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Showing records 176 to 200 of 4494. [First] Page: 4 5 6 7 8 9 10 11 12 Last
Fluent Integration of Laboratory Data into Biocatalytic Process Simulation Using EnzymeML, DWSIM, and Ontologies
Alexander S. Behr, Julia Surkamp, Elnaz Abbaspour, Max Häußler, Stephan Lütz, Jürgen Pleiss, Norbert Kockmann, Katrin Rosenthal
June 7, 2024 (v1)
Subject: Materials
Keywords: biocatalysis, data integration, electronic laboratory notebook, ontology, process simulation
The importance of biocatalysis for ecologically sustainable syntheses in the chemical industry and for applications in everyday life is increasing. To design efficient applications, it is important to know the related enzyme kinetics; however, the measurement is laborious and error-prone. Flow reactors are suitable for rapid reaction parameter screening; here, a novel workflow is proposed including digital image processing (DIP) for the quantification of product concentrations, and the use of structured data acquisition with EnzymeML spreadsheets combined with ontology-based semantic information, leading to rapid and smooth data integration into a simulation tool for kinetics evaluation. One of the major findings is that a flexibly adaptive ontology is essential for FAIR (findability, accessibility, interoperability, reusability) data handling. Further, Python interfaces enable consistent data transfer.
Post-Production Finishing Processes Utilized in 3D Printing Technologies
Antreas Kantaros, Theodore Ganetsos, Florian Ion Tiberiu Petrescu, Liviu Marian Ungureanu, Iulian Sorin Munteanu
June 7, 2024 (v1)
Subject: Materials
Keywords: 3D printing, additive manufacturing, automation, industry applications, materials innovation, post-processing techniques, quality assurance, robotics in post-processing, surface finishing
Additive manufacturing (AM) has revolutionized production across industries, yet challenges persist in achieving optimal part quality. This paper studies the enhancement of post-processing techniques to elevate the overall quality of AM-produced components. This study focuses on optimizing various post-processing methodologies to address prevalent issues such as surface roughness, dimensional accuracy, and material properties. Through an extensive review, this article identifies and evaluates a spectrum of post-processing methods, encompassing thermal, chemical, and mechanical treatments. Special attention is given to their effects on different types of additive manufacturing technologies, including selective laser sintering (SLS), fused deposition modeling (FDM), and stereolithography (SLA) and their dedicated raw materials. The findings highlight the significance of tailored post-processing approaches in mitigating inherent defects, optimizing surface finish, and enhancing mechanical... [more]
Development of Thin-Layer Chromatography−Densitometric Procedure for Qualitative and Quantitative Analyses and Stability Studies of Cefazolin
Joanna Żandarek, Małgorzata Starek, Monika Dąbrowska
June 7, 2024 (v1)
Subject: Materials
Keywords: cefazolin, stability testing, TLC–densitometry, validation method
Cefazolin is a first-generation cephalosporin used to treat severe infections of the respiratory tract, urinary tract, skin, and soft tissues. This study presents the optimal conditions for the determination of cefazolin by thin-layer chromatography with densitometric detection. A chloroform−methanol−glacial acetic acid mixture (6:4:0.5, v/v/v) was selected as the mobile phase, while TLC silica gel 60F254 plates were used as the stationary phase. Next, the developed procedure was validated in accordance with ICH guidelines. The obtained results showed that the method is selective, precise, and accurate in a linearity range of 0.04−1.00 µg/spot (r > 0.99). Subsequently, qualitative and quantitative analyses of formulations containing cefazolin were performed. It was found that the amount of antibiotic is highly consistent with the content declared by manufacturers. The suitability of the developed method for stability testing under varying environmental conditions was also verified. It... [more]
