Mixed System Research Articles

Research and design of multiple gas mixing system in modified atmosphere packaging

Despite the abundant production of fruits and vegetables in Xinjiang, there is an increasing trend in waste rates. Gas-controlled packaging techniques are employed post-harvest to enhance freshness and extend shelf life. However, the multi-gas mixing system at the core of this equipment often encounters challenges such as insufficient stability, limited precision, high costs, and inadequate intelligence. In this context, we have developed and designed a multi-gas mixing system for gas-conditioned packaging. The system integrates Internet of Things technology, uses a programmable controller as the core, proposes a ternary gas distribution model based on the ideal gas equation and Dalton’s law of partial pressures, and utilizes RS-485 bus, TCP/IP protocol, among others. This ensures communication between the equipment and data transmission with the cloud server while enabling remote control of the gas mixing and blending process via a mobile phone terminal. The system runs stably through testing, with the average relative deviations of CO2 and O2 gas concentrations being 0.86% and 0.72%, respectively. This fulfills the technical prerequisites for achieving a gas concentration precision of less than 1%, addressing challenges related to inadequate precision in gas blending, unstable performance, and limited visual representation. Moreover, it significantly reduces equipment costs and operational complexities while serving as a valuable reference for advancing multivariate gas mixing and blending technology in Xinjiang’s fruit and vegetable gas-conditioned packaging.

Breed differentiation in northern Ethiopian cattle: The application of univariate and multivariate analyses of phenotypic traits.

The aim of this study was to characterize and differentiate the Adwa, Arado, Medenes, and Begait cattle breeds in northern Ethiopia via univariate and multivariate analyses of phenotypic traits. Sixteen qualitative characteristics and nine morphometric traits were recorded for a total of 946 (604 females and 342 males) purposively selected adult cattle. The frequency, general linear model (GLM), and canonical discriminant (CANDISC) analysis procedures of the Statistical Analysis Software (SAS 9.0) were used to analyze the data. Qualitatively, Medenes and Begait, cattle breeds from lowland agroecology and livestock-based production systems, possess a convex facial profile, relatively larger dewlap, naval flap, and perpetual sheath, as well as more uniform and lighter body colors than the Adwa and Arado cattle breeds, which are from the midland agroecology and mixed crop-livestock production systems. Morphometrically, clear differences were observed among all of the studied cattle breeds, where the Begait, Medenes, Arado, and Adwa cattle breeds were ordered in descending order according to their overall body size. Moreover, multivariate analysis revealed significant differences among the breeds where each breed was placed under a separate group. However, such phenotypic distinctions among the four cattle breeds do not necessarily indicate genetic dissimilarities. Therefore, further inclusive genetic characterization studies involving the use of representative samples from the Adwa and Medenes cattle breeds are recommended to quantify the degree of genetic relationships among these breeds. Moreover, owing to the unknown breed-level population size, urgent conservation programs as well as genetic improvement strategies are needed to ensure sustainable utilization.

Deciphering Co(III)‐Catalyzed Oxidative C−H/C−H Annulation Towards Maleimide‐Fused Imidazopyridine AEEgens†

A cobalt(III)‐catalyzed dual C(sp2)−H/C(sp2)−H activation of 2‐arylimidazopyridines and its annulation with N‐substituted maleimides leads to polycyclic aromatic heterocycles. This sustainable oxidative annulation uses earth‐abundant, less toxic, and cost‐effective cobalt(III) catalyst that complement expensive 2nd and 3rd‐row metals. This oxidative annulation features a broad substrate scope with very good functional group tolerance. These maleimide‐fused imidazopyridines display strong fluorescence in the region of 527− 536 nm with a Stokes shift of 83−87 nm and possess an excited state lifetime of 14.6−16.1 ns. Interestingly, such luminescent compounds show aggregation‐enhanced emission (AEE) behavior in the iPr‐OH/hexane mixed solvent system. Furthermore, field emission scanning microscopy (FESEM) reveals their spherical nano‐aggregates with an average diameter of ~216.8 nm. They can also be used as cellular‐imaging and picric acid‐sensing probes.

