Browse
Subjects
Records with Subject: Materials
Showing records 26 to 50 of 4208. [First] Page: 1 2 3 4 5 6 Last
Optimal Pathways for Nitric Acid Synthesis Using P-Graph Attainable Region Technique (PART)
Yiann Sitoh, Viggy Wee Gee Tan, John Frederick D. Tapia, Raymond R. Tan, Dominic C. Y. Foo
January 12, 2024 (v1)
Subject: Materials
Keywords: attainable region, chemical reaction network, nitric acid synthesis, P-graph, process network synthesis
Developing a chemical reaction network is considered the first and most crucial step of process synthesis. Many methods have been employed for process synthesis, such as the attainable region (AR) theory. AR states that a region of all possible configurations can be defined with all the potential products and reactants. The second method is process network synthesis (PNS), a technique used to optimise a flowsheet based on the feasible materials and energy flow. P-graph is an algorithmic framework for PNS problems. P-graph attainable region technique (PART) is introduced here as an integration of both AR and P-graph to generate optimal reaction pathways for a given process. A descriptive AR plot is also developed to represent all the possible solution structures or reaction pathways. A case study of a conventional nitric acid synthesis process was used to demonstrate this technique.
Fe3O4@Granite: A Novel Magnetic Adsorbent for Dye Adsorption
Gamze Topal Canbaz
January 12, 2024 (v1)
Subject: Materials
Keywords: Adsorption, chemical co-precipitation, Fe3O4, magnetic granite, Reactive Black 5
Magnetic granite (MG), a new and low-cost adsorbent, was prepared by the chemical co-precipitation of Fe2+ and Fe3+ using granite (G), which is a magmatic rock type. The adsorption of the Reactive Black 5 (RB5) dye from aqueous solutions on Fe3O4-modified granite was examined in a batch system. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), X-ray fluorescence spectrometry (XRF), X-ray diffractometry (XRD), N2 adsorption−desorption, vibrating-sample magnetometry (VSM), and point-of-zero charge (pHpzc) analysis were used to characterize the prepared MG. Magnetic granite displayed significant magnetization and could be easily separated using external magnets. The maximum adsorption capacity was 29.85 mg/g at 298 K. According to kinetic and isothermal examinations, the pseudo-second-order model and Langmuir isothermal adsorption were the best fit for adsorption. It was found that the enthalpy change ΔH (kJ/mol) was −31.76,... [more]
Fractal Characterization of Particle Size and Coordinate Distribution of Dispersed Phase in the Steelmaking Process of Combined Blowing Conversion
Shiyi Chen, Xiaolei Zhou, Zhihao Zheng, Ren Chen, Shan Yu, Chunyang Shi
January 12, 2024 (v1)
Subject: Materials
Keywords: combined blowing converter, coordinate distribution, dispersed phase, fractal characterization, particle size distribution, water model
A two-dimensional water model was used to simulate the process of combined blowing. The effect of boundary conditions on the size and coordinate distribution of the dispersed phase was investigated. The results showed that the frequency of the dispersed phase at a certain size level is proportional to its size; the coordinates of the dispersed phase can be expressed in a dimensionless form that shows its uniformity of distribution. An empirical equation for the influence of the boundary conditions on the size and coordinate distribution of the dispersed phase in combined blowing process is also presented.