Design, Construction, and Characterization of a Solar Photovoltaic Hybrid Heat Exchanger Prototype
Sandro Guadalupe Perez Grajales, Angel Horacio Hernández, David Juárez-Romero, Guadalupe Lopez Lopez, Gustavo Urquiza-Beltran
June 7, 2024 (v1)
Subject: Materials
Keywords: heat exchanger, PH/T, photovoltaic cell, thermal efficiency
In this experimental work, a prototype of a hybrid solar−thermal−photovoltaic (HE-PV/T) heat exchanger has been designed, built, and characterized, with rectangular geometry and 12 fins inside, to obtain better heat flow and higher performance in order to achieve a better heat transfer coefficient, reducing and optimizing the working area. The heat exchanger contains 12 photovoltaic cells connected in series, with an angle of inclination of approximately 18° towards the south and a surface area of 0.22 m2, smaller than those available on the market, which individually capture 147.05 W/m2 as a photovoltaic panel and 240 W/m2 as a solar collector. Mathematical models found in the literature from previous work were used for the electrical and thermal evaluations. The temperature of the PV cells was reduced to 13.2 °C and the thermal level of the water was raised to a temperature above 70 °C, with a photovoltaic−thermal coupling power of 307.11 W and a heat transfer coefficient of 5790 W/m... [more]
The Application of Pipette-Tip and Magnetic Dummy-Template Molecularly Imprinted Solid-Phase Extraction Coupled with High-Performance Liquid Chromatography with Diode Array and Spectrofluorimetric Detection for the Determination of Coumarins in Cosmetic S
Andrea Špačková, Katarína Hroboňová, Michal Jablonský
June 7, 2024 (v1)
Subject: Materials
Keywords: coumarins, HPLC, molecularly imprinted polymers, personal care products, safety testing, solid-phase extraction
In this study, adsorbents based on molecularly imprinted polymers (MIPs) in two solid-phase extraction application forms, pipette tip and magnetic extraction, were used for the selective extraction of coumarins. The pipette-tip solid-phase extraction reduced solvent volumes; the magnetic MIP extraction was simple and effective for phase separation. Parameters affecting extraction, such as the amount of adsorbent, type of washing solvent, volume of the elution solvent, and extraction times for magnetic extraction, were optimized. The MIP-based adsorbents displayed high selectivity and extraction efficiency, resulting in recoveries ranging from 70.3 to 102.0% (RSD % less than 5.5%) for five coumarins under study, 6,7-dihydroxycoumarin-6-β-D-glucoside, coumarin, 7-methoxycoumarin, 6-methylcoumarin, and dicoumarol. The extracts were analyzed by high-performance liquid chromatography with diode array (DAD) and fluorescence (FLD) detectors, reaching limits of quantification of 0.5 and 0.9 µg... [more]
Physico-Chemical Characterization of Encapsulated Fennel Essential Oil under the Influence of Spray-Drying Conditions
Maja Repajić, Ivona Elez Garofulić, Nina Marčac Duraković, Marta Balun, Karla Cegledi, Ena Cegledi, Erika Dobroslavić, Verica Dragović-Uzelac
June 7, 2024 (v1)
Subject: Materials
Keywords: encapsulation, essential oil, Foeniculum vulgare Mill., gum arabic, maltodextrin, oil retention, powder, wall material, β-cyclodextrin
In this study, fennel essential oil (EO) was spray-dried, varying the wall material type (two-component blends of maltodextrin (MD), β-cyclodextrin (β-CD) and gum arabic (GA)), the wall material ratio (1:1, 1:3 and 3:1) and the drying temperature (120, 160 and 200 °C). A total of 27 powders were analyzed for their moisture content, solubility, hygroscopicity, bulk density and particle size, while powder recovery and oil retention were determined in terms of encapsulation efficiency. The morphology and chemical composition of the powder obtained under optimal conditions were additionally analyzed by scanning electron microscopy and gas chromatography-mass spectrometry. The results showed that all of the powders had generally good properties, exhibiting a low moisture content, high powder recovery and high oil retention. A 1:3 MD:GA mixture and a drying temperature of 200 °C were found to be optimal for the spray-drying of fennel EO, producing a powder with a low moisture content (3.25%)... [more]
