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Showing records 3270 to 3294 of 4494. [First] Page: 1 128 129 130 131 132 133 134 135 136 Last
Advanced Characterization of Organic Matter Decaying during Composting of Industrial Waste Using Spectral Methods
Saloua Biyada, Mohammed Merzouki, Hamada Imtara, Mohamed F. Alajmi, Karima Elkarrach, Hamza Mechchate, Raffaele Conte, Mohamed Benlemlih
February 23, 2023 (v1)
Subject: Materials
Keywords: cellulose, compost, maturity, PLS-R, scanning electron microscopy, spectroscopy analysis, textile waste
To date, compost maturation monitoring is carried out by physical-chemical and microbiological analysis, which could be considered an overweening consumption of time and products. Nowadays, spectroscopy is chosen as a simple tool for monitoring compost maturity. In the present investigation, spectroscopy analysis was performed in the interest of corroborating the compost maturity. This goal was achieved by using the X-ray diffraction, infrared spectroscopy, and scanning electron microscopy. X-ray diffraction analysis showed the presence of the cellulose fraction in compost samples. At the same time, the intensity of pics decreased depending on composting time, thus proving that there was organic matter degradation. Infrared and scanning electron microscopy analysis allow for confirming these results. The correlation between spectroscopies analysis and physical-chemical properties was employed by partial least squares-regression (PLS-R) model. PLS-R model was applied to build a model to... [more]
Conductive Compartmented Capsules Encapsulating a Bitumen Rejuvenator
Amir Tabaković, Joseph Mohan, Aleksandar Karač
February 23, 2023 (v1)
Subject: Materials
Keywords: alginate, bitumen healing, conductive alginate capsules, conductivity, induction heating, rejuvenation, self-healing
This paper explores the potential use of conductive alginate capsules encapsulating a bitumen rejuvenator as a new extrinsic self-healing asphalt method. The capsules combine two existing self-healing asphalt technologies: (1) rejuvenator encapsulation and (2) induction heating to create a self-healing system that will provide rapid and effective asphalt pavement repair. The work presents a proof of concept for the encapsulation process, which involves embedding the capsules into the bitumen mortar mixture and the survival rate of the capsules in the asphalt mixture. A drip capsule production process was adopted and scaled up to the production of 20l wet capsules at rate of 0.22 l/min. To prove the effectiveness and its ability to survive asphalt production process, the capsules were prepared and subjected to thermogravimetric analysis (TGA) and uniaxial compression Test (UCT). The test results demonstrated that the capsules had suitable thermal characteristics and mechanical strength... [more]
Improvement of Enzymatic Saccharification of Cellulose-Containing Raw Materials Using Aspergillus niger
Ekaterina Budenkova, Stanislav Sukhikh, Svetlana Ivanova, Olga Babich, Vyacheslav Dolganyuk, Philippe Michaud, Olga Kriger
February 23, 2023 (v1)
Subject: Materials
Keywords: Aspergillus niger, bioethanol, cellulase activity, cellulose-containing raw materials, enzymatic hydrolysis, ultraviolet treatment
Enzymatic hydrolysis of cellulose-containing raw materials, using Aspergillus niger, were studied. Filter paper, secondary cellulose-containing or starch-containing raw materials, miscanthus cellulose after alkaline or acid pretreatment, and wood chip cellulose, were used as substrates. The study focused on a wild A. niger strain, treated, or not (control), by ultraviolet (UV) irradiations for 45, 60, or 120 min (UV45, UV60, or UV120), or by UV irradiation for 120 min followed by a chemical treatment with NaN3 + ItBr for 30 min or 80 min (UV120 + CH30 or UV120 + CH80). A mixture of all the A. niger strains (MIX) was also tested. A citrate buffer, at 50 mM, wasthe most suitable for enzymatic hydrolysis. As the UV exposure time increased to 2 h, the cellulase activity of the surviving culturewas increased (r = 0.706; p < 0.05). The enzymatic activities of the obtained strains, towards miscanthus cellulose, wood chips, and filter paper, were inferior to those obtained with commercial e... [more]