A Perspective on the Prospect of Pickering Emulsion in Reservoir Conformance Control with Insight into the Influential Parameters and Characterization Techniques
Muhammad Mohsin Yousufi, Iskandar bin Dzulkarnain, Mysara Eissa Mohyaldinn Elhaj, Shehzad Ahmed
January 12, 2024 (v1)
Subject: Materials
Keywords: conformance control, emulsion, Pickering emulsion
In reservoir conformance control, polymer gels and foams are majorly used; however, they have drawbacks such as inducing formation damage, having weaker shear resistance, requiring a higher pumping rate, and limited penetration depth. Emulsions are a potential alternative that can address these issues, but they are not widely used. Current surfactant-based emulsions require high emulsifier concentrations for stability and often rely on multiple additives to address various factors, which makes the surfactant synthesis and utilization of emulsions quite challenging. However, Pickering emulsions, which utilize solid particles for emulsion stabilization, have emerged as a promising solution for reservoir conformance control. Compared to conventional polymer gels and foams, Pickering emulsions offer superior shear resistance, deeper penetration, and reduced formation damage. This review provides an overview of recent developments in the utilization of Pickering emulsions for conformance co... [more]
Comparative Study of Rhodamine B Treatment: Assessing of Efficiency Processes and Ecotoxicity of By-Products
Thomas Chadelaud, Hicham Zeghioud, Alonso Reynoso de la Garza, Omar Fuerte, Adriana Benítez-Rico, Messika Revel, Tomás E. Chávez-Miyauchi, Hayet Djelal
January 12, 2024 (v1)
Subject: Materials
Keywords: eco-toxicity assessment, photocatalysis, Rhodamine B degradation, Saccharomyces cerevisiae, TiO2-Ce
In this work, a comparative study between two processes was performed—biodegradation and photocatalysis, as an advanced oxidation process—to discover which one is more efficient to degrade Rhodamine B, a synthetic dye widely used in the textile and food industries. The advantage of this study is that it correlates treatment efficiency with the ecotoxicity of the by-products resulting from the treatments. Since the COVID-19 pandemic, it has been difficult to use activated sludge because of the risk factor of COVID-19 infection. Therefore, biodegradation tests were conducted with the yeast Saccharomyces cerevisiae in this study. For the photocatalysis assays, TiO2 doped with 5 per cent Cerium was used as a catalyst under UV light irradiation. S. cerevisiae cannot reduce RhB by biodegradation. However, a 13 per cent biosorption was observed with an uptake capacity of 4.2 mg g−1 dry matter of S. cerevisiae cultivated in the presence of 5 mg L−1 of RhB after 150 min. At a 5 mg L−1 of RhB co... [more]
Multi-Scale Fractal Characteristics of the Pore System in Low-Permeability Conglomerates from the Junggar Basin
Jiayu Zheng, Weichao Tian, Yang Gao, Zhigang Wen, Yunpeng Fan, Heting Gao, Shuangfang Lu, Xiaoyin Zheng
January 12, 2024 (v1)
Subject: Materials
Keywords: fractal characteristics, Junggar Basin, low-permeability conglomerates, NMR, pore system
The pore structure and its complexity play a critical role in fluid migration and recovery efficiency. Multiple pore types, broad pore size distribution (PSD), and extremely irregular pore morphology hinder the comprehensive investigation of pore systems and their complexity in low-permeability conglomerates. In this study, the multi-scale pore system and fractal characteristics of the Permian Lower Wuerhe Formation and Triassic Baikouquan Formation conglomerates from the Junggar Basin were investigated, combining physical property analysis, casting thin sections, scanning electron microscopy, and Nuclear magnetic resonance (NMR). The results show that the pore system of conglomerates consists of residual intergranular pores (RIPs), dissolution pores (DPs), clay-related pores (CRPs), and microfractures. Three types of PSD were identified according to the shape of the T2 spectrum. Based on the fractal characteristics derived from NMR data, pore systems in conglomerates were divided into... [more]
Enhancing Electric Discharge Machining Performance by Selecting Electrode Design and Geometrical Parameters for Square, Triangular, and Hexagonal Profiled Holes
Madiha Rafaqat, Nadeem Ahmad Mufti, Muhammad Qaiser Saleem, Naveed Ahmed, Ateekh Ur Rehman, Sadaf Zahoor, Muhammad Asad Ali
January 12, 2024 (v1)
Subject: Materials
Keywords: electric discharge machining, land thickness, material removal rate, relief angle, tool design, tool wear rate
