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•The economic feasibility of jatobá bark extraction was evaluated.•Annual productivity and the extract selling price influenced the feasibility.•Extraction by agitation, supercritical ...fluid and ultrasound were economically feasible.•Cost of raw material presented the major impact in operational expenditure.•Extraction from jatobá bark by agitation is the most attractive for investors.
The aim of this study was to provide a comprehensive economic evaluation for the transition from lab-scale to large-scale production of jatobá bark extracts containing phenolic compounds. Building upon previous technical research, the present work compares conventional agitation (AG) to modern supercritical fluid extraction (SFE), and ultrasound-assisted extraction (UAE). SuperPro Designer was used to estimate the project’s economic indicators. Moreover, freeze drying and spray drying were evaluated as possible operations for water removal from the extract. The operating costs (OPEX) analysis at the most economical process condition showed the primary influence of raw material cost (CRM), regardless of the technique. Additionally, utilities cost (CUT) had a greater impact on UAE and AG than SFE. A sensitivity analysis revealed that extract selling price and productivity significantly impacted return on investment (ROI), followed by CRM and CUT. In summary, SFE, AG, and UAE were feasible for the recovery of phenolic extracts from jatobá bark, with payback times of 4.2, 2.0, and 3.4 years, respectively. This work shows the economic feasibility and potential scalability of these extraction processes, laying a foundation for future industrial implementation and commercialization of jatobá bark extracts.
•Robust thermodynamic building block modeling approach for reactive extraction of nuclear metals.•Complex metal extraction system involving macro concentrations is modeled using a hierarchy of ...sub-systems.•Unique feature of predicting equilibrium concentrations of all the species.•Models developed applicable at industrial scale and can be extended to develop mixture models for separation of Zr and Hf.
Pure component thermodynamic models are developed for solvent extraction involving ionic reaction equilibrium for distribution of macro concentrations of zirconium and hafnium between an aqueous phase containing HNO3 and an organic solvent phase containing diluted TBP. The concentration range considered is 10−03 to 100 M. A framework based on chemical speciation calculation is used for the purpose. Experimental procedures adopted to obtain the required solvent extraction data for modeling and validating these models are detailed. Measured equilibrium concentrations of total zirconium, total HNO3, total nitrate in the aqueous phase and total zirconium in the organic phase are used to obtain the thermodynamic parameters such as equilibrium constants and activity coefficient model parameters for zirconium and hafnium extraction systems.
The novel framework is useful for computing equilibrium concentrations of all the species present in the respective systems. It is also demonstrated that the pure component models developed for extraction of zirconium and hafnium are effective over a wide range of concentrations. These pure component models can be used to simulate and optimize industrial scale zirconium – hafnium separation process.
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•As bioaccessibility varied in 11 As-contaminated soils.•As bioaccessibility in soils varied with four in vitro assays.•Bioaccessible As was from first three fractions of sequential ...extraction.•0.43M HNO3 extractable As was correlated to all four assays.
Arsenic bioaccessibility varies with in vitro methods and soils. Four assays including unified BARGE method (UBM), Solubility Bioaccessibility Research Consortium method (SBRC), in vitro gastrointestinal method (IVG), and physiologically based extraction test (PBET), were used to determine As bioaccessibility in 11 contaminated soils (22–4,172mgkg−1). The objective was to understand how bioaccessible As by different methods was related to different As pools based on sequential extraction and 0.43M HNO3 extraction. Arsenic bioaccessibility was 7.6–25, 2.3–49, 7.3–44, and 1.3–38% in gastric phase (GP), and 5.7–53, 0.46–33, 2.3–42, and 0.86–43% in intestinal phase (IP) for UBM, SBRC, IVG, and PBET, respectively, with HNO3-extractable As being 0.90–60%. Based on sequential extraction, As was primarily associated with amorphous (AF3; 17–79%) and crystallized Fe/Al oxides (CF4; 6.4–73%) while non-specifically sorbed (NS1), specifically sorbed (SS2), and residual fractions (RS5) were 0–10%, 3.4–20% and 3.2–25%. Significant correlation was found between As bioaccessibility by PBET and NS1+SS2 (R2=0.55−0.69), and UBM-GP and NS1+SS2+AF3 (R2=0.58), indicating PBET mostly targeted As in NS1+SS2 whereas UBM in NS1+SS2+AF3. HNO3-extractable As was correlated to bioaccessible As by four methods (R2=0.42–0.72) with SBRC-GP having the best correlation. The fact that different methods targeted different As fractions in soils suggested the importance of validation by animal test. Our data suggested that HNO3 may have potential to determine bioaccessible As in soils.