Analysis of the Performance of a Solar Thermoelectric Generator for Variable Leg Geometry with Nanofluid Cooling
Cristian Francisco Ramos-Castañeda, Miguel Angel Olivares-Robles, Juan Vicente Méndez-Méndez
February 23, 2023 (v1)
Subject: Materials
Keywords: convection coefficient, nanofluids, radiation heat, solar-thermoelectric generator (Solar-TEG), thermal concentration ratio
In this study, the impact of nanofluid use in solar-thermoelectric generators (Solar-TEG) on thermal performance is investigated through analysis and simulation methodology. For conventional cooling analysis, we use air as a coolant and graphene nanoplatelet aqueous nanofluids (GNAN) for nanofluid cooling. We make a comparison between traditional and nanofluid cooling to find the best performance. GNAN at a dispersion of 0.025, 0.05, 0.075, and 0.1-wt% are added to the cooling system. GNAN has been used in the technological development of energy conversion. It has been proposed as a material to achieve better efficiency in Solar-TEG. Five different geometries are developed to analyze the efficiency in a Solar-TEG to find the optimal design. The impact of the thermal concentration relationship, substrate area, and convective transfer coefficient on Solar-TEG performance is investigated. To simplify and speed up simulations, we use equivalent models based on FEM. We are considering the p... [more]
Phytosynthesis of Copper Nanoparticles Using Extracts of Spices and Their Antibacterial Properties
Gayathri Vijayakumar, Hindhuja Kesavan, Anisha Kannan, Dhanalakshmi Arulanandam, Jeong Hee Kim, Kwang Jin Kim, Hak Jin Song, Hyung Joo Kim, Senthil Kumaran Rangarajulu
February 23, 2023 (v1)
Subject: Materials
Keywords: antimicrobial activity, copper nanoparticles, green synthesis, spice extract, zone of inhibition
To prevent microbial growth, chemical solvents are typically utilized. However, chemical solvents are hazardous to human health with low antimicrobial effects. Metallic-element (such as copper, silver, and gold) nanoparticles have many applications in biotechnology and biomedicine. Copper nanoparticles (CuNPs) are efficient owing to their antimicrobial, anti-inflammatory, and anti-proliferative properties. The objective of this study was to perform biogenic synthesis of copper nanoparticles using three different spices (star anise, seed of Illicium verum; nutmeg, seed of Myristica fragrans; and mace, membrane covering the seed of Myristica fragrans) and determine their antibacterial properties. CuNPs of spices were prepared by dissolving copper sulfate in the respective plant extract. They were then characterized by UV-Vis spectroscopy, FTIR, GC-MS, EDAX, and SEM analysis. Results of UV-Vis spectroscopy showed the maximum absorbance peak at 350 nm. SEM analysis showed that the sizes of... [more]
Effect of  Nb5+ and In3+  Ions on Moisture Sensitivity of Electrospun Titanium/Tungsten Oxide Nanostructures: Microstructural Characterization and Electrical Response
Georgenes M. G. Silva, Victor N. S. Leão, Michel F. G. Pereira, Pedro M. Faia, Evando S. Araújo
February 23, 2023 (v1)
Subject: Materials
Keywords: characterization, electrospinning, mixed metal oxide, nanostructures, preparation
In this work, Nb5+ and In3+ ions were used as dopants in titanium/tungsten oxide nanostructures that are produced by the electrospinning and sintering process, for relative humidity (RH) detection. The microstructural properties were investigated by SEM, EDS, XRD, Raman and FTIR techniques. The electrical response characterization of the samples was performed by electrical impedance spectroscopy in the range of 400 Hz to 40 MHz, at 20 °C. The sensors sensitivity to moisture was evaluated in terms of the impedance variations to RH (10−100%). The combined analysis of the microstructural characterization results confirmed the surface interaction between the oxides and the ions incorporation in Ti crystal lattice. All the studied sensors showed a conduction transition from p- to n-type at around 30−40% RH: besides, they also displayed better sensitivity to moisture than those obtained in a previous work using titanium/tungsten combination using a different fabricationn route... [more]
Impact of Ballast Fouling on the Mechanical Properties of Railway Ballast: Insights from Discrete Element Analysis
