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Showing records 1 to 25 of 1814. [First] Page: 1 2 3 4 5 Last
Plant-mediated bimetallic nanoparticles synthesis for catalytic degradation of malachite green
Preeti Bairwa, Vijay Devra
August 30, 2024 (v1)
Keywords: bimetallic nanoparticles, biosynthesis, malachite green, oxidative degradation
Nanotechnology, an innovative field focused on nanosized materials, is combined with plant biotechnology through the green chemical strategy of synthesizing plant-induced nanoparticles (NPs). Synthesizing these NPs through novel, cost-effective, and eco-friendly methods plays a significant role in degrading and eliminating organic pollutants. The presence of dangerous biological agents and chemicals in water that surpass the standard threshold and could potentially impact human health and the environment is called water pollution. In the current study, we synthesized copper–silver bimetallic nanoparticles (BMNPs) using a novel, robust, and inexpensive method with leaf broth of Azadirachta indica as both the reducing and capping agent. Scanning electron microscopy and transmission electron microscopy investigations were used to examine the morphology of the synthesized BMNPs, and results indicate that synthesized NPs are in spherical core–shell morphology with a size of 20 nm. Research... [more]
New Insight into the Degradation of Sunscreen Agents in Water Treatment Using UV-Driven Advanced Oxidation Processes
Tajana Simetić, Jasmina Nikić, Marija Kuč, Dragana Tamindžija, Aleksandra Tubić, Jasmina Agbaba, Jelena Molnar Jazić
August 28, 2024 (v1)
Keywords: hydroxyl and sulfate radicals, magnetic biochar, toxicity evaluation, UV filters, UV-driven AOPs
This study evaluates, for the first time, the effects of UV/PMS and UV/H2O2/PMS processes on the degradation of sunscreen agents in synthetic and natural water matrices and compares their effectiveness with the more conventional UV/H2O2. Investigations were conducted using a mixture of organic UV filters containing 4-methylbenzylidene camphor (4-MBC) and 2-ethylhexyl-4-methoxycinnamate. Among the investigated UV-driven AOPs, UV/PMS/H2O2 was the most effective in synthetic water, while in natural water, the highest degradation rate was observed during the degradation of EHMC by UV/PMS. The degradation of UV filters in the UV/PMS system was promoted by sulfate radical (68% of the degradation), with hydroxyl radical contributing approximately 32%, while both radical species contributed approximately equally to the degradation in the UV/H2O2/PMS system. The Vibrio fischeri assay showed an increase in inhibition (up to 70%) at specific stages of UV/H2O2 treatment when applied to natural wat... [more]
Exploration and Frontier of Coal Spontaneous Combustion Fire Prevention Materials
Dandan Han, Guchen Niu, Hongqing Zhu, Tianyao Chang, Bing Liu, Yongbo Ren, Yu Wang, Baolin Song
August 28, 2024 (v1)
Subject: Materials
Keywords: coal spontaneous combustion, fire-fighting materials, research status, synergistic inhibition, visualization
Mine fires have always been one of the disasters that restrict coal mining in China and endanger the life safety of underground workers. The research and development of new fire prevention materials are undoubtedly important to ensure the safe and efficient production of modern mines. At present, the main inhibiting materials used are grout material, inert gas, retarding agent, foam, gel, and so on. In order to explore the current situation of coal spontaneous combustion (CSC) fire prevention, the existing fire prevention materials were reviewed and prospected from three aspects: physical, chemical, and physicochemical inhibition. The results show that, at present, most of the methods of physicochemical inhibition are used to inhibit CSC. Antioxidants have become popular chemical inhibitors in recent years. In terms of physical inhibition, emerging biomass-based green materials, including foams, gels, and gel foams, are used to inhibit CSC. In addition, CSC fire-fighting materials also... [more]
Comparison of the Limit of Detection of Paracetamol, Propyphenazone, and Caffeine Analyzed Using Thin-Layer Chromatography and High-Performance Thin-Layer Chromatography
Katarzyna Bober-Majnusz, Alina Pyka-Pająk
August 28, 2024 (v1)
Subject: Biosystems
Keywords: detectability, drug analysis, TLC densitometry
TLC (thin-layer chromatography) and HPTLC (high-performance thin-layer chromatography) in normal (NP) and reversed (RP) phase systems were combined with densitometry to analyze caffeine, propyphenazone, and paracetamol. This work aims to check whether comparable limit of detection (LOD) values can be obtained on TLC and HPTLC plates. Analyses were performed on five (NP) or four (RP) different stationary phases (chromatographic plates), testing, in both cases, three mobile phases. It is shown that by using both TLC and HPTLC plates, it is possible to develop chromatographic conditions that enable the detection of compounds analyzed in amounts ranging from a dozen to several dozen µg/spot. In the RP system, lower LOD values for all tested compounds were obtained using TLC than HPTLC. However, performing analyses in the NP, similar (of the same order) LOD values were obtained for caffeine, propyphenazone, and paracetamol when using both TLC and HPTLC plates. For example, during the NP-HPT... [more]
Editorial on the Special Issue “Natural Compounds Applications in Drug Discovery and Development”
Alina Bora, Luminita Crisan
August 28, 2024 (v1)
Subject: Biosystems
Nature is an amazing source of natural bioactive compounds derived from numerous species of plants, marine bacteria, and fungi [...]
