Maximum Extraction Efficiency Research Articles

Extraction of apple pomace polyphenols using natural deep eutectic solvents: A sustainable approach

To effectively utilize apple pomace resources, we extracted apple pomace polyphenols using natural deep eutectic solvent (NADES) as the medium, with a solvent-to-solid ratio of 50 mL/g, for a duration of 120 min. Compared to conventional extraction solvents (ethanol and methanol), four NADES significantly enhanced the extraction efficiency of polyphenols from apple pomace. Notably, NADES 1 (betaine: urea = 1:1, 30% water) and NADES 2 (betaine: malic acid = 1:1, 30% water) exhibited superior extraction capabilities, with maximum values reaching 5.245 ± 0.124 mg GAE/g pomace and 5.157 ± 0.164 mg GAE/g pomace, respectively, in Qinguan apple pomace. Both solvents reached their maximum extraction efficiency within 120 min, with NADES 1 achieving a maximum extraction amount of 4.8325 mg GAE/g and NADES 2 achieving 5.3039 mg GAE/g from Fuji apple pomace. NADES 1 and NADES 2 were more efficient in extracting monophenols such as quercetin, rutin, gallic acid, and procyanidin, whereas organic solvents (methanol and ethanol) were more effective for monophenols like methyl gallate and phlorizin. Furthermore, polyphenol extracts obtained using NADES from Fuji apple pomace displayed varying levels of antibacterial effectiveness, with NADES 4 (glucose: lactic acid = 1:5, 60% water) and NADES 2 showing superior efficacy against Escherichia coli and Staphylococcus aureus. This comprehensive study not only demonstrated the potential of NADES in extracting polyphenols from apple pomace but also highlighted their applicability as natural preservatives in the food industry.

Selective extraction of Li and Mn from spent lithium-ion battery smelting slag: Insights from isomorphous replacement in minerals

Recycling the high content of valuable metal elements contained in spent lithium-ion batteries (SLIBs) has attracted significant interest. By leveraging the concept of substitution of isomorphous replacement in earth minerals, this study proposes a novel approach for the selective extraction of Li and Mn from the artificial spodumene-type lithium-rich slag comprising LiAlSi2O6 and Mn2SiO4 through two-step selective roasting process with Na2SO4 and CaCl2, respectively. The thermodynamic calculations confirmed the feasibility of selective Li extraction by Na2SO4 roasting, with the experimental results showing that over 99 % Li was preferentially extracted as LiNaSO4. In the subsequent CaCl2 roasting step for Mn recovery, the Mn2SiO4 was effectively transformed into soluble Na2MnCl4, achieving a maximum Mn extraction efficiency of 86.5 %. The leaching kinetics of the Na2SO4 roasting products were investigated, revealing that the leaching of Li was governed by diffusion and chemical reactions in line with the shrinking core model. Characterization methods such as XRD, SEM, XPS, and TG-DSC were employed to reveal the phase transformation mechanisms of Li and Mn during Na2SO4 and CaCl2 roasting, respectively. The proposed process introduces a novel paradigm for its remarkable selective recovery of Li and Mn from SLIBs smelting slag.

A salt/salt aqueous two-phase system based on pH-switchable deep eutectic solvent for the extraction and separation of mulberry polysaccharides

With the aim of expanding the potential application scope of mulberries, eleven pH-switchable deep eutectic solvents were screened for the ultrasonic-assisted extraction of mulberry polysaccharides, and a salt/salt aqueous two-phase system was constructed for the efficient separation of mulberry polysaccharides by regulating the system pH. DES-9 (tetraethylammonium chloride: octanoic acid molar ratio = 1: 2) with a critical response pH value of approximately 6.1 was concluded to be the best extraction solvent for extracting mulberry polysaccharides. A maximum polysaccharide extraction yield of 270.71 mg/g was obtained under the optimal conditions. The maximum polysaccharide extraction efficiency was 78.09 % for the pH-driven tetraethylammonium chloride/K2HPO4 aqueous two-phase system. An acidic β-pyran mulberry polysaccharide with a low-molecular weight of 9.26 kDa and a confirmed monosaccharide composition were obtained. This efficient and environmentally friendly polysaccharide separation method offers a new approach for the efficient extraction and utilization of other plant polysaccharides.

