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Records with Subject: Materials
3545. LAPSE:2023.3184
Assessment of Wine Adulteration Using Near Infrared Spectroscopy and Laser Backscattering Imaging
February 22, 2023 (v1)
Subject: Materials
Keywords: chemometry, food adulteration, laser backscattering, wine authenticity
Food adulteration is in the focus of research due to its negative effect on safety and nutritional value and because of the demand for the protection of brands and regional origins. Portugieser and Sauvignon Blanc wines were selected for experiments. Samples were made by water dilution, the addition of sugar and then a combination of both. Near infrared (NIR) spectra were acquired in the range of 900−1700 nm. Partial least squares regression was performed to predict the adulteration level. The model including all wines and adulterations achieved a prediction error of 0.59% added sugar and 6.85% water dilution. Low-power laser modules were used to collect diffuse reflectance signals at wavelengths of 532, 635, 780, 808, 850, 1064 nm. The general linear model resulted in a higher prediction error of 3.06% added sugar and 20.39% water dilution. Instead of classification, the present study investigated the feasibility of non-destructive methods in the prediction of adulteration level. Lase... [more]
3546. LAPSE:2023.3183
Horned Melon (Cucumis metuliferus E. Meyer Ex. Naudin)—Current Knowledge on Its Phytochemicals, Biological Benefits, and Potential Applications
February 22, 2023 (v1)
Subject: Materials
Keywords: antifungal potential, horned melon, kiwano, medicine plant with prospective benefits, phytochemicals
Recent studies reveal that numerous non-edible parts of fruits and vegetables, as well as food wastes, are a good source of phytochemicals that can be extracted and reintroduced into the food chain as natural food additives. Horned melon or kiwano (Cucumis metuliferus E. Mey. Ex. Naudin) is a fruit rich in various phytochemical components important in the daily diet. After primary processing, horned melon non-edible parts (e.g., peels and seeds) can represent raw materials that can be utilized in numerous applications. Among under-researched fruits, this study aims to present the potential of using horned melon edible and non-edible parts based on current knowledge on nutritional value, phytochemicals, biological activity, as well as biological benefits. Overall, this review concluded that the biological properties of horned melon are associated with the phytochemicals present in this fruit and its waste parts. Further studies should be conducted to identify phytochemicals and valorize... [more]
3547. LAPSE:2023.3181
The Influencing Factors for Volume Stability of Ladle Slag
February 22, 2023 (v1)
Subject: Materials
Keywords: calcination temperatures, CaO reactivity, ladle slag, volume stability
The purpose of this study was to investigate the mechanism causing the unsoundness of ladle slag. Calcination temperature may have an impact on the level of reactivity of f-CaO. When CaO was produced at a higher temperature, the reactivity of CaO was lower. For example, dead burnt CaO (DCaO) was produced at higher temperatures than light burnt CaO (LCaO); therefore, DCaO had less reactivity than LCaO. In a hydration test, DCaO (1500 °C) showed 62 times lower reactivity than LCaO (900 °C), which meant that DCaO would result in the delay of hydration of CaO easily. Additionally, DCaO would cause unsoundness more easily than LCaO when adding the same number of cementitious materials. For this reason, using ASTM C114-18 (Standard Test Methods for Chemical Analysis of Hydraulic Cement) to quantify DCaO content may underestimate DCaO content by up to 20%. Conversely, this method was more suitable for f-CaO since it had high reactivity. Moreover, this study demonstrated that ladle slag would... [more]
3548. LAPSE:2023.3162
The Potential of Spectroscopic Techniques in Coffee Analysis—A Review
February 22, 2023 (v1)
Subject: Materials
Keywords: adulterants, chemometrics, coffee, defective beans, discrimination, prediction, roasting, spectroscopy
