as graphs and tables using the bvp4c scheme in MATLAB. It is noticed that both directional velocities undergo significant negative changes as a result of enhanced values of the rotational parameter. The higher levels of the radiation parameter resulted in significant enhancements in the thermal profile. The falling behavior of the nanoparticle concentration profile is recorded against a greater quantity of both chemical reaction parameters. Based on our analysis, when the Biot number changes from 0.4 to 0.8, the most significant heat transmission gradient occurs.

DUALITY: DETECTABILITY VERSUS STABILIZABILITY IN THE STOCHASTIC CONTEXT

The aim of this paper is to extend to the stochastic framework the well known duality relation between the detectability property and the stabilizability property of a finite dimensional, linear time invariant, deterministic system. We consider continuous time linear stochastic systems having the state space representation described by a system of Itˆo differential equations with periodic coefficients possibly subject to some stochastic perturbations modeled by a standard homogeneous Markov process with a finite number of states. It will be seen that in the case when the given system is affected by jump Markov perturba tions a state space representation of the dual triple may be rigorously defined if and only if the transition probability matrix of the Markov process is double stochastic (in the sense that the sums of all elements from its each row and each column are equal 1).

Selective diesterase-like activity of bioinspired FeIIINiII and FeIIIZnII complexes and their 3-aminopropyl silica composites: A homo- and heterogeneous catalytic study

In this study, the preparation and characterization of two new mixed-valence heterodinuclear complexes [FeIIINiII(BPPAMFF)(μ-OAc)2(H2O)]ClO4 (1) and [FeIIIZnII(BPPAMFF)(μ-OAc)2(H2O)]ClO4 (2) with the bioinspired ligand 2-[(N-benzyl-N-2-pyridylmethylamine)]-4-methyl-6-[N-(2-pyridylmethyl)aminomethyl)])-4-methyl-6-formylphenol (H2BPPAMFF) are reported. These compounds were immobilized in 3-aminopropyl silica (APS) to afford composites APS-1 and APS-2 successfully. The aldehyde-containing ligand provided a reactive functional group, which could serve as a cross-linking group to bind the complexes to the directly amino-modified SiO2 surface. The complexes’ chemical integrity on the APS inorganic platform were probed by spectroscopical techniques, such as FTIR, UV–Vis and EPR. Potentiometric and spectrophotometric titrations allowed the chemical species present in solution to be rationalized, and identified which of them were potentially active in the hydrolytic cleavage of phosphodiester 2,4-BDNPP. Kinetic studies showed that FeIIINiII species (1 and APS-1) presented higher catalytic efficiency (E = kcat/KM) than FeIIIZnII species (2 and APS-2). Catalytic mechanisms were proposed based on a series of kinetic experiments, in which all the catalysts tested behaved as selective phosphodiesterases. In addition, it was also demonstrated that the hydrolase activity of the immobilized catalytic centers, APS-1 and APS-2, was better than the homogeneous processes, where second coordination sphere effects may be involved in directing and stabilizing the transition state.

Homogeneous Catalysts of RedOx Processes Based on Heteropolyacid Solutions. VI: Developing a Process for Low-Temperature Oxidation of CO with Oxygen

Research on the development of a homogeneous process for low-temperature oxidation of carbon monoxide in the presence of a “platinum group metal + vanadium-containing heteropolyacid (HPA)” catalytic system has been presented. The optimal reaction conditions, ensuring the maximum rate of CO oxidation to CO2, have been determined; for this reaction the kinetic features have been established, and its mechanism has been proposed. It has been shown that homogeneous systems based on PdII complex exhibit high activity and productivity, but have low stability and operate only at pH below 1,5. The stability of the catalyst can be increased by simultaneous introduction of σ- and π-donor ligands into the system; however, it is more effective to use the PtIV complex in the presence of catalytic amounts of palladium salt at a ratio of 100/1. The transition from HPA solutions with a low content of vanadium atoms (H7PMo8V4O40) to solutions of modified compositions (H10P3Mo18V7O84) ensures an increase in the activity and productivity of the system, with the kinetics of CO oxidation being maintained. The combined homogeneous catalyst PtIV + PdII + H10P3Mo18V7O84 remains stable during multi-cycle use without reducing activity, operates without an induction period and can be used at pH range of 1,7–2,0, which simplifies the process equipment.