Modeling Surface Roughness and Flow of Gases in Threaded Connections to Analyze Sealing Performance
Wenqi Zhu, Yu Liang, Lv Zhao
June 7, 2024 (v1)
Subject: Materials
Keywords: finite element analysis, gap flow model, metallic seal, surface roughness, threaded connection
Oil casings and premium threaded connections play vital roles in the oil and gas extraction industry. The present work establishes an integrated modeling framework for the sealability assessment of premium threaded connections which can be easily implemented and employed by engineers. The framework incorporates a part-scale finite element analysis of the make-up process, a micro-scale simulation of the contact behavior, and a mechanism-informed gap flow model. It is found that complete sealing can be achieved when the contact pressure exceeds 1540 MPa for Gaussian rough surfaces presenting a roughness of 1.6 μm. The seal surface fit is revealed to be critical for sealing performance, as it slightly changes the optimum make-up torque (up to 4%) but significantly changes contact pressure (up to 22%). At an optimum make-up torque, the connection with the loosest seal surface tolerance fit is prone to gas leakage when considering an inlet pressure of 110 MPa. The proposed modeling framewor... [more]
Microwave-Assisted Synthesis of 5-Substituted 3-Amino-1,2,4-triazoles from Aminoguanidine Bicarbonate and Carboxylic Acids
Mustafa Kemal Gümüş, Mykola Yu. Gorobets, Nesimi Uludag
June 7, 2024 (v1)
Subject: Materials
Keywords: 3-amino-1,2,4-triazoles, aminoguanidine, carboxylic acids, microwave-assisted synthesis
The effect of the molar ratio between reagents, reaction time and temperature on the yield of 5-substituted 3-amino-1,2,4-triazoles obtained by the direct condensation of carboxylic acids with aminoguanidine bicarbonate under acid catalysis conditions was studied. As a result, a general green straightforward synthesis of the title compounds bearing aliphatic substituents or a phenyl ring was developed using sealed reaction vials under controlled microwave synthesis conditions that are suitable for the application of volatile starting carboxylic acids. Our straightforward synthetic method proposed in this work increases the synthetic accessibility of these widely used building blocks and therefore is able to significantly expand the structural diversity of compounds containing a triazole moiety for the needs of drug discovery.
The Wetting Characteristics and Microscopic Wetting Mechanism of Coal under High-Pressure Nitrogen Environment
Piao Long, Bin Shi, Yunxing Cao, Yufei Qi, Xinyi Chen, Liuyang Li
June 7, 2024 (v1)
Subject: Materials
Keywords: capillary pressure, coalbed methane, contact angle, surface roughness, wettability
The wettability of coal is an important factor influencing hydraulic stimulation. Field-trial data has proven that high-pressure N2 injection plays a positive role in increasing the coalbed methane (CBM) production rate. For the purpose of investigating the mechanism by which N2 promotes the gas rate, multiple experiments were conducted sequentially on the wettability of anthracite under different N2 pressures. Testing of the coal surface contact angle was conducted under 0.1−8 MPa nitrogen pressure using a newly built contact angle measuring device. The coal samples were collected from the Xinjing Coal Mine in the Qinshui Basin, China. The test results revealed that the contact angle increased with increasing N2 pressure. That is, the contact angle was 77.9° at an N2 pressure of 0.1 MPa and gradually increased to 101.4° at an infinite N2 pressure. In contrast, the capillary pressure decreased with an increasing N2 pressure, from 0.298 MPa to −0.281 MPa. The relationship between contac... [more]
Synergistic Effect of Plasma-Activated Water with Micro/Nanobubbles, Ultraviolet Photolysis, and Ultrasonication on Enhanced Escherichia coli Inactivation in Chicken Meat
Kochakon Moonsub, Phisit Seesuriyachan, Dheerawan Boonyawan, Wassanai Wattanutchariya
June 7, 2024 (v1)
Subject: Materials
