Binary Components Research Articles

Fair Representation Learning with Maximum Mean Discrepancy Distance Constraint (Student Abstract)

Unsupervised learning methods such as principal component analysis (PCA), t-distributed stochastic neighbor embedding (t-SNE), and autoencoding are regularly used in dimensionality reduction within the statistical learning scene. However, despite a pivot toward fairness and explainability in machine learning over the past few years, there have been few rigorous attempts toward a generalized framework of fair and explainable representation learning. Our paper explores the possibility of such a framework that leverages maximum mean discrepancy to remove information derived from a protected class from generated representations. For the optimization, we introduce a binary search component to optimize the Lagrangian coefficients. We present rigorous mathematical analysis and experimental results of our framework applied to t-SNE.

Effectiveness and chemical insights: Exploring interactions between nanomicelles and monoterpenoids for head lice treatment

This study evaluates the pediculicidal activity of nanoformulations containing different binary essential oil component mixtures (eugenol:linalool, 1,8 -cineole:linalool, and eugenol:thymol) using immersion bioassays. These have allowed us to evaluate the knockdown time affecting 50% of the individuals (KT50). In addition, the type of interaction between the components in each mixture was established in terms of the combination index (IC). The KT50 values were 6.07; 8.83; 7.17 and 27.23 h for linalool, 1,8 -cineole, eugenol, and thymol, respectively. For the eugenol:linalool mixtures, the efficacy was lower or equal to that obtained for the nanoformulations of the pure compounds, with values of KT50 about 13.33, 8.16 and 6.71 h for mixtures with ratios 3:1, 1:1 and 1:3, respectively. These mixtures present IC > 1, evidencing antagonistic interaction, which is enhanced with eugenol content. In the case of the binary mixtures of 1,8 -cineole: linalool, KT50 values were similar to those obtained for eugenol:linalool mixtures with similar ratios. In this case, IC assumes values close to unity, suggesting additive interactions independently of the mixture composition. On the other side, mixtures of eugenol:thymol with 1:1 and 1:3 ratios showed values of 9.40 and 32.93 h, while the mixture with a 3:1 ratio showed the greatest effectiveness (KT50 of 4.42 h). Eugenol:thymol mixtures show synergistic interaction (IC < 1) for combinations 3:1 and 1:1, while no interaction was observed for 1:3 combination. This indicates that eugenol enhances thymol activity. These results must be considered an important step forward to the development of effective pediculicidal nanoformulations based on botanical compounds.

High performance bilayer MoTe2 transistors with co-sputtered ternary HfAlO2 high-k dielectric

We demonstrated that ternary HfAlO2 amorphous film prepared with common co-sputtering technology can be a suitable gate dielectric for bilayer MoTe2 transistors. The film quality can be improved by optimizing the sputtering process and post-annealing treatment, which is superior to its binary Al2O3 and HfO2 components and satisfies gate dielectric criteria. The bilayer MoTe2 transistors with ∼29-nm-thick HfAlO2 gate dielectric exhibit an Ion/Ioff ratio of over 108 by a low operating voltage, together with a small subthreshold swing ≈ 71.22 mV/dec. These promising characteristics favor the development of high-performance and low-power ultrathin MoTe2-based beyond-silicon electronics.

Investigation on the thermodynamic performance and machinery mass in the N2O-based mixtures recompression Brayton cycle for a nuclear-powered spacecraft