Luyu Wang, Mohamed Meguid, Hani S. Mitri
February 23, 2023 (v1)
Subject: Materials
Keywords: ballast degradation, micro-mechanical parameters, railway ballast fouling, shear strength
Ballast fouling is a major factor that contributes to the reduction of shear strength of railway ballast, which can further affect the stability of railway supporting structure. The major sources of ballast fouling include infiltration of foreign fines into the ballast material and ballast degradation induced by train movement on the supported tracks. In this paper, a discrete element model is developed and used to simulate the shear stress−strain response of fouled ballast assembly subjected to direct shear loading. A simplified computational approach is then proposed to model the induced ballast fouling and capture the mechanical response of the ballast at various levels of contamination. The approach is based on the assumption that fine particles comprising the fouling material will not only change the interparticle friction angle, but also the contact stiffness between the ballast particles. Therefore, both the interparticle friction coefficient and effective modulus are adjusted b... [more]
Stem Bark Extract as a Green Corrosion Inhibitor for Mild Steel in Acid Medium
Aparecida Cristina Mauro, Bernardo Dias Ribeiro, Rafael Garrett, Ricardo Moreira Borges, Talis Uelisson da Silva, Sérgio de Paula Machado, Joyce Rodrigues de Araujo, Sanair de Oliveira Massafra, Francisco Odencio Rodrigues de Oliveira Junior, Eliane D’Elia
February 23, 2023 (v1)
Subject: Materials
Keywords: corrosion inhibitor, electrochemical measurements, LC-MS, mild steel, Ziziphus joazeiro stem bark extract
The aqueous extract of Joazeiro stem bark (EJSB) and its high molecular weight fraction (HMWF) were examined as potential corrosion inhibitors of mild steel in 1 mol L−1 hydrochloric acid media, using weight-loss measurements, potentiodynamic polarization curves and an electrochemical impedance spectroscopy (EIS).Varying the concentration of the inhibitors from 100 to 800 mg L−1, the results show an increase in anticorrosive efficiency from 85.4 to 89.8 and 89.8 to 93.0% for EJSB and its HMWF, respectively, using the data of the gravimetric essay, and from 84.5 to 94.5 and 89.9 to 94.7% for EJSB and its HMWF, respectively, from the impedance data. The composition of the crude extract was chemically characterized by liquid chromatography-high resolution mass spectrometry. Additionally, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used, respectively, to morphologically and chemically characterize the surface. Considering that the saponin molecules, t... [more]
A Bibliometric Survey on Polyisobutylene Manufacture
Jessica B. Alves, Mateus K. Vasconcelos, Lys H. R. Mangia, Maxmiliano Tatagiba, Juliana Fidalgo, Daniela Campos, Pedro L. Invernici, Marcio V. Rebouças, Marcio Henrique S. Andrade, José Carlos Pinto
February 23, 2023 (v1)
Subject: Materials
Keywords: cationic polymerization, HR-PIB, PIB, polyisobutylene
Polyisobutylenes (PIB) constitute a versatile family of polymer materials that have been used mainly as fuel and lubricant additives. Particularly, the current commercial demand for highly reactive polyisobutylene (HR-PIB) products motivates the development of new processes and procedures to produce PIBs with high polymer yields, narrow molar mass distributions and high vinyl contents. For this reason, a bibliometric survey is presented here to map and discuss important technical aspects and technological trends in the field of solution cationic polymerization of isobutylenes. It is shown that investigations in this field are concentrated mainly on developed countries and that industrial initiatives indicate high commercial interest and significant investments in the field. It is also shown that use of catalyst systems based on AlCl3 and ether cocatalysts can be very beneficial for PIB and HR-PIB manufacture. Finally, it is shown that investigations search for cheaper and environmental... [more]
Rapid, Sensitive, and Sustainable Reversed-Phase HPTLC Method in Comparison to the Normal-Phase HPTLC for the Determination of Pterostilbene in Capsule Dosage Form