Keywords: microbubbles/nanobubbles, pathogen inactivation, plasma technology, plasma-activated water (PAW), ultrasonication, ultraviolet
The use of integrated plasma-activated water (PAW) with micro/nanobubbles (MNBs), ultraviolet (UV) photolysis, and ultrasonication (US) for the synergistic efficiency of Escherichia coli inactivation in chicken meat was investigated. A 2k factorial design was employed to optimize the combined treatment parameters for pathogen disinfection in Design of Experiments (DOE) techniques. Its effectiveness was evaluated based on electrical conductivity (EC), oxidation−reduction potential (ORP), hydrogen peroxide (H2O2) concentration, and E. coli inactivation. The most significant impact on E. coli reduction was observed for MNBs, UV treatment time, and their interaction (MNBs and UV). Optimal E. coli inactivation (6 log10 CFU/mL reduction) was achieved by combining PAW with MNB and UV for 10 and 20 min, respectively. Integrating PAW with appropriate supplementary technologies enhanced E. coli inactivation by 97% compared to PAW alone. This novel approach provides a promising alternative for pa... [more]
Application of Raman Spectroscopy to Evaluate the Structure Changes of Lubricating Grease Modified with Montmorillonite after Tribological Tests
Rafal Kozdrach
June 7, 2024 (v1)
Subject: Materials
Keywords: coefficient of friction, lubricant, montmorillonite, Raman spectroscopy, structural evolution, tribo-characteristics, wear limit
This study shows the experimental data obtained by Raman spectroscopy to evaluate the structural changes of vegetable lubricants modified with montmorillonite after tribological tests. The analysis of the friction factor and limiting load of wear in the test for the examined grease compound shows a substantial effect on this parameter for grease. A change in the evaluated tribo-parameter results in a modification of the structure of the tested lubricant and changes in the protection efficiency of the tribological system. The amount of thickener, oil base and additive in the grease structure has an influence on the value of anti-wear properties, as shown by the data obtained in the tribological test described in this paper. The Raman spectroscopy tests showed that, in the tribological processes, some of the ingredients undergo an oxidative reaction, which leads to the formation of oxygenated organic substances that form an organic layer on the metal surface and counteract the wear of th... [more]
Hollow Fiber Membrane Modification by Interfacial Polymerization for Organic Solvent Nanofiltration
Abdulaziz Y. Alammar, Seung-Hak Choi, Maria Giovanna Buonomenna
June 7, 2024 (v1)
Subject: Materials
Keywords: hollow fiber, interfacial polymerization, organic solvent nanofiltration, thin film composite (TFC) membrane
Hollow fiber (HF) organic solvent nanofiltration (OSN) membranes have recently attracted significant interest in the field of membrane technology. Their popularity stems from comparative advantages, such as high packing density, fouling resistance, and easier scalability for larger applications, unlike flat-sheet/spiral-wound OSN membranes, which may present challenges in these aspects. The combination of interfacial polymerization (IP) and HF configuration has opened up new opportunities for developing advanced membranes with enhanced separation performance that can be tailored for various OSN applications. The objective of this review is to discuss the latest advancements in developing thin film composite (TFC) HF membranes, with a focus on the IP method. Novel materials and processes are discussed in detail, emphasizing the fabrication of greener, interfacially polymerized HF OSN membranes. In addition, the commercial viability and limitations of TFC HF membranes are highlighted, pr... [more]
Synthesis of Activated Biochar from the Bark of Moringa oleifera for Adsorption of the Drug Metronidazole Present in Aqueous Medium
Caio Henrique da Silva, Thiago Peixoto de Araújo, Alexandre Teixeira de Souza, Mara Heloisa Neves Olsen Scaliante, Wardleison Martins Moreira
June 7, 2024 (v1)
Subject: Materials
Keywords: activated biochar, Adsorption, drug, Moringa oleifera