As a reliable energy system with a long service life, nuclear energy can produce massive power for spacecraft in deep space exploration. Due to the compact layout and excellent performance, the supercritical recompression Brayton cycle has received extensive attention and has become a hot research topic in thermoelectric conversion technology. The critical properties of the working medium are a constraint on the cycle performance. Adding additional gas into a pure S-N2O working medium can effectively change the properties of the critical point and improve the cycle performance. However, there is no standard for selecting appropriate binary mixture components to determine which additive gas can improve cycle efficiency. In this work, several gases are chosen as the potential N2O-based mixtures (N2O-O2, N2O-He, N2O-Kr, N2O-Ar, N2O-H2S, N2O-CO, N2O-SO2, N2O-CH4, N2O-C2H6, N2O-C3H8, N2O-C4H8, N2O-C4H10, N2O-C5H10, N2O-C5H12, N2O-C6H6) as the working medium in the system. The detailed sensitivity analysis reveals the influence of essential parameters (the split ratio, pressure ratio, selection minimum operating temperature, maximum operating temperature, and minimum operating pressure) on the thermodynamic efficiency and Brayton machinery unit mass. According to the analysis results, the thermal efficiency improves with an increase in the split ratio, pressure ratio, and maximum operating temperature and decreases in the selection minimum operating temperature and minimum operating pressure for all mixtures. The exergy efficiency also showed a similar variation trend. However, the influence of the maximum working temperature on it is different from that of the thermal efficiency, which decreases with the increase of the maximum working temperature. The cycles operated close to the critical area can provide better cycle performance, and N2O-He has the best thermal performance among all proposed N2O-based mixtures, which can be used as a potential choice as the working medium for future nuclear-powered spacecraft.

Elusive hot stripped helium stars in the Galaxy

Context. Stellar evolution theory predicts the existence of helium-core remnants of the primary components of intermediate-mass close binaries that lost most of their hydrogen-helium envelopes due to the mass exchange. These remnants are expected to be observed as hot helium-rich stars with masses of (1−7) M⊙, located in the area of the Hertzsprung-Russell diagram between OB subdwarfs and Wolf-Rayet stars. While several thousands of such stripped helium stars are expected to exist in the Galaxy, none of them have been identified so far. Aims. We aim to provide comprehensive predictions of the numbers and fundamental properties of stripped helium stars and their binary companions in the Galaxy. This is a necessary first step to guide observations, to enable a comparison between binary evolution models and realistic stellar populations, and to determine the feedback parameters of stripped helium stars in the Galaxy. Methods. We expanded the previously considered space of parameters describing close binary systems producing stripped helium stars and applied a population synthesis based on a grid of evolutionary models computed by the code MESA, using a spin-dependent algorithm for the treatment of mass and angular momentum loss from the system. Results. We show that the number of Galactic binaries hosting (1−7) M⊙ He-stars is ≃20 000 and that it steeply declines with an increase in the He-star mass (≃3000 with mass ≳2 M⊙). The decisive factor that defines the low number of stripped He-stars is runaway mass-loss after Roche lobe overflow (RLOF) by primary components of the binaries, which leads to the formation of common envelopes and the further merger of components. This effect strongly restricts the initial ranges of masses of components of the progenitors of stripped stars and orbital periods. In addition, stripped helium stars are much less numerous than expected, since a significant fraction of binaries in which the primaries have masses less than (5−7) M⊙ produce subdwarfs with masses ≲1 M⊙. Our calculations show that the overwhelming majority of helium stars reside in binaries with an early-type companion star and can be identified neither by the UV excess nor by emission features. The large periods of a significant fraction of binaries hosting stripped stars (≳several hundred days) also hamper their discovery.

Airborne Ouzo: Evaporation-induced emulsification and phase separation dynamics of ternary droplets in acoustic levitation

We experimentally investigated the evaporation dynamics of acoustically levitated Ouzo droplets (a mixture of ethanol, water, and anise oil). Acoustic levitation has gained significant attention in various fields owing to its potential to create a lab-in-a-drop. Although evaporation is a key process in nature and industry, many studies have focused on single and binary components, and ternary droplets in acoustic levitation have rarely been experimentally investigated. In this study, the evaporation-induced spontaneous emulsification (the Ouzo effect) and phase separation process at 40–90 vol. % ethanol were visualized. We estimated the concentration change by evaporation of each component in the levitated ternary droplets based on an evaporation model to determine the experimental results. Our experimental results revealed four distinct stages of evaporation in levitated Ouzo droplets: (1) preferential evaporation of the volatile component (ethanol), (2) spontaneous emulsification (myriad micro-oil droplets generation), (3) phase separation forming a core–shell droplet, and (4) water evaporation completion resulting in the remaining oil droplets. Finally, we analyzed the emulsification process using a spacetime diagram. These findings suggest that acoustic levitation is suitable for physicochemical manipulation in mid-air.