Manufacturing of dies, molds, and their allied components requires the machining of holes with different profiles. Electric discharge machining (EDM) die-sinking is a crucial process used in the dies and molds manufacturing industry. By nature, EDM die-sinking is a relatively slow process in terms of material removal rate (MRR) and there are high amounts of tool material loss in terms of tool wear rate (TWR) which directly influence dimensional accuracies and surface roughness (SR). Therefore, the process is continuously evolving to address these limitations. The present research is aligned in this direction such as to bring improvements in MRR, TWR, and SR through modifications to the conventional electrode design and its geometrical parameters. Traditional designs of EDM electrodes have a uniform cross-section through the tool’s entire length and have only one geometrical parameter, i.e., the tool’s cross-section. To improve the EDM performance, traditional designs are completely mod... [more]
Design of Continuous Kneading System for Active Anode Material Fabrication Using Retrofitted Assembly of Co-Rotating Screw Extruder
Gang-Ho Lee, Hyenoseok Yi, Hye-Ryeong Cho, Yu-Jin Kim, Sei-Min Park, Seong-Jin Yoon, Dong-Jin Seo, Kyeongseok Oh, Jeong-Mi Yeon, Sun-Yong Choi, Seong-Ho Yoon, Joo-Il Park
January 12, 2024 (v1)
Subject: Materials
Keywords: anode material, artificial graphite, kneading process, lithium ion battery, twin-screw extruder
As the demand for artificial graphite for lithium-ion battery (LIB) anode materials is on the rise, technologies for optimizing the manufacturing processes and reducing the production costs of artificial graphite are crucial. At the same time, globally, regulations on the generation of harmful volatile substances during the artificial graphite production process are also becoming increasingly stringent. In this study, we focused on a continuous kneading process that minimizes the emission of volatile substances during the manufacturing of artificial graphite. To this end, a carbonized material was first prepared from a mixture of needle coke and binder pitch and processed at 3200 °C using two types of co-rotating twin-screw extruder-based continuous kneading equipment to ultimately obtain artificial graphite. The physical properties of the carbonized as well as graphitized materials were analyzed, which revealed the superior performance of the LIB anode material, namely a discharge cap... [more]
Construction of a Multifunctional PCM@Catalyst Composite and Its Application in the Fluid Catalytic Cracking Process
Guoqing An, Zhixiang Cheng, Ying Ouyang, Siqi Liu, Hongyi Gao
January 12, 2024 (v1)
Subject: Materials
Keywords: Al-Si alloy, catalyst, catalytic cracking, multifunctional composite, phase change microcapsules
Fluid catalytic cracking (FCC) is one of the most important processes in gasoline/diesel oil production, but the strong endothermic effect accompanied by this reaction often results in the deactivation of the catalyst. In this paper, a novel multifunctional phase change material (PCM)@Catalyst composite was designed and constructed, in which the PCM could be used to store waste heat and regulate the temperature for enhancing the catalytic efficiency of the FCC catalyst. Firstly, a core/shell Al-12wt%Si@Al2O3 was prepared via subsequent vapor treatment and high-temperature calcination of an Al-12wt%Si sphere. The Al species in the Al-12wt%Si served as the source of metal ions and was transformed in situ into a well-defined Al2O3 shell, which greatly improved the thermal stability and prevented the leaking of the Al-12wt% Si core in the high-temperature situation. The PCMs@Catalyst composite was then fabricated by casting the mixed powder of Al-12wt%Si@Al2O3 and Y zeolite into a granulat... [more]
Prediction Model of the Remaining Useful Life of the Drill Bit during Micro-Drilling of the Packaging Substrate
Xianwen Liu, Sha Tao, Tao Zhu, Zhaoguo Wang, Hongyan Shi
January 12, 2024 (v1)
Subject: Materials
Keywords: degradation rate, micro-drilling, offset coefficient, packaging substrate, remaining useful life, similarity principle
The packaging substrate plays a significant role in electrical connection, heat dissipation, and protection for the chips. With the characteristics of high hardness and the complex material composition of packaging substrates, drill bit failure is an austere challenge in micro-drilling procedures. In order to monitor the health state of the drill bit and predict its remaining useful life (RUL) in micro-drilling of packaging substrate, an improved RUL prediction model is established based on the similarity principle, degradation rate, and offset coefficient. And then, a micro-drilling experiment on packaging substrate is carried out to collect the axial drilling force through the precision drilling force measurement platform. Axial drilling force signals, which are processed via the Wiener filtering method, are used to analyze the effectiveness of the improved RUL prediction model. The experiment results indicate that, compared to the curves of the traditional RUL prediction model, the... [more]
Properties of Cement Thermal Insulation Materials Containing Tailing Waste for Connecting Mines Assessed Using the Orthogonal Method with the Response Surface Method
