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Showing records 3845 to 3869 of 4494. [First] Page: 1 151 152 153 154 155 156 157 158 159 Last
Regional Geological Disasters Emergency Management System Monitored by Big Data Platform
Xiaoping Qian
February 21, 2023 (v1)
Subject: Materials
Keywords: big data platform, disaster warning, emergency management system, geological disasters
In order to deal with the hazards caused by geological disasters in time, an emergency management system is proposed based on association rule data mining. With the support of a big data platform, a regional geological disaster emergency management system is built based on monitoring data. In the result analysis, the association rule algorithm demonstrates high computing power in the test, which can filter the data with strong association rules. In addition, the big data platform can allow data visualization, which has good data storage capacity and disaster early warning capacity. In the simulation test of the emergency management system, it was found that the system is feasible in theory. When it is applied to the actual disaster emergency management, it wasfound that, in the face of geological disasters, the processing speed of relevant departments increased by 59.4%, and the allocation of personnel and materials wasmore reasonable. The above results show that the big data platform... [more]
Electrospinning Composites as Carriers of Natural Pigment: Screening of Polymeric Blends
Sergiana dos Passos Ramos, Letícia Guerreiro da Trindade, Tatiana Martelli Mazzo, Elson Longo, Fabiana Perrechil Bonsanto, Veridiana Vera de Rosso, Anna Rafaela Cavalcante Braga
February 21, 2023 (v1)
Subject: Materials
Keywords: anthocyanins, C-phycocyanin, carotenoids, composites, electrospun, PEO, rheological properties, Spirulina, zein
Several studies have already demonstrated that electrospinning is an excellent tool for forming nano/microfibers. However, the number of parameters affecting the formation of the structures has become a great challenge, including the polymeric solutions’ rheological properties, directly affecting the morphology of the fibers formed. The present work aimed to produce polymeric composites and determine their rheological properties, comparing them to the morphology of the fibers formed by electrospinning. Also, to evaluate their potential use as the carriers of natural pigments. To this end, a distinct combination of solutions containing Chitosan/Gelatin, Chitosan/poly(ethylene) oxide (PEO) and Zein/PEO was produced and submitted to electrospinning. The sample containing zein manufactured the structures smaller in diameter (201.3 ± 58.6 nm) among those studied. Besides, it was observed that adding PEO to the solutions impacts the increase in viscosity and shear thinning behavior, guarante... [more]
Synthesis and Characterization of Nanoformulation of the Broad-Spectrum Enzyme Inhibitor Mancozeb by Polyethylene Glycol Capping and Its Dissipation Kinetics in Water Using TiO2 Nanoparticles
Wafa Mahmoud Daqa, Adil Alshoaibi, Faheem Ahmed, Tentu Nageswara Rao
February 21, 2023 (v1)
Subject: Materials
Keywords: dissipation half-life (DT50), mancozeb nanoformulation, photocatalytic, photolytic, polyethylene glycol, TiO2 nanoparticles
The poly(ethylene) glycol (PEG) capped mancozeb nanoformulation was prepared by the ultrasonic method using a 1% mancozeb solution and 20% capping agent, PEG-4000. The synthesized nanoformulation was characterized using UV-visible, FTIR, SEM and TEM techniques. The photolytic and photo catalytic experiments were carried out in a Borosil glass bottle in the presence of sunlight, varying the pH proportions at a single fortification level (1.0 g/mL) in ground water, under sunlight. The optimal catalyst concentration for complete degradation was observed to be 0.1 percent. The mancozeb nanoformulation in water was determined using the HPLC-PDA method, and the rate constant and the 50% degradation (DT50) values were calculated based on the results. The photolytic results show that there is no significant loss of residues due to adsorption. Titanium dioxide (TiO2) was discovered to be an excellent decontaminating catalyst in a variety of water samples. The compound survives for several days... [more]