Techno-economic and environmental analyses of the pyrolysis of food waste to produce bio-products

Food waste has become a source of concern as it is generated abundantly worldwide and needs to be valorised into new products. In this study, cucumber, tomato, and carrot wastes were investigated as pyrolysis feedstocks as a single component (cucumber), a binary component mixture (cucumber and tomato), and a ternary component blend (cucumber, tomato, and carrot). Fourteen scenarios were simulated and evaluated based on varying the feedstock blend (single, binary, and tertiary), temperature (300 and 500 °C), and feedstock moisture content (5, 20, and 40%). Using an established empirical model, the effect of these parameters on product yields, techno-economic implications, energy requirements, and life cycle analysis (LCA) outcomes were investigated. The best performers of each scenario were determined, and their strengths and weaknesses were identified and compared with other scenarios. In terms of product yields, all three systems (single, binary, and tertiary) followed a similar pattern: bio-oil yields increased as temperature and feedstock moisture content increased, while biochar yields decreased as temperature and feedstock moisture content increased. The production of syngas, on the other hand, was only observed at elevated temperatures. The total energy requirement exhibited an increase with increasing temperature and feedstock moisture content. The economic evaluation revealed that the return on investment (ROI) value for the single component at 5% moisture content at 300 °C is 29%, with a payback period (PB) of only 3.4 years, which is potentially very appealing. The water footprint increased with increasing pyrolysis temperature but decreased with increasing moisture content in all scenarios. The land footprint is observed to remain constant despite changes in process conditions. The study's findings contribute to the pyrolysis process's scalability, technological advancement, and commercialisation.

Discerning the catalytic treatment of cationic dye wastewater in photoreactor comprising ternary (Co3+/Co2+)-embedded SnO2/ZnFe2O4 composite sensitive toward ultra-violet illumination.

Herein, magnetic (Co3+/Co2+)-integrated SnO2, SnO2/ZnFe2O4, and ZnFe2O4 composites have been prepared from triply distilled water and 30% of isopropanol in the water medium. The phase evolution, microstructure, and magnetism were investigated successfully and tested for cationic dye wastewater degradation containing Rhodamine 6G and Methylene Blue under ultra-violet irradiation. Composite spheres are attributed to efficient heterojunction interfaces between ZnFe2O4 and SnO2 semiconductors with the support of (Co3+/Co2+) nanoparticles. The results provide a simple, low-cost, environmentally friendly, and scalable method of ternary composites to degrade mixed dyes. Co3+/Co2+-implanted SnO2/ZnFe2O4 offered narrowed bandgap energy, more light absorption, diminishing electron-hole recombination, and more charge carriers toward cationic dye wastewater than the binary components. The rate constant of Rhodamine 6G degradation was observed at 0.0237min-1, and Methylene Blue degradation was observed at 0.0187min-1 at 90min under UV (λ = 365nm) irradiation. Capturing studies of various organic reactive species and mechanisms of composites was also proposed in detail.

Synergistic effect mechanism of biomass ash-derived K-Ca-Si catalytic system on syngas production and reactivity characteristics of high-sulfur petroleum coke gasification

In this study, three typical biomass ash (BA) components, KCl, CaCO3 and SiO2, are selected as model compounds to construct BA-based key ternary component system for petroleum coke (PC) gasification. Gas product analysis was conducted using gas chromatography to study the influence of different catalysts on the gas product distribution, gas yield and carbon conversion of PC gasification, and clarify the synergistic effects of binary and ternary components in K-Ca-Si catalytic system. In addition, electron scanning microscopy (SEM) and Raman techniques are used to characterize the physicochemical structure of gasification semi-char to reveal the synergistic mechanism of K-Ca-Si system. The results show that the yield of different gases is ordered as H2 > CO > CO2 and the increment of H2 yield, CO yield, syngas yield and carbon conversion in K-Ca-Si catalytic system is 43.41 mmol/g, 26.67 mmol/g, 80.37 mmol/g and 0.49, compared with single PC gasification, respectively. By comparing the theoretical and actual value of gas yield and carbon conversion, it is found that there are synergistic catalytic effects for K-Ca-Si ternary catalyst, but Si will inhibit the activity of K and Ca. Coupled with SEM and Raman analysis, synergistic mechanism of ternary catalytic system can be revealed. KCl and CaCO3 reduce the graphitization degree of semi-char by reacting with carbon matrix, and CaCO3 can stimulate the pore structure development of semi-char, which accelerate reaction between KCl and carbon matrix to form intermediate active sites, thus favoring gasification reaction and exhibiting a synergistic effect. SiO2, on the other hand, will combine with KCl and CaCO3 to form inert silicates, resulting in the deactivation of KCl and CaCO3. It could be concluded that for high K-high Ca-low Si ternary catalytic system, KCl and CaCO3 would still show a synergistic effect due to higher CaCO3 content than SiO2.