Enhancing anti-diabetic activity and reducing cytotoxicity of T. crispa extracts through sustainable approach of pressurized hot water extraction and micelle-mediated separation

In this study, pressurized hot water extraction (PHWE) was evaluated for the recovery of anti-diabetic borapetoside C (BPC) from T. crispa stems. The maximum BPC extraction efficiency obtained at 100 ˚C, 2.5 MPa and 5.0 mL/min was considerably higher than that obtained by the conventional methods. Under optimized conditions, one-site kinetic desorption model could most accurately describe the PHWE behavior, suggesting an intra-particle diffusion-controlled mechanism. The undesirable compounds in the extract were further removed by micelle-mediated separation (MMS), in which Tween 80 was added, followed by NaCl addition and slight temperature increase to induce phase separation. At the most suitable MMS condition, with 0.028 mM Tween 80, 0.4 M NaCl, at 85 ˚C, the majority (87 %) of BPC could be recovered in the aqueous phase after 40 min. After MMS, the resulting extract exhibited low cytotoxicity against L6 and HepG2 cells while maintaining significant α-glucosidase and α-amylase inhibition activities.

Simultaneous Determination of 8 Antioxidants and Free Sulfur Migrating from Container Closure System into Antibody Drug using High Performance Liquid Chromatography

<p>Background: The additives from container closure systems used in biopharmaceuticals, including antioxidants and vulcanizing agents, may leach into drug products during production or storage and result in patient exposure. Thus, there is an urgent demand for developing a robust and sensitive method for the simultaneous determination of these additives. </p> <p> Method: An approach utilizing vortex-assisted liquid-liquid microextraction coupled with highperformance liquid chromatography has been developed for the simultaneous determination of 8 antioxidants and free sulfur in biopharmaceutical samples. The extraction parameters, such as the choice of extraction solvent, HCl volume, vortex time, and disperser solvent, were optimized to ensure maximum extraction efficiency. </p> <p> Results: The optimized method was validated successfully, exhibiting acceptable recovery rates ranging from 89.2% to 109.0%, excellent repeatability (2.9% to 5.1%, n=6), and intermediate precision (3.7% to 5.9%, n=12), and satisfactory linearity with an R2 value of 1.000 for all the additives. Additionally, the limits of detection and quantification were determined to be in the range of 1.9– 30.0 μg/L and 7.5–120.0 μg/L, respectively. </p> <p> Conclusion: The proposed method was effectively applied to the analysis of additives in biopharmaceutical samples.</p>

A sustainable utilization approach of waste biomass resources to smart materials for buildings

Resource utilization of solid waste promotes resource conservation, energy transformation and sustainable development. In this study, we developed a synthetic strategy for converting biomass waste, such as waste bamboo powder, into a smart material with thermochromic properties - hydroxypropyl cellulose (HPC). The synthesis process includes extraction of cellulose and modification with hydroxypropyl groups. The maximum extraction efficiency of cellulose from raw bamboo powder was up to 48 % by carefully adjusting the reaction conditions including NaOH concentration, reaction time, and treatment temperature. The maximum yield of modification process was achieved to 1.32 g/g by optimizing alkalization temperature, alkalization time, NaOH concentration, propylene oxide concentration, etherification temperature and etherification time. The samples were characterized by a variety of techniques such as FTIR, 1H NMR, XRD, SEM to validate the micro-structure of the extracted cellulose the HPC materials. Moreover, this study explored the potential application of HPC hydrogel in smart window application, and evaluated its building energy saving efficiency under different climate conditions through computational simulation. The corresponding results showed that the HPC hydrogel smart window could have significant energy saving potential compared to ordinary clear glass window. This novel approach of converting waste resources into high valued thermochromic materials for smart windows, not only reduces waste disposal demand for excessive land-use and energy consumption but also shows a positively contributes to sustainable development, environmental protection, as well as energy conservation.

Very Stable and Efficient Tandem Quantum-Dot Light-Emitting Diodes Enabled by IZO-Based Interconnecting Layers.