Numerical Simulation Study of a Pusher Feed Classifier Based on RNG-DPM Method
Youhang Zhou, Xin Zou, Zhuxi Ma, Chong Wu, Yuze Li
August 28, 2024 (v1)
Keywords: multi-stage particle classifier, numerical simulation, pusher feed, RNG-DPM method
The classifier is an essential tool for the development of contemporary engineering technology. The application of classifiers is to categorize mixed-sized particles into multi-stage uniform particle sizes. In current studies, the particles in the classifier obtain their initial velocity when feeding. The classification effect is impacted by the inability to precisely control the initial state of the particles. To solve this problem, a pusher feed classifier was designed in this study, and a numerical simulation was performed to investigate its flow field characteristics and classification performance using the RNG-DPM method. A pusher is utilized to achieve particle feeding without initial velocity and to precisely control the initial state of the particles in the classification flow field. A newly developed two-way air inlet structure is designed to provide a superimposed flow field and enable the five-stage classification. Our results show that this pusher feed classifier has the be... [more]
Erosive Wear Caused by Large Solid Particles Carried by a Flowing Liquid: A Comprehensive Review
Can Kang, Minghui Li, Shuang Teng, Haixia Liu, Zurui Chen, Changjiang Li
August 28, 2024 (v1)
Keywords: erosive wear, experiment, large particle, mechanism, multiphase flow, numerical model
The erosive wear encountered in some industrial processes results in economic loss and even disastrous consequences. Hitherto, the mechanism of the erosive wear is not clear, especially when the erosive wear is caused by large particles (>3.0 mm) carried by a flowing liquid. Current approaches of predicting erosive wear need improvement, and the optimization of relevant equipment and systems lacks a sound guidance. It is of significance to further explore such a subject based on the relevant literature. The present review commences with a theoretical analysis of the dynamics of large particles and the fundamental mechanism of erosion. Then the characteristics of the erosion of various equipment are explicated. Effects of influential factors such as particle size and properties of the target material are analyzed. Subsequently, commonly used erosion models, measurement techniques, and numerical methods are described and discussed. Based on established knowledge and the studies reported,... [more]
Effect of A Moringa Oil−Beeswax Edible Coating on the Shelf-Life and Quality of Fresh Cucumber
Shekha Al-Rashdi, Nusaiba Al-Subhi, Mai Al-Dairi, Pankaj B. Pathare
August 28, 2024 (v1)
Keywords: color, cucumber, edible coating, storage temperature, vitamin C
Cucumbers are a popular vegetable consumed worldwide and are known for their nutritional value, containing carbohydrates, antioxidants, vitamin C, etc. The abundance of a high moisture content is correlated to cucumber perishability, which encourages investigation into ways to maintain its quality and increase shelf-life. This study was carried out to determine the effect of a moringa oil−beeswax coating on the quality of fresh cucumber at different storage temperatures for 27 days of storage. Freshly harvested cucumbers were divided into two groups: the first group was coated with the moringa oil−beeswax edible coating, while the other one was not coated (control). Each group was divided into three other subgroups, for storage at 4, 10, and 22 °C. Different quality parameters, including weight loss, color change, firmness, total soluble solid (TSS), vitamin C, and pH, were evaluated. The findings showed that the weight loss of cucumber was highly increased in non-coated samples stored... [more]
Pressure Interpolation in Water Distribution Networks by Using Gaussian Processes: Application to Leak Diagnosis
Pedro-Antonio Liy-González, Ildeberto Santos-Ruiz, Jorge-Alejandro Delgado-Aguiñaga, Adrián Navarro-Díaz, Francisco-Ronay López-Estrada, Samuel Gómez-Peñate
August 28, 2024 (v1)
Keywords: Gaussian process, leak diagnosis, pressure monitoring, spatial interpolation, water distribution network