seeds, in particular, have been used for water and wastewater treatment due to their ability to remove many pollutants. Therefore, the present work aims to produce bioadsorbent materials by pyrolysis using biomass from the seed shell of Moringa oleifera to remove the drug Metronidazole present in an aqueous medium. The biochars produced were activated with phosphoric acid (H3PO4) and potassium hydroxide (KOH) to compare the material’s modifications and adsorption mechanisms with the biochar in nature (BCM). The biochars were characterized by Point-of-zero charges (pHpzc), Scanning Electron Microscopy (SEM), X-ray Diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. The studies showed that the adsorption behavior varied with the pH of the solution. The adsorption study verified that the activated biochars presented better results, so in the kinetic study, the adsorption behavior occurred rapidly in the initial minutes until stabilizing within 3−4... [more]
Monitoring Yeast Cultures Grown on Corn Stover Hydrolysate for Lipid Production
Afonso Fontes, Ricardo Francisco, Frederico Castelo Ferreira, Nuno Torres Faria, Susana Marques, Alberto Reis, Patrícia Moura, Rafal Lukasik, José Santos, Teresa Lopes da Silva
June 7, 2024 (v1)
Subject: Materials
Keywords: flow cytometry, lignocellulosic materials, lipids, oleaginous yeasts
Microbial oils can be used as an alternative sustainable and renewable feedstock to fossil reserves for producing lubricants and polyurethane materials. Two oleaginous yeasts were grown on non-detoxified corn stover hydrolysate supplemented with corn steep liquor and mineral medium in shake flasks. Trichosporon oleaginosus DSM 11815 displayed the highest lipid production. This strain was further cultivated in a bench bioreactor, using the same culture medium, under a batch regime. Flow cytometry was used to monitor the T. oleaginosus culture using the dual staining technique (SYBR Green and PI) for cell membrane integrity detection. Values of 42.28% (w/w) and 0.06 g/Lh lipid content and lipid productivity, respectively, were recorded for T. oleaginosus cultivated in the bench bioreactor operated under a batch regime. During the cultivation, most of the yeast cells maintained their integrity. T. oleaginosus has the potential to be used as an oil microbial source for a wide range of indu... [more]
Environmentally Friendly Leaching of Antimony from Mining Residues Using Deep Eutectic Solvents: Optimization and Sustainable Extraction Strategies
Michaela Sudová, Martin Sisol, Maria Kanuchova, Michal Marcin, Jakub Kurty
June 7, 2024 (v1)
Subject: Materials
Keywords: antimony, critical raw materials, deep eutectic solvents, hydrometallurgy, leaching, mining waste, solvometallurgy
This paper focuses on the environmental leaching of antimony, a critical mineral, using deep eutectic solvents. Mining residues often contain embedded antimony, posing environmental risks. Deep eutectic solvents, known for being low in toxicity, cost-effective, and environmentally friendly, present a promising avenue for sustainable antimony extraction. The study focuses on optimizing the leaching process through experimental analysis by considering variables such as temperature, time, and percentage of solids. Different deep eutectic solvent (DES) compositions are being studied, including choline chloride with malonic acid, thiourea, and ethylene glycol in different molar ratios, to identify the most effective solvent system for antimony extraction. A sample, originally obtained from mining waste produced via the flotation of antimonite ore, was used to test these three types of DESs. By optimizing the leaching process by changing the ratio of solid and liquid components, as well as t... [more]
Calculation Method of the Phase Recovery of Gas Cap Reservoir with Bottom Water
Mingzhe Li, Yizhong Zhang, Maolin Zhang, Bin Ju, Long Yang, Xu Guo
June 7, 2024 (v1)
Subject: Materials
Keywords: formation pressure, hydrocarbon reservoirs, material balance equation, phase equilibrium, phase recovery