Theoretically, tandem quantum-dot light-emitting diodes (QLEDs) hold great promise for achieving both high efficiency and high stability in display applications. However, in practice, their operational stability remains considerably inferior to that of state-of-the-art devices. In this study, we developed a new tandem structure with optimal electrical and optical performance to simultaneously improve the efficiency and stability of tandem QLEDs. Electrically, upon development of a barrier-free interconnecting layer enabled by an indium-zinc oxide bridging layer and a conductive ZnMgO layer, the driving voltage of the tandem QLEDs is remarkably reduced. Optically, upon development of a top-emitting structure and optimization of the cavity length guided by a theoretical simulation, a maximum light extraction efficiency is achieved. As a result, the red tandem QLEDs exhibit a maximum external quantum efficiency of 49.01% and a T95 lifetime at 1000 cd/m2 of >50 000 h, making them one of the most efficient and stable QLEDs ever reported.

GC-MS determination of polychlorinated biphenyls in water using extractive freezing-out of analytes

A method for determining polychlorinated biphenyls (PCBs) in water using the method of concentrating analytes through extractive freezing-out under the effect of a centrifugal forces (EFC) has been developed. A mathematical model for analyte extraction using a three-factor Box-Behnken design demonstrated that the content of acetonitrile in the extraction mixture is a significant factor, whereas the degree of PCBs chlorination and the concentration of analytes are insignificant parameters. Analysis of the surface area of the model allowed the determination of the optimal range of the acetonitrile concentration, which fell between 14 and 21%. A 15% content of acetonitrile in the extraction mixture provided maximum extraction efficiency for 7 different PCBs (>92%) across a wide range of analyte concentrations (1.0 – 5000 ng/liter). The relative standard deviations in the repeatability and reproducibility range from 4.2 to 6.8% and 5.3 to 8.1%, respectively, the accuracy of analyte determination being 10 – 15%. Petroleum hydrocarbons were not extracted into the acetonitrile extract and did not interfere with the determination of PCBs, which provided longer operation of the detector without any loss in the sensitivity. Co-extraction of polycyclic aromatic hydrocarbons and chlorinated pesticides did not affect the extraction of PCBs from water (95 – 100%) and did not touch on the metrological indicators of the determination procedure.

Water Purification Using Choline-Amino Acid Ionic Liquids: Removal of Amoxicillin.

Antibiotics are the main active pharmaceutical ingredients (APIs) for the treatment and prevention (prophylaxis) of bacterial infections, for which they are essential for health preservation. However, depending on the target bacterial strain, an efficient treatment may imply weeks of continuous intake of antibiotics, whose unmetabolized fraction ends up in the wastewater system by human and animal excreta. The presence of these chemical compounds in wastewater is known to damage aquatic ecosystems and cause antibiotic resistance of pathogenic agents, which threatens the future application of these medicines. Aqueous two-phase systems (ATPSs), an emergent extraction technology for biomolecules such as proteins and vitamins, could provide more eco-friendly and cost-effective extractive alternatives given their nontoxicity and low energetic requirements. Moreover, choline-amino acid ([Ch][AA]) ionic liquids (also known as CAAILs or ChAAILs) are considered one of the greenest classes of ionic liquids due to their favorable biocompatibility, biodegradability, and ease of chemical synthesis. In this work, partition studies of amoxicillin were performed in three ATPSs containing dipotassium hydrogen phosphate (K2HPO4) and the CAAILs (cholinium l-alaninate, [Ch][Ala]; cholinium glycinate, [Ch][Gly]; and cholinium serinate, [Ch][Ser]) at 298.15 K and 0.1 MPa. To better characterize the extract and reduce errors in quantification, the effect of pH on the intensity and stability of the UV-vis spectra of amoxicillin was studied prior to the partition studies, and computational chemistry was used to validate the molecular structure of the synthesized ionic liquids. During experimental determinations, it was observed that the extraction of amoxicillin was favored by less polar ionic liquids, achieving maximum partition coefficients (K) and extraction efficiencies (E) of K = (16 ± 6)·101 and E / % = 97 ± 2, respectively, for {[Ch][Gly] (1) + K2HPO4 (2) + Water (3)} in the longest tie-line.