Prawez Alam, Faiyaz Shakeel, Mohammed H. Alqarni, Ahmed I. Foudah, Md. Faiyazuddin, Sultan Alshehri
February 23, 2023 (v1)
Subject: Materials
Keywords: AGREE score, pterostilbene, sustainable HPTLC, validation
The greenness evaluation of literature analytical methods for pterostilbene (PT) analysis was not performed. Accordingly, the rapid, sensitive, and green/sustainable reversed-phase high-performance thin-layer chromatography (RP-HPTLC) method was developed and compared to the normal-phase (NP)-HPTLC (NP-HPTLC) for the estimation of PT with a classical univariate calibration. The RP quantification of PT was performed using green solvent systems; however, the NP analysis of PT was performed using routine solvent systems. The PT was detected at 302 nm for both of the methods. The greenness scores for the current analytical assays were evaluated by the analytical GREEnness (AGREE) metric approach. The classical univariate calibration for RP and NP methods indicated the linearity range as 10−1600 and 30−400 ng band−1, respectively. The RP method was more reliable for PT analysis compared to the NP method. The PT contents in commercial capsule dosage form were found to be 100.84% using the RP... [more]
Green Synthesis of Silver Nanoparticles Using Extract of Artemisia absinthium L., Humulus lupulus L. and Thymus vulgaris L., Physico-Chemical Characterization, Antimicrobial and Antioxidant Activity
Aiste Balciunaitiene, Pranas Viskelis, Jonas Viskelis, Paulina Streimikyte, Mindaugas Liaudanskas, Elena Bartkiene, Paulina Zavistanaviciute, Egle Zokaityte, Vytaute Starkute, Modestas Ruzauskas, Vita Lele
February 23, 2023 (v1)
Subject: Materials
Keywords: A. absinthium, green synthesis, H. lupulus, plant extracts, silver nanoparticles, T. vulgaris
The novelty of this study is twofold: AgNPs were obtained and characterized using Artemisia absinthium (A. absinthium), Humulus lupulus (H. lupulus), and Thymus vulgaris (T. vulgaris) plants extracts; moreover, a green and environmentally friendly approach for the synthesis of silver nanoparticles (AgNPs) using aqueous extracts was developed. This paper discusses new approaches about the synthesis of AgNPs. T. vulgaris, H. lupulus, and A. absinthium, which are renewable and common plants, perfect as reducing, stabilizing, and capping agent for green synthesis of silver nanoparticles (AgNPs). The extracts and synthesized AgNPs were characterized by various physico-chemical, phytochemical, morphological scanning electron microscope (SEM/EDS) and transmission electron microscope scanning (TEM), and antibacterial activity. The antioxidant activity of extracts and AgNPs were also assessed by 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+), 2,2-diphenyl-1-picrylhydrazyl (DPP... [more]
Study of Creep Mechanical Properties and a Rheological Model of Sandstone under Disturbance Loads
Xiaofeng Li, Zhixiang Yin
February 23, 2023 (v1)
Subject: Materials
Keywords: constitutive model, creep, creep characteristics, disturbance load, sandstone
The stress environments of rock masses are complex. To explore the mechanical properties of sandstone under earthquake or disturbance loads, laboratory triaxial creep tests under different disturbance loads were conducted on sandstone from Fuxin, Liaoning Province, China. Given the disturbance load, a creep deformation pattern for sandstone was analyzed, and the influence of the disturbance load on the mechanical properties of rock was considered. Thus, a constitutive model of rock under creep disturbance load was established. The results show that (1) the creep curve can be divided into four stages: attenuation creep, steady creep, disturbance creep, and acceleration creep; the increment of disturbance creep varies for different disturbance loads and the larger the disturbance load, the larger the disturbance creep deformation; (2) with increasing disturbance loads, the long-term strength, failure time, and elastic modulus of sandstone decreases linearly, while the peak strain increas... [more]
Selective Gold and Palladium Adsorption from Standard Aqueous Solutions
Paolo Trucillo, Ernesto Di Maio, Amedeo Lancia, Francesco Di Natale
February 23, 2023 (v1)
Subject: Materials
Keywords: Adsorption, Extraction, hydrometallurgy, leaching, platinum group metals, precious metals