Hongwei Deng, Chunzhen Ran, Yao Liu
January 12, 2024 (v1)
Subject: Materials
Keywords: high ground temperature, non-linear fit, optimum fit ratio, orthogonal method, response surface method, thermal insulation material
High temperature in deep mines has become the main concern to limit the production capacity of mines. To mitigate the adverse impact of the underground high-temperature environment on mine production, an orthogonal test was used to design an experimental scheme, i.e., the contents of tailings, glass beads, and ordinary Portland cement PC32.5 (PC) were set as the main horizontal factors to prepare thermal insulation material samples with different combination ratios. Compressive strength and thermal conductivity were investigated, as well as the microstructure. Based on the response surface method (RSM), the interaction between the horizontal factors was explored and analyzed using Design Expert 12 software, and thus non-linear fitting equations were established with the volume fractions of the main horizontal factors as independent variables and compressive strength and thermal conductivity as dependent variables in the analysis parameters of thermal insulation materials. The results s... [more]
Static and Fatigue Characterization of Adhesive T-Joints Involving Different Adherends
Georgino C. G. Serra, José A. M. Ferreira, Paulo N. B. Reis
January 12, 2024 (v1)
Subject: Materials
Keywords: damage mechanisms, fatigue strength, mechanical testing, static characterization, structural adhesives, T-joints
It is very important to understand the damage mechanisms as well as the mechanical response of T-joints involving different materials on the base plate. For this purpose, two configurations were studied. In one, the joint is composed of a base plate and a T-element, both in Al 6063-T5, while in the other one, the aluminum base plate was replaced by a glass fiber composite. Finally, each configuration was divided into two batches, where in one, the elements were bonded with a stiff adhesive (Araldite® AV 4076-1/HY 4076) while in the other, a more ductile adhesive (Araldite® AW 106/HV 953 U) was used. The static and fatigue strength of all configurations was evaluated in bending. In all cases, the damage occurred at the end of the T-element, where a crack appeared and propagated toward the interior of the T-joint. The bending strength is highest for joints involving aluminum and the ductile adhesive, which is 2.8 times higher than the same configuration involving composite base plates an... [more]
Synergistic Catalysis of Reservoir Minerals and Exogenous Catalysts on Aquathermolysis of Heavy Oil
Yunlei Zang, Huaizhu Liu, Dong Chen, Shu Zhang, Shanjian Li, Gang Chen
January 12, 2024 (v1)
Subject: Materials
Keywords: catalytic aquathermolysis, heavy oil, reservoir minerals, synergistic
In this study, based on existing heavy oil extraction technology, combined with the mineral composition in a reservoir, the synergistic catalytic effect of reservoir minerals and exogenous catalysts under the reaction system of a hydrogen-rich environment not only reduces the viscosity of thick oil but also reduces the extraction cost and further improves the recovery rate of heavy oil. In this study, the impacts of different reservoir minerals and exogenous catalysts on the aquathermolysis of heavy oil were investigated. The research results showed that the sodium montmorillonite within the reservoir minerals exhibited an optimal catalytic effect, and the synergistic catalytic effect of sodium montmorillonite and catalyst C-Fe (catechol iron) resulted in a viscosity reduction rate of 60.47%. Furthermore, the efficiency of different alcohols as hydrogen donors was screened, among which ethanol had the best catalytic effect. Under the optimal reaction conditions, the viscosity reduction... [more]
Molecular Dynamics Calculation of the Coordination Behavior of Yb (III) in Sodium Carbonate Solution
Qiaofa Lan, Youming Yang, Ziyu Xie, Haoran Guo, Donghui Liu, Xiaolin Zhang
January 12, 2024 (v1)
Subject: Materials
Keywords: carbonate, coordination, density functional theory, molecular dynamics, Yb (III)
Yb (III) shows complex behavior of coordination dissolution and precipitation in carbonate solutions, but the properties of CO32− coordination and hydration to Yb (III) in the solution have not been explicated. In this work, the dissolution rule of Yb (III) with CO32− concentration has been studied. The radial distribution function and the coordination number of CO32− and H2O to Yb (III) were calculated by molecular dynamics simulation, and the complex ion form of Yb was obtained. The ultraviolet−visible spectrum and the ionic structures of Yb (III) complex ions were geometrically optimized and calculated by using density functional theory. Then, the experimental ultraviolet−visible spectra and density functional theory results were combined to verify the molecular dynamics calculations. The results indicate that Yb (III) undergoes precipitation in low-concentration carbonate solution, but, in high-concentration carbonate solution, Yb (III)’s carbonates will undergo dissolution. The ma... [more]