Adsorption Characteristics and Mechanism of Methylene Blue in Water by NaOH-Modified Areca Residue Biochar
Yixin Lu, Yujie Liu, Chunlin Li, Haolin Liu, Huan Liu, Yi Tang, Chenghan Tang, Aojie Wang, Chun Wang
February 21, 2023 (v1)
Subject: Materials
Keywords: Adsorption, areca residue, biochar, methylene blue, modification
To solve the water pollution problem caused by methylene blue (MB), areca residue biochar (ARB) was prepared by pyrolysis at 600 °C, and modified areca residue biochar (M-ARB) was obtained by modifying ARB with 1.5 mol/L NaOH, and they were utilized to adsorb and eliminate MB from water. The structural characteristics of ARB and M-ARB were examined, and the main influencing factors and adsorption mechanism of MB adsorption process were investigated. The outcomes demonstrated an increase in M-ARB’s specific surface area and total pore volume of 66.67% and 79.61%, respectively, compared with ARB, and the pore structure was more abundant, and the content of oxygen element was also significantly increased. When the reaction temperature was 25 °C, starting pH of the mixture was 10, the initial MB concentration was 50 mg/L, the ARB and M-ARB dosages were 0.07 g/L and 0.04 g/L, respectively, the adsorption equilibrium was achieved at about 210 min, and the elimination rate for MB exceeded 94%... [more]
Development of Co-Amorphous Loratadine−Citric Acid Orodispersible Drug Formulations
Emőke Margit Rédai, Emese Sipos, Robert Alexandru Vlad, Paula Antonoaea, Nicoleta Todoran, Adriana Ciurba
February 21, 2023 (v1)
Subject: Materials
Keywords: co-amorphous, direct compression, loratadine, lyophilization, orally disintegrating
This study aimed at the preparation and characterization of co-amorphous loratadine−citric acid orally disintegrating dosage forms (ODx). A co-amorphous loratadine−citric acid was prepared by solvent evaporation method in three different molecular ratios. DSC, FTIR, and dissolution studies have been conducted for the binary system. The co-amorphous system was used to obtain oral lyophilizates and orally disintegrating tablets by direct compression. Diameter, thickness, hardness, disintegration time, uniformity of mass, and dissolution was determined for the dosage forms. DSC curves showed a lack of sharp endothermic peaks for the binary systems. FTIR spectra presented a hypsochromic modification of the characteristic peaks. Dissolution studies indicated a five-fold increase in the dissolved amount compared to pure loratadine in water. Disintegration times of direct compression ODx varied in the range of 34−41 s and for freeze-dried ODx in the range of 8−9 s. Friability was under 1% in... [more]
Magnetic Activated Biochar Fe3O4-MOS Made from Moringa Seed Shells for the Adsorption of Methylene Blue
Meiping Li, Cheng Dong, Caixia Guo, Ligang Yu
February 21, 2023 (v1)
Subject: Materials
Keywords: Adsorption, methylene blue (MB), moringa seed shells, ultrasonic-assisted impregnation
In recent years, more and more biochars have been employed to treat dye wastewater. In order to increase the utilization of moringa seed shell resources and enrich the removal method of methylene blue (MB) in solution, in the current study, the magnetic moringa seed shells biochar was prepared through ultrasonic-assisted impregnation and pyrolysis, while Fe3O4 was used to activate the material to obtain adsorption (Fe3O4-MOS). The prepared adsorbents were characterized by SEM-EDS, XRD, XPS, FTIR, N2 adsorption and desorption and VSM. Under the suitable experimental conditions, the removal rate can be close to 100% and the maximum adsorption capacity of MB could be 219.60 mg/g. The Freundlich model provided a good match to the data presented by the adsorption isotherm, and the adsorption of MB on Fe3O4-MOS was a spontaneous and endothermic reaction. Study of the mechanism indicated that pore adsorption, electrostatic interaction, hydrogen bond, and π-π interaction were the major adsorpt... [more]
