Feasible Conditions Research Articles

Preparation and kinetic studies of a new antibacterial sodium alginate gelatin hydrogel composite.

This study involved synthesis of a novel antibacterial heterocyclic compound, sodium 2-(2-(3-phenyl-1, 2, 4-oxadiazol-5-yl) phenoxy) acetate abbreviated as Na-POPA. Further development of a biocompatible, pH-responsive hydrogel drug carrier prepared utilizing the natural polymers gelatin and sodium alginate. The compound loaded on the hydrogel represented new drug delivery system. Comprehensive characterization of Na-POPA was performed using Fourier-transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (¹H NMR), carbon-13 nuclear magnetic resonance (¹³C NMR), and high-resolution mass spectrometry (HRMS). The compound was loaded onto the sodium alginate/gelatin hydrogel carrier under feasible experimental conditions. The successful incorporation of Na-POPA into the hydrogel matrix was confirmed via scanning electron microscopy (SEM), powder X-ray diffraction (pXRD) analysis and FT-IR spectroscopy. Cytotoxicity assays revealed that the all the loaded and unloaded compound induced cell toxicity at large concentration much lower than many reported results. The hydrogel reduced the inherent cytotoxicity of Na-POPA and enhanced its biocompatibility. The release kinetics of Na-POPA from the hydrogel were evaluated spectrophotometrically at different pH conditions simulating biological fluids. The release rate at pH 1.2 was greater than the release at pH 6.8, with a higher cumulative release observed at pH 6.8. The release kinetics obeyed the pseudo-second-order kinetic model, indicating a controlled release mechanism influenced by the hydrogel's physicochemical properties. Electrochemical impedance spectroscopy and cyclic voltammetry further confirmed that the compound release was pH-dependent. The high swelling and solubility at pH 6.8 enhance the release. The larger amount released at 6.8 (target intestine) because of more solubility, leaching and swelling rather than shrinking.

Assisted reproductive technology and the risk of birth defects mediated by multifetal pregnancy: evidence from the China Birth Cohort Study

BackgroundBoth assisted reproductive technology (ART) and multifetal pregnancy have been reported to be associated with an increased risk of birth defects (BDs). However, it is unclear whether multifetal pregnancy is a mediator that increases the risk of BDs in ART-conceived pregnancies. ObjectivesTo investigate the risk of BDs associated with ART, and to quantify the mediating effect of multifetal pregnancy between ART and BDs. Study DesignFrom November 2017 to August 2021, 132,386 pregnant women from 50 study sites in 17 provinces of China were monitored from their first trimester until delivery (or miscarriage/termination). BDs were detected in both live births and stillbirths. Directed acyclic graph was drawn to understand the causal relationship between ART and BDs, and inverse probability of treatment weighting was used to adjust for confounders. Then, log-binomial generalized estimating equation was established in the inverse probability weighted cohort to estimate the adjusted relative risk (RR) of BDs associated with ART compared to natural conception, while addressing the cluster effect of study sites. Mediation analysis was performed to assess the mediating effect of multifetal pregnancy between ART and BDs. Number needed to harm was calculated for multifetal pregnancy versus singleton pregnancy among ART-conceived pregnancies. ResultsA total of 126,035 naturally conceived and 5124 ART-conceived pregnancies were included in the analysis. The incidence of BDs in the ART conception group (4.2%) was significantly higher than that in the natural conception group (2.5%), with an adjusted RR of 1.48 (95% CI, 1.24 to 1.78). Multifetal pregnancies were also more common in the ART conception group (21.4%) than the natural conception group (1.1%). Mediation through multifetal pregnancy accounted for 25% of the risk of BDs associated with ART. Notably, if ART-conceived pregnant women could have singleton pregnancy rather than multifetal pregnancy, one case of BDs could be potentially avoided for every 52 (95% CI, 29 to 233) pregnancies. ConclusionsMultifetal pregnancy mediated the effect of ART on BDs. Therefore, when ART treatment is needed, single embryo transfer should be considered under clinically feasible conditions for the prevention of BDs.