This work presents the reconstruction of the pressure head map of a water distribution system (WDS). This approach relies on historical data collected from a reduced number of sensors placed at some nodes of the WDS. Thus, a Gaussian regression process is then applied to estimate the pressure head at those nodes without a sensor, which allows the reconstruction of the pressure map for the whole network. Then, for leak diagnosis purposes, a dataset of pressure head maps of the WDN is created considering leaky scenarios, and a correlation method is applied to estimate the leak location. Then, for clarity, the Hanoi network is used to evaluate the performance of this leak diagnosis strategy in a simulation environment, assuming the availability of only three sensors. The results showed the potential for pressure head map reconstruction and leak localization.
Achievements and Challenges of Matrix Solid-Phase Dispersion Usage in the Extraction of Plants and Food Samples
Agnieszka Zgoła-Grześkowiak, Tomasz Grześkowiak, Magdalena Ligor, Robert Frankowski
August 28, 2024 (v1)
Keywords: conventional and new types of sorbents, Extraction, MSPD, plants and food applications
A review of the application of matrix solid-phase dispersion (MSPD) in the extraction of biologically active compounds and impurities from plants and food samples with a particular emphasis on conventional and new types of sorbents has been provided. An overview of MSPD applications for the isolation of organic residues from biological samples, determined using chromatographic and spectroscopic techniques, has been presented. In this study, procedural solutions that may extend MSDP applicability for the extraction such as vortex-assisted, ultrasound-assisted, microwave-assisted, and extraction with a magnetic sorbent have been discussed. Special attention has been paid to MSPD sorbents including modified silica, diatomite, magnesium silicate, alumina, carbon materials (carbon nanotubes, graphene oxide, graphene, or graphite), molecularly imprinted polymers, and cyclodextrin. An important aspect of the MSPD procedure is the use of high-purity and environmentally friendly solvents for ex... [more]
Investigating the Physical and Operational Characteristics of Manufacturing Processes for MFI-Type Zeolite Membranes for Ethanol/Water Separation via Principal Component Analysis
Hamdi Chaouk, Emil Obeid, Jalal Halwani, Wiem Abdelbaki, Hanna Dib, Omar Mouhtady, Eddie Gazo Hanna, Célio Fernandes, Khaled Younes
August 28, 2024 (v1)
Subject: Materials
Keywords: ethanol/water separation, MFI-type zeolite membranes, Microporous materials, pervaporation, Principal Component Analysis
In this study, Principal Component Analysis (PCA) was applied to discern the underlying trends for 31 distinct MFI (Mobil No. 5)-zeolite membranes of 11 textural, chemical, and operational factors related to manufacturing processes. Initially, a comprehensive PCA approach was employed for the entire dataset, revealing a moderate influence of the first two principal components (PCs), which collectively accounted for around 38% of the variance. Membrane samples exhibited close proximity, which prevented the formation of any clusters. To address this limitation, a subset acquisition strategy was followed, based on the findings of the PCA for the entire dataset. This resulted in an enhanced overall contribution and the revelation of diverse patterns among the membranes and the considered manufacturing factors (total variance between 55% and 77%). The segmentation of the data unveiled a robust correlation between silica (SiO2) concentration and pervaporation conditions. Additionally, a nota... [more]
Synthesis, Characterization, and Photocatalytic Properties of Sol-Gel Ce-TiO2 Films
Lidija Ćurković, Debora Briševac, Davor Ljubas, Vilko Mandić, Ivana Gabelica
August 28, 2024 (v1)
Subject: Materials
Keywords: Ce-TiO2, characterization, ciprofloxacin, photocatalysis
In this study, nanostructured cerium-doped TiO2 (Ce-TiO2) films with the addition of different amounts of cerium (0.00, 0.08, 0.40, 0.80, 2.40, and 4.10 wt.%) were deposited on a borosilicate glass substrate by the flow coating sol-gel process. After flow coating, the deposited films were dried at a temperature of 100 °C for 1 h, followed by calcination at a temperature of 450 °C for 2 h. For the characterization of sol-gel TiO2 films, the following analytic techniques were used: X-ray diffraction (XRD), differential thermal analysis (DTA), thermal gravimetry (TG), differential scanning calorimetry (DSC), diffuse reflectance spectroscopy (DRS), and energy dispersive X-ray spectroscopy (EDS). Sol-gel-derived Ce-TiO2 films were used for photocatalytic degradation of ciprofloxacin (CIP). The influence of the amount of Ce in TiO2 films, the duration of the photocatalytic decomposition, and the irradiation type (UV-A and simulated solar light) on the CIP degradation were monitored. Kinetics... [more]