In gas cap reservoirs underlain by bottom water, the connection between the reservoir and the aquifer leads to an increasing invasion of bottom water as reservoir development progresses. The average formation pressure of the reservoir will change, and the separated phase recovery of the gas cap reservoir with bottom water will be affected by the change in the average formation pressure. The traditional average formation pressure calculation formulas do not consider the water influx, so the accurate calculation of separated recovery cannot be obtained by those calculation methods. The development of gas cap reservoirs with bottom water presents several challenges, including the simultaneous production of oil and gas, undetermined rates of bottom water influx, and uncertain formation pressure and gas-to-oil ratios. These factors contribute to substantial discrepancies between theoretical calculations and actual observations. A more accurate and comprehensive approach is required to addre... [more]
An Experimental Study on Nodular Iron Machined Surfaces Utilizing a Capable 2D Finite Element Model for Precise Surface Roughness Estimation
Ibrahim T. Teke, Ahmet H. Ertas
June 7, 2024 (v1)
Subject: Materials
Keywords: 2D surface roughness estimation technique (2D-SRET), cast iron, machining, microstructure, nodular iron, surface roughness
Nodular iron plays a crucial role in various industries, especially in large-scale applications such as gearboxes. Ensuring that nodular iron remains free from oil leakage and that contact surfaces are properly aligned is essential, given its operational requirements. Achieving flat contact faces through precise machining is therefore of utmost importance. As surface roughness and flatness are closely linked, it is vital to investigate the machining process parameters involved. This study focuses on addressing surface quality issues with EN-GJS-600-3 cast iron by optimizing machining parameters. CMM measurements were utilized to analyze the relationship between surface roughness and flatness, with a surface profile used to assess flatness. Furthermore, a new 2D surface roughness estimation method (2D-SRET) was created and tested with experimental data in order to improve the precision of assessing the discrete flat surface machining procedure.
Activation of Low-Quality Coal Gangue Using Suspension Calcination for the Preparation of High-Performance Low-Carbon Cementitious Materials: A Pilot Study
Hongbo Zhang, Shaowu Jiu, Qianwen Gao, Sijun Zhao, Yanxin Chen, Feng Cheng, Ding Han, Ruihong Shi, Kaixin Yuan, Jiacheng Li, Yuxin Li, Zichun Wang, Bo Zhao
June 7, 2024 (v1)
Subject: Materials
Keywords: cementitious material, decarbonization, low-quality coal gangue, process optimization, suspension calcination
Although the calcination-based activation of coal gangue is important for its valorization in the form of cementitious materials, the related works mainly focus on high-quality coal gangue, neglecting its low-quality counterpart. To bridge this gap, we herein conducted the pilot-scale suspension calcination of low-quality coal gangue; explored the effects of calcination temperature, particle size, and O2 content on the phase composition of the calcined product, kaolinite decomposition, decarbonization, and silica/alumina dissolution; and evaluated calcination-product-based cementitious materials. Under optimal conditions (temperature = 875−900 °C; particle size = 39.71−46.84 μm; and O2 content = 12−14%), the carbon content of the calcined product equaled 1.24−1.87 wt%, and the dissolution rates of activated alumina and silica were 77.6−79.5% and 49.4−51.1%, respectively. The 28 d compressive strength (50.8−55.7 MPa) and true activity index (98.8−108.4%) of the cementitious material pre... [more]
Characterization of Contact Pressure Distribution and Bruising Prediction of Apple under Compression Loading
Jiaping Wang, Chao Wang, Jie Wu
June 7, 2024 (v1)
Subject: Materials
Keywords: apple, bruising prediction, compression loading, contact pressure distribution, finite element analysis, pressure-sensitive film