Synthesis of Silver Nanoparticles: From Conventional to ‘Modern’ Methods—A Review
Ngoc Phuong Uyen Nguyen, Ngoc Tung Dang, Linh Doan, Thi Thu Hoai Nguyen
January 12, 2024 (v1)
Subject: Materials
Keywords: AgNPs, biological synthesis, chemical synthesis, physical synthesis, silver nanoparticles
Silver nanoparticles, also known as AgNPs, have been extensively researched due to their one-of-a-kind characteristics, including their optical, antibacterial, and electrical capabilities. In the era of the antibiotics crisis, with an increase in antimicrobial resistance (AMR) and a decrease in newly developed drugs, AgNPs are potential candidates because of their substantial antimicrobial activity, limited resistance development, and extensive synergistic effect when combined with other drugs. The effect of AgNPs depends on the delivery system, compound combination, and their own properties, such as shape and size, which are heavily influenced by the synthesis process. Reduction using chemicals or light, irradiation using gamma ray, laser, electron beams or microwave and biological synthesis or a combination of these techniques are notable examples of AgNP synthesis methods. In this work, updated AgNP synthesis methods together with their strength and shortcomings are reviewed. Furthe... [more]
The Evaluation of the Fire Safety of the Digestate as An Alternative Bedding Material
Jana Jaďuďová, Iveta Marková, Milada Šťastná, Zuzana Giertlová
January 12, 2024 (v1)
Subject: Materials
Keywords: bedding material, heat loading, ignition temperature, solid phase of digestate
Digestate is the material remaining after the anaerobic digestion of a biodegradable feedstock. The use of digestate as a bedding material is analyzed marginally. The aim of the paper is to monitor the change of the solid phase of digestate due to the action of radiant heat and, based on the results, determine the options of using the solid phase of the digestate for bedding material. Experimental determination of the digestate ignition temperature was carried out according to EN 50281-2-1 (1998) by a hotplate device. Different amounts of samples (3, 5, and 10 g) on the course of thermal degradation were monitored. The results showed higher temperatures of thermal degradation in samples of additionally dried digestate, where these processes were observed earlier in terms of time. Samples of 3 and 10 g of digestate are not suitable as bedding material due to the fire safety of the material.
Experimental Investigation of Stress Sensitivity of Elastic Wave Velocities for Anisotropic Shale in Wufeng−Longmaxi Formation
Yutian Feng, Hongming Tang, Haoxuan Tang, Yijiang Leng, Xuewen Shi, Jia Liu
January 12, 2024 (v1)
Subject: Materials
Keywords: acoustic wave velocity, material anisotropy, microfractures, stress anisotropy, stress sensitivity
The shale of the Wufeng−Longmaxi formation in the Sichuan Basin is the preferred layer for shale gas exploration in China, and its petrophysical characteristics are the key to geological and engineering sweet spot prediction. However, the characteristics and impact mechanisms of its acoustic wave velocity and elastic anisotropy are currently unclear. In this paper, the Wufeng−Longmaxi shale is taken as the research object, and the P-wave and S-wave velocities of the samples are tested under the loading and unloading processes of confining pressure. The stress sensitivity variations in parameters such as wave velocity, wave velocity ratio, and anisotropy are discussed. P-wave and S-wave anisotropy parameters are correlated under different pressure conditions. X-ray diffraction, casting thin sections, scanning electron microscopy, micron CT scanning, and other analytical techniques are used to explore the mechanisms of stress sensitivity of elastic parameters. The research results indica... [more]
Hydrogen/Deuterium Exchange in Ambrox Could Improve the Long-Term Scent and Shelf Life of Perfumes
Antonio Rosales Martínez, Ignacio Rodríguez-García
January 12, 2024 (v1)
Subject: Materials
Keywords: ambrox, deuteration, perfumes
Ambrox is a marine natural compound with a delicious ambergris-type scent widely used in fine perfumery. The increase in the long-term scent and shelf life of perfumes has become a paramount endeavor in the fragrance industry. To the best of our knowledge, the exchange of hydrogen by deuterium to decrease the volatility of the constituents of a perfume has not yet been investigated. In this article, we propose this new use of deuteration to synthesize deuterated ambrox in order to decrease its volatility and improve the long-term scent and extend the shelf-life of perfumes.