Long-term deep reinforcement learning for real-time economic generation control of cloud energy storage systems with varying structures

Energy storage systems play a crucial role in modern power systems. Consequently, a mixed cloud energy storage (CES) system is proposed. The mixed CES system comprises consumers and prosumers. The consumers can only consume energy. The prosumers can either produce or consume energy at different time intervals. The proposed mixed CES system is designed for investigating the generation control challenges in mixed interconnected power systems. To optimize the active power balance and economic efficiency of the mixed CES system, a long-term deep reinforcement learning (LDRL) artificial intelligence approach is proposed as the real-time economic generation controller to control the mixed CES system. The LDRL consists of a reinforcement mechanism and two models: a long short-term memory model for economic dispatch and a deep neural networks model for smart generation control. The reinforcement framework updates policies for the prosumers. The efficacy of proposed method is validated across three mixed systems, i.e., the improved IEEE 300-bus, Polish 2383-bus, and mixed systems with varying structures. The numerical simulations verify that the LDRL method can efficiently and economically control the mixed CES systems with diverse structures.

Investigating gender stereotypes in nursing/midwifery and engineering students in Ireland

Stereotypical behaviour in higher education has been linked with inequality with relevant negative output. This project's aim is to replicate the design of a previous study by expanding further into exploring the gender stereotypes’ relationships for two traditionally gendered polarised areas of study: Engineering and Nursing/Midwifery and assessing participants’ earlier experiences in their secondary education. Survey participants were Engineering and Nursing/Midwifery students (N = 161) of a university in Ireland. Results came positive for stereotypical biases in favour to men in Science, Technology, Engineering and Mathematics (STEM), and specifically for Mathematics. Stereotypes emerged stronger among the female participants. While comparing the two genders within each of the two study areas, significant differences emerge among the female Nursing/Midwifery and female Engineering participants. Female Engineering participants appear with stronger preference, attitude and importance towards STEM than their Nursing/Midwifery counterparts. Nevertheless, Mathematics is an indicator subject for success in higher education and the need to strengthen critical thinking, evidenced based practice and quality of quantitative research in female dominated areas such as Nursing/Midwifery has been recognised. In addition to identified stereotypes, differences in respondents’ views/elements of their interaction with STEM were associated with the type of secondary school they attended. Further research is recommended on traits that could contribute to the formation of gender biased stereotypes in single and mixed gender education systems with an aim to reverse them.

Testing the Mating System Model of Parasite Complex Life Cycle Evolution Reveals Demographically Driven Mixed Mating.

AbstractMany parasite species use multiple host species to complete development; however, empirical tests of models that seek to understand factors impacting evolutionary changes or maintenance of host number in parasite life cycles are scarce. Specifically, one model incorporating parasite mating systems that posits that multihost life cycles are an adaptation to prevent inbreeding in hermaphroditic parasites and thus preclude inbreeding depression remains untested. The model assumes that loss of a host results in parasite inbreeding and predicts that host loss can evolve only if there is no parasite inbreeding depression. We provide the first empirical tests of this model using a novel approach we developed for assessing inbreeding depression from field-collected parasite samples. The method compares genetically based selfing rate estimates to a demographic-based selfing rate, which was derived from the closed mating system experienced by endoparasites. Results from the hermaphroditic trematode Alloglossidium renale, which has a derived two-host life cycle, supported both the assumption and the prediction of the mating system model, as this highly inbred species had no indication of inbreeding depression. Additionally, comparisons of genetic and demographic selfing rates revealed a mixed mating system that could be explained completely by the parasite's demography (i.e., its infection intensities).