Graphite Made from Coal by High-Temperature Treatment: An Insight into the Nanometric Carbon Structural Evolution

Graphite made from coal will not only widen the graphite mineral resource, but also significantly improve the value of coal utilization. In this study, anthracite coal was heated in the temperature range of 500 to 2900 °C to study the size increase of nanometric graphite crystallites from anthracite to real graphite. The carbon content rapidly increases to 99.2% when heated from room temperature to 1600 °C, and then gradually increases to 100% when the treated temperature increases to 2900 °C. The FTIR results show that methyl, methylene, and aromatic hydrocarbon, preexisting in the raw anthracite, were preserved in the JZS-500 sample, but that when the treated temperature ≥ 1000 °C, these C-H bonds almost disappear. The basic structural units (nano graphitic carbon) grow into distorted columns, and the basic structural units and micro-columns re-oriented and coalesced to form local molecular oriented domains with the temperature increase from anthracite to JZS-1500. When the temperature ≥ 1600 °C, amorphous carbon, onion-like carbon, turbostratic layers, and graphitic carbon co-occur within the graphitized coals. At the sub-micron scale, carbonization is a homogenous process, whereas graphitization is a heterogenous process. The average graphite crystalline size (La, lateral extension; Lc, stacking height) rapidly increases as the treatment temperature increases from 1600 to 2300 °C. Three coal structural transformation stages were classified according to the nanometric carbon structural evolution with temperature. This study will contribute to the efficient and value-added utilization of coal to make graphite materials.

Application of Response Surface Methodology to Optimize Mononitrotoluen Aquatic Removal by Photo-fenton Process

In this study, the effectiveness of pH (1-5), hydrogen peroxide concentration (5-10 mM), ion Fe2+ concentration (0,1-0,5 mM), and reaction time on treatment of mononitrotoluen by homogeneous Photo-Fenton process was evaluated. The response surface methodology (RSM) was applied to design the experiment and determine the optimal treatment. The results indicated, at optimized pH=3, C0MNT=100 mg/L, CFe2+= 0.4 mM, CH2O2= 2.5 mM, the MNT treatment efficiency reached 99.4% after 5 minutes.

Long-read genome assembly of the insect model organism Tribolium castaneum reveals spread of satellite DNA in gene-rich regions by recurrent burst events.

Eukaryotic genomes are replete with satellite DNAs (satDNAs), large stretches of tandemly repeated sequences that are mostly underrepresented in genome assemblies. Here we combined nanopore long-read sequencing with a reference-guided assembly approach to generate an improved, high-quality genome assembly, TcasONT, of the model beetle Tribolium castaneum Enriched by 45 Mb in repetitive regions, the new assembly comprises almost the entire genome sequence. We use the enhanced assembly to conduct global and in-depth analyses of abundant euchromatic satDNAs. Unexpectedly, we show the extensive spread of satDNAs in gene-rich regions, including long arrays. The sequence similarity relationships between satDNA monomers and arrays indicate a recent exchange of satDNA arrays between different chromosomes. We propose a scenario of their genome dynamics characterized by repeated bursts of satDNAs spreading through euchromatin, followed by a process of elongation and homogenization of arrays. We find that suppressed recombination on the X Chromosome has no significant effect on the spread of satDNAs but the X rather tolerates the amplification of satDNAs into longer arrays. Analyses of arrays' neighboring regions show a tendency of one satDNA to be associated with transposable-like elements. Using 2D electrophoresis followed by Southern blotting, we prove Cast satDNAs' presence in the fraction of extrachromosomal circular DNA (eccDNA). We point to two mechanisms that enable this satDNA spread to occur: transposition by transposable elements and insertion mediated by eccDNA. The presence of such a large proportion of satDNA in gene-rich regions inevitably gives rise to speculation about their possible influence on gene expression.

Optimization of the Homogenization Process of Ginseng Superfine Powder to Improve Its Powder Characteristics and Bioavailability.