Oxidative Amidation of Ferrocenyl Aldehydes with Amines Catalyzed by Chalcogenised Fe3Se2(CO)9 Cluster: Direct Transformation of Aldehyde to Amides.

With the interest and knowing the importance of ferrocenyl conjugates, a direct amidation of ferrocenyl aldehyde has been developed under feasible conditions. Varieties of amines has been oxidatively coupled with ferrocene aldehyde in the presence of highly economical and robustly stable iron chalcogenide ironcarbonyl clusters [Fe3E2(CO)9, E= S, Se, and Te] and TBHP. The reaction worked in greener solvent water at a moderate temperature of 70 °C and the ferrocenyl-amides in just 30 minutes. All the varieties of amines were found to be well tolerated for the present method, and due to the high medicinal importance of ferrocenyl-amides, sole focus of this report was concentrates on the synthesis of various new ferrocenyl-amides in good to excellent amounts.

51 Feasibility of paediatric postoperative telemedicine in Nunavik

Abstract Background To access surgical care, Inuit children from Nunavik are relocated by plane to an urban tertiary hospital. Current processes that require an in-person follow-up appointment extend their stay away from home despite an overall low rate of postoperative complications. Telemedicine presents the opportunity to reduce this delay, but little is known about its feasibility for paediatric postoperative care in Nunavik. Objectives To determine the feasibility of paediatric postoperative telemedicine in Nunavik. Design/Methods In this mixed methods study using a convergent parallel design (August 2022 – May 2023), we recruited eleven healthcare providers who regularly interact with Inuit families of Nunavik. We conducted individual semi-structured in-depth interviews about postoperative care in this setting and analyzed the data thematically. In parallel, we conducted a narrative synthesis of the literature and gathered input from collaborators to assess the potential resources needed to enable postoperative telemedicine in the region. We then determined the capability for telemedicine in each of the fourteen villages of Nunavik using data provided by the regional health board. A meeting with specialists responsible for telemedicine in the region was held to discuss findings and future steps. We analyzed and compared qualitative and quantitative results to determine the degree of postoperative telemedicine readiness in the region. Results The main themes influencing the feasibility of telemedicine were general considerations for telemedicine use as a follow-up modality, patient characteristics most suitable for postoperative telemedicine, resources needed for telemedicine use as a follow-up modality, and the feasibility of postoperative telemedicine as determined by healthcare providers. All interviewees deemed paediatric postoperative telemedicine in this region feasible but highlighted conditions for its success. The narrative review uncovered limited literature on telemedicine use in Nunavik. As of January 2023, the two regional hospitals and three health centers had full capabilities for postoperative telemedicine. The nine other health centers had partial capabilities, mainly due to limited access to stable high-speed Internet and Internet bandwidth. Only regional hospitals had access to hospitalization, imaging, readaptation, and laboratory departments. The participating specialists deemed telemedicine feasible if patient load and burden of administrative work are manageable. Conclusion Postoperative paediatric telemedicine in Nunavik is feasible from a resource, healthcare providers and specialists standpoint. Leveraging centers with appropriate capacity would allow the increase in telemedicine usage in Nunavik. Next steps in this research program include interviews with families to evaluate their needs, preferences and attitudes toward postoperative paediatric telemedicine.

New Insights for High-Throughput CO2 Hydrogenation to High-Quality Fuel.