Comparative Analysis of Fuzzy Logic, PID, and FOPID Controllers in DC Microgrid Voltage Regulation for Power Plants: Integrating Renewable Energy Sources

The worldwide direction moving towards sustainable energy solutions requires more advanced control mechanisms within power systems, especially in DC microgrids that combine renewable energy sources like solar panels and wind turbines with conventional power setups. This paper addresses the necessary challenge of maintaining steady and efficient DC voltage control—important for the dependability and performance of power plants. Specifically, it looks at the efficiency of four different control strategies: classic PID (Proportional-Integral-Derivative) controllers, Fuzzy Logic Controllers (FLC), Fractional Order PID (FOPID) controllers, and a new mixed system that merges Fuzzy Logic with PID controllers in a Fuzzy-PI layout. Our approach utilizes a strict comparative analysis using MATLAB Simulink simulations, assessing each controller’s capacity to manage dynamic load shifts, adjust to the unpredictability of renewable energy inputs, and preserve strong voltage stability under various operational cases. The simulations are crafted to single out the most effective control strategy to boost efficiency and toughness in microgrid operations. This study adds substantially to the progress of control strategies in hybrid energy systems, offering important insights into the creation of more complex and reliable power management solutions. By evaluating the performance of these varied controllers, we aim to underline potential upgrades in control systems that could support better energy management in intricate grid setups, thereby encouraging the wider inclusion of renewable energy technologies into power grids.

A Study on the Automatic IoT Based Multiple Solid Mixing and Product Measurement System

Abstract: This project presents an automated system for mixing multiple solid materials and measuring the final product, using Internet of Things (IoT) technology. The system automatically mixes different solid ingredients in the right proportions, ensuring consistency and accuracy. It uses sensors to monitor the mixing process in real-time, sending data to a central control system that makes adjustments as needed. The system also measures the weight and volume of the final product to ensure it meets the required specifications. With IoT integration, the system allows remote monitoring, data tracking, and performance analysis, reducing human error and improving efficiency. This technology is flexible and can be used in industries like food processing, pharmaceuticals, and chemicals, offering a more precise and automated approach to solid mixing and product measurement.

The Role of Micro Propulsion in Enabling Autonomous Operations of Nanosatellites

Micro-Electro-Mechanical Systems (MEMS)-based propulsion devices have significant potential for providing high specific power. The application of Micro Power Generation technology to space propulsion systems can enhance orbit and station-keeping capabilities, potentially at lower costs. New-generation spacecraft and satellites are becoming smaller and require micro-propulsion systems for all aspects of their operations. The development of micro-propulsion systems with associated combustors for micro-electricity generation, utilizing liquid fuel, presents major challenges in fuel injection, mixing, combustion, and chemical reactor systems. A micro-spacecraft with high-accuracy station-keeping and attitude control capabilities needs to have low mass and deliver small impulses. Each nanosatellite will weigh a maximum of 10 kg, including the propellant mass. Provisions for orbital manoeuvres, attitude control, multiple sensors, and instruments, along with full autonomy, will result in a highly capable miniaturized satellite. All onboard electronics will endure a total radiation dose of 100 k rads over a two-year mission lifetime. Nanosatellites designed for in-situ measurements will be spin-stabilized and equipped with a complement of particles and fields instruments. Nanosatellites intended for remote measurements will be three-axis stabilized and equipped with imaging and radio wave instruments. Key technologies under development include: advanced, miniaturized chemical propulsion systems; miniaturized sensors; highly integrated, compact electronics; autonomous onboard and ground operations; miniaturized onboard orbit determination methods; onboard RF communications capable of transmitting data to Earth from significant distances; lightweight and efficient solar array panels; lightweight, high-output battery cells; a miniaturized heat transport system; lightweight yet strong composite materials for nano-satellite and deployer-ship structures; and simple, reusable ground systems.