As consumer demands evolve for health supplements, traditional ginseng products are facing challenges in enhancing their powder characteristics and bioavailability. The objective of this study was to prepare a novel ginseng superfine powder using a high-pressure homogenization (HPH) process. Response surface methodology was employed to determine the effects of HPH parameters (pressure, number of passes, and concentration) on particle size and the dissolution of the saponin components of the superfine powders. The Box-Behnken design of experiments was applied to ascertain the optimal HPH parameters for the smallest particle size and the highest dissolution of the saponin components. For the powders obtained at different parameters, the characterization of tap density, bulk density, flowability, water-holding capacity, appearance, and taste were observed. The optimized experimental conditions for the HPH process were as follows: 15,000 psi (pressure), 3 (number of passes), and 1 kg/L (concentration). The optimized values were 55 μm (particle size) and 83 mg/g (dissolution of the saponin components), respectively. The method offered technical support for the application of the HPH process in the preparation of ginseng powders. The objects of this research could be broadened to include a diverse array of botanical materials, addressing contemporary demands for cost-effectiveness and sustainability within the industry.

Development of thermomorphic ionic liquids derived from organophosphorus acids for homogeneous extraction processes

Development of thermomorphic ionic liquids derived from organophosphorus acids for homogeneous extraction processes

Continental-scale sediment mixing and dispersal across northern Gondwana: detrital zircon U-Pb-O-Hf isotopic evidence from the Cambro-Ordovician sandstones overlying the Arabian Shield

ABSTRACT The juvenile Neoproterozoic basement of the Arabian Shield is overlain with angular unconformity by a voluminous Cambro-Ordovician cover sequence known as the Saq Formation and Wajid Group. Provenance studies of this vast siliciclastic cover over the Saudi Arabian part of the Arabian-Nubian Shield (ANS) have to date been based solely on U-Pb zircon data and heavy minerals. We present the first combined in-situ U-Pb, δ18O and Lu-Hf isotopic data for detrital zircon from the Saq and Wajid units exposed along the northeastern margin and southern part of the Arabian Shield. U-Pb age spectra reveal prominent age peaks at ca. 0.8–0.55 Ga and 1.1–0.9 Ga with subordinate peaks at ca. 2.2–1.7 Ga and 2.7–2.5 Ga. The δ18O secular variation mirrors global compilations with Archaean zircon defining a restricted δ18O range of ca. 4.0–8.0 ‰ and younger zircon showing wide variation in δ18O up to ca. 14 ‰. The ca. 0.8–0.55 Ga age peak has the largest variation in εHf(t) with about half of all these Neoproterozoic zircon grains being juvenile (εHf(t) > 5), which are interpreted to be sourced from the juvenile terranes of the ANS. Neoproterozoic zircon with evolved εHf(t) signatures require a more distal source beyond the ANS. As extensive ca. 1.1–0.9 Ga crust is lacking in the vicinity of the ANS, the ca. 1.1–0.9 Ga age peak is interpreted to be derived from either contemporaneous orogenic belts in Central Africa or recycled from older sedimentary rocks containing these age components. Extreme variations in δ18O of post – Archaean zircon, together with the evolved εHf(t), indicate crustal thickening and increased incorporation of supracrustal material associated with collisional orogenesis. The remarkable similarities in age spectra and isotopic compositions of the Saq Formation and Wajid Group sandstones with those from other regions in northern Gondwana indicate a continental–scale homogenization and dispersion process.

Ultra-high-pressure homogenization in chicory root juice production

The demand for freshly squeezed natural fruit juices has increased in recent years, however their shelf life is quite short. Thermal processes applied to extend the shelf life of such products and increase their storage stability cause significant losses in color and other sensory properties, depending on the temperature applied. Therefore, the preference for high-pressure homogenization as an alternative to thermal processes is on the rise. We aimed to determine effects of ultra-high-pressure homogenization and production stages on some quality properties of chicory root juice. Ultra-high-pressure homogenization was applied at the pressure levels of 0 (Control), 50, 100, 150, and 200 MPA. The samples also included juice after homogenization with an ULTRA-TURRAX disperser and after a water bath. Ultra-high-pressure homogenization affected such quality characteristics of chicory root juice as total soluble solids (p < 0.01), pH (p < 0.01), L* (p < 0.01), a* (p < 0.01), b* (p < 0.01), a*/b* (p < 0.01), chroma (p < 0.01), hue angle (p < 0.01), and total color difference ΔE (p < 0.01). Higher levels of ultra-high-pressure homogenization pressure increased pH (p < 0.05), a* values (p < 0.05), and the a/b* ratio (p < 0.05) but reduced L* (p < 0.05), b* (p < 0.05), chroma (p < 0.05), and hue angle (p < 0.05) values of the juice samples. Thus, the use of ultra-high-pressure homogenization (100 and 200 MPa) contributed to improving the total soluble solids and redness values of chicory root juice. Our study showed that the ultra-high-pressure homogenization process improved the quality of chicory root juice.