Experimental Characterization of a Microfluidic Device Based on Passive Crossflow Filters for Blood Fractionation
Inês M. Gonçalves, Inês Castro, Filipe Barbosa, Vera Faustino, Susana O. Catarino, Ana Moita, João M. Miranda, Graça Minas, Patrícia C. Sousa, Rui Lima
February 21, 2023 (v1)
Subject: Materials
Keywords: blood analogue, blood on chip, cell separation, crossflow microfluidic device, optical absorbance spectrophotometry, passive microfluidic device
The separation of red blood cells (RBCs) from blood plasma and the analysis of individual RBCs are of great importance, as they provide valuable information regarding the health of their donor. Recent developments in microfluidics and microfabrication have contributed to the fabrication of microsystems with complex features to promote the separation and analysis of RBCs. In this work, the separation capacity of a multi-step crossflow microfluidic device was evaluated by using a blood analogue fluid made by Brij L4 micelles and human RBCs separated from whole blood, suspended in a solution with hematocrits (Ht) of 0.5 and 1%. All the samples collected at the outlets of the device were experimentally analyzed and compared. The absorbance spectrum was also measured for the prepared blood samples. The results indicate that the tested blood analogue fluid has exhibited a flow behavior similar to that of blood. In addition, the optical absorbance spectrophotometry revealed that it was possib... [more]
Exploration of Cucumber Waste as a Potential Biorefinery Feedstock
Yang Gao, Hannah K. Briers, Avtar S. Matharu, Jiajun Fan
February 21, 2023 (v1)
Subject: Materials
Keywords: biorefinery, cellulosic materials, cucumber, essential oils, hydro-distillation, vacuum microwave hydro-distillation
The exploration of cucumber waste as a potential biorefinery feedstock is reported. Initially, extractives (essential oils) were isolated from cucumber waste via vacuum microwave hydro-distillation (VMHD). The yield and quality of the extractive were compared with respect to traditional hydro-distillation (HD). The essential oils were obtained over a range of microwave power (500, 750, 1000 W) and vacuum pressures (100, 200, 300 mbar). The highest quality (0.49 wt %) was obtained at a microwave irradiation power of 500 W and a vacuum of 300 mbar. VMHD is much quicker and more energy-efficient than HD. Within the context of a zero-waste biorefinery, the extractive-free residues were the solid residues from two different extraction methods were compared and characterized by ATR-IR, 13C solid-state NMR spectroscopy, SEM, TGA, and CHN elemental analysis. The resultant residues are cellulosic-rich, and no significant changes were observed with VMHD and HD treatment. The results indicated th... [more]
Insight into the Acidity and Catalytic Performance on Butane Isomerization of Thermal Stable Sulfated Monoclinic Zirconia
Daofeng Huang, Wenhua Feng, Li Zhang, Bin Yue, Heyong He
February 21, 2023 (v1)
Subject: Materials
Keywords: butane isomerization, monoclinic, solid-state NMR, sulfated zirconia
Sulfated monoclinic zirconia (M-SZ) with high thermal stability and high catalytic performance on butane isomerization were obtained by hydrothermal method followed with sulfation treatment. The acidity of M-SZ was studied by 31P MAS NMR, with trimethylphosphine (TMP) as the probe molecule, and the catalytic performance of 1-13C-n-butane over M-SZ was monitored by 13C MAS NMR spectroscopy. Both Brønsted and Lewis acids were observed on M-SZ. Only Brønsted acid strength shows close relation to the activation energy of butane isomerization, and the M-SZ catalyst with the strongest Brønsted acid strength shows the lowest activation energy of 46.4 kJ·mol−1. The catalytic stability tests were evaluated at 673 K for 240 h, which shows that sulfated monoclinic zirconia has higher thermal stability than sulfated tetragonal zirconia.