This review provides an overview of recent studies on the potential of spectroscopy techniques (mid-infrared, near infrared, Raman, and fluorescence spectroscopy) used in coffee analysis. It specifically covers their applications in coffee roasting supervision, adulterants and defective beans detection, prediction of specialty coffee quality and coffees’ sensory attributes, discrimination of coffee based on variety, species, and geographical origin, and prediction of coffees chemical composition. These are important aspects that significantly affect the overall quality of coffee and consequently its market price and finally quality of the brew. From the reviewed literature, spectroscopic methods could be used to evaluate coffee for different parameters along the production process as evidenced by reported robust prediction models. Nevertheless, some techniques have received little attention including Raman and fluorescence spectroscopy, which should be further studied considering their... [more]
3549. LAPSE:2023.3157
Chemical Recycling of Mixed Plastics in Electronic Waste Using Solvent-Based Processing
February 22, 2023 (v1)
Subject: Materials
Keywords: chemical recycling, dissolution, electronic waste, flame retardant, precipitation, solvent
Currently, less than 20% of electronic waste (E-waste) produced in the U.S. is recycled. To improve the recycling rate of E-waste, the study aimed to: (1) identify the major plastics found within electronic shredder residue (ESR), (2) design solvents and processing conditions capable of separating out 90% of the plastic in ESR, and (3) estimate the energy efficiency of the solvent-based process developed. Preliminary screening showed 25 wt.% of the ESR was composed of plastics, with two polymers dominating the sorted plastic fraction—polystyrene (PS, 40 wt.%) and acrylonitrile butadiene styrene (ABS, 25 wt.%). Subsequently, solvents and anti-solvents were screened using Hansen Solubility Parameter Theory for PS, ABS, and ESR dissolution. The pre-screening results showed dichloromethane (DCM) and tetrahydrofuran (THF) as the most effective solvents for PS and ABS, with methanol (MeOH) and ethylene glycol (EG) as the most effective anti-solvents. By optimizing the dissolution time and th... [more]
3550. LAPSE:2023.3152
Enhanced Saccharification of Purple Alfalfa via Sequential Pretreatment with Acidified Ethylene Glycol and Urea/NaOH
February 22, 2023 (v1)
Subject: Materials
Keywords: ethylene glycol, pretreatment, purple alfalfa, saccharification, urea/NaOH
Purple Alfalfa is an inexpensive, abundant, readily available lignocellulosic material. This work was attempted to develop an efficient combination pretreatment by sequential HClO4−ethyl glycol−H2O (1.2:88.8:10, w/w/w) extraction at 130 °C in 0.5 h and urea/NaOH (urea 12 wt%, NaOH 7 wt%) soaking at −20 °C for 0.5 h for the pretreatment of purple alfalfa. The porosity, morphology, and crystallinity of pretreated purple alfalfa were characterized with SEM, FM, XRD, and FTIR. This combination pretreatment had a significant influence on hemicellulose removal and delignification. The above changes could enhance cellulose accessibility to enzymes and improve the enzymatic digestibility of cellulose. High yields of reducing sugars from pretreated purple alfalfa were obtained at 93.4%. In summary, this combination pretreatment has high potential application in the future.
3551. LAPSE:2023.3140
A Spinel (FeNiCrMnMgAl)3O4 High Entropy Oxide as a Cycling Stable Anode Material for Li-Ion Batteries
February 22, 2023 (v1)
Subject: Materials
Keywords: in-situ X-ray diffraction, lithium-ion battery, phase transformation, spinel-type high entropy oxide
Recently, high entropy oxides (HEO) with special stabilization effects have been widely investigated as new anode materials for lithium-ion batteries. However, the lithium storage mechanism of HEO is still under debate. In this work, we applied a modified solution combustion synthesis method with a subsequent ball milling refinement process to prepare a six-component (FeNiCrMnMgAl)3O4 spinel high entropy oxide (6-SHEO). The novel 6-SHEO anode features outstanding electrochemical performance, enabling a stable capacity of 657 mAh g−1 at a current rate of 0.2 A g−1 after 200 cycles, and good high-rate capability with 350 mAh g−1 even at 4 A g−1. In addition, the lithium storage behavior of this 6-SHEO anode was explored in detail through in-situ XRD and ex-situ TEM approaches. Surprisingly, a reversible spinel to rock salt phase transition behavior and spinel phase residue phenomenon was firstly observed by this route. Furthermore, for better understanding of the phase change behavior in... [more]
3552. LAPSE:2023.3134
A Short-Cut Data Mining Method for the Mass Spectrometric Characterization of Block Copolymers
February 22, 2023 (v1)
Subject: Materials
Keywords: copolymers, data mining, mass spectrometry, Mass-remainder analysis