Assessment of homogeneous electro-Fenton process coupled with microbial fuel cell utilizing Serratia sp. AC-11 for glyphosate degradation in aqueous phase

Glyphosate (GLY), a globally-used organophosphate herbicide, is frequently detected in various environmental matrices, including water, prompting significant attention due to its persistence and potential ecological impacts. In light of this environmental concern, innovative remediation strategies are warranted. This study utilized Serratia sp. AC-11 isolated from a tropical peatland as a biocatalyst in a microbial fuel cell (MFC) coupled with a homogeneous electron-Fenton (EF) process to degrade glyphosate in aqueous medium. After coupling the processes with a resistance of 100 Ω, an output voltage value of 0.64 V was obtained and maintained stable throughout the experiment. A bacterial biofilm of Serratia sp. AC-11 was formed on the carbon felt electrode, confirmed by attenuated total reflectance-Fourier transformed infrared (ATR-FTIR) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). In the anodic chamber, the GLY biodegradation rate was 100% after 48 h of experimentation, with aminomethylphosphonic acid (AMPA) remaining in the solution. In the cathodic chamber, the GLY degradation rate for the EF process was 69.5% after 48 h experimentation, with almost all of the AMPA degraded by the in situ generated hydroxyl radicals. In conclusion, the results demonstrated that Serratia sp. AC-11 not only catalyzed the biodegradation of glyphosate but also facilitated the generation of electrons for subsequent transfer to initiate the EF reaction to degrade glyphosate. This dual functionality emphasizes the unique capabilities of Serratia sp. AC-11, it as an electrogenic microorganism with application in innovative bioelectrochemical processes, and highlighting its role in sustainable strategies for environmental remediation.

Scalable Synthesis of Organic Core/Shell Architectures toward Dual-Wavelength Optical Waveguides.

Organic core/shell heterostructures have undergone rapid progress in materials chemistry owing to the integration of a wide array of unique properties. Nonetheless, the intricate challenge of regulating homogeneous nucleation and phase separation processes in excessively analogous cocrystal structures presents a formidable barrier to expanding the synthesis strategy for organic core/shell heterostructures. Herein, we successfully achieved a phase separation growth process facilitated by the organic alloy interface layer through a dynamic visualization to capture the intricate morphological evolution. By finely regulating the nucleation process, homogeneous self-assembly induced by high chemical and structural compatibility is circumvented, enabling the formation of organic core/shell heterostructures. Notably, this core/shell architecture boasts dual-wavelength emission at 496 and 696 nm, accompanied by an optical loss coefficient of 0.092 dB per micrometer. This methodology shows potential for extending to the scalable design of other conformational cocrystal heterostructure systems, thereby offering valuable insights into the realm of organic photonics.

Influence of chemical forms and homogenization process on the stability of vitamin A in infant follow-on formulas

Vitamin A is an essential micronutrient for infant development, and its stability is crucial to ensure adequate intake. This study aimed to investigate the vitamin A stability in infant follow-on formulas (IFF) depending on its chemical forms and on the homogenization process. For this propose, model IFF representative of commercialized formulas were formulated with varying vitamin A forms (retinol, retinyl esters or carotenoids) and homogenization process applied. Losses of vitamin A were assessed either before or after the homogenization process, or after a storage of 20 days at 40 °C. The homogenization process led to a vitamin A loss up to 14.3% at high pressure (350/40 bars, 8 passes) explained by important shearing forces leading to local heating of molecules. The presence of carotenoids and especially β-carotene led to a stabilization effect with a loss of only 40.7% of vitamin A during storage compared to 84.9% without carotenoids. Carotenoids provide a better resistance to lipid oxidation due to their synergetic effect with vitamin E. This study highlights that a good knowledge of vitamin A reactivity during processing and selection of chemical form with potential synergy with other compounds can improve its stability in IFF.