Application of AFM on Identifying Mechanical Properties of Individual Minerals and Surface Properties of Crack with High Resolution in Shale
Shizhong Cheng, Mao Sheng, Peng Xu
January 5, 2024 (v1)
Subject: Materials
Keywords: atomic force microscope, mechanical properties, mineral and crack in shale
Improving the resolution and accuracy of the mechanical properties of organic-rich shale is very important. The results can reveal the mechanical properties of shale from micro scale and serve as a guide for the design of hydraulic fracture optimization parameters. This study introduced an advanced technique to obtain the mechanical properties of shale with high resolution (58.6 nm/pixel) by combining SEM, EDS, and Atomic Force Microscopy (AFM). To locate the target area in SEM and AFM accurately, a positioning technique that uses special distributions of pyrite was established. AFM PeakForce QNM mode was selected due to its advantages at capturing topography and mechanical properties in material. Results illustrated the ability of AFM to obtain the mechanical properties (modulus) of individual mineral components in shale, the detailed topography of crack, and mechanical properties of minerals in a specific area. In particular, the mechanical properties of minerals around crack explain... [more]
Energy Dissipation of Hydraulic Support Columns under Rockfall Impact Load in Steeply Dipping Coal Seams
Ming Liu, Bohao Luan, Yang Xiao
January 5, 2024 (v1)
Subject: Materials
Keywords: energy dissipation, hertz contact theory, rockfall, rockfall disaster prevention, steeply dipping coal seams
Rockfall disasters have long restricted the further improvement of the safety level of steeply dipping coal seams (SDCSs). When a rockfall disaster occurs, it causes damage to the hydraulic support and other equipment at the working face. An effective way to carry out protection design is using the law of rockfall migration and energy evolution. Therefore, this study used the polyhedral rockfall migration and its impact process on the hydraulic support equipment of the working face as the research object and analyzed the influence of relevant parameters on the maximum contact deformation, maximum impact force, and energy absorption of the column during the collision and contact between the rockfall and the hydraulic support column. Firstly, with hexahedral rockfall as an example, the migration process of rockfall was simulated using PFC3D software. Secondly, according to the Hertz contact theory, the contact model of the shock process between the rockfall and the hydraulic support colu... [more]
Factor Analysis of the Physical−Mechanical Properties for Geopolymers Based on Brick Dust and Biomass Bottom Ash as Eco-Friendly Building Materials
Juan María Terrones-Saeta, Ana Teresa Luís, Emilio Romero, Juan Carlos Fortes Garrido, Jesús Diaz-Curiel, José Antonio Grande
January 5, 2024 (v1)
Subject: Materials
Keywords: ceramic, circular mining, construction materials, data mining, factorial analysis, geopolymer, structures, wastes
The production of building materials is unavoidable if the well-being and development of society are to be maintained. However, in manufacturing these materials, significant greenhouse gas emissions and environmental effects are produced. For this reason, and with the aim of reducing the impact of the manufacture of these materials, this work developed a geopolymeric material made up solely of wastes, brick dust and biomass bottom ashes which replaced the traditional ceramic materials. To evaluate the quality of this sustainable geopolymeric material, different groups of specimens were formed with different percentages of both residues, subsequently determining the physical properties of the new-formed geopolymers and guaranteeing they accomplish the prescriptions of the ceramic regulations for construction. In addition, the results of the geopolymer characterisation tests were statistically analysed using factor analysis, with the sole purpose of establishing connections and interdepe... [more]
Experimental Studies of Methane Adsorption on Activated Carbon and 3D Graphene Materials
Ziwen Zhu, Muyuan Zhang
January 5, 2024 (v1)
Subject: Materials
Keywords: 3D graphene materials, activated carbon, Adsorption, carbon-based materials, methane storage