In the case of CO2 thermal-catalytic hydrogenation, highly selective olefin generation and subsequent olefin secondary reactions to fuel hydrocarbons in an ultra-short residence time is a huge challenge, especially under industrially feasible conditions. Here, we report a pioneering synthetic process that achieves selective production of high-volume commercial gasoline with the assistance of fast response mechanism. In situ experiments and DFT calculations demonstrate that the designed NaFeGaZr presents exceptional carbiding prowess, and swiftly forms carbides even at extremely brief gas residence times, facilitating olefin production. The created successive hollow zeolite HZSM-5 further reinforces aromatization of olefin diffused from NaFeGaZr via optimized mass transfer in the hollow channel of zeolite. Benefiting from its rapid response mechanism within the multifunctional catalytic system, this catalyst effectively prevents the excessive hydrogenation of intermediates and controls the swift conversion of intermediates into aromatics, even in high-throughput settings. This enables a rapid one-step synthesis of high-quality gasoline-range hydrocarbons without any post-treatment, with high commercial product compatibility and space-time yield up to 0.9 kggasoline ⋅ kgcat -1 ⋅ h-1. These findings from the current work can provide a shed for the preparation of efficient catalysts and in-depth understanding of C1 catalysis in industrial level.

Hybrid Surgical treatment of thoraco-abdominal aneurysm: case report

The conventional surgical treatment of TAAA is complex and is associated with important perioperative mortality and mobidity. There is consensus that endovascular aneurysm repair (EVAR) is the preferred treatment for high-risk patients, but the availability of endovascular-branched grafts are quite limited. As an alternative for such dilema, the hybrid approach came as another possibility for high risk patients where totally endovascular treatment is not feasible and clinical condition for convencional surgery is prohibitive. Thus, the objective of this study is to report our service's experience with the hybrid surgical technique for treatment of this severe condition. Male patient, 73 years old, diagnosed with fusiform aortic aneurysm at the thoracoabdominal transition level, measuring 10.1 x 8.9 cm, associated with a large retroperitoneal hematoma, likely corresponding to an aneurysm rupture. The hybrid strategy was chosen, involving two stages: conventional surgery and endovascular procedures. However, approximately 24 hours after the first surgery the patient had refractory cardiac arrest at intensive care unit. Surgical treatment of thoracoabdominal aneurysm is a complex issue, and the trend over time is tending toward total endovascular treatment, and these devices will undoubtedly evolve and be used more and more in the years to come. However, the hybrid repair will likely remain a standard procedure for a while, until total endovascular procedures become more common and the necessary endovascular materials widely available.

Disclosing differential precipitation behavior of a novel high Mg-containing Al-Mg-Zn-Si alloy

The application of traditional Al-Mg-Zn alloy in aerospace field is limited due to poor corrosion resistance for β-phase at grain boundaries and low strength for the lack of T phase. Here we propose a novel high Mg-containing Al-Mg-Zn-Si alloy with a novel alloying strategy of high Mg content combining with a suitable microalloying Si, obtaining small and densely precipitated nanoscale T’ phase in the matrix, co-existing T’ and η’ phases adjacent to grain boundary and T phase at grain boundary. The formation of GPT’ zone in the matrix is dramatically enhanced due to energetically favorable substitution of Al by Si and furtherly facilitates homogeneous growth of T’ phase by solute redistribution. η’ phase is transformed from T’ phase or evolved from GPIIη’ zone along grain boundary due to feasible thermodynamic condition of Mg-poor and Zn-rich domain by distinct Mg and Zn exsolution on grain boundary. The present alloying design makes it possible that differential precipitation behavior of T’ phase and T’ + η’ phases can simultaneously occur in the matrix and adjacent to grain boundary, the alloy has obviously advantaged overall performance over traditional Al-Zn-Mg-(Cu) alloys, which raises a new perspective for developing new high-performance lightweight aluminum alloys.