MMV method: a new approach to compare protein sequences under binary representation

In the present work, a new form of descriptor using minimal moment vector (MMV) is introduced to compare protein sequences in the frequency domain under their component wise binary representations. From every sequence, 20 different binary component sequences are formed, each corresponding to 20 amino acids. Each such vector is now shifted from the time domain to the frequency domain by applying the Fast Fourier Transform (FFT). Next, the power spectrum calculated from the FFT values for each component sequence is so normalized that the sum of the components equals 1. The descriptor is defined as a 20-component vector composed of the 20 second-order minimal moments calculated from the normalized spectrum of the 20 component sequences. Once the descriptor is known, the distance matrix is created by applying the Euclidean Distance measure. The phylogenetic tree is generated by applying the unweighted pair group method with the arithmetic mean (UPGMA) algorithm using Molecular Evolutionary Genetics Analysis11 (MEGA11) software. In this work, the datasets used for similarity studies are 9 NADH dehydrogenase 5 (ND5), 12 Baculoviruses, 24 Transferrins (TF) proteins, and 50 Spike Protein of coronavirus. A qualitative measure using rationalized perception is used to compare the effectiveness of the proposed method. Quantitative measure based on symmetric distance (SD) is used to compare the phylogenetic trees of the present method with those obtained by other methods. It is observed that the phylogenetic trees generated by the proposed technique are at par with their known biological references, and they produce results better than those of the earlier methods. Communicated by Ramaswamy H. Sarma

Simultaneous variable selection and estimation in semiparametric regression of mixed panel count data.

Mixed panel count data represent a common complex data structure in longitudinal survey studies. A major challenge in analyzing such data is variable selection and estimation while efficiently incorporating both the panel count and panel binary data components. Analyses in the medical literature have often ignored the panel binary component and treated it as missing with the unknown panel counts, while obviously such a simplification does not effectively utilize the original data information. In this research, we put forward a penalized likelihood variable selection and estimation procedure under the proportional mean model. A computationally efficient EM algorithm is developed that ensures sparse estimation for variable selection, and the resulting estimator is shown to have the desirable oracle property. Simulation studies assessed and confirmed the good finite-sample properties of the proposed method, and the method is applied to analyze a motivating dataset from the Health and Retirement Study.

Research Progress on Superhydrophobic Surface Preparation Methods and Mechanical Durability

Abstract: Superhydrophobic surfaces have great application prospects due to their unique surface- wetting characteristics. However, superhydrophobic surfaces' micro-nano binary rough structure and low surface energy components are easily damaged or lost by wear and grease, which affects their durability and limits their practical application, so it is of great significance to study the durability of superhydrophobic surfaces. The review first introduces the preparation methods and application fields of superhydrophobic surfaces, then sorts out the test methods for the durability performance of superhydrophobic surfaces, methods to improve the durability of superhydrophobic surfaces are summarized， and finally points out some problems in the current research on the durability of superhydrophobic surfaces, aiming to have a comprehensive understanding of the research progress of durable superhydrophobic surfaces, provide some theoretical guidance for the development of durable superhydrophobic surfaces, and look forward to the development direction and trend of durable superhydrophobic surface research in the future. There have been substantial improvements achieved in the preparation techniques to increase the mechanical durability of superhydrophobic surfaces and widen their applications. This review examines pertinent patents and articles on the fabrication of superhydrophobic surfaces from both domestic and foreign sources. The paper introduces the fundamental preparation methods for superhydrophobic surfaces and examines three common techniques: the template method, the spraying method, and the etching method. Additionally, the study discusses these preparation methods and presents future development trends based on the latest research findings. Aiming at the mechanical durability of superhydrophobic surfaces, the test methods for the durability performance of superhydrophobic surfaces under mechanical action are reviewed. The paper also suggests four key methods for enhancing the durability of superhydrophobic surfaces. The refinement of superhydrophobic surface preparation techniques plays a crucial role in enhancing durability and broadening the applications of these surfaces. Additionally, it holds the potential to unlock new possibilities across various domains. The future holds promising prospects for the invention of additional patents and papers focused on superhydrophobic surfaces.