The intensive exploitation of resources on a global level has led to a progressive depletion of mineral reserves, which were proved to be insufficient to meet the high demand for high-technological devices. On the other hand, the continuous production of Waste from Electrical and Electronic Equipment (WEEE) is causing serious environmental problems, due to the complex composition of WEEE, which makes the recycling and reuse particularly challenging. The average metal content of WEEE is estimated to be around 30% and varies depending on the manufacturing period and brand of production. It contains base metals and precious metals, such as gold and palladium. The remaining 70% of WEEEs is composed of plastics, resins, and glassy materials. The recovery of metals from WEEEs is characterized by two main processes well represented by the literature: Pyrometallurgy and hydrometallurgy. Both of them require the pre-treatment of WEEEs, such as dismantling and magnetic separation of plastics. In... [more]
An Imperfect Production−Inventory Model with Mixed Materials Containing Scrap Returns Based on a Circular Economy
Rung-Hung Su, Ming-Wei Weng, Chih-Te Yang, Hsin-Ting Li
February 23, 2023 (v1)
Subject: Materials
Keywords: circular economy, green manufacturing, imperfect processes, inventory, scrap returns
The implementation of scrap recovery activities has been shown to improve the financial performance of many firms, and this kind of circular economy (CE) is particularly evident in industries with green manufacturing (GM). In this paper, we consider an imperfect multiple-stage production system that manufactures paired products made from mixed materials containing scrap returns, in which the scrap returns are converted from defective products. The feed rates of scrap returns for two products are different, and the product with the higher feed rate is placed in the second order of the process to avoid unlimited accumulation of scrap returns. The proposed problem is formulated as a joint economic order quantity (EOQ) and economic production quantity (EPQ) model aimed at cost minimization. The decision variables of the proposed model include the production run time of two products, order quantity of new material, and the extent of investment in converted equipment. We also prove that the... [more]
Effect of Pulse Type and Substitution Level on Dough Rheology and Bread Quality of Whole Wheat-Based Composite Flours
Yiqin Zhang, Ruijia Hu, Michael Tilley, Kaliramesh Siliveru, Yonghui Li
February 23, 2023 (v1)
Subject: Materials
Keywords: bread texture, chickpea, dough rheology, green pea, lentil, Mixolab, pulse, whole grain bread, yellow pea
Pulse flours are commonly added to food products to improve the functional properties, nutritional profiles, product quality and health benefits. This study aimed at assessing the effects of the partial replacement (0−25%) of whole wheat flour with diversified whole pulse flours (yellow pea, green pea, red lentil, and chickpea) on dough properties and bread quality. The pulse flours had higher protein contents and ash, but lower moisture content and larger average particle size, compared to whole wheat flour. Increasing the substitution level of pulse flours decreased dough viscosity, stability, development time and bread volume, and accelerated bread retrogradation. The incorporation of 5% yellow pea flour led to a similar bread quality as that with only whole wheat flour. Among all the tested pulse flours, the composite flour containing yellow pea flour or chickpea flour had overall better potential for bread making by providing good dough handling properties and product quality. Thi... [more]
A Numerical Procedure for Multivariate Calibration Using Heteroscedastic Principal Components Regression
Alessandra da Rocha Duailibe Monteiro, Thiago de Sá Feital, José Carlos Pinto
February 23, 2023 (v1)
Subject: Materials
Keywords: heteroscedastic principal components regression (H-PCR), measurement error, multivariate analysis, near infrared spectroscopy (NIRS), numerical procedure