DESAFIOS NA IMPLEMENTAÇÃO DE INFRAESTRUTURA DE SANEAMENTO BÁSICO EM ÁREAS RURAIS E REMOTAS

In the context of universalizing basic sanitation, which is essential for promoting public health and social equity, this study examines the challenges in implementing sanitation infrastructure in rural and remote areas. Through a bibliographic and qualitative analysis, the study investigates the main difficulties related to geographical isolation, low population density, scarcity of financial and technical resources, and the limitations in public policies. The research is based on academic articles, technical standards, and relevant case studies, such as the Rural Health and Basic Sanitation Program in the Piauí Area (PROSAR-PI), which highlight the importance of community participation and sanitary education for the success of the initiatives. The results indicate that, while simplified and accessible technical solutions are effective in remote contexts, integration with social strategies and specific public policies is essential to ensure the sustainability of the implemented systems. Additionally, decentralized initiatives and inter-institutional partnerships emerge as viable alternatives to overcome economic and logistical challenges. However, the research limitations emphasize the need for future studies exploring the application of innovative technologies and the analysis of mixed systems on different scales. The research concludes that, to achieve significant advances in basic sanitation in rural regions, it is crucial to adopt an integrated approach that considers technical, social, and financial aspects, thus promoting sustainable development and improving the quality of life of the populations served.

Chemometrically driven multiplexed metal ion detection using a triple emitting quantum dots-based nanoprobe.

Metal ion pollution poses a global concern due to its significant risks to both human health and environmental well-being. The toxicity of these ions can increase when they coexist, interacting with each other and with other harmful substances, even at low concentrations. Therefore, an accurate, rapid, and cost-effective methodology is urgently needed for the simultaneous quantification of multiple metal ions. This study presents a new approach for the multiplexed detection of various metal ions (Ag+, Cu2+, Hg2+, Al3+, Pb2+, Fe3+, Fe2+, Zn2+, Ni2+, Cd2+, and Ca2+) using a triple-emission nanoprobe comprising carbon dots and distinctly capped CdTe quantum dots, specifically green-emitting glutathione -quantum dots and red-emitting 3-mercaptopropionic acid-quantum dots. The method achieved high accuracy by analysing first- and second-order photoluminescence data with distinct advanced chemometric tools. R2P values for partial least squares and unfolded partial least square models exceeding 0.9 for several metal ions at low concentrations (mmol L-1) were obtained. Additionally, PL second-order data yielded significantly better results than PL first-order data, attributed to the distinct behaviour of the metal ions over time. Interestingly, it was also noted for the first time the significant contribution of the molar ratio between the metal ions on the models' accuracy. This novel method provides a highly accurate and efficient way to detect multiple metal ions simultaneously, paving the way for improved environmental monitoring and pollution assessment. The utilization of the proposed method contributes to a better understanding of the complex interactions in mixed metal ion systems, allowing for earlier detection and mitigation of metal ion contamination threats.

Unraveling the Phase Behavior and Stability of Surfactant-Free Microemulsions: From Molecular Interactions to Macroscopic Properties.

Surfactant-free microemulsions (SFMEs), formed in mixed ternary systems such as water/ethanol/oil, have garnered substantial interest due to their unique properties and broad applications in areas such as enzyme-catalyzed reactions and nanoparticle synthesis. In this work, we conducted an in-depth investigation of the spontaneous nucleation and stabilization mechanisms of SFMEs, employing experimental techniques, molecular dynamics (MD) simulations, and Flory-Huggins (F-H) theory. The formation of multiscale nanostructures (characteristic scales of ∼1 and ∼100 nm) and their interfacial charging characteristics in SFMEs have been revealed experimentally. MD simulations investigated the structure and stability on the microscopic scale, enhancing our understanding of molecular interactions within these microemulsions. Our theoretical analysis revealed that the stability of mesoscopic nanodroplets within SFMEs hinges on a delicate balance between mixing entropy and internal energy. Equilibrium between these energies results in stable nanodroplet solutions, showcasing a delicate balance that can be manipulated by adjusting the volume fractions of the components and their interaction parameters. This research not only advances the theoretical understanding of SFMEs but also highlights their potential in industrial applications, emphasizing the importance of integrating theoretical and experimental approaches to develop functional nanostructured materials.