Investigation of Catalytic and Photocatalytic Degradation of Methyl Orange Using Doped LaMnO3 Compounds
Paula Sfirloaga, Madalina-Gabriela Ivanovici, Maria Poienar, Catalin Ianasi, Paulina Vlazan
February 21, 2023 (v1)
Subject: Materials
Keywords: Catalysis, doping, kinetic parameters, MO degradation, perovskite
LaMnO3 and 1% Pd-, Ag-, or Y-doped perovskite type nanomaterials were prepared by the sol-gel method, followed by heat treatment at a low temperature (600 °C for 6 h). The investigation through X-ray diffraction and FT-IR spectroscopy indicated that all samples were well crystallized, without secondary phases, and that the transition metal doping changed the crystal structure from the R-3c space group for the undoped LaMnO3 to the Pm-3m space group for the doped perovskite compounds. In this research paper, the efficiencies of the perovskite LaMnO3 materials for methyl orange removal were analyzed, wherein the effect of the doping ions and of the pH on the catalytic activity were studied together with a kinetic approach for the LaMnO3 materials at different values of the pH. Moreover, in the catalytic activity, it should be noted that a slightly better performance was obtained for the Ag-doped materials compared to the Y- and Pd-doped perovskite samples. The results presented for the p... [more]
How to Choose the Suitable Steel of Wellhead, Wellbore, and Downhole Tools for Acid Gas Reinjection Flooding
Yudi Geng, Zhendong Liu, Wenguang Zeng, Yibo Feng, Baodong Ding, Wenxia Li, Qinying Wang
February 21, 2023 (v1)
Subject: Materials
Keywords: acid gas reinjection flooding, CO2-H2S corrosion, material selection scheme, packer device, pitting corrosion
The material selection of injection gas wells in acid gas flooding is the bottleneck of the successful implementation of the technical scheme. Through standard and literature research, the materials of the wellhead, wellbore, and packer for reinjection well in acid gas flooding are preliminarily established, and then the suitable materials are further screened by using the weight-loss and surface characterization method. Finally, a new type of packer is designed to optimize the wellbore material. The results show that 35CrMo (CR = 0.0589 mm/y) steel is used for wellhead materials, 625 alloy steel is selected as the sealing surface, and 625 or 825 alloys (with CR ≤ 0.0055 mm/y) steel is used for wellhead sealing material. The main material of the packer is 718 Alloy (with CR ≤ 0.0021 mm/y). The cost of T95 steel within 20 years (1263 ten thousand yuan) of service is much smaller than that of G3 alloy (1771 ten thousand yuan), but after 30 years of service, its cost is close to that of G... [more]
Cavity Size Effect on Host-Guest Property of Tiara-like Structural Mn(SR)2n Nanoclusters Probed by NMR Spectroscopy
Changlin Zhou, Shida Gong, Jishi Chen, Zonghua Wang
February 21, 2023 (v1)
Subject: Materials
Keywords: cavity size effect, host-guest property, Mn(SR)2n, NMR, tiara-like structure
The lack of detect technology hinders the understanding of host-guest (H-G) chemical properties for thiolate-protected tiara-like structural nanoclusters (Mn(SR)2n). In this work, NMR spectroscopy is demonstrated as a powerful tool to probe the H-G structure of Mn(SR)2n both experimentally and theoretically. A low-field shifting and wide chemical shift (CS) signal of the H nucleus in CH2Cl2 is observed in the NMR spectrum of the mixture of CH2Cl2 and Pd8(PET)16 (PET is 2-phenylethanethiol), agreeing with the theoretical results that a deshielding area appears in the central cavity of Pd8(SR)16. All Mn(SR)2n own similar nucleus-independent chemical shift maps and deshielding cavities, which means that the H nucleus in small molecules trapped by Mn(SR)2n should have consistent low-field shifted CSs. However, such a phenomenon was only observed in the NMR spectrum of the mixed solution of Pd8(SR)16 and CH2Cl2, indicating that Pd8(SR)16 is the only one in the series of Pdn(SR)2n (n = 4~16)... [more]
Determination of 7 Kinds of Alkaloids in Semen Nelumbinis and Its Products by HPLC
Feifei Zhong, Li Ouyang, Nan Deng, Fangping Yin, Jiajie He, Deqing Lei, Jieying Gao, Hui Zeng, Zhaoxia Wang, Lu Wang, Lixia Yang, Hui Zhou
February 21, 2023 (v1)
Subject: Materials
Keywords: alkaloids, high performance liquid chromatography (HPLC), Semen Nelumbinis, single factor experiment