A new data mining approach as a short cut method is given for the determination of the copolymer composition from mass spectra. Our method simplifies the copolymer mass spectra by reduction of the number of mass peaks. The proposed procedure, namely the selection of the mass peaks, which is based on the most abundant peak of the mass spectrum, can be performed manually or more efficiently using our recently invented Mass-remainder analysis (MARA). The considerable reduction of the MS spectra also simplifies the calculation of the copolymer quantities for instance the number- and weight-average molecular weights (Mn and Mw, respectively), polydispersity index (Đ = Mw/Mn), average molar fraction (cA) and weight fraction (wA) of the comonomer A and so on. These copolymer properties are in line with those calculated by a reference method taking into account all the mass peaks of the copolymer distribution. We also suggest a highly efficient method and template for the determination of the... [more]
3553. LAPSE:2023.3133
Influence of Graphene Nano Fillers and Carbon Nano Tubes on the Mechanical and Thermal Properties of Hollow Glass Microsphere Epoxy Composites
February 22, 2023 (v1)
Subject: Materials
Keywords: carbon nano tube, epoxy, graphene, hollow glass microsphere, mechanical and thermal properties, nano fillers
The present work aimed to analyze the roll of carbon nano tubes and graphene nano fillers on the mechanical and thermal characteristics of hollow glass microsphere reinforced epoxy composites. Composites with varying content of hollow glass microballoons (2, 4, 6, 8, and 10 wt %) reinforced in epoxy matrix were fabricated. Additionally, two more types of composites, one with graphene nano fillers and the other with carbon nano tube at a constant 0.5 wt %, were fabricated with varying weight percentages of hollow glass microballoons (2, 4, 6, 8, and 10%). The composites were fabricated using an open mold casting process. Composites were tested for thermal and mechanical properties. The tensile and flexural moduli were found to rise as the HGM concentration increased. Graphene-filled HGM/epoxy composites revealed the highest modulus compared with HGM/epoxy and HGM/CNT/epoxy composites. The impact strength of all composite types decreased as the HGM content increased. Neat epoxy specimens... [more]
3554. LAPSE:2023.3131
Valorization of Vine Prunings by Slow Pyrolysis in a Fixed-Bed Reactor
February 22, 2023 (v1)
Subject: Materials
Keywords: bio-oil, biochar, pyrolysis, vine prunings
The paper aimed at studying the slow pyrolysis of vine pruning waste in a fixed bed reactor and characterizing the pyrolysis products. Pyrolysis experiments were conducted for 60 min, using CO2 as a carrier gas and oxidizing agent. The distribution of biochar and bio-oil was dependent on variations in heat flux (4244−5777 W/m2), CO2 superficial velocity (0.004−0.008 m/s), and mean size of vegetal material (0.007−0.011 m). Relationships among these factors and process performances in terms of yields of biochar (0.286−0.328) and bio-oil (0.260−0.350), expressed as ratio between the final mass of pyrolysis product and initial mass of vegetal material, and final value of fixed bed temperature (401.1−486.5 °C) were established using a 23 factorial design. Proximate and ultimate analyses, FT-IR and SEM analyses, measurements of bulk density (0.112 ± 0.001 g/cm3), electrical conductivity (0.55 ± 0.03 dS/m), pH (10.35 ± 0.06), and water holding capacity (58.99 ± 14.51%) were performed for bioc... [more]
3555. LAPSE:2023.3125
Diels−Alder Cycloadditions of Bio-Derived Furans with Maleimides as a Sustainable «Click» Approach towards Molecular, Macromolecular and Hybrid Systems
February 22, 2023 (v1)
Subject: Materials
Keywords: biobased furans, covalent adaptable networks, Diels–Alder reaction, dynamers, dynamic systems, maleimides, plant biomass, platform chemicals
This mini-review highlights the recent research trends in designing organic or organic-inorganic hybrid molecular, biomolecular and macromolecular systems employing intermolecular Diels−Alder cycloadditions of biobased, furan-containing substrates and maleimide dienophiles. The furan/maleimide Diels−Alder reaction is a well-known process that may proceed with high efficiency under non-catalytic and solvent-free conditions. Due to the simplicity, 100% atom economy and biobased nature of many furanic substrates, this type of [4+2]-cycloaddition may be recognized as a sustainable “click” approach with high potential for application in many fields, such as fine organic synthesis, bioorganic chemistry, material sciences and smart polymers development.