Many methods have been developed to allow for consideration of measurement errors during multivariate data analyses. The incorporation of the error structure into the analytical framework, usually described in terms of the covariance matrix of measurement errors, can provide better model estimation and prediction. However, little effort has been made to evaluate the effects of heteroscedastic measurement uncertainties on multivariate analyses when the covariance matrix of measurement errors changes with the measurement conditions. For this reason, the present work describes a new numerical procedure for analyses of heteroscedastic systems (heteroscedastic principal component regression or H-PCR) that takes into consideration the variations of the covariance matrix of measurement fluctuations. In order to illustrate the proposed approach, near infrared (NIR) spectra of xylene and toluene mixtures were measured at different temperatures and stirring velocities and the obtained data were... [more]
Reactive Chromatography Applied to Ethyl Levulinate Synthesis: A Proof of Concept
Carmelina Rossano, Claudio Luigi Pizzo, Riccardo Tesser, Martino Di Serio, Vincenzo Russo
February 23, 2023 (v1)
Subject: Materials
Keywords: Dowex 50WX-8, ethyl levulinate, ion-exchange resin, levulinic acid, reactive chromatography
Levulinic acid (LA) has been highlighted as one of the most promising platform chemicals, providing a wide range of possible derivatizations to value-added chemicals as the ethyl levulinate obtained through an acid catalyzed esterification reaction with ethanol that has found application in the bio-fuel market. Being a reversible reaction, the main drawback is the production of water that does not allow full conversion of levulinic acid. The aim of this work was to prove that the chromatographic reactor technology, in which the solid material of the packed bed acts both as stationary phase and catalyst, is surely a valid option to overcome such an issue by overcoming the thermodynamic equilibrium. The experiments were conducted in a fixed-bed chromatographic reactor, packed with Dowex 50WX-8 as ion exchange resin. Different operational conditions were varied (e.g., temperature and flow rate), pulsing levulinic acid to the ethanol stream, to investigate the main effects on the final con... [more]
Modelling and Control of Corticotropin Permeation from Hydrogels across a Natural Membrane in the Presence of Albumin
Wioletta Siemiradzka, Barbara Dolińska, Florian Ryszka
February 23, 2023 (v1)
Subject: Materials
Keywords: albumin, corticotropin, release/permeation process, rheological stability, spectrophotometric determination, transdermal dosage form
(1) Background: Skin is a difficult barrier to overcome, especially for molecules with masses greater than 500 Da. It has been suggested that albumin may contribute to more effective penetration of many therapeutic substances. In this study, an attempt was made to use albumin in semi-solid formulations to increase the skin penetration of another peptide—corticotropin (ACTH). (2) Methods: Hydrogels were prepared at two concentrations: 15 mg/g and 20 mg/g corticotropin, then albumin was added to them in different stoichiometric ratios. The degree of ACTH release from hydrogels, both with and without albumin addition, was investigated. For selected hydrogels the process of corticotropin permeation through a model membrane, i.e., pig skin, was examined. (3) Results: The study of corticotropin release showed that the addition of albumin, depending on its amount, may delay or increase the release process. Similarly, a study of ACTH permeation through porcine skin showed that albumin can dela... [more]
The Quality of Horsemeat and Selected Methods of Improving the Properties of This Raw Material
Renata Stanisławczyk, Mariusz Rudy, Stanisław Rudy
February 23, 2023 (v1)
Subject: Materials
Keywords: freezing, glycolysis, horsemeat, marinating, quality
Horsemeat has a strictly defined group of consumers whose demand varies depending on the country or region. There is no tradition of consuming horsemeat in Poland. From a technological point of view, this raw material is as good as other types of meat. In the opinion of the consumer, compared to other species of animals, horsemeat is characterized by an intense red-brown colour and greater cohesiveness resulting from the type of muscle fibres. This meat has a sweetish taste due to the high carbohydrate content. The management of horsemeat often involves the use of modern freezing methods. Freezing horsemeat with the use of liquefied carbon dioxide is a method that increases its suitability for consumption as well as for export purposes in comparison with the traditional air-cooling method. To eliminate the unfavourable quality features of horsemeat, there are substances used to improve the functional and sensory properties of this meat. This paper discusses the research and development... [more]