Objective: To establish a method for the simultaneous determination of seven alkaloids in Semen Nelumbinis and its products, the extraction technology and HPLC method were optimized by the single factor experiment. Methods: Firstly, the samples were extracted ultrasonically with 1% formic acid ethanol and purified by PXC SPE column. Then, the extracts and the purified liquid were taken after concentration with nitrogen for quantitative analysis of seven alkaloids by HPLC method. Next, the contents of alkaloids in five samples were determined. Results: The method was fully validated and the result showed that seven kinds of alkaloids had good linear relation in the corresponding range of mass concentration, r2 > 0.999, where the detection limit was 0.5−1.5 mg/kg, the quantification limit was 1.25−4.5 mg/kg, the recovery was 83.33−116.04%, and the RSD of detection method was 1.06−5.25% (n = 7). In five samples, the contents of Lotusine and Neferine were the highest, Berberine Hydrochlori... [more]
Application Status and Development Trend of Continuous Casting Reduction Technology: A Review
Yi Nian, Liqiang Zhang, Chaojie Zhang, Naqash Ali, Jianhua Chu, Jiale Li, Xiang Liu
February 21, 2023 (v1)
Subject: Materials
Keywords: center segregation, continuous casting billet, heavy reduction technology (HR), soft reduction technology (SR)
Continuous casting is a dominant steelmaking process due to its steady-state nature, enhanced yield of steel production, and low consumption of energy and manpower. However, the production of defect-free cast products is still a big challenge, as the internal defects, including macro-segregation of alloying elements, cracks, and pores, can be easily formed during the solidification process, which seriously deteriorates the microstructure and mechanical properties of the cast products. Therefore, this paper puts forward the common solutions to overcome these problematic issues. The reduction technology can effectively improve the center segregation of the billet, bloom, and slab. The history of the development of the reduction technology is summarized and classified according to the variations in research trend. Furthermore, the basic principles and parameters of reduction technology are described to implement them in the actual production process. This paper compares the similarities a... [more]
Catalytic Pyrolysis of Waste Plastics over Industrial Organic Solid-Waste-Derived Activated Carbon: Impacts of Activation Agents
Kezhen Qian, Wenmin Tian, Wentao Li, Shutong Wu, Dezhen Chen, Yuheng Feng
February 21, 2023 (v1)
Subject: Materials
Keywords: Carbon, Catalysis, industrial organic solid waste, pyrolysis of plastics
Renewable source-derived carbon is found to be a green alternative catalyst to zeolite for the pyrolysis of plastics. However, only polyethylene (PE) catalytic pyrolysis over biomass-derived carbon has been extensively studied. In this work, carbon was produced from industrial organic solid waste using different activation agents, and their catalytic performance on the thermal degradation of typical polymers, namely PE, polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET) were investigated. The degradation mechanisms and the roles of different active sites of the carbons are discussed. Steam failed to activate the carbon, which has a low specific surface area (6.7 m2/g). Chemical activation using H3PO4 and ZnCl2 produces carbons with higher specific surface area and more porosity. The pyrolysis characteristics of LDPE, PP, PS, and PET catalyzed by the carbons were studied using TGA and a fixed-bed reactor. The thermogravimetric results indicate that all three carb... [more]
Recent Advances in Lithium Extraction Using Electrode Materials of Li-Ion Battery from Brine/Seawater
Jianpeng Sun, Dongdong Liang, Xiangchao Meng, Zizhen Li
February 21, 2023 (v1)
Subject: Materials
Keywords: electrochemical, electrode materials, lithium, mechanism, systems
With the rapid development of industry, the demand for lithium resources is increasing. Traditional methods such as precipitation usually take 1−2 years, and depend on weather conditions. In addition, electrochemical lithium recovery (ELR) as a green chemical method has attracted a great deal of attention. Herein, we summarize the systems of electrochemical lithium extraction and the electrode materials of the Li-ion battery from brine/seawater. Some representative work on electrochemical lithium extraction is then introduced. Finally, we prospect the future opportunities and challenges of electrochemical lithium extraction. In all, this review explores electrochemical lithium extraction from brine/seawater in depth, with special attention to the systems and electrode of electrochemical lithium extraction, which could provide a useful guidance for reasonable electrochemical-lithium-extraction.