Herein, a magnetic borate‐functionalized MXene composite with multiple boronic affinity sites was fabricated by embedding Fe3O4 nanoparticles with 4‐formylphenylboronic acid functionalized Ti3C2Tx ...nanosheets and served as sorbent for the simultaneous extraction of catecholamines (CAs) in urine samples. The morphology and structure of the magnetic materials were investigated using scanning microscopy, vibrating sample magnetometer, X‐ray photoelectron spectrometer, and X‐ray diffraction. The introduction of polyethyleneimine can amplify the bonded boronic acid groups, thereby effectively improving the adsorption capacities for CAs based on the multiple interactions of boronic affinity, hydrogen bonding, and metal coordination. The adsorption performance was investigated using the kinetics and isotherms models, and the main parameters that influence the extraction efficiency were optimized. Under the most favorable magnetic solid‐phase extraction condition, a sensitive method for the analysis of CAs in urine samples was developed by combining magnetic solid‐phase extraction conditions with high‐performance liquid chromatography detection. The findings illustrated that the proposed approach possessed a wide linearity range of 0.05–250 ng/mL with an acceptable correlation coefficient (R2 ≥ 0.9984) and detection limits of 0.010–0.015 ng/mL for the target CAs. The research not only provides a notable composite with multiple boronic affinity sites but also offers an effective and feasible measure for the detection of CAs in biological samples.
•Magnetic nanoparticles (MNPs) overcome limitations in solid-phase extraction (SPE).•MNPs are characterized by ease of surface modification and versatility.•Great interest has been aroused in the use ...of MNPs in SPE.•MNPs allow easy and rapid isolation of analytes using a magnet.•Magnetic SPE isolates analytes from samples with complex matrices effectively.
The need to obtain meaningful results as the basis for determining the content of trace amounts of analytes has become the driving force behind the development of modern analytical techniques, including sample-preparation techniques, such as solid-phase extraction (SPE). Recently, great interest was aroused in the use of magnetic nanoparticles (MNPs) in SPE. These materials exhibit high selectivity, and, in small amounts, can provide high recovery of analytes, even from large-volume samples. MNPs allow easy, rapid isolation of analytes using an external magnetic field. Simplicity in use, ease of surface modification and the versatility of MNPs mean that they are now widely used in many fields, including biotechnology, medicine and analytical chemistry. In magnetic SPE, these materials provide effective isolation and/or enrichment of the analytes, from samples with complex matrices (e.g. biological, environmental and food samples).
•A hierarchical 2D/2D Ti3C2Tx/NiCo MOF heterostructure is fabricated through in-situ growth of ultrathin NiCo MOF nanosheets on the few-layer Ti3C2Tx MXene sheets.•The carboxylate groups of BDC2− can ...form stable bond with the termination groups on the Ti3C2Tx surface and hydroxyl groups in the lignin molecules.•The Li+ intercalation/extraction mechanism of the Ti3C2Tx/NiCo MOF heterostructure electrode is explored.
Metal-organic framework (MOFs) have been regarded as ideal lithium-ion battery (LIB) anodes with abundant active sites, porous structure, shortened ion diffusion pathways, and adjustable component, but the MOF anodes suffer from the low electronic conductivity. Herein, we rationally design a 2D/2D Ti3C2Tx/NiCo MOF heterostructure through in-situ growth of ultrathin NiCo MOF nanosheets on the few-layer Ti3C2Tx MXene sheets. The carboxylate groups of BDC2− can form stable bond with the termination groups (e.g., -OH) on the Ti3C2Tx surface and hydroxyl groups in the lignin molecules, resulting in stable Ti3C2Tx/NiCo MOF interface and good structure stability of the 2D/2D Ti3C2Tx/NiCo MOF heterostructure. The Ti3C2Tx/NiCo MOF heterostructure could combine the advantages of 2D MXene nanosheets and 2D bimetallic MOF structure. The 2D bimetallic NiCo MOF can offer plenty of exposed active sites for Li+ intercalation, while the 3D conductive network structure based on the Ti3C2Tx can not only enhance the electronic conductivity, but also facilitate the electrode/electrolyte interface contact and promote the charge diffusion. The obtained 2D/2D Ti3C2Tx/NiCo MOF heterostructure anode demonstrates a high capacity of 637 mAh g−1 at 0.2 A g−1 after 200 cycles. Furthermore, the Li+ intercalation/extraction mechanism of the Ti3C2Tx/NiCo MOF heterostructure electrode is explored in detail.
A hierarchical 2D/2D Ti3C2Tx/NiCo MOF heterostructure is constructed through in-situ growth of NiCo MOF nanosheets on the few-layer Ti3C2Tx sheets. The carboxylate groups of benzene dicarboxylate ligand can form stable bond with the termination groups on the Ti3C2Tx surface and hydroxyl groups in the lignin molecules, resulting in stable and homogeneous Ti3C2Tx/NiCo MOF heterostructure. Display omitted
A novel pre‐treatment was proposed for the simultaneous determination of aflatoxins, ochratoxin A and zearalenone in foodstuffs using high‐performance liquid chromatography with fluorescence ...detection. The analytical procedure was based on a first step using a quick, easy, cheap, effective, rugged, and safe based extraction procedure, followed by salting out and purification with a C18 solid‐phase extraction column as interference removal clean‐up. Subsequently, collected supernatant was subjected to dispersive liquid–liquid microextraction. Response surface methodology based on central composite design was employed to optimize conditions in the microextraction procedure. Under the optimum conditions, satisfactory analytical performance with recoveries ranging from 63.22 to 107.6% were achieved in different types of cereals and beans, as well as desirable precisions (0.81–8.13%). Limits of detections and quantifications for these six mycotoxins ranging from 0.03 to 13 μg/kg and 0.22 to 44 μg/kg, respectively, were obtained. Finally, the established method was successfully validated by four certified reference materials (P = 0.897 > 0.05) and applied to 79 samples from local markets.