Development of a polyethyleneimine/poly(N-isopropylacrylamide) semi-IPN hydrogel for use in the temperature-swing adsorption and selective desorption of hydrophobic organic compounds

BackgroundA novel polyethyleneimine/poly(N-isopropylacrylamide) semi-interpenetrating polymer network (PEI/poly(NIPA) semi-IPN) hydrogel was developed as a high-performance adsorbent for use in purifying wastewater containing multiple organic compounds and recovering each organic compound. Thermosensitive poly(NIPA) with a lower critical solution temperature (LCST) of ∼33 °C in water can perform the temperature-swing adsorption, i.e., reversibly adsorb/desorb adsorbates as the temperature varies across the LCST owing to its hydrophilic/hydrophobic transition. In addition, PEI, which is a branched polymer with primary, secondary, and tertiary amine groups, can adsorb acidic adsorbates via acid-base interactions. Thus, the developed hydrogel can adsorb adsorbates via hydrophobic and/or acid-base interactions. MethodsThe PEI/poly(NIPA) semi-IPN hydrogel was prepared by free radical polymerization of NIPA and a cross-linking monomer in an aqueous solution dissolving PEI, and characterized as an adsorbent for hydrophobic organic compounds in aqueous media. FindingsThe removal (water purification) and mutual separation (recovery) of binary components (p-nitrophenol and 4-iodoaniline as model adsorbates) were demonstrated via adsorption at 50°C, followed by two-step desorption at 20°C in water and an aqueous HCl solution. This process was based on the presence or absence of hydrophobic and acid-base interactions.

Curvature sensing lipid dynamics in a mitochondrial inner membrane model

Membrane curvature is essential for many cellular structures and processes, and factors such as leaflet asymmetry, lipid composition, and proteins all play important roles. Cardiolipin is the signature lipid of mitochondrial membranes and is essential for maintaining the highly curved shapes of the inner mitochondrial membrane (IMM) and the spatial arrangement of membrane proteins. In this study, we investigate the partitioning behavior of various lipids present in the IMM using coarse-grained molecular dynamics simulations. This study explores curved bilayer systems containing phosphatidylcholine (PC), phosphatidylethanolamine (PE), and cardiolipin (CDL) in binary and ternary component mixtures. Curvature properties such as mean and Gaussian curvatures, as well as the distribution of lipids into the various curved regions of the cristae models, are quantified. Overall, this work represents an advance beyond previous studies on lipid curvature sensing by simulating these systems in a geometry that has the morphological features and scales of curvature consistent with regions of the IMM. We find that CDL has a stronger preference for accumulating in regions of negative curvature than PE lipids, in agreement with previous results. Furthermore, we find lipid partitioning propensity is dominated by sensitivity to mean curvature, while there is a weaker correlation with Gaussian curvature.

Spectroscopy of the binary TNO Mors–Somnus with the JWST and its relationship to the cold classical and plutino subpopulations observed in the DiSCo-TNO project