Numerical Analysis of Heat Transfer Enhancement Due to Nanoparticles under the Magnetic Field in a Solar-Driven Hydrothermal Pretreatment System
Yang Yu, Kai Wang, Yurong Zhao, Qicheng Chen, Nanhang Dong
February 21, 2023 (v1)
Subject: Materials
Keywords: heat transfer enhancement, magnetic field, microalgae, nanofluids, numerical simulation
Solar-driven hydrothermal pretreatment is an efficient approach for the pretreatment of microalgae biomass for biofuel production. In order to enhance the heat transfer, the magnetic fields effects on flow and heat transfer of nanofluids were investigated in a three-dimensional circular pipe. The magnetic fields were applied in different directions and magnetic field intensities to the flow. In this paper, Finite Volume Method was used to simulate flow and heat transfer of nanofluids under a magnetic field, and the Discrete Phase Model was selected to calculate two-phase flow, which was water mixed with metal nanoparticles. The research was also carried out with the various physical properties of nanoparticles, including the volume share of nanoparticles, particle diameter, and particle types. When the magnetic fields were applied along the X, Y, and Z directions and the intensity of magnetic fields was 0.5 T, the heat transfer coefficients of Cu-H2O nanofluids flow were increased even... [more]
Cytotoxicity and Thermal Characterization Assessment of Excipients for the Development of Innovative Lyophilized Formulations for Oncological Applications
Francesca Susa, Tania Limongi, Michela Millone, Valentina Cauda, Roberto Pisano
February 21, 2023 (v1)
Subject: Materials
Keywords: biopharmaceuticals, cytotoxicity, drug formulations, excipient, freeze-drying, lyophilization
Freeze-drying, also known as lyophilization, significantly improves the storage, stability, shelf life, and clinical translation of biopharmaceuticals. On the downside, this process faces complex challenges, i.e., the presence of freezing and drying stresses for the active compounds, the uniformity and consistency of the final products, and the efficiency and safety of the reconstituted lyophilized formulations. All these requirements can be addressed by adding specific excipients that can protect and stabilize the active ingredient during lyophilization, assisting in the formation of solid structures without interfering with the biological and/or pharmaceutical action of the reconstituted products. However, these excipients, generally considered safe and inert, could play an active role in the formulation interacting with the biological cellular machinery and promoting toxicity. Any side effects should be carefully identified and characterized to better tune any treatments in terms of... [more]
Dependence of the Atomic Structure of Solid Solutions in the Pd-Cu System Ordered According to the B2 Type on the Composition
Valentin M. Ievlev, Konstantin A. Solntsev, Alexander L. Vasiliev, Semen V. Gorbunov, Alexey I. Dontsov, Nataliya R. Roshan, Sergey V. Kannykin, Alexey V. Ovcharov, Bugakov V. Alexander
February 21, 2023 (v1)
Subject: Materials
Keywords: hydrogen permeability, ordering, Pd–Cu system, solid solution, structure
Owing to exceptionally high selectivity, membranes based on palladium alloys are widely used for obtaining high-purity hydrogen. An important issue for providing high hydrogen permeability of the membranes is to form the required phase composition. The structural organization of the solid solutions consisting of Cu−36.4 at .% Pd and Cu−50 at .% Pd were studied by X-ray diffraction (XRD), electron diffraction (ED), high-resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray spectroscopy (EDXS). It was found that the former composition can be ordered in the temperature range of 300−400 °C and in the heating (up to 800 °C)−cooling cycle. In the presence of excess Cu atoms (27.2%), this structure can be represented by CsCl type structural units (β-phase) and distributed body center cubic (BCC) copper structural units in the corresponding concentration dose. The formation of a single crystal ordered phase within the mosaic blocks of the disordered phase was establis... [more]