Influence of aggregate size on pervious concrete properties with and without construction and demolition waste

This research evaluates the impact of aggregate sizes on pervious concrete properties, comparing aggregates of 12.5 mm and 19 mm, as well as replacing natural aggregates with recycled aggregates set at 0% and 50%. Four types of pervious concrete were produced, and their properties were determined: density, porosity, permeability coefficient, compressive strength, flexural tensile strength, and abrasion resistance. The results indicate that water permeability is directly related to pore size and is influenced by aggregate size (90% of the variation in pervious concrete permeability) and, to a lesser extent, by recycled aggregate content (10% of the variation). Mixes with larger aggregates (19 mm) demonstrated higher permeability coefficients. Replacing natural aggregates with recycled aggregate did not significantly affect the mechanical properties of pervious concrete, highlighting the effectiveness of waste processing and mixing procedures, allowing for the incorporation of 50% of recycled aggregate. The concretes met the requirements of the American Concrete Institute, suggesting technically feasible conditions for sustainable practices in the construction industry.

Stability analysis of random fractional-order nonlinear systems and its application

The research on stability analysis and control design for random nonlinear systems have been greatly popularized in recent ten years, but almost no literature focuses on the fractional-order case. This paper explores the stability problem for a class of random Caputo fractional-order nonlinear systems. As a prerequisite, under the globally and the locally Lipschitz conditions, it is shown that such systems have a global unique solution with the aid of the generalized Gronwall inequality and a Picard iterative technique. By resorting to Laplace transformation and Lyapunov stability theory, some feasible conditions are established such that the considered fractional-order nonlinear systems are respectively Mittag-Leffler noise-to-state stable, Mittag-Leffler globally asymptotically stable. Then, a tracking control strategy is established for a class of random Caputo fractional-order strict-feedback systems. The feasibility analysis is addressed according to the established stability criteria. Finally, a power system and a mass–spring-damper system modeled by the random fractional-order method are employed to demonstrate the efficiency of the established analysis approach. More critically, the deficiency in the existing literatures is covered up by the current work and a set of new theories and methods in studying random Caputo fractional-order nonlinear systems is built up.

Gap bridging in laser welding of EN AW 5083 with different joint configurations via beam oscillation and filler wire

The extended use of laser welding in the industry requires a less sensitive process in terms of geometrical tolerances of the joint edges. As the industrial availability of laser systems increases, the demand to use laser welding technology possibly with parts coming from less precise production steps is increasing. Gap formation is often caused by the edge quality of the parts coming from previous manufacturing steps such as sheet forming. Al alloy sheets deformed to box-shaped 3D forms often require welded joints on the edges in lap, but, and corner joint configurations. These joints are hard to carry out by laser welding due to the large gap formation caused by the tolerances of the deformation processes involved. Laser welding of Al alloys is already challenging in the absence of gap formation, while these joint configurations have been not feasible with a stationary beam due to incomplete fusion and defect formation. Laser welding with beam oscillation and wire feeding can improve the weldability of these joints. The oscillating motion of the high-intensity beam can achieve a deep weld together with a wider seam. Combined with wire feeding, the process can close gaps in the butt, lap, and corner joint configurations. On the other hand, the added oscillation and wire-related parameters require extending the experimental space, which requires a methodological study to identify feasible conditions. Accordingly, this work proposes a methodological approach to identify and set laser welding process parameters with beam oscillation and wire feeding for an EN AW 5083. Process parameters were initially studied using a simple analytical model that depicts the beam trajectory. Bead-on-plate tests were conducted to assess beam size, power, and weld speed ranges. Lap, butt, and corner joint conditions with a 0.5-mm gap were welded with high quality by manipulating the laser power, oscillation amplitude, and wire feed rate. The results show that welding speeds could be maintained as high as 55 mm/s with complete filling of gaps of up to 0.5 mm, eliminating the surface undercuts and achieving weld widths in the order of 2.5 mm. Moreover the results show the possibility control the depth of the welds from 3 mm to full-penetration conditions.