Broad-Spectrum Technical and Economic Assessment of a Solar PV Park: A Case Study in Portugal
António Farracho, Rui Castro
August 28, 2024 (v1)
Keywords: bifacial modules, DC–AC ratio, string length, tracking systems, utility-scale solar PV park
While technical optimization focuses on maximizing the annual energy yield of utility-scale PV parks, the ultimate goal for power plant owners is to maximize investment profit. This paper aims to bridge the gap between technical and economic approaches by using simulation data from a real-case utility-scale PV park. It analyzes how changes in configuration parameters such as the DC−AC ratio and string length and PV technologies like solar tracking systems and bifacial modules impact the economic metrics of the project, i.e., net present value (NPV) and internal rate of return (IRR). PVSyst software was utilized as a simulation tool, while in-house developed software implementing appropriate technical and economic models served as a comparison platform and was used to validate the outputs generated through PVSyst. Results indicate that the commonly used horizontal single-axis tracking configuration may economically underperform compared with fixed-tilt setups. The optimal DC−AC ratio fe... [more]
Research and Practice on Implementing Segmented Production Technology of Horizontal Well during Extra-High Water Cut Stage with Bottom Water Reservoir
Dong Zhang, Yanlai Li, Zongchao Zhang, Fenghui Li, Hongjie Liu
August 28, 2024 (v1)
Subject: Materials
Keywords: bottom water, extra-high water cut, horizontal well, segmented production technology
Bohai X oilfield has reached the extra-high water cut stage of more than 95%, dominated by the bottom water reservoir. The oilfield mainly adopts horizontal-well exploitation, with the characteristics of high difficulty and low success rate for well water plugging. To solve the above problem, the segmented production technology of horizontal wells was developed to guide oilfield applications and tap their potential. In the segmented design stage, the horizontal section is objectively segmented by drilling condition analysis, optimally based on drilling through interlayers or permeability discrepancy formation, simultaneously combined with the numerical simulation method. When implementing measures, annulus chemical packer materials are squeezed between segments to effectively inhibit the fluid flow between the open hole and the sand-packing screen pipe. Moreover, the packers are used to seal between segments to effectively restrain the flow between the screen and the central tube, achi... [more]
The Influence of Complex Piston Movement on the Output Flow Rate of a Hingeless Bent-Axis Axial Piston Pump
Junqiang Shi, Jiaxing Shi, Jingcheng Gao, Dongjing Chen, Xiaotao Li, Ying Li, Jin Zhang
August 28, 2024 (v1)
Keywords: correction factor, output flow rate, simulation analysis, swash-plate axial piston pump
Wobble-plate axial piston pumps, characterized by the lack of a slipper mechanism, experience reduced leakage in comparison to their swash-plate counterparts, which contributes to their higher volumetric efficiency. Presently, the primary focus of the research conducted by scholars both domestically and internationally is concentrated on wobble-plate axial piston pumps. The performance studies within this field are predominantly focused on investigating flow pulsation. They also investigate pressure pulsation. Additionally, they investigate cavitation phenomena. Research on inclined-axis axial piston pumps has been limited. This study focused on analyzing the operational form of the piston within an inclined-axis axial piston pump. A correction factor k was introduced based on the motion characteristics of the piston. The application of this factor significantly improved the accuracy of the simulations when compared to the experimental results. Specifically, at a load pressure of 10 MP... [more]