Incremental Few-Shot Object Detection Perez-Rua, Juan-Manuel; Zhu, Xiatian; Hospedales, Timothy M. ...
2020 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR)
Conference Proceeding
Odprti dostop
Existing object detection methods typically rely on the availability of abundant labelled training samples per class and offline model training in a batch mode. These requirements substantially limit ...their scalability to open-ended accommodation of novel classes with limited labelled training data, both in terms of model accuracy and training efficiency during deployment. We present the first study aiming to go beyond these limitations by considering the Incremental Few-Shot Detection (iFSD) problem setting, where new classes must be registered incrementally (without revisiting base classes) and with few examples. To this end we propose OpeN-ended Centre nEt (ONCE), a detector designed for incrementally learning to detect novel class objects with few examples. This is achieved by an elegant adaptation of the efficient CentreNet detector to the few-shot learning scenario, and meta-learning a class-wise code generator model for registering novel classes. ONCE fully respects the incremental learning paradigm, with novel class registration requiring only a single forward pass of few-shot training samples, and no access to base classes - thus making it suitable for deployment on embedded devices, etc. Extensive experiments conducted on both the standard object detection (COCO, PASCAL VOC) and fashion landmark detection (DeepFashion2) tasks show the feasibility of iFSD for the first time, opening an interesting and very important line of research.
The first step in the isolation and purification of bioactive compounds from plant material is extraction. Extraction of secondary metabolites such as phenolic acids and flavonoids is difficult due ...to their insoluble nature. While conventional extraction methods such as Soxhlet, heat reflux, and maceration are successful procedures in the extraction of bioactive compounds and the equipment involved in these methods are distinct from each other. An appropriate extraction technique that balances product quality, process efficiency, production costs, and environmentally acceptable methods should be used for the extraction of bioactive compounds from plant tissues. The application of innovative extraction methods in the food industries has been extensively investigated, due to increased consumer expectations for greener options that do not include hazardous chemicals, as well as industry concerns about sustainable, nontoxic extraction techniques. Innovative technologies, such as high hydrostatic pressure (HHP), ultrasound (US), pulsed electric field (PEF), supercritical fluid (SF), and others, are increasingly replacing the conventional methods. The use of novel and combined novel technologies increases extractability, resulting in yields with higher extraction rates. It also yields lower impurities in the final extract and preserves thermo-sensitive compounds, uses different inorganic solvents, and consumes low energy. The purpose of the present review is to evaluate the efficiency of the different conventional, novel, and combined novel technologies involved in the extraction of bioactive compounds from plant materials.
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•The various conventional techniques for extraction of bioactive compounds are reviewed.•The paper also reviewed the various novel technologies for extraction of bioactive compounds.•The focus of the paper is combined novel technologies for extraction of bioactive compounds.•Efficiency of the extraction process can be increased by combining two technologies.
In this work, monodisperse and nano‐porous poly(bismaleimide‐co‐divinylbenzene) microspheres with large specific surface area (427.6 m2/g) and rich pore structure were prepared by one‐pot self‐stable ...precipitation polymerization of 2,2′‐bis4‐(4‐maleimidophenoxy) phenyl propane and divinylbenzene. The prepared poly(bismaleimide‐co‐divinylbenzene) microspheres were employed as dispersive solid‐phase extraction (DSPE) adsorbent for the extraction of triazine herbicides. Under optimized conditions, good linearities were obtained between the peak area and the concentration of triazine herbicides in the range of 1–400 µg/L (R2 ≥ 0.9987) with the limits of detection of 0.12–0.31 µg/L. Triazine herbicides were detected using the described approach in vegetable samples (i.e., cucumber, tomato, and maize) with recoveries of 93.6%–117.3% and relative standard deviations of 0.4%–3.5%. In addition, the recoveries of triazine herbicides remained above 80.7% after being used for nine DSPE cycles, showing excellent reusability of poly(bismaleimide‐co‐divinylbenzene) microspheres. The adsorption of poly(bismaleimide‐co‐divinylbenzene) microspheres toward triazine herbicides was a monolayer and chemical adsorption. The adsorption mechanism between triazine herbicides and adsorbents might be a combination of hydrogen bonding, electrostatic interaction, and π‐π conjugation. The results confirmed the potential use of the poly(bismaleimide‐co‐divinylbenzene) microspheres‐based DSPE coupled to the high‐performance liquid chromatography method for the detection of triazine herbicide residues in vegetable samples.
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