Optimization of lactic acid production from apple and tomato pomaces by thermotolerant bacteria

The production of lactic acid (LA) through biomass fermentation represents a promising alternative to the chemical synthesis. The use of agri-food by-products as fermentable carbohydrate sources can improve process sustainability by reducing waste and valorizing residual biomass. This study assessed the use of apple and tomato pomaces for producing LA through fermentation using thermotolerant bacteria under aerobic and non-sterile conditions. Three bacteria were evaluated and Heyndrickxia coagulans DSM 2314 was selected for its ability to produce LA from hydrolyzates of apple pomace (APH) and tomato pomace (TPH). The fermentation conditions were optimized to maximize LA production from APH, TPH and a mixture of both hydrolyzates. Therefore, LA productions ranged from 36.98 ± 0.41 to 40.72 ± 0.43 g/L, with yields from 0.86 ± 0.02 to 1.01 ± 0.01 g/g. Yeast extract was necessary as a nitrogen source for fermenting APH, while TPH and the mixture of both hydrolyzates did not require any supplementation. Other nitrogen sources, such as wine lees, urea and NH3Cl, were tested for fermenting APH. However, mixing this hydrolyzate with TPH proved to be the most viable alternative. This study demonstrates the potential for valorizing apple and tomato pomaces into LA under feasible fermentation conditions.

Facile route for processing natural polymers for the formulation of new low-cost hydrophobic protective hybrid coatings for carbon steel in petroleum industry

This research helps with the creation, assessment, and characterization of a new hybrid protective coating for carbon steel alloy in acid conditions. The findings of this study will be useful for both chemical and petrochemical companies as well as scientists. This study aims to protect C-steel in acid pickling solution 1.0M HCl and formulate new hydrophobic protective hybrid organic–inorganic coatings from biopolymers chitosan and plant resin guar gum. Eight coating samples of chitosan in the absence and the presence of guar gum, silica and two heterocyclic compounds are prepared at feasible operational conditions using hot melt method. The aiding additives improved compatibility between coating constituents as confirmed by using different methods of analysis. This new processing approach has addressed the problems of using chitosan in corrosion control such as solubility in acid media and low mechanical strength. Coating samples of chitosan and its composites with the heterocyclic compounds (2-Hydrazinyl-6-methyl-4, 5-dihydro pyrimidine-4-on) or (2-Hydrazinyl-6-phenyl-4, 5-dihydro pyrimidine-4-on) are potent biocides. Coating shifts corrosion potential of carbon steel by 30 mV to more noble direction relative to the active potential 520 mV of bare carbon steel surface. Impedance and polarization measurements indicate that coating samples protect metal surface as mixed-type inhibitor by adsorption mechanism. There is a good agreement between percentages protection %P of coating calculated using the values of charge transfer resistance, Rct, and corrosion current density, icorr. All %P values are above 99% for all coating samples. Guar gum plant resin increases gloss of the coating film. Silica fills the pores in the polymeric film and increases the stuffiness of the polymeric coating film by modifying the particle size. All coated samples have high contact angle ranging from 150° to 165° indicating low wettability and high hydrophobicity of coating film on the metal surface.

Design and analysis of grid mooring system for gravity net cage with a comprehensive optimization method

The design of gravity net cage mooring systems is a complex endeavor, which is critical for preventing major accidents caused by mooring system failures. A comprehensive optimization method is proposed to enhance the reliability and performance of the net cage mooring system by integrating static and dynamic phases. The proposed method initiates static simulations based on the catenary theory to refine the initial range of parameters. This preparatory step ensures the subsequent dynamic analysis is carried out based on feasible initial conditions with the lumped mass method. The dynamic simulation captures the complex interactions and behavior of the mooring systems under various environmental conditions. The multi-objective optimization provides feasible solutions with simultaneous consideration of both processes. Three different scenarios are optimized with the forces and motions compared after the time domain analysis, resulting in a satisfactory set of solutions. The results show that variations in the angle of the mooring line of the net cage primarily impact the net cage's movement and volume in different environments.