Towards Reliable Prediction of Performance for Polymer Electrolyte Membrane Fuel Cells via Machine Learning-Integrated Hybrid Numerical Simulations
Rashed Kaiser, Chi-Yeong Ahn, Yun-Ho Kim, Jong-Chun Park
August 28, 2024 (v1)
Keywords: electrochemical, fuel cell, limitations, Machine Learning, mass transfer, numerical modeling, PEMFC, progress
For mitigating global warming, polymer electrolyte membrane fuel cells have become promising, clean, and sustainable alternatives to existing energy sources. To increase the energy density and efficiency of polymer electrolyte membrane fuel cells (PEMFC), a comprehensive numerical modeling approach that can adequately predict the multiphysics and performance relative to the actual test such as an acceptable depiction of the electrochemistry, mass/species transfer, thermal management, and water generation/transportation is required. However, existing models suffer from reliability issues due to their dependency on several assumptions made for the sake of modeling simplification, as well as poor choices and approximations in material characterization and electrochemical parameters. In this regard, data-driven machine learning models could provide the missing and more appropriate parameters in conventional computational fluid dynamics models. The purpose of the present overview is to expl... [more]
Comparison of Tetraselmis suecica Cell Disruption Techniques: Kinetic Study and Extraction of Hydrosoluble Compounds
Hussein Rida, Jérôme Peydecastaing, Hosni Takache, Ali Ismail, Pierre-Yves Pontalier
August 28, 2024 (v1)
Subject: Biosystems
Keywords: Extraction, high-pressure homogenization, kinetics, microalgae, ultrasonication
The optimization of cell disruption is a critical step in microalgal biorefineries. We used the same batch of Tetraselmis suecica culture to compare two mechanical cell disruption techniques, focusing on the extraction yield of water-soluble molecules. The conditions for high-pressure homogenization (HPH) studied were two passes at a moderate pressure of 300 bars. For ultrasound (US) treatment, we used an amplitude of 20% (equivalent to 100 W) for 25 min. These conditions were chosen on the basis of a preliminary screen of extraction conditions. HPH extracted proteins and pigments more efficiently than US, whereas US was superior for uronic acid extraction. Interestingly, the two methods had similar extraction yields for carbohydrates under the studied conditions. We also analyzed the kinetics of molecule release by considering the centrifugation time lag for HPH and applying a first-order kinetic model for US. HPH outperformed US in terms of the immediate extraction and release of mol... [more]
Study on the Deactivation Mechanism of Ru/C Catalysts
Zhi Cao, Tianchi Li, Baole Li, Xiwen Chen, Chen Zuo, Weifang Zheng
August 28, 2024 (v1)
Keywords: deactivation mechanism, free radical site, Ru/C catalysts
Employing catalytic decomposition to break down reducing agents in intermediate-level radioactive waste during nuclear fuel reprocessing offers significant advantages. This study focuses on investigating the deactivation behavior of 5% Ru/C catalysts by two different synthesis processes used for reducing agent destruction. Deactivation experiments were conducted by subjecting the 5% Ru/C catalysts to 100 and 150 reaction cycles. Changes in the concentration of free radicals on the carbon-based carrier were measured to analyze the loading position and loss of Ru ions. Additionally, sorption−desorption curves and pore size distributions of the four catalysts were obtained. Analysis results reveal that Ru ions on the catalyst adsorb onto active free radical sites on the carbon-based carrier. Under ultrasonic conditions, some Ru ions partially desorb from the free radical sites on the carbon-based carrier, and desorbed Ru ions may adsorb onto weak free radical sites, while undesorbed Ru io... [more]
Production Feature Analysis of Global Onshore Carbonate Oil Reservoirs Based on XGBoost Classier
Guilin Qi, Baolei Liu
August 28, 2024 (v1)
Subject: Optimization
Keywords: carbonate reservoir, data mining, production feature, XGBoost