A tandem approach for precipitant-free highly selective recovery of valuable metals from end-of-life lithium-ion batteries using a green deep eutectic solvent

Recently, recycling lithium-ion batteries (LIBs) waste and the efficient recovery of valuable metals has become crucial for the circular economy. Deep eutectic solvents (DESs) have shown immense potential for metal extraction from end-of-life (EoL) LIBs. However, a complicated subsequent separation process is required due to the non-selectivity of the DES components for metal. Herein, we propose a tandem precipitant-free hydrometallurgical process for the selective recovery of Li and other valuable metals (Ni, Co, Mn) from EoL LIBs using a green DES. The process parameters, viz., reaction temperature (T), time (t), pulp density (S/L), and molar ratio (MR) of ethylene glycol to tartaric acid, were optimized via the statistical optimization technique of response surface methodology. The results revealed maximum extraction efficiencies of 99.2 ± 0.5%, 96.1 ± 1.4%, 95.2 ± 1.2%, and 97.8 ± 1.5% for Li, Ni, Co, and Mn, respectively, under the optimized process conditions of T = 118 °C, t = 17 min, S/L = 42 g/L, and MR = 3:1. The kinetic study showed that interfacial reaction governed the extraction process. A plausible mechanism depicting the role of DES constituents in synergistically facilitating the extraction reaction was elucidated. Moreover, Li and other metals (Ni, Co, and Mn) were selectively separated and recovered with an overall efficiency of ∼99%. The reusability of the recovered metal products and the DES were also assessed for a closed-loop recycling process. At the outset, the proposed process paves the way for a greener alternative for recycling valuable metals from EoL LIBs rather than conventional acid-based leaching processes.

Design of adaptive hybrid MPPT controllers with universal input voltage DC–DC converter for RES’s

At present, conventional energy production is absent because of the more hazardous gases released into the environment, the high effect on human health, more cost required for maintenance, plus less usefulness for highly populated areas. So, the Renewable Energy Sources are more focused for the present automotive industry application. In this work, the Proton Exchange Membrane Fuel Stack is considered for analyzing the proposed DC–DC converter circuit. The advantages of this fuel stack are high energy density, fast functioning nature, more robustness, and more usefulness for the various water membrane conditions of the fuel stack. However, the disadvantages of the fuel stack are excessive current generation, plus more current conduction losses. So, the wide voltage supply single switch power converter is introduced in this work for optimizing the current production of the fuel stack network. The merits of this converter circuit are high stability, good reliability, low voltage appearing across the switches, plus a uniform power supply. Here, the converter switching pulses are obtained by proposing the Modified Continuous Step Change Adaptive Fuzzy Logic with Grey Wolf Optimization hybrid controller. This controller provides high maximum power extraction efficiency from the fuel stack which is equal to 99.421%. Also, this controller's Maximum Power Point Tracking time is 0.0285 s.

Synthesis of polyethylene glycol-grafted magnetic nanoparticles for the fast and efficient extraction of anabolic substances from human urine

Anabolic steroids and β-agonists are commonly prohibited substances found in doping control studies; therefore, the determination of anabolic substances in biological samples is crucial. To analyze the anabolic compounds in urine, an adsorbent, polyethylene glycol (PEG)-grafted magnetic nanoparticle material (Fe3O4@SiO2-PEG), with low toxicity and strong biocompatibility was prepared in this investigation. Compared to those of Fe3O4 and Fe3O4@SiO2, the grafted PEG chains (approximately 5.4 wt.%) on the magnetic nanoparticles improved the extraction efficiencies by factors of 3.9–17.0 and 2.5–2.9, respectively, likely due to the electrostatic attraction and hydrogen bonding. To achieve maximum extraction efficiency, several extraction parameters were optimized, including the kind and volume of desorption solvent, pH, and the extraction and desorption time. The standard curves were linear within the range of 0.5–20 μg/L for methyltestosterone and trenbolone, and 0.02–5 μg/L for clenbuterol. The limits of detection for the three drugs were 0.01–0.12 μg/L. The limits of quantification were 0.02–0.40 μg/L. The levels of precision of the optimized method were assessed based on the respective intra- and inter-day and batch-to-batch relative standard deviations in the ranges of 3.2–5.2 % (n = 5), 5.9–11.3 % (n = 4), and 6.7–9.2 % (n = 3). The Fe3O4@SiO2-PEG nanoparticles could exclude urine matrix interferences (matrix effect of 91.8–98.1 %) and achieve satisfactory recoveries (75.5–116.1 %), affording sensitive and accurate determination of trace anabolic substances in urine.