Characterization of mechanical properties of carbon nanotube fibers prepared by chemical vapor deposition

A chemical vapor deposition (CVD) method for preparing carbon nanotube fibers was proposed. This method used ethanol/acetone as the carbon source, ferrocene as the catalyst and thiophene as the promoter. It used a high-temperature gas-phase flow reaction to spin out carbon tube fibers. Subsequently, the mechanical properties of carbon tube fibers prepared under different conditions (carbon source, gas flow and raw material ratio) were characterized and analyzed. The results demonstrated that the carbon fiber prepared with ethanol as the carbon source under specific synthesis conditions has good continuity and can be prepared for 3 hours in succession. In a feasible condition (Fe, S, C ratio, air flow ratio, and growth temperature), using pure acetone as the carbon source can prepare carbon nanotube fibers with fiber-specific strength > 1.5N / tex.

Ensuring a sustainable and healthy primary school of the future: Finding answers through group concept mapping

Objectives: Overweight and obesity among school-aged children pose a threat to both their academic performance and public health. The Healthy Primary School of the Future (HPSF) initiative was established to address this issue. Our objective was to explore the conditions that make HPSF sustainable based on the perspectives of relevant stakeholders. Design: The study utilised Group Concept Mapping, a structured methodology for conducting mixed-methods participative research, combining qualitative data collection with quantitative data analysis measures. Method: Participants included parents, teachers, school directors, politicians, labour unions, educational, nutrition and health scientists and policymakers. They were asked to respond to the prompt, ‘A necessary condition to make the HPSF sustainable is . . .’. The statements generated were then assessed for their importance and feasibility. Using multidimensional scaling and hierarchical cluster analyses, we identified the shared vision among the stakeholders. Results: A total of 106 unique statements were generated and grouped statistically into 10 clusters. The most significant clusters were identified as Financing; Accessibility for everyone; and Content/Lifestyle/School Programme. The clusters that were deemed most feasible included Content/Lifestyle/School Programme; Accessibility for everyone; and Evaluation. Conclusion: Achieving sustainability for the HPSF requires a comprehensive approach that addresses the conditions outlined in all 10 clusters. Based on the ratings of feasibility and importance, our recommendation is to prioritise implementation of Content/Lifestyle/School Programme and Accessibility for everyone. Subsequently, efforts should be directed towards realising the less feasible but crucial conditions, such as Financing and Evaluation, followed by the remaining six clusters of conditions as identified.

Development and performance evaluation of a high solar contribution resorption-compression cascade heat pump for cold climates

Absorption-resorption heat pumps (ARHPs) have great potential in utilizing low-temperature solar heat for efficient winter heating, but are limited by their weak adaptability to cold climates relative to absorption heat pumps (AHPs) and vapor compression heat pumps (VCHPs). In this work, a resorption-compression cascade system consisting of ARHP and VCHP subsystems is proposed and investigated, with the goal of achieving efficient winter heating with improved solar contribution in cold climates. Thermodynamic models of the two subsystems and of the whole cascade system are developed for system feasibility verification and performance evaluations. Feasible operation temperature and pressure conditions are identified in terms of internal subsystem matching. Based on these operation conditions, the primary energy ratio (PER) – which is a key performance evaluation index – is investigated over a range of solar fractions (f). The results show that for cases without solar contribution, the PER can be generally >0.95 under feasible operating conditions. In addition, the primary energy saving ratio (PESR) and heating capacity lift ratio (εlift), as well as the heat source temperature (Th) and ambient temperature (Tamb) restriction, are all investigated and compared to those of other, competing heating systems. The results show that the proposed system can reduce the Th demand to 69 °C (with a minimum Tamb of −21 °C) and extend the operational Tamb to −31 °C (with a minimum Th of 90 °C), while importantly achieving PESR > 0.20 and εlift > 20 % under the above extreme conditions. Moreover, when integrating the system with solar heat with f > 43 %, the proposed solar-assisted system has a clear PER advantage over an equivalent VCHP system in the Tamb range from −31 °C to 10 °C, highlighting the possibility of achieving higher solar contribution in cold climates.