Carbonate reservoirs account for 60% of global reserves for oil, making them one of the most important types of sedimentary rock reservoirs for petroleum production. This study aimed to identify key production features that significantly impact oil production rates, enhancing reservoir management and optimizing production strategies. A comprehensive dataset is built from reserves and production history data of 377 onshore carbonate oilfields globally, encompassing features such as production, recovery rate, and recovery degree of the whole lifecycle of an oilfield. XGBoost classifier is trained by K-fold cross-validation and its hyperparameters are optimized by Optuna optimization framework. The results show that XGBoost has the best performance evaluated with metrics including accuracy, precision, recall, and F1 score comparing with decision tree, random forest, and support vector machine. Key production features are identified by analyzing the classification feature importance of XGB... [more]
A Lightweight Safety Helmet Detection Algorithm Based on Receptive Field Enhancement
Changpeng Ji, Zhibo Hou, Wei Dai
August 28, 2024 (v1)
Keywords: attention mechanism, lightweight, receptive field enhancement module, safety helmet detection, YOLOv5s
Wearing safety helmets is an important way to ensure the safety of workers’ lives. To address the challenges associated with low accuracy, large parameter values, and slow detection speed of existing safety helmet detection algorithms, we propose a receptive field-enhanced lightweight safety helmet detection algorithm called YOLOv5s-CR. First, we use a lightweight backbone, a high-resolution feature fusion network, and a small object detection layer to improve the detection accuracy of small objects while substantially decreasing the model parameters. Next, we embed a coordinate attention mechanism into the feature extraction network to improve the localization accuracy of the detected object. Finally, we propose a new receptive field enhancement module (RFEM) to substitute the SPPF module in the original network, enabling the model to acquire features under multiple receptive fields, thereby enhancing the detection precision of multi-scale objects. Using the Safety Helmet Detection da... [more]
Classification of Microseismic Signals Using Machine Learning
Ziyang Chen, Yi Cui, Yuanyuan Pu, Yichao Rui, Jie Chen, Deren Mengli, Bin Yu
August 28, 2024 (v1)
Keywords: classification, convolutional neural network, microseismic signals
The classification of microseismic signals represents a fundamental preprocessing step in microseismic monitoring and early warning. A microseismic signal source rock classification method based on a convolutional neural network is proposed. First, the characteristic parameters of the microseismic signals are extracted, and a convolutional neural network is constructed for the analysis of these parameters; then, the mapping relationship model between the characteristic parameters of the microseismic signals and the rock class is established. The feasibility of the proposed method in differentiating acoustic emission signals under different load conditions is verified by using acoustic emission data from laboratory uniaxial compression tests, Brazilian splitting tests, and shear tests. In the three distinct laboratory experiments, the proposed method achieved a source rock classification accuracy of greater than 90% for acoustic emission signals. The proposed and verified method provide... [more]
The Effect of Microbial Compound Fertilizer on the Heavy Metal Binding Forms and Enzyme Activity in Soil
Zheng Zhao, Changyin Huang, Baohui Liang, Siyu Wang, Huiwen Sun, Simeng Bian, Xiaoran Sun
August 28, 2024 (v1)
Subject: Biosystems
Keywords: heavy metal binding forms, heavy-metal-polluted soil, microbial compound fertilizer, physicochemical properties, soil enzyme activity
Nowadays, heavy metal pollution in soil caused by human production activities is increasingly serious. The heavy metal ions in soil inhibit plant growth and endanger human health as they can disrupt the physicochemical properties of soil. However, the elimination of heavy metals in soil is so difficult that more and more researchers are studying effective soil conditioners. The negatively charged groups in microbial communities can bind with heavy metal ions in the soil to remove them. In this paper, Cr- and Cd-polluted soils were used to simulate heavy-metal-polluted soil, and microbial compound fertilizer (MOF) was used as a soil conditioner for removing Cr and Cd in soil. The effects of different additive amounts of MOF on the physicochemical properties, the concentration of metal binding forms in soil and the enzyme activity of soil were investigated. The results showed that when the addition amount of fertilizer was 10%, the improvement effect on Cr- and Cd-polluted soils was the... [more]