The optimisation of caffeic acid reactive extraction by trioctylphosphine oxide using response surface methodology

ABSTRACT Caffeic acid is a valuable product due to its wide-ranging utilities. Currently, caffeic acid can be produced via fermentation process using native or engineered microorganisms. The reactive extraction is a prominent technique that is used for the recovery of carboxylic acids. In this work, caffeic acid was recovered by an organophosphate (trioctylphosphine oxide) from its aqueous solution in the presence of different kinds of solvents namely 1-butanol, ethyl propionate, and ethyl methyl ketone. The values of reactive extraction parameters were optimised by Box–Behnken design. 98.19% The maximum extraction efficiency was obtained as 98.19% at the optimum conditions of 0.003 mol kg−1 caffeic acid concentration, 50% (v/v) trioctylphosphine oxide quantity, and 306.2 K in the presence of 1-butanol as the solvent. Our study is the first ever to examine the reactive extraction of caffeic acid, and therefore very important in modern scientific disciplines.

Pomegranate seed oil extraction by cold pressing, microwave and ultrasound treatments

AbstractIn this study, pomegranate seed oil was extracted by microwave-assisted extraction, ultrasound-assisted extraction, and cold pressing techniques. Dimethyl succinate was the solvent of microwave and ultrasound-assisted extraction methods. The optimum conditions were determined by using response surface methodology (RSM, Design Expert software version 7.0 and Box-Behnken design). The ultrasound-assisted extraction technique was found to be superior to the microwave-assisted extraction technique in terms of extraction efficiency. The maximum extraction efficiency of microwave-assisted extraction was 22.01% under the optimized conditions (liquid/solid ratio, 5/1; time, 3 min; and microwave power, 300 W). The maximum extraction efficiency obtained by ultrasound-assisted extraction was 26.31% under the optimized conditions (liquid/solid ratio, 10/1; pulse duration/pulse interval ratio, 1; temperature 60 °C; and time, 20 min). The extraction efficiencies were compared at the optimum conditions with hexane, which is the most used solvent for pomegranate seed oil extraction, and the difference was insignificant. The results of this study are very important, especially in the field of green chemistry and chemical engineering.

Process kinetics optimization for extraction of essential oil from the peel of Citrus sinensis for the development of food packaging film