Microstructure and Magnetic Properties Dependence on the Sputtering Power and Deposition Time of TbDyFe Thin Films Integrated on Single-Crystal Diamond Substrate
Zhenfei Lv, Xiulin Shen, Jinxuan Guo, Yukun Cao, Chong Lan, Yanghui Ke, Yixian Yang, Junyi Qi
February 21, 2023 (v1)
Subject: Materials
Keywords: magnetic properties, microstructure, single-crystal diamond, TbDyFe, thin film
As giant magnetostrictive material, TbDyFe is regarded as a promising choice for magnetic sensing due to its excellent sensitivity to changes in magnetic fields. To satisfy the requirements of high sensitivity and the stability of magnetic sensors, TbDyFe thin films were successfully deposited on single-crystal diamond (SCD) substrate with a Young’s modulus over 1000 GPa and an ultra-stable performance by radio-frequency magnetron sputtering at room temperature. The sputtering power and deposition time effects of TbDyFe thin films on phase composition, microstructure, and magnetic properties were investigated. Amorphous TbDyFe thin films were achieved under various conditions of sputtering power and deposition time. TbDyFe films appeared as an obvious boundary to SCD substrate as sputtering power exceeded 100 W and deposition time exceeded 2 h, and the thickness of the films was basically linear with the sputtering power and deposition time based on a scanning electron microscope (SEM)... [more]
Elimination of PCDD/Fs over Commercial Honeycomb-Like Catalyst of V2O5-MoO3/TiO2 at Low Temperature: From Laboratory Experiments to Field Study
Jianwen Lai, Yunfeng Ma, Jiayao Wu, Hong Yu, Xiaodong Li, Xiaoqing Lin
February 21, 2023 (v1)
Subject: Materials
Keywords: de-chlorination effect, field study, laboratory study, PCDD/Fs, V2O5-MoO3/TiO2 catalyst
With the need for ultra-low emissions and the strict regulation of PCDD/Fs from MSWI plants, traditional SCR catalysts have been applied to remove PCDD/Fs. In this study, we compared one typical commercial V2O5-MoO3/TiO2 catalyst’s performance in removing PCDD/Fs under laboratory and industrial conditions. Various characterization methods like XRF, XPS, BET, and H2-TPR were applied to analyze the catalyst’s properties. The laboratory results showed that the adsorption could significantly affect the removal at low temperatures. The RE on PCDD/Fs was 59.4% (55.0% for toxicity RE), 88.5% (90.3%), and 78.0% (76.0%) at 160 °C, 180 °C, and 200 °C, respectively, showing that 180 °C is the most suitable operation temperature for this V2O5-MoO3/TiO2 catalyst. The field study was conducted at 180 °C, and the results revealed that the competition between water vapor and the interaction of SO2 could lower the RE. However, comparisons between laboratory and field conditions showed that this V2O5-Mo... [more]
Cutting Force Prediction for Trochoid Milling of 300M Ultra-High Strength Steel
Ke Zhou, Changming Zhang, Siyuan Du
February 21, 2023 (v1)
Subject: Materials
Keywords: 300M steel, chip thickness, milling forces, prediction model, trochoid milling
Trochoid milling can improve the quality of machining of difficult materials as well as the efficiency of machining. However, its complex tool trajectory makes it difficult to predict the instantaneous cutting forces during cutting. Therefore, in this paper, the transient cutting thickness model in the cycloidal milling process was established using numerical combined with analytical methods, and the semi-mechanical cutting force model was established. Experiments were designed to compare the differences between the cutting force coefficients extracted from the slot milling experiments and those extracted from the trochoid milling. Finally, experiments were designed to validate the established cutting force model. The results showed that there was an error of 5−23% between the tangential cutting force coefficients extracted from slot milling and the tangential cutting force coefficients extracted from trochoid milling, while there was an error of 21−35% in the radial cutting force coef... [more]
Which Is an Appropriate Quadratic Rheological Model of Fresh Paste, the Modified Bingham Model or the Parabolic Model?