Synthesis of Silver-Decorated Magnetite Nanoparticles Using Self-Assembly Methods
Gye Seok An
August 28, 2024 (v1)
Subject: Materials
Keywords: amino functionalization, magnetite (Fe3O4), self-assembly, silver (Ag) nanoparticles, superparamagnetic nanoparticle
This study investigated the synthesis and functional characteristics of Fe3O4@Ag core−shell nanoparticles, focusing on the impact of amino functionalization on their structural and chemical properties. Utilizing self-assembly methods driven by electrostatic interactions, we achieved the effective adsorption of Ag nanoparticles into Fe3O4 cores previously modified with silane (APTES) or polymer (PEI) precursors. Our results elucidate how the type of amino precursor affects the surface charge and subsequent adsorption dynamics, revealing that PEI-modified Fe3O4 nanoparticles exhibit more substantial Ag nanoparticle adsorption than those modified with APTES. This enhanced adsorption was attributed to the higher density of the amine groups introduced by PEI, which also affected the electrostatic properties of the nanoparticles, as evidenced by their zeta-potential values. Moreover, this study highlighted the role of electrostatic attraction in the self-assembly process, facilitating a cont... [more]
Recovery of High-Value Compounds from Yarrowia lipolytica IMUFRJ 50682 Using Autolysis and Acid Hydrolysis
Rhonyele Maciel da Silva, Bernardo Dias Ribeiro, Ailton Cesar Lemes, Maria Alice Zarur Coelho
August 28, 2024 (v1)
Subject: Materials
Keywords: antioxidant activity, Fourier transform infrared spectroscopy (FTIR), glycerol, mannoprotein, protein, thermogravimetry, ultrafiltration
This study aimed to evaluate the sequential hydrolysis of the biomass from unconventional and versatile Y. lipolytica to recover mannoproteins, carbohydrates, and other compounds as well as to determine the antioxidant activity of ultrafiltered fractions. The crude biomass underwent autolysis, and the resulting supernatant fraction was used for mannoprotein recovery via precipitation with ethanol. The precipitate obtained after autolysis underwent acid hydrolysis, and the resulting supernatant was ultrafiltered, precipitated, and characterized. The process yields were 55.5% and 46.14% for the crude biomass grown in glucose and glycerol, respectively. The mannoprotein with higher carbohydrate content (from crude biomass grown in glycerol) exhibited a higher emulsification index of 47.35% and thermal stability (60% weight loss). In contrast, the mannoprotein with higher protein content (from crude biomass grown in glucose) showed a better surface tension reduction of 44.50 mN/m. The tech... [more]
Adsorption and Diffusion Characteristics of CO2 and CH4 in Anthracite Pores: Molecular Dynamics Simulation
Yufei Gao, Yaqing Wang, Xiaolong Chen
August 28, 2024 (v1)
Keywords: anthracite, coalbed methane, diffusion coefficient, molecular dynamics simulation, radial distribution function
CO2-enhanced coalbed methane recovery (CO2-ECBM) has been demonstrated as an effective enhanced oil recovery (EOR) technique that enhances the production of coalbed methane (CBM) while achieving the goal of CO2 sequestration. In this paper, the grand canonical Monte Carlo simulation is used to investigate the dynamic mechanism of CO2-ECBM in anthracite pores. First, an anthracite pore containing both organic and inorganic matter was constructed, and the adsorption and diffusion characteristics of CO2 and CH4 in the coal pores under different temperature and pressure conditions were studied by molecular dynamics (MD) simulations. The results indicate that the interaction energy of coal molecules with CO2 and CH4 is positively associated with pressure but negatively associated with temperature. At 307.15 K and 101.35 kPa, the interaction energies of coal adsorption of single-component CO2 and CH4 are −1273.92 kJ·mol−1 and −761.53 kJ·mol−1, respectively. The interaction energy between ant... [more]
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