AbstractThe goals of the present work were to achieve maximum extraction efficiency from Citrus sinensis peel and effective utilization of its bioactive compounds. This work focused on studying the physicochemical characteristics and yield percentage of citrus essential oil (CEO) extracted from citrus peels at different extraction times, extraction temperatures, solid–liquid ratios, and solvent combinations, and the data of yield percentage was subjected to find the best kinetic model for better yield. C. sinensis peel powder was subjected to Soxhlet extraction of essential oil at varied solid:liquid ratios (1/2, 1/4, 1/6, 1/8, and 1/10), time intervals in minutes (120, 150, 180, 210, 240, 270, and 280), temperatures (50, 60, 70, 80, 90, and 100°C), and solvents (n‐hexane, petroleum ether, chloroform, methanol, and water) to characterize their impact on yield percentage. The essential oil extraction kinetics were assessed using the experimental data and two different kinetic models (zero‐order and first‐order kinetic model). The bioactive compounds were assessed using GC–MS, as well. Amongst the other solvents, maximum extraction yield was observed at 90°C for 270 min using n‐hexane. GC–MS results showed that d‐limonene was the predominant compound constituting 41.41%. A good agreement between applied kinetic models and experimental data was demonstrated by the first‐order model (R2 = .9830) and the zero‐order kinetic model (R2 = .9719). Thus, the effective conditions for maximum extraction yield of CEO peels were optimized and the extracted CEO can be used in food packaging applications for shelf‐life extension.Practical applicationsEffective food waste management is vital for promoting sustainable resource usage, reducing environmental impact, saving money and energy, addressing global hunger, and upholding ethical and social responsibilities. It is important to minimize food waste throughout the entire food supply chain. Citrus peels are the by‐products of the citrus fruit processing industry and households which contribute to organic waste and its management is an important consideration for environmental sustainability. Thus, this study aims to manage these wastes by extracting essential oil from them and optimizing their process. The role of Citrus sinensis essential oil in the food industry includes natural flavoring with a consistent flavor profile, versatility in culinary applications, provides a natural and clean label, and are cost‐effective. Also, the universally recognized and enjoyed flavor of C. sinensis makes its essential oil a popular choice for products with broad consumer appeal. However, it is essential to follow regulatory guidelines for food‐grade essential oils and adhere to recommended usage levels. The results of this study have practical implications for improving yield, quality, efficiency, and sustainability of the extracted essential oil in the food industry. The optimized data can positively impact various aspects of food production, by enhancing flavor profiles, reducing the processing time and costs, and thus facilitating scale‐up potential. In addition, proper storage conditions should be maintained to ensure the stability and quality of the extracted essential oil over time.

Optimization of Ultrasonic Extraction Parameters for the Recovery of Phenolic Compounds in Brown Seaweed: Comparison with Conventional Techniques.

Seaweed, in particular, brown seaweed, has gained research interest in the past few years due to its distinctive phenolic profile that has a multitude of bioactive properties. In order to obtain the maximum extraction efficiency of brown seaweed phenolic compounds, Response Surface Methodology was utilized to optimize the ultrasound-assisted extraction (UAE) conditions such as the amplitude, time, solvent:solid ratio, and NaOH concentration. Under optimal conditions, UAE had a higher extraction efficiency of free and bound phenolic compounds compared to conventional extraction (stirred 16 h at 4 °C). This led to higher antioxidant activity in the seaweed extract obtained under UAE conditions. The profiling of phenolic compounds using LC-ESI-QTOF-MS/MS identified a total of 25 phenolics with more phenolics extracted from the free phenolic extraction compared to the bound phenolic extracts. Among them, peonidin 3-O-diglucodise-5-O-glucoside and hesperidin 5,7-O-diglucuronide are unique compounds that were identified in P. comosa, E. radiata and D. potatorum, which are not reported in plants. Overall, our findings provided optimal phenolic extraction from brown seaweed for research into employing brown seaweed as a functional food.

Miniaturized on-spot protein denaturation/microwave-assisted extraction for spectrofluorimetric determination of favipiravir in dried plasma: Application to real human sample and inclusive incurred sample reanalysis study

The development of high-throughput sample preparation methods is a key step for upgrading the throughput of classical analytical techniques. In this work, a miniaturized on-spot protein denaturation coupled with microwave-assisted extraction sample treatment method was developed for extraction and subsequent spectrofluorimetric determination of favipiravir (FAV) in human plasma spots. Dried plasma spotting was performed using only 10 µL of plasma on filter paper discs followed by on-spot protein denaturation using 10 µL methanol. Maximum extraction efficiency was achieved using water: methanol (1:1) as extraction solvent with 50 % microwave power for 60 sec. The fluorescence intensity of extracted FAV was measured at 432 nm after excitation at 361 nm. According to the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH -M10) guidelines for bioanalytical method validation, spiked plasma samples showed very good linearity between 100 and 1000 ng/mL. The accuracy and precision of the developed method were indicated by mean recovery (%) within 100 ± 15 % for all tested concentrations levels. The obtained results were further compared with a reported protein precipitation method using both F-test and t-test revealing no significant difference between either method. Moreover, the method was successfully applied for FAV determination in real human samples for an incurred sample reanalysis study revealing no metabolite back conversion. The developed method showed superior green performance using analytical Eco-scale, Green Analytical Procedure Index (GAPI), and Analytical Greenness Metric Approach (AGREE) tools compared to a classical protein precipitation method. According to Blue Applicability Grade Index (BAGI), and whiteness tools, the developed method outperformed all reported methods for FAV determination in plasma in terms of practicality and analytical functionality. Compared to reported sample treatment methods, this method exhibited excellent analytical performance, increased throughput, hundred-fold reduction of sample volume (10 μL), significant reduction of organic solvent consumption (260 μL methanol) and produced negligible wastes. Thus, it can be adopted for routine work in pharmacokinetics and clinical trial studies.