The pressure distribution characteristics of an apple subjected to compressive loading were investigated using the pressure-sensitive film (PSF) technique combined with apple bruise measurements. Pressure was unevenly distributed in the elliptical contact region. The average pressure had no effect on bruising because it changed slightly in the range of 0.26−0.31 MPa with increasing load. Pressures of 0.20−0.40 MPa accounted for 72% of the total pressure area. Comparatively, the area where pressure over 0.50 MPa was distributed could be ignored and showed little contribution to the bruise area. The contact edge subjected to pressure below 0.10 MPa showed that no bruising occurred. As a result, the relationship between the ≥0.10 MPa pressure area strongly correlated with the bruise area according to a linear equation, with a correlation coefficient of ≥0.99. When this relationship was applied to determine the bruise area with FE, satisfactory predicted results were obtained with minor er... [more]
Hyperspectral and Microtomographic Analyses to Evaluate the Stability of Quercetin and Calcium Effervescent Tablets Exposed to Heat and Ultraviolet Radiation
Beata Szulc-Musioł, Piotr Duda, Michał Meisner, Beata Sarecka-Hujar
June 7, 2024 (v1)
Subject: Materials
Keywords: effervescent tablets, heat, hyperspectral analysis, stability, stressful conditions, UV radiation, X-ray computed microtomography
This study aimed to assess the changes occurring during the storage of tablets of three effervescent preparations available in Polish pharmacies containing calcium and quercetin from various manufacturers under stressful conditions (45 °C, UV radiation) using a hyperspectral Specim IQ camera (Finland), X-ray microtomography (Germany), and selected pharmacopoeial parameters. All measurements were made three times at the beginning of the experiment (day 0) and then on days 3 and 10. In general, for all analyzed preparations, the values of reflectance (within a range from visible light to near-infrared) were significantly higher on day 0 than after 10 days of heat and UV (p < 0.001 each). The hardness of the tablets of all analysed preparations was higher on days 3 and 10 compared to day 0. Significant differences were found in the density of the internal structure of the tested preparations (p < 0.001), but in Preparations 1 and 2 on day 10, the density was higher compared to the i... [more]
Barrier, Mechanical, Thermal, and Rheological Properties of Plasticized Biopolymeric Films Manufactured by Co-Extrusion
Heidy Lorena Calambás Pulgarin, Carolina Caicedo
June 7, 2024 (v1)
Subject: Materials
Keywords: acetyltributyl citrate, starch, Tween 20, twin-screw extruder, water vapor permeability
The thermal, rheological, mechanical, and barrier properties of flat biopolymeric films processed by extrusion with different proportions of plasticizer and surfactant were evaluated. In the first stage, pellets were developed through twin-screw extrusion using a temperature profile in the ascending step process. These samples were analyzed using rotational rheology analysis to understand the viscoelastic transitions through the behavior of the storage and loss modulus, as well as the incidence of complex viscosity concerning concentration. The interaction among the components was analyzed under infrared spectroscopy after the two processing stages, revealing the miscibility of the mixture due to the action of the surfactant. The degradation temperatures increased by more than 20 °C, generating thermal stability, and the temperatures related to polymer transitions were determined. In the second stage, co-extrusion was carried out using pellets from the blend with a melt flow index (MFI... [more]
Polyelectrolyte Platforms with Copper Nanoparticles as a Multifunctional System Aimed at Healing Process Support
Agata Lipko, Anna Grzeczkowicz, Magdalena Antosiak-Iwańska, Marcin Strawski, Monika Drabik, Angelika Kwiatkowska, Ewa Godlewska, Ludomira H. Granicka
June 7, 2024 (v1)
Subject: Materials
Keywords: copper nanoparticles, human lung A549 cell line, polyelectrolyte layer coating