Mengyuan Li, Peiyu Yan, Jianguo Han, Lijie Guo
February 21, 2023 (v1)
Subject: Materials
Keywords: cementitious materials, fresh paste, modified Bingham model, parabolic model, rheological parameter, the Couette inverse problem
The physical meaning and calculating process of the rheological parameters of two nonlinear rheological models, the parabolic model and the modified Bingham model, were compared. The fluidity test and a rheological experiment on cementitious materials were performed. The Couette inverse problem is a key issue in measuring and solving the rheological parameters of fresh cementitious materials. The solution of the Couette inverse problem based on the modified Bingham model is discontinuous when the coefficient of the quadratic term is equal to zero, resulting in a large deviation between the fitting curve and the rheological experimental data. The credibility of the rheological parameters of the pastes calculated based on the modified Bingham model is low. The formulas for calculating yield stress, fiducial differential viscosity and the degree of shear thickening or shear thinning of the parabolic model have been developed. The credibility of the rheological parameters of the pastes cal... [more]
Non-Woven Filters Made of PLA via Solution Blowing Process for Effective Aerosol Nanoparticles Filtration
Anna Jackiewicz-Zagórska, Karol Mika, Agata Penconek, Arkadiusz Moskal
February 21, 2023 (v1)
Subject: Materials
Keywords: air cleaning, nanofibers, nanoparticles filtration, non-woven filter, PLA, solution blow spinning
With the development of civilization, the awareness of the impact of versatile aerosol particles on both human health and the environment is growing. New materials are needed to purify the air to control this impact The aspect of processing the produced waste is not negligible. In view of the above, this study proposes utilizing the solution blow spinning process (SBS) for manufacturing a biodegradable filtration structure that ensures high efficiency of nanoobject filtration, with a low pressure drop. Polylactic acid (PLA) was used to produce a nanofiber layer on the coconut substrate. The advantage of this method is the ability to blow fibers with diameters in the nano-scale, applying relatively simple, cost-effective, and easy to scale-up equipment. This work selected appropriate process parameters to produce good quality filters. Moreover, the process conditions influence on the morphology of the obtained structures and, thus, also the filtration properties, were examined. For test... [more]
From Synthetic Route of Silica Nanoparticles to Theranostic Applications
Pragya Pallavi, Karthick Harini, Sultan Alshehri, Mohammed M. Ghoneim, Areej Alshlowi, Pemula Gowtham, Koyeli Girigoswami, Faiyaz Shakeel, Agnishwar Girigoswami
February 21, 2023 (v1)
Subject: Materials
Keywords: diagnosis, nanomedicine, silica nanoparticles, synthesis, therapy
The advancements in nanotechnology have quickly developed a new subject with vast applications of nanostructured materials in medicine and pharmaceuticals. The enormous surface-to-volume ratio, ease of surface modification, outstanding biocompatibility, and, in the case of mesoporous nanoparticles, the tunable pore size make the silica nanoparticles (SNPs) a promising candidate for nano-based medical applications. The preparation of SNPs and their contemporary usage as drug carriers, contrast agents for imaging, carrier of photosensitizers (PS) in photodynamic, as well as photothermal treatments are intensely discussed in this review. Furthermore, the potential harmful responses of silica nanoparticles are reviewed using data obtained from in vitro and in vivo experiments conducted by several studies. Moreover, we showcase the engineering of SNPs for the theranostic applications that can address several intrinsic limitations of conventional therapeutics and diagnostics. In the end, a p... [more]
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