Efficient control of the fully passive oscillating foil in 2D confined flows with adjustment of the heave damping

A foil that is free to pitch and heave in an upstream flow can oscillate very regularly and with large amplitudes given that its inertial properties and support stiffness in pitch and heave are well adapted to the flow velocity. Useful energy can be extracted from these oscillations via an appropriate damping in heave that models the presence of an electric generator. In recent years, the structural parameters of such a fully passive oscillating-foil turbine (OFT) have been optimized, yielding a maximum energy extraction efficiency of 51.0% under the assumptions of 2D and unconfined flow. However, the turbine is normally deployed in channels with finite cross-sectional area, thus impacting the flow rate passing through the turbine via the blockage effect. In this work, we extend the applicability of the 2D optimized structural parameters to 2D confined scenarios with a simple tuning of the viscous heave damping coefficient. Performance is determined via a fluid-structure interaction solver based on an unsteady Reynolds-averaged Navier–Stokes approach. As expected, confining the turbine increases the heave amplitude and the power, up to a point where the motions become chaotic, and thus require an increase in the heave damping coefficient. This study shows that in all confined 2D scenarios, reasonably good performances of the fully passive OFT can be maintained when using its optimal structural parameters obtained in 2D unconfined conditions, given that the generator is adjusted accordingly.

Application of an Ionic Liquid as a Bulk Liquid Membrane for Nicotinic Acid Separation: Determination and Optimization Study

Nicotinic acid (NA) is a crucial molecule that is commonly employed in the pharmaceutical, biochemical, and food sectors. It is essential to separate nicotinic acid from both industrial effluents and production broth. In this study, the separation of NA from aqueous media by bulk ionic liquid membrane (BILM) has been investigated. 1-Butyl-3-methylimidazolium hexafluorophosphate, [BMIM][PF6], has been utilized as a membrane solvent and tributyl phosphate (TBP), has been utilized as a carrier in ionic liquid membrane. The effects of nicotinic acid concentration (0.02–0.1 mol/L) in aqueous solution, the carrier concentration (0–2 mol/L) in ionic liquid membrane, and the stripping phase type (water/NaOH) and NaOH concentration (0.1–0.2 mol/L) have been examined. Furthermore, Box-Behnken design (BBD) has been applied to determine the relationship between these parameters. The effects of these parameters on the separation were determined by calculating the feed and stripping phase efficiencies. Maximum extraction and stripping efficiencies have been obtained at optimum BILM conditions of nicotinic acid concentration in aqueous solution of 0.02 mol/L, carrier concentration ionic liquid membrane of 2 mol/L, and NaOH concentration of 0.2 mol/L. These efficiency values have also been determined as 90.05% (experimental value) and 95.21% (BBD value) for extraction and 93.92% (experimental value) and 82.36% (BBD value) for stripping, respectively.

A multisource energy harvesting circuit for vibration and light energy with MPPT

SummaryThe article presents a multisource energy harvesting circuit (MEHC) for vibration and light energy with maximum power point tracking (MPPT). The MEHC has a cold start capability and extracts energy from piezoelectric transducers (PZTs) and photovoltaic cells (PVs) simultaneously when the multi PZTs reach their peak open‐circuit (OC) voltage, detected by the peak voltage detector and the PV1 cell voltage exceeds the MPP voltage (MPP voltage is approximately 0.7 times the PV cell's OC voltage) during the off‐peak time of the PZTs. The experimental results indicate that the output power of the MEHC is 2.8 mW under certain conditions, and the maximum energy extraction efficiency of the PVs is about 75%. The output power of the MEHC is 4.59 times of that without PVs.