(1) Purpose: The aim of the study was to develop a nanocomposite with copper nanoparticles constituting a bacteriostatic surface to maintain human lung cell function. (2) Methods: A polyelectrolyte layer coating that incorporated copper nanoparticles was designed. As a bacteriostatic factor, copper nanoparticles were applied as a colloidal solution of copper nanoparticles (ColloidCuNPs) and a solution of copper nanoparticles (CuNPs). The influence of the polyelectrolytes on selected Gram (+) and Gram (−) strains was examined. The function and morphology of the human adenocarcinoma A549 cell line, comprising human epithelial lung cells cultured in the presence of nanocomposite layer coatings, were evaluated. We applied fluorescence and scanning electron microscopies, as well as flow cytometry, for these studies. Furthermore, the layer coating material was characterized by atomic force microscopy (AFM) and energy dispersive X-ray analysis (EDX). (3) Results: It was observed that the poly... [more]
Inhibition Localized Corrosion of N80 Petroleum Pipeline Steel in NaCl-Na2S Solution Using an Imidazoline Quaternary Ammonium Salt
Shanjian Li, Te Du, Guotao Cui, Haoxuan He, Panfeng Wu, Yongfei Li
June 7, 2024 (v1)
Subject: Materials
Keywords: corrosion inhibitor, imidazoline, N80 steel, occluded cell
In this paper, the local corrosion inhibition effect of imidazoline on N80 oil pipeline steel in a NaCl-Na2S solution was studied by the simulated blocking tank cell method, and the corrosion processes of the cathode and anode in the blocking zone were simulated. The blocking corrosion behavior of the pipeline tubing steel N80 in simulated corrosion solutions without and with different concentrations of an imidazoline corrosion inhibitor was studied by chemical analysis and electrochemical analysis. The results show that in the three solution systems, after the anode polarization of the occluded cell, the solution in the occluded region is acidified, the pH value decreases sharply, the migration of Cl− and S2− increases, and the concentration is increased in the blocked area. After adding the imidazoline corrosion inhibitor, the imidazoline inhibitor can reduce the migration of small-radius anions (Cl− and S2−) to the occluded area, inhibit the acidification of the solution in the occl... [more]
Coke Substitution with Anthracite in Sintering Production
Pavlina Pustejovska, Michal Sikora, Simona Jursova, Kristyna Pustejovska, Edyta Kardas
June 7, 2024 (v1)
Subject: Materials
Keywords: anthracite, coke breeze, sintering
This article summarises the possibility of replacing the coke breeze sintering fuel with an economically and ecologically more suitable fuel, anthracite. The main focus is on the possibility of replacing coke breeze with anthracite, during which, the replacement process is accelerated and the other properties are also affected. The analyses performed showed that the replacement of coke breeze with different amounts of anthracite does not have a negative effect if the initial permeability of the sintering bed is the same.
Performance Evaluation on Open-Graded Friction Course Reinforced by Double-Adding Fibers Technology
Cihe Chen, Chimou Li, Saibang Zhang, Wenchang Liu, Hongwei Lin, Hongchao Zhang
June 7, 2024 (v1)
Subject: Materials
Keywords: asphalt mixture, fiber modification, glass fiber, lignin fiber, OGFC
The use of an open-graded friction course (OGFC) as a road surface demonstrates significant advantages in reducing driving noise and improving road drainage and safety. This study aims to enhance the overall performance of OGFC-13 by incorporating double-adding fiber technology. Laboratory tests were conducted on six OGFC-13 mixes modified with varying fiber ratios of lignin fibers (LFs) and glass fibers (GFs). Both GF and LF significantly improved high-temperature performance, with dynamic stability values increasing proportionally to GF content. The LF:GF = 0.15:0.15 ratio achieved peak shearing strength, demonstrating better improvement over single-fiber modification. Furthermore, both fibers effectively enhanced resistance to cracking, with GF-reinforced specimens excelling in bending stress and LF-reinforced specimens demonstrating the highest flexural strain. Water stability evaluations highlighted the substantial positive impact of LF and GF, with simultaneous addition resulting... [more]
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