3556. LAPSE:2023.3110
Effect of Drying Techniques on the Physical, Functional, and Rheological Attributes of Isolated Sunflower Protein and Its Hydrolysate
February 22, 2023 (v1)
Subject: Materials
Keywords: convection drying, freeze drying, functionality, molecular weight, sunflower protein, turbidity, viscosity
The influence of freeze and convection (at 40 and 50 °C) drying on the physical, functional, and rheological attributes of sunflower protein (SP) and its hydrolysate (SPH) was investigated. Compared with convectively-dried samples, the lightness, turbidity, bulk density, and particle size values of the freeze-dried SP and SPH were substantially higher, but the browning index was lower (p < 0.05). Additionally, freeze-dried samples exhibited good solubility and foaming characteristics, whereas lower emulsion properties with the most pH values were observed. Furthermore, SPHs possessed higher solubility as well as foamability over SPs under varying pH values (2.0−10.0), whilst reduction in the emulsion activity index was clearly observed (p < 0.05). Convectively-dried powders exhibited greater viscosity and consistency coefficient; and significantly lower flow behavior index of dispersions, relative to the respective freeze-dried preparations, indicating that dehydration methods in... [more]
3557. LAPSE:2023.3107
Property Determination, FA Composition and NMR Characterization of Palm Oil, Used Palm Oil and Their Methyl Esters
February 22, 2023 (v1)
Subject: Materials
Keywords: characterization, nuclear magnetic resonance, palm oil, thermal degradation, waste palm oil
The search for a cost-effective, environmentally friendly and sustainable feedstock for biodiesel production has attracted attention among researchers. After frying, palm oil may become thermally degraded and unsuitable for consumption. In the current effort, neat palm oil (NPO), waste palm oil earlier utilized for frying fish and chips (WPOFC) and waste palm oil previously utilized to fry sausage and chips (WPOSC) were transesterified into waste palm oil methyl ester, namely, WPOMEFC and WPOMESC, respectively. The PO, WPOs and their ester derivatives were subjected to physicochemical properties, fatty acid (FA) compositions and 1H and 13C nuclear magnetic resonance (NMR) analyses. The thermal degradation, transesterification process and the foods the palm oil was used to fry affected the density, kinematic viscosity, acid value, pH, iodine value and FA profile of the samples. The outcome of the characterization reveals that the 1H and 13C NMR spectra of NPO, WPOFC and WPOSC show clear... [more]
3558. LAPSE:2023.3103
Silica-Based Core-Shell Nanocapsules: A Facile Route to Functional Textile
February 22, 2023 (v1)
Subject: Materials
Keywords: anti-ultraviolet, functional textile, phase change material, silica-based core-shell nanocapsules, thermal energy storage, thermal regulation
In this work, we present a surfactant-free miniemulsion approach to obtain silica-based core-shell nanocapsules with a phase change material (PCM) core via in-situ hydrolytic polycondensation of precursor hyperbranched polyethoxysiloxanes (PEOS) as silica shells. The obtained silica-based core-shell nanocapsules (PCM@SiO2), with diameters of ~400 nm and silica shells of ~14 nm, reached the maximum core content of 65%. The silica shell had basically no significant influence on the phase change behavior of PCM, and the PCM@SiO2 exhibited a high enthalpy of melt and crystallization of 123−126 J/g. The functional textile with PCM@SiO2 has been proposed with thermoregulation and acclimatization, ultraviolet (UV) resistance and improved mechanical properties. The thermal property tests have shown that the functional textile had good thermal stability. The functional textile, with a PCM@SiO2 concentration of 30%, was promising, with enthalpies of melting and crystallization of 27.7 J/g and 27... [more]
3559. LAPSE:2023.3095
CO2 Sequestration through Mineral Carbonation: Effect of Different Parameters on Carbonation of Fe-Rich Mine Waste Materials
February 21, 2023 (v1)
Subject: Materials
Keywords: carbon sequestration, CCS, CCU, Fe-rich waste, mine waste, mineral carbonation
Mineral carbonation is an increasingly popular method for carbon capture and storage that resembles the natural weathering process of alkaline-earth oxides for carbon dioxide removal into stable carbonates. This study aims to evaluate the potential of reusing Fe-rich mine waste for carbon sequestration by assessing the influence of pH condition, particle size fraction and reaction temperature on the carbonation reaction. A carbonation experiment was performed in a stainless steel reactor at ambient pressure and at a low temperature. The results indicated that the alkaline pH of waste samples was suitable for undergoing the carbonation process. Mineralogical analysis confirmed the presence of essential minerals for carbonation, i.e., magnetite, wollastonite, anorthite and diopside. The chemical composition exhibited the presence of iron and calcium oxides (39.58−62.95%) in wastes, indicating high possibilities for carbon sequestration. Analysis of the carbon uptake capacity revealed tha... [more]
3560. LAPSE:2023.3092