Agroecological performance of smallholder dairy cattle systems in the Peruvian Amazon

CONTEXTIn Peru, silvopastoral systems have been included as a national measure to address deforestation and mitigate carbon emissions. Limited studies have assessed the sustainability of mixed livestock-crop systems using tools that address multiple Sustainable Development Goals (SDG). OBJECTIVEWe assessed the sustainability of smallholder dairy farms in the Peruvian Amazon as affected by system type (silvopastoral or conventional) and herd size (medium or large) using the Tool for Agroecological Performance Evaluation (TAPE). Furthermore, we explored the linkages among TAPE indicators including the 10 Elements of Agroecology (EA), an overall evaluation scale (Characterization of Agroecological Transition; CAET), and 11 SDG-linked Core Criteria of Performance (CCP). METHODSTwenty-two farmers of the San Martin region were surveyed. Data were subjected to analysis of variance, Pearson correlations, and fitted to linear and quadratic functions. RESULTS AND CONCLUSIONSSilvopastoral systems showed a greater agroecological transition than conventional systems (69.0 vs. 60.2; CAET mean) regardless of herd size.Results suggested that EA and CCP were essentially independent of each other if linearity was assumed. However, concave quadratic relationships were detected between the CAET and 4 CCP: Farm Income, Agricultural Net Income, Dietary Diversity, and Women's Empowerment. For these CCP, depressed values for farms with intermediate CAET (60 to 69) suggested that they neither reap the full benefits of agroecological practices found mainly in silvopastoral farms (CAET >70) nor the full benefits of conventional practices (CAET <60). SIGNIFICANCEThe implementation of agroecological practices in smallholder systems may support positive economic and social sustainability outcomes.

Mechanism of protein component addition on digestive properties of starch in fermented barley

Previous studies have found that removing protein from fermented barley flour promotes starch hydrolysis. In this paper, we investigate how the addition of fermented barley proteins to fermented starch affects starch digestive properties and explore the underlying mechanisms. The results show that the starch-protein complex (with a mass ratio of 1:0.35) forms larger protein aggregates during the co-gelatinization of starch and protein, which limits the swelling of starch and thus inhibits starch digestion. Analysis of the peak positions in the infrared spectrograms revealed that the absorption peaks of the starch-protein complexes shifted from 3313.65 cm−1 to 3302.49 cm−1. The addition of sodium dodecyl sulfate (SDS) to some extent lowered the storage modulus (G′) and loss modulus (G″) of the mixed system. The proteins confer a stronger resistance to enzymatic hydrolysis on the starch through the formation of hydrogen bonds and participation in hydrophobic interactions. The protein inhibits the activity of α-amylase, with inhibition as high as 77.32% at a protein concentration of 80 mg/mL and a semi-inhibitory concentration of 35.22 mg/mL. Thus, the addition of protein attenuates starch digestion. These findings elucidate the mechanism of protein effects on starch digestion properties during fermented barley digestion and provide a theoretical basis for the subsequent preparation of low-glycemic starch foods.

Ultra-high molecular weight poly(vinylamine) polyelectrolyte-functionalized 3D graphene oxide composite aerogels with pH-adaptability for the multi-selective adsorption of organic pollutants

Developing new adsorbents with multi-selectivity is essential for achieving efficient adsorption of various organic pollutants in wastewater. Hence, a novel ultra-high molecular weight poly(vinylamine) (PVAm) polyelectrolyte-functionalized graphene oxide (GO) composite aerogel (CA) adsorbent (PVAm@GO-CA) was successfully prepared via rapid electrostatic assembly and in-situ covalent cross-linking processes. The resulting PVAm@GO-CA exhibits a well-defined 3D porous structure, large specific surface area, and abundant primary amino groups (–NH2), providing numerous adsorption sites. Experimental results demonstrate that the –NH2 groups in PVAm@GO-CA exhibit varying degrees of protonation at different pH levels, allowing for precise controlof the adsorption selectivity for specific organic pollutants with different electrical charges. The results showed that the prepared PVAm@GO-CA is highly efficient for multi-selective adsorption of the anionic dye methyl orange (MO) at pH < 3, the partially ionized 1-naphthol at pH = 6–8, and the cationic dye methylene blue (MB) at pH > 9. The maximum removal capacities for MO, 1-naphthol and MB, as calculated by the Langmuir model, were 796.8, 456.6 and 612.5 mg/g under optimal pH conditions in a mixed system, respectively. The adsorption mechanism of PVAm@GO-CA involves hydrogen bonding, electrostatic interactions, π-π interactions, and nucleophilic/electrophilic interactions with various organic pollutants. This studypaves the way for the preparation ofPVAm@GO-CA withacontrolled surface microenvironment, enablingefficient multi-selective adsorption of multiple organic pollutants through pH regulation.