Introducing Oxygen Vacancies in Li4Ti5O12 via Hydrogen Reduction for High-Power Lithium-Ion Batteries
Yiguang Zhou, Shuhao Xiao, Zhenzhe Li, Xinyan Li, Jintao Liu, Rui Wu, Junsong Chen
February 23, 2023 (v1)
Subject: Materials
Keywords: density functional theory, electronic conductivity, high-rate performance, Li4Ti5O12, oxygen vacancy
Li4Ti5O12 (LTO), known as a zero-strain material, is widely studied as the anode material for lithium-ion batteries owing to its high safety and long cycling stability. However, its low electronic conductivity and Li diffusion coefficient significantly deteriorate its high-rate performance. In this work, we proposed a facile approach to introduce oxygen vacancies into the commercialized LTO via thermal treatment under Ar/H2 (5%). The oxygen vacancy-containing LTO demonstrates much better performance than the sample before H2 treatment, especially at high current rates. Density functional theory calculation results suggest that increasing oxygen vacancy concentration could enhance the electronic conductivity and lower the diffusion barrier of Li+, giving rise to a fast electrochemical kinetic process and thus improved high-rate performance.
Application of Magnetic Composites in Removal of Tetracycline through Adsorption and Advanced Oxidation Processes (AOPs): A Review
Beibei Fan, Yi Tan, Jingxin Wang, Bangxi Zhang, Yutao Peng, Chengpeng Yuan, Chungyu Guan, Xing Gao, Shihao Cui
February 23, 2023 (v1)
Subject: Materials
Keywords: Adsorption, advanced oxidation processes, magnetic composites, tetracycline
Water pollution induced by the tetracycline (TC) has caused global increasing attention owing to its extensive use, environmental persistence, and potential harm for human health. Adsorption and advanced oxidation processes (AOPs) have been promising techniques for TC removal due to ideal effectiveness and efficiency. Magnetic composites (MCs) which exploit the combined advantages of nano scale, alternative sources, easy preparation, and separation from wastewater are widely used for catalysis and adsorption. Herein, we intensively reviewed the available literature in order to provide comprehensive insight into the applications and mechanisms of MCs for removal of TC by adsorption and AOPs. The synthesis methods of MCs, the TC adsorption, and removal mechanisms are fully discussed. MCs serve as efficient adsorbents and photocatalysts with superior performance of photocatalytic performance in TC degradation. In addition, the TC can be effectively decomposed by the Fenton-based and SO4•−... [more]
Bladder Substitution: The Role of Tissue Engineering and Biomaterials
Martina Casarin, Alessandro Morlacco, Fabrizio Dal Moro
February 23, 2023 (v1)
Subject: Materials
Keywords: biomaterial, regenerative medicine, tissue engineering, urinary bladder, urinary diversions
Tissue engineering could play a major role in the setting of urinary diversion. Several conditions cause the functional or anatomic loss of urinary bladder, requiring reconstructive procedures on the urinary tract. Three main approaches are possible: (i) incontinent cutaneous diversion, such as ureterocutaneostomy, colonic or ileal conduit, (ii) continent pouch created using different segments of the gastrointestinal system and a cutaneous stoma, and (iii) orthotopic urinary diversion with an intestinal segment with spherical configuration and anastomosis to the urethra (neobladder, orthotopic bladder substitution). However, urinary diversions are associated with numerous complications, such as mucus production, electrolyte imbalances and increased malignant transformation potential. In this context, tissue engineering would have the fundamental role of creating a suitable material for urinary diversion, avoiding the use of bowel segments, and reducing complications. Materials used for... [more]