Influence of Normal-to-High Anodizing Voltage on AAO Surface Hardness from 1050 Aluminum Alloy in Oxalic Acid.

Anodic aluminum oxide (AAO) has been widely applied for the surface protection of electronic component packaging through a pore-sealing process, with the enhanced hardness value reaching around 400 Vickers hardness (HV). However, the traditional AAO fabrication at 0~10 °C for surface protection takes at least 3-6 h for the reaction or other complicated methods used for the pore-sealing process, including boiling-water sealing, oil sealing, or salt-compound sealing. With the increasing development of nanostructured AAO, there is a growing interest in improving hardness without pore sealing, in order to leverage the characteristics of porous AAO and surface protection properties simultaneously. Here, we investigate the effect of voltage on hardness under the same AAO thickness conditions in oxalic acid at room temperature from a normal level of 40 V to a high level of 100 V and found a positive correlation between surface hardness and voltage. The surface hardness values of AAO formed at 100 V reach about 423 HV without pore sealing in 30 min. By employing a hybrid pulse anodization (HPA) method, we are able to prevent the high-voltage burning effect and complete the anodization process at room temperature. The mechanism behind this can be explained by the porosity and photoluminescence (PL) intensity of AAO. For the same thickness of AAO from 40~100 V, increasing the anodizing voltage decreases both the porosity and PL intensity, indicating a reduction in pores, as well as anion and oxygen vacancy defects, due to rapid AAO growth. This reduction in defects in the AAO film leads to an increase in hardness, allowing us to significantly enhance AAO hardness without a pore-sealing process. This offers an effective hardness enhancement in AAO under economically feasible conditions for the application of hard coatings and protective films.

Valorization of Cashew Apple Waste into a Low-Alcohol, Healthy Drink Using a Co-Culture of Cyberlindnera rhodanensis DK and Lactobacillus pentosus A14-6.

This study investigated the potential of microbial fermentative transforming processes in valorizing the cashew apple by-product into a low-alcohol, health-benefiting beverage. We particularly investigated the use of a non-Saccharomyces yeast, Cyberlindnera rhodanensis DK, as the main targeted microbe. At 30 °C without agitation, C. rhodanensis DK caused changes in key parameters during the fermentation of cashew apple juice (CAJ) in terms of varied pH values and initial sugar concentrations. This result indicated that pure CAJ, with pH adjusted to 6 and with the original 6.85% (w/v) total sugar content, was the most feasible condition, as glucose and fructose were mostly consumed at 12 days of fermentation. A co-culture approach with either Saccharomyces cerevisiae TISTR 5088 or Lactobacillus pentosus A14-6 was investigated to improve both physicochemical and fermentation characteristics. Co-fermentation with S. cerevisiae TISTR 5088 resulted in significantly increased ethanol accumulation to 33.61 ± 0.11 g/L, but diminished bioactive compounds, antioxidant activity, and antidiabetic potential. In contrast, co-fermentation with L. pentosus A14-6 demonstrated excellent outcomes, as it significantly increased sugar consumption and finally remained at only 4.95 g/L compared to C. rhodanensis DK alone, produced lower levels of ethanol at only 19.47 ± 0.06 g/L, and higher total titratable acid (TTA), resulting in a final pH of 3.6. In addition, co-fermentation with this lactic acid bacterium significantly enhanced bioactive compounds and antioxidant activity and also retained potential antidiabetic properties. These findings highlight the feasibility of using tailored microbial fermentation strategies to produce low-alcohol beverages with enhanced health-promoting properties from CAJ; however, product-development processes following health food regulations and sensory evaluation are necessary.