Regulatory mechanism of blending additives on interface interaction and phase separation of the heterogeneous braid-reinforced hollow fiber membranes

The exfoliation of the polymer layer from the reinforcement material is the key challenge for applying braid-reinforced hollow fiber membranes (BR HFMs). In this work, a mixed amphiphilic additive system was constructed and adopted in BR HFMs preparation by non-solvent induced phase separation (NIPS). The effect of the mixed system on the state of the casting solution and phase inversion process, the interaction between the casting solution and the braid material, together with the structure and filtration performance was studied. The role of the mixed system on the interface coordination and membrane structure formation mechanisms was elucidated. The results showed that both the composition of the mixed amphiphilic additives and the interaction time between the casting solution and braid material threw much light on the interface coordination and membrane formation. The interfacial compatibility of the casting solution and braid material was obviously improved, resulting in the enhancement of the binding force between the braid and PVDF membrane layer. The permeation flux and anti-exfoliation performance were simultaneously improved with the proper addition of the mixed amphiphilic additives. The stability of the BR HFMs was primarily testified by filtration of real sludge suspension solution with back-washing operation.

Toward nanosuspension preparation by modeling the solubility of levofloxacin and ofloxacin in ethanol + water solvent mixtures at different temperatures

The present study was conducted to assess the solubility of levofloxacin and ofloxacin in different mono- and mixed solvent systems at different temperatures to provide an experimental basis for the preparation of levofloxacin and ofloxacin nanosuspensions. To this end, the solubility of both compounds was evaluated using a solid–liquid equilibrium technique in DMSO, acetone, ethanol, NMP, and water monosolvents and ethanol–water mixed solvents at different volume fractions and temperatures. The modified versions of the van’t Hoff and Gibbs equations were recruited to calculate the thermodynamic properties of the solutions. The correlation between the solubility data of levofloxacin and ofloxacin and different mathematical models, including the Yalkowsky, Jouyban-Acree, and van’t Hoff models and their combinations was studied. According to the results, the highest and lowest solubility of levofloxacin and ofloxacin were attainable in 1 (pure ethanol monosolvent) and 0.1 v/v of ethanol fractions in ethanol/water mixed solvent. Moreover, the solubility of both compounds was superior at higher temperatures. Afterwards, the nanosuspensions were prepared using the solvent-antisolvent method. Different characterization techniques revealed the formation of the smallest particles with relatively irregular morphology in the 0.1 v/v volume fraction of ethanol in water. The XRD analysis exhibited the typical crystalline diffractions of levofloxacin and ofloxacin and the thermal transitions and stability of both compounds were investigated using DSC and TGA techniques. The results obtained in this study could be used to enhance the solubility and bioavailability of levofloxacin and ofloxacin during the drug formulation development and manufacturing processes.

Development of a seroepidemiological tool for bat-borne and shrew-borne hantaviruses and its application using samples from Zambia.