Context. Trans-Neptunian objects (TNOs) are remnants of small icy bodies from planetary formation that orbit in the region beyond Neptune. Within the population of TNOs, Trans-Neptunian binaries (TNBs) provide a valuable opportunity to test the models of the formation and evolution of planetesimals in the trans-Neptunian region. Various theories have been proposed to describe the observed separations between binary components, their relative sizes, and other orbital parameters. The colors of TNOs have been used to trace the dynamical history of the outer Solar System and the colors of TNB components provide tests for formation theories. However, spectral information for the components of small TNBs, crucial information that could validate formation mechanisms, has until now remained elusive. Aims. The main goal of this work is to characterize the near-infrared spectral properties of the TNB plutino (341520) Mors–Somnus, the only TNB with resolved components in the James Webb Space Telescope (JWST) Large Cycle 1 General Observer program “DiSCo-TNOs” (PID 2418; PI: Pinilla-Alonso). The secondary goal is to use the surface compositions of the individual components of the Mors–Somnus system to probe formation and dynamical evolution in the outer Solar System through comparison to the surface properties of the cold classical and plutino (3:2 resonant) dynamical groups. Methods. To achieve these goals, we measured the spectral slope of the continuum and identified absorption bands in the individual spectra of Mors and Somnus, as well as in those of the cold classicals and plutinos obtained with the NIRSpec Integral Field Unit (IFU) and the PRISM/CLEAR disperser (0.6–5.3 μm), and compared these results to shed light on the dynamical evolution of the Mors–Somnus binary. Results. The spectra of Mors and Somnus are similar and indicate the presence of complex organic materials, CO2, CO, OH-compounds, and tentative nitrogen-rich materials. We find a high degree of compositional diversity in the plutino population, a group of TNOs that likely formed elsewhere and moved to their current orbits during the migration of Neptune, while the cold classical TNOs, which likely formed in situ, appear more homogeneous. Conclusions. The very wide separation between the components, their nearly equal sizes, and the high orbital inclination of the system suggest this plutino binary is a survivor of the primordial population of objects beyond 30 au. The similarities found between the spectral features of the plutinos Mors and Somnus and those of all of the cold classical TNOs in the DiSCo-TNOs sample as well as the high degree of compositional heterogeneity found in the plutino population provide compositional evidence for evaluation of Neptune’s migration in the trans-Neptunian region early on in the history of the Solar System.

Electrochemical investigation and thermodynamic assessment of the Mg-Pd system

This paper presents the results of electromotive force measurements using coulometric titration technique for liquid and solid Mg-Pd alloys with concentrations up to 0.70 Mg mole fraction and at 918 K. These measurements made it possible to verify the homogeneity range of the occurring phases and phase boundaries in the investigated system. Based on the obtained results and other thermodynamic data found in the literature, the phase diagram of the Mg-Pd system was optimized using the CALPHAD method and ab initio calculations. The thermodynamics of the intermetallic phases, the liquid phase, and the solid solutions were described by the correct equations, which can be used in the future to calculate multicomponent systems with the Mg-Pd system as one of the binary components. The thermodynamic calculations successfully reproduced the Mg-Pd phase diagram.

Algorithm of management actions for the formation and implementation of a resilient health care quality system.

Aim: Development of an algorithm of management actions for the formation of a resilient system of quality of medical care in health care institutions of obstetric and gynecological profile and formalization of its closed structural and logical scheme. Materials and Methods: A set of theoretical approaches of social medicine and methods of business process reengineering is used, taking into account the dominant ones: systemic and integrated approach and alarm and process approaches; the concept of resilience; quality of medical care; reproductive health care using business ecosystem methods. Results: The algorithm of management actions for the formation of a resilient system of quality of medical care in obstetric and gynecological health care institutions, which is formalized in nine stages: analysis of needs and identification of problems; substantiation of performance requirements; development of a health care quality strategy; involvement of stakeholders; formation of a system of relative indicators; development of an action plan; implementation of a set of measures; monitoring and evaluation; improving the quality of health care. Conclusions: The results made it possible: construction of a closed structural and logical scheme of management actions, taking into account the combination of factors of influence, harmonized with the main functions of the resilient system, which determine the peculiarities of its functioning; justification of the boundaries of managerial and social responsibility of management entities according to the binary components of the medical and social justification of the process of improving the quality of medical care.