Two kinds of slit pore carbon materials, namely activated carbon (AC) and 3D graphene materials (3D-GS), were purchased to examine their methane storage capabilities. The structural analysis and characterization of AC and 3D-GS were carried out using X-ray diffraction (XRD), scanning electron microscopy (SEM), the X-ray energy dispersive spectrum (EDS), and N2 adsorption/desorption isotherms. Additionally, a thermodynamic framework was employed in the Henry’s law region to evaluate the potential well between the adsorbed fluid and adsorbent. The adsorption behavior of methane on two materials at room temperature and high pressure was also investigated. The results show that the Toth equation is the most suitable model for predicting adsorption isotherms than the Langmuir and L-F equations and determines that the absolute uptake of methane storage on AC and 3D-GS are, respectively, 7.86 mmol·g−1 and 8.9 mmol·g−1 at 298 K and 35 bar. In the Henry’s law region, the isosteric heat of metha... [more]
Study of the Effect of Eudragit RSPO on the Photostability of Venlafaxine in a Physical Mixture and in a Melt Form
Anna Maślanka, Marek Szlósarczyk, Przemysław Talik, Joanna Szafraniec-Szczęsny, Krzysztof Woyna-Orlewicz, Paweł Żmudzki, Urszula Hubicka
January 5, 2024 (v1)
Subject: Materials
Keywords: DSC, eudragit, excipients, kinetic studies, photodegradation, photostability, solid dosage, UHPLC/MS/MS, venlafaxine
The effect of Eudragit RSPO on the photostability of venlafaxine in a physical mixture and as a melt was studied. A validated ultra-high-performance liquid chromatography mass spectrometry method was used to determine the content of venlafaxine alongside degradation products. The most likely structures of the degradation products were determined by mass spectrometry. The samples were evaluated before and after exposure to ultraviolet A by differential scanning calorimetry and scanning electron microscopy. The kinetic parameters of the decomposition of venlafaxine in the physical mixture and melt form were calculated and comparable to those of venlafaxine as an active pharmaceutical ingredient. The results indicate that the process of venlafaxine decomposition is more than three times slower in the venlafaxine−eudragit melt than in its physical mixture with eudragit and its pure form. The strong photoprotective nature of the tested polymer against venlafaxine in the melt form was also c... [more]
Preparation of a New Adsorbent Material from Agro-Industrial Waste and Comparison with Commercial Adsorbent for Emerging Contaminant Removal
Luís Fernando Cusioli, Daniel Mantovani, Rosângela Bergamasco, Angelo Marcelo Tusset, Giane Gonçalves Lenzi
January 5, 2024 (v1)
Subject: Materials
Keywords: emerging contaminants, product quality, production cost, sustainable material
An adsorbent was developed from agro-industrial residues derived from the seed husks of Moringa oleifera Lam., in which the hydrochar process was used as it is a sustainable, low-cost and easy-to-operate process. In comparison, a commercial adsorbent, activated charcoal from babaçu coconut, was used. Both materials were characterized using SEM, FTIR, zeta potential and BET, showing their morphologies, chemical compositions and textural analyses that proved the adsorption capacity of each material. A cost study was also carried out regarding the production of the materials. For both materials, an equilibrium study was carried out using the following contaminants: metformin, diuron, methylene blue and lead. We aimed to study the use of agro-industrial waste as a new adsorbent material, which was shown to have an average removal for all the contaminants tested of around 84.56−99.13%. The new adsorbent developed had many interactions with the studied contaminants, allowing its use on a lar... [more]
Preliminary Exploration of the Technology of Coal Reshaping and Replacement Mining of Abandoned Coal in Goafs
Li Li, Xiao Zhang, Bin Hu, Shun Lei
January 5, 2024 (v1)
Subject: Materials
Keywords: coal recycling, filling material, replacement mining
Recycling of coal resources left behind in goafs and the treatment and utilization of solid waste from mines are topical issues faced by the global coal mining industry at present. With the annual reduction of recoverable reserves of coal resources and the dependence on coal resources that are difficult to replace, the problems have become increasingly prominent, seriously limiting the development of coal resources and the implementation of environmental protection work. The mutual influence between the strength of filling materials and the size of loose coal in the CRRM process through numerical simulation experiments, laboratory rock mechanics experiments, and on-site large-scale similar simulation material experiments is explored. It is ultimately believed that selecting a filling material with a 20 cm particle size of loose coal and a 90% proportion of loose coal for 7 days can meet the requirements of the CRRM process, and this conclusion has been verified through on-site engineer... [more]
Showing records 26 to 50 of 4208. [First] Page: 1 2 3 4 5 6 Last
[Show All Subjects]