Rodent-borne orthohantaviruses are the causative agents of hemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome. Apart from the classic rodent-borne hantaviruses, numerous species of hantaviruses have been identified in shrews and bats; however, their antigenicity and pathogenicity are unknown. This study focused on developing a serological method to detect antibodies against bat- and shrew-borne hantaviruses. Five bat-borne (Brno, Dakrong, Quezon, Robina, and Xuan Song) and 6 shrew-borne (Asama, Altai, Cao Bang, Nova, Seewis, and Thottapalayam) viruses were selected based on the phylogenetic differences in their N proteins. The recombinant N (rN) proteins of these viruses were expressed as antigens in Vero E6 and 293T cell lines using the pCAGGS/MCS vector. Antisera against the Nus-tagged rN fusion proteins of these viruses (mouse anti-Brno, Dakrong, Quezon, Robina, Xuan Song, Asama, Cao Bang, and Nova, while rabbit anti-Altai, Seewis and Thottapalayam) were also generated. Antigenic cross-reactivity was examined in antisera and rN-expressing Vero E6 cells. The rN proteins of almost all the tested viruses, except for the Quezon and Robina viruses, showed independent antigenicity. For serological screening of bat samples, 5 rNs of the bat-borne viruses were expressed together in a single transfection protocol. Similarly, 6 rNs of shrew-borne viruses were expressed. Reactivities of the mixed antigen system were also examined across the singly transfected Vero cell lines to ensure that all antigens were expressed. Using these antigens, bat serum samples collected from Zambia were screened using the indirect immunofluorescence antibody test (IFAT). Selected positive samples were individually tested for the respective antigens by IFAT and western blot assays using rN-expressing 293T cell lysates. Of the 1,764 bat serum samples tested, 11.4% and 17.4% were positive for bat and shrew mixed antigens, respectively. These samples showed positive reactions to the Brno, Dakrong, Quezon, Xuan Son, Robina, Asama, Altai, Cao Bang, or Thottapalayam virus antigens. These observations suggest that the mixed-antigen screening system is useful for serological screening For Orthohantavirus infections and that bats in Zambia are likely exposed to not only bat-borne hantaviruses but also to shrew-borne hantaviruses.

Testing the prediction capability of trained models: sildenafil citrate solubility in propylene glycol and 1-propanol mixtures at different temperatures

ABSTRACT This study investigates the thermodynamic characteristics, equilibrium solubility, and solvation dynamics of sildenafil citrate within binary solvent systems composed of propylene glycol and 1-propanol. Utilizing both determination and computational approaches, the solubility patterns of sildenafil citrate were quantitatively assessed, revealing direct proportionality with increments in temperature and the concentration of propylene glycol. A comparative analysis using three distinct mathematical models to represent the solid–liquid phase equilibrium was conducted. Among these, the Jouyban-Acree-van’t Hoff model yielded the most comprehensive correlation by covering the effects of both temperature and solvent composition variations on the solubility, with a mean relative deviation (MRD%) of 6.4%, suggesting a robust alignment between the modelled and experimental solubility data. Previously trained models were tested to predict the solubility of the drug in mono- and mixed-solvents at various temperatures where accurate predictions were obtained with the MRD% of 19.1% (for mono-solvents), 8.1 and 14.4% (for mixed solvent systems).

Construction of Core‐Shell Structure in PA6/ABS/SEBS Blends for Achieving Stiffness‐Toughness Balance

A mixed system of styrene‐ethylene‐butene‐styrene copolymer (SEBS) and acrylonitrile‐butadiene‐styrene copolymer (ABS) is used to modify polyamide 6 (PA6). The incorporation of maleic anhydride‐grafted SEBS (SEBS‐g‐MAH) facilitates a reaction between the anhydride functional groups and the terminal amine group of PA6, resulting in SEBS predominantly localizing at the interface between PA6 and ABS. This leads to the formation of core‐shell structure particles within the PA6 matrix, where ABS forms the hard core and SEBS constitutes the soft shell. As the content of SEBS‐g‐MAH increases, the thickness of SEBS shell grows, enhancing the impact strength of PA6/ABS (70/15) by 3.5 times at 30 parts of SEBS‐g‐MAH. The introduction of MAH‐grafted ABS as a compatibilizer in the PA6/ABS/SEBS‐g‐MAH (60/30/10) system significantly reduces the size of core‐shell particles, yielding a 3.4‐fold increase in impact strength and a simultaneous twofold increase in tensile strength at 10 parts of ABS‐g‐MAH. This dual enhancement provides an optimal balance between rigidity and toughness.