Solubility Enhancement of Poorly Water-Soluble Drug Ritonavir using Polyvinylpyrrolidone and Chitosan-based Platform Technique

The antiviral medication ritonavir (RTV) belongs to the biopharmaceutics classification system (BCS) class II drug category and is known for its high permeability and poor solubility. Therefore, the prime objective of this research was to increase the rate of dissolution and improve the solubility of RTV using a polymer system. Solid dispersions consisting of binary polymer components i.e., chitosan (CH) and polyvinylpyrrolidone (PVP) were prepared using microwave microwave-assisted physical mixing technique and optimization of solid dispersion was performed with 32 factorial designs. Dispersions were analyzed for their physicochemical characteristics by the use of X-ray diffraction (XRD), differential scanning calorimetry (DSC), and fourier transform infrared spectroscopy (FTIR). The polymeric dispersions prepared were evaluated for the release of RTV throughout 1 h in 0.1N sodium chloride in a USP class II dissolving device. The phase solubility study demonstrated a considerable improvement in the saturation solubility of RTV when CH and PVP K30 were present either individually or in combination. Virtual interaction studies between the drug and polymers revealed physical interactions driven by van der Waals and hydrophobic forces between RTV and excipients. Carbonyl, amine, and hydroxyl groups, among others, were probably present in both RTV and CH, which allowed for these interactions to take place. There was no discernible interaction between the RTV and the polymers included in the FTIR research. The dispersion strategies have improved the dissolving rate, according to the in-vitro drug release investigation. A formulation including a polymeric dispersion of the optimal concentration of PVP and chitosan may efficiently boost the release of RTV, according to the in-vitro release profile.

Black hole–neutron star mergers: using kilonovae to constrain the equation of state

ABSTRACT The merging of a binary system involving two neutron stars (NSs), or a black hole (BH) and an NS, often results in the emission of an electromagnetic (EM) transient. One component of this EM transient is the epic explosion known as a kilonova (KN). The characteristics of the KN emission can be used to probe the equation of state (EoS) of NS matter responsible for its formation. We predict KN light curves from computationally simulated BH–NS mergers, by using the 3D radiative transfer code possis. We investigate two EoSs spanning most of the allowed range of the mass–radius diagram. We also consider a soft EoS compatible with the observational data within the so-called 2-families scenario in which hadronic stars co-exist with strange stars. Computed results show that the 2-families scenario, characterized by a soft EoS, should not produce a KN unless the mass of the binary components are small (MBH ≤ 6 M⊙ and MNS ≤ 1.4 M⊙) and the BH is rapidly spinning (χBH ≥ 0.3). In contrast, a strong KN signal potentially observable from future surveys (e.g. the Vera Rubin Observatory) is produced in the 1-family scenario for a wider region of the parameter space, and even for non-rotating BHs (χBH = 0) when MBH = 4 M⊙ and MNS = 1.2 M⊙. We also provide a fit that allows for the calculation of the unbound mass from the observed KN magnitude, without running timely and costly radiative transfer simulations. Findings presented in this paper will be used to interpret light curves anticipated during the fourth observing run (O4), of the advanced LIGO, advanced Virgo, and KAGRA interferometers and thus to constrain the EoS of NS matter.

LUMINOSITY OUTBURSTS IN INTERACTING PROTOPLANETARY SYSTEMS

FU Orionis type objects (fuors) are characterized by rapid (tens to hundreds years) episodic outbursts, during which the luminosity increases by orders of magnitude. One of the possible causes of such events is a close encounter between stars and protoplanetary disks. Numerical simulations show that the fuor-like outburst ignition requires a very close encounter ranging from a few to a few tens of au. In contrast, the observed stellar objects in fuor binaries are usually hundreds of au apart. Simple mathematical estimates show that if such a close approach took place, the binary stellar components would have an unrealistic relative velocity, at least an order of magnitude greater than the observed velocity dispersion in young stellar clusters. Thus, the bursts are either triggered with a certain delay after passage of the periastron or their ignition does not necessary require a close encounter and hence the outburst is not caused by the primordial gravitational perturbation of the protoplanetary disk. In this work, an encounter of a star surrounded by a protoplanetary disk with a diskless external stellar object was modeled using numerical hydrodynamics simulations. We showed that even fly-bys with a relatively large periastron (at least 500 au) can result in fuor-like outbursts. Moreover, the delay between the periastron passage and the burst ignition can reach several kyr. It was shown for the first time by means of numerical modeling that the perturbation of the disk caused by the external object can trigger a cascade process, which includes the development of the thermal instability in the innermost disk followed by the magneto-rotational instability ignition. Because of the sequential development of these instabilities, the rapid increase in the accretion rate occurs, resulting in the luminosity increase by more than two orders of ma-gnitude.