Simultaneous increase of parameters of an experimental absorption system: Neural network inverse optimization methodology with multi-inputs

The Absorption Heat Transformer (AHT) has become an alternative proposal to weaken the trend of thermal pollution because it contributes to the recovery of residual heat and the use of solar thermal energy for its activation. Recently, compact designs have been developed that share two heat exchangers in one shell to reduce heat losses and save maintenance costs. The evaluation of the performance of AHTs depends on multiple parameters, which have been optimized using models based on ideal conditions. Multivariable optimization with artificial intelligence has considered experimental data to obtain feasible conditions related to the operation of the AHT. However, these models have focused only on determining one parameter at a time, reflecting a limitation. This study aims to develop a new optimization strategy to simultaneously maximize two relevant parameters associated with the efficiency of a compact experimental AHT. The optimization methodology is applied to increment the values of the heat generated in the absorber (QAB) and the Exergy Coefficient of Performance (ECOP) using the same objective function. This objective function is resolved when reaching the desired output parameters by determining multiple optimal conditions of the AHT. Initially, the modeling of the experimental data was carried out using an artificial neural network (ANN) for the diagnosis and prediction of the QAB and the ECOP. The model was validated by comparing the experimental values of QAB and ECOP against predicted values through a linear regression model, with a satisfactory result of R2>0.98. Subsequently, the multivariable inverse artificial neural network methodology for multiple output parameters (ANNim-m) was used and coupled with the Particle Swarm Optimization algorithm (ANNim-m-PSO) to generate the new multivariate optimization strategy and improve QAB and ECOP parameters simultaneously. Finally, 4 random tests with different initial operating conditions were optimized. Based on the optimization of the 4 tests, the QAB heat load was increased by 87.7 %, 54.2 %, 30.79 %, and 22.66 % from initial experimental conditions of 2.7, 9.0, 14.23 and 23.29 kW, respectively. In the case of ECOP, elevations of 28.5 %, 23.4 %, 15.4 %, and 16.18 % were obtained for initial values of 0.3801, 0.455, 0.5180, and 0.5729, respectively. It is determined that the parameters QAB and ECOP have a high sensitivity when the inlet temperature of the absorber of the external circuit (TAB) decreases. The results reveal that it is feasible to use the ANNim-m-PSO model, because the optimization was able to significantly maximize both QAB and ECOP parameters of the 40 kW experimental AHT.

Asphalt pyro-rejuvenators based on waste tyres: An approach to improve the rheological and self-healing properties of aged binders

Waste Tyres (WT) are a significant fraction of industrial waste and a source of environmental hazards with limited valorisation. To reduce this problem, currently there is a growing interest in valuing the WT through pyrolysis to obtain multifunctional liquids to improve the rheological and self-healing properties of aged binders. This research provides a comprehensive study on using WT mixtures as precursors for asphalt rejuvenators by means of pyrolysis and distillation processes. To this end, WT polymeric fractions from light (WT-L) and mining trucks (WT-M) were used as feedstock and characterised for compositional and thermal properties. Additionally, micropyrolysis coupled with gas chromatography/mass spectrometry (Py-GC-MS) was used to identify the major products in pyrolysis vapours, to elucidate the reaction maps describing thermal degradation of WTs and to predict the feasible reaction conditions. The pyrolysis liquids were produced after a screening of reaction conditions and subjected to distillation, following a response surface model to produce an optimised pyro-rejuvenator. The results showed that the pyrolytic rejuvenator obtained through pyrolysis at 465 °C and distillation cutting at 160–200 °C is mainly composed of hydrocarbons and aromatic substances (95.5%), with a significant proportion of limonene (33.71%). Furthermore, the pyrolytic rejuvenator exhibited highly desirable physical properties in the context of its application and excellent oxidative stability (85.7%). Otherwise, it was determined that bitumen mixtures with 3%–6% doses of pyro-rejuvenator improved the viscosity, softening point, and penetration of aged binders, restoring their physical properties to the virgin state. In conclusion, pyro-rejuvenators can be successfully used as a promising solution to produce more durable and sustainable pavements with improved rheological and healing properties.