Preparation of a Novel CO2-Responsive Polymer/Multiwall Carbon Nanotube Composite
Yonggang Ma, Xin Chen, Dehui Han, Zhe Zhao, Wenting Lu
February 23, 2023 (v1)
Subject: Materials
Keywords: ATRP, CO2-responsive, composite, multiwall carbon nanotube (MWCNT), polymer
A CO2-responsive composite of multiwall carbon nanotube (MWCNT) coated with polydopamine (PDA) and polydimethylamino-ethyl methacrylate (PDMAEMA) was prepared. The PDA was first self-polymerized on the surface of carbon nanotube. 2-bromoisobutyryl bromide (BiBB) was then immobilized by PDA and then initiated the ATRP of DMAEMA on the carbon nanotube surface. The resulting composite was characterized by Fourier-transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The CO2-responsive test was performed by bubbling CO2 into the mixture of MWCNT-PDA-PDMAEMA composite in water. A well-dispersed solution was obtained and the UV-Vis transmittance decreased dramatically. This is attributed to the reaction between PDMAEMA and CO2. The formation of ammonium bicarbonates on the surface of carbon nanotubes leads to the separation of nanotube bundles. This process can be reversed as the removal of CO2 by bubbling N2.
Novel Correlations between Spectroscopic and Morphological Properties of Activated Carbons from Waste Coffee Grounds
Egle Rosson, Paolo Sgarbossa, Mirto Mozzon, Federico Venturino, Sara Bogialli, Antonella Glisenti, Aldo Talon, Elisa Moretti, Sara Maria Carturan, Sergio Tamburini, Alessia Famengo, Ana Paula da Costa Ribeiro, Sadjia Benhabiles, Rida Kamel, Federico Zorzi, Roberta Bertani
February 23, 2023 (v1)
Subject: Materials
Keywords: activated carbon, chemical and morphological characterization, pyrolysis, Raman and XPS and XRD spectroscopies, spent coffee grounds
Massive quantities of spent coffee grounds (SCGs) are generated by users around the world. Different processes have been proposed for SCG valorization, including pyrolytic processes to achieve carbonaceous materials. Here, we report the preparation of activated carbons through pyrolytic processes carried out under different experimental conditions and in the presence of various porosity activators. Textural and chemical characterization of the obtained carbons have been achieved through Brunauer−Emmett−Teller (BET), ESEM, 13C solid state NMR, XPS, XRD, thermogravimetric and spectroscopic determinations. The aim of the paper is to relate these data to the preparation method, evaluating the correlation between the spectroscopic data and the physical and textural properties, also in comparison with the corresponding data obtained for three commercial activated carbons used in industrial adsorption processes. Some correlations have been observed between the Raman and XPS data.
Fabrication Process for On-Board Geometries Using a Polymer Composite-Based Selective Metallization for Next-Generation Electronics Packaging
Sarthak Acharya, Shailesh Singh Chouhan, Jerker Delsing
February 23, 2023 (v1)
Subject: Materials
Keywords: CBM chemistry, challenges, electronics packaging, functionalization, laser assisted fabrication, polymerization, polyurethane, selective metallization, surface modification, UV laser
Advancements in production techniques in PCB manufacturing industries are still required as compared to silicon-ICs fabrications. One of the concerned areas in PCBs fabrication is the use of conventional methodologies for metallization. Most of the manufacturers are still using the traditional Copper (Cu) laminates on the base substrate and patterning the structures using lithography processes. As a result, significant amounts of metallic parts are etched away during any mass production process, causing unnecessary disposables leading to pollution. In this work, a new approach for Cu metallization is demonstrated with considerable step-reducing pattern-transfer mechanism. In the fabrication steps, a seed layer of covalent bonded metallization (CBM) chemistry on top of a dielectric epoxy resin is polymerized using actinic radiation intensity of a 375 nm UV laser source. The proposed method is capable of patterning any desirable geometries using the above-mentioned surface modification f... [more]
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