SWEET-Cat: A view on the planetary mass-radius relation

SWEET-Cat (Stars With ExoplanETs Catalog) was originally introduced in 2013, and since then, the number of confirmed exoplanets has increased significantly. A crucial step for a comprehensive understanding of these new worlds is the precise and homogeneous characterization of their host stars. We used a large number of high-resolution spectra to continue the addition of new stellar parameters for planet-hosting stars in SWEET-Cat following the new detection of exoplanets listed both in the Extrasolar Planets Encyclopedia and in the NASA exoplanet archive. We obtained high-resolution spectra for a significant number of these planet-hosting stars, either observed by our team or collected through public archives. For FGK stars, the spectroscopic stellar parameters were derived for the spectra following the same homogeneous process using ARES+MOOG as for the previous SWEET-Cat releases. The stellar properties were combined with the planet properties to study possible correlations that could shed more light on the star-planet connection studies. We have increased the number of stars with homogeneous parameters by 232 (sim 25<!PCT!> -- from 959 to 1191). We focus on the exoplanets that have had both mass and radius determined to review the mass-radius relation, and we find results consistent with the ones previously reported in the literature. For the massive planets, we also revisit the radius anomaly, confirming a metallicity correlation for the radius anomaly already hinted at in previous results.

Stochastic stability of random stacking of blocks

The paper explores the stability of a tower obtained by stacking identical rectangular blocks on top of each other with an inherent randomness due to slight positional offsets between successive blocks. With probabilistic modeling techniques, the diffusive behavior of the stacking process is studied and the collapse is seen as a first passage time problem. In the considered model, alignment errors are idealized as independent Gaussian random variables with zero mean and given standard deviation. We derive expressions for the joint probability density functions of block positions, and analyze their correlation. The study extends to the stochastic stability of a stack of given height, by exploring the statistical characteristics of the center of gravity of the part of tower above each block. Eventually, the probabilistic analysis of collapse is developed to quantify the statistics of the number of blocks that can be heaped up before the tower topples. Although this problem may initially appear playful, it offers an illustrated introduction to first passage problems on a non homogenous process. From a practical standpoint, this analysis offers a simple understanding of the influence of alignment errors on the overall stability of a stack, which may find several fields of application.

Interactions, structures, and functions of pomegranate peel reinforced starch film

This work aimed to exploit the effects of pomegranate peel (PP) addition (10 %) and homogenization process (0–12,000 rpm) on the film-forming behavior and interactions of starch film to improve its microstructures and properties. Microrheology results showed that the viscosity of the film suspension was reduced by homogenization, and the amylopectin aggregation was restricted by PP particles under film formation. This helped improve the accessibility of starch and PP, increasing the hydrogen bond energy in the composites from 18.12 to 19.35 kJ/mol and promoting the ester bonds as confirmed by the FTIR results. As a result, the starch film reinforced by PP and homogenization showed a uniform and compact microstructure with reduced water activity, increased UV-blocking capacity (from 67.46 % to 90.11 %), enhanced mechanical resistance, and reduced water vapor permeability (from 4.70 to 2.21 × 10−10·g·m−1·s−1·Pa−1). Additionally, the starch film with 10 % PP also presented superior antimicrobial properties and antioxidant activity with rates of over 86 %, providing an effective strawberry preservation function.

Mechanism of homogenization temperature and time on Fe-containing phase transition in AA8014 aluminum alloy

The presence of coarse Fe-containing phases detrimentally affects the fracture toughness of 8xxx aluminum alloys, and their complete dissolution during homogenization is unattainable. Therefore, it is essential to determine the optimal homogenization temperature and time to facilitate particle breakup during hot rolling, necessitating the development of effective homogenization processes. This study systematically examines the effect of homogenization temperature and time on the transition of Fe-containing phases in AA8014 aluminum alloy using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The transition mechanisms of Fe-containing phases during homogenization were elucidated through first-principles calculations, thermodynamics, and kinetics calculations. Under homogenization conditions of 610–650 ℃/12 h and 630 ℃/1–20 h, the Al6(Fe,Mn) phase initially transforms into the α-Al12(Fe,Mn)3Si phase with a “micropore structure” via the reaction. Subsequently, the α-Al12(Fe,Mn)3Si phase transforms into the Al3(Fe,Mn) phase. First-principles calculations confirm the sequential stability enhancement of the Al6(Fe,Mn), α-Al12(Fe,Mn)3Si+6Al, and Al3(Fe,Mn) phases. Homogenization kinetics indicate an optimal homogenization time of 11.5 h at 630 ℃, rationalizing the observed phase transitions and homogenization treatment. This study provides a foundation for the manufacture of 8xxx series aluminum alloys.