Novel Green Approaches for the Preparation of Gold Nanoparticles and Their Promising Potential in Oncology
February 21, 2023 (v1)
Subject: Materials
Keywords: biogenetic, cancer treatment, gold nanoparticles, nanomedicines, pathway
The difficulty of achieving targeted drug delivery following administration of currently marketed anticancer therapeutics is a still a concern. Metallic nanoparticles (NPs) developed through nanotechnology breakthroughs appear to be promising in this regard. Research studies pertaining to gold NPs have indicated their promising applicability in cancer diagnosis, drug delivery and therapy. These NPs have also recently paved the path for precise drug delivery and site-specific targeting. Our review paper thus highlights the scope and impact of biogenetically generated gold nanoparticles (NPs) in cancer therapy. In a critical, constructive, and methodical manner, we compare the advantages offered by gold NPs over other metal NPs. Moreover, we also focus on novel ‘greener’ strategies that have been recently explored for the preparation of gold NPs and shed light on the disadvantages of conventional NP synthesis routes. Future prospects pertaining to the use of gold NPs in oncotherapy and d... [more]
3561. LAPSE:2023.3088
Effect of Solid Volume Concentration on Rheological Properties of Chengdu Clay Slurry
February 21, 2023 (v1)
Subject: Materials
Keywords: Chengdu clay mud, rheological experiment, rheological model, solid volume concentration
The determination of rheological model about the debris flow is the basis of the simulation of mud flow impact distance and sedimentary fan. By using a mcr301 rheometer, rheological experiments of Chengdu clay slurry with different solid volume concentrations were carried out and the effect of solid volume concentration on shear stress were analyzed. Then the rheological process of Chengdu clay slurry with different solid volume concentration was fitted on the basis of the power law model, the Bingham model and the H−B model. The conclusions are drawn as follows: Chengdu clay mud is a typical shear-thinning non-Newtonian body. The influence of solid concentration on the flow curve is different. When the solid volume concentration is not less than 34% and the shear rate is less than 1.0 s−1, the shear stress increases rapidly as the shear rate increases. Meanwhile, when the shear rate is greater than 1.0 s−1 the shear stress decreases with the increase in the shear rate. When the solid... [more]
3562. LAPSE:2023.3068
HPW/PAM Catalyst for Oxidative Desulfurization-Synthesis, Characterization and Mechanism Study
February 21, 2023 (v1)
Subject: Materials
Keywords: desulfurization, heteropoly acid, PAM, recycle use
In this work, polyacrylamide (PAM) was first used in the loading of heteropoly acids, and then the HPM/PAM-n catalyst was synthesized by simple reaction. The FTIR and SEM measurements showed that the HPM/PAM-n (n = 10,000, 20,000, 30,000) was successfully synthesized. In addition, the HPM/PAM-n effect on desulfurization was measured, which showed the optimal desulfurization efficiency. The optimal process condition for HPM/PAM-10000 desulfurization was optimized by a single-factor experiment. The optimal condition was as follows: The temperature was 60 °C, the amount of the catalyst was 0.2 g, the oxygen to sulfur ratio was 16, and the reaction time is 100 min. The catalyst was suitable for recycled use, and the desulfurization efficiency was high after 10 times. In the end, the oxidative desulfurization mechanism was put forward.
3563. LAPSE:2023.3060
High-Performance Thin-Layer Chromatography (HPTLC) Method for Identification of Meloxicam and Piroxicam
February 21, 2023 (v1)
Subject: Materials
Keywords: high-performance thin-layer chromatography, HPTLC, meloxicam, NSAIDs, piroxicam, thin-layer chromatography, TLC
Background: High-performance thin-layer chromatography (HPTLC) is an advantageous, modern analytical technique based on the principles of thin-layer chromatography (TLC), which provides essential benefits, such as improved sample application, better and faster separation, and less mobile phase usage. The aim of this work was to develop a simple and rapid HPTLC method that could be used for the identification of meloxicam and piroxicam. Methods: HPTLC. The analysis was carried out using silica gel 60 F254 glass TLC plates and as the mobile phase: hexane: ethyl acetate: glacial acetic acid, in a ratio of 65:30:5 v/v/v. For the standard solution preparation, ethanol was used. Front: 60 mm. Detection was performed at 366 nm. Results: The Rf value for meloxicam was 0.81 and the Rf value for piroxicam was 0.57. The proposed method can be used in the detection of the analyzed compounds in very low concentrations. It was established that the detection limit of meloxicam was 0.04 μg per band an... [more]
3564. LAPSE:2023.3057
Cobalt Oxide Nanorod-Modified GCE as Sensitive Electrodes for Simultaneous Detection of Hydroquinone and Catechol
February 21, 2023 (v1)
Subject: Materials
Keywords: Co3O4 nanorod, electrochemical method, hydroquinone and catechol, simultaneous detection
An electrochemical sensor based on a cobalt oxide nanorod (Co3O4NR) modified glassy carbon electrode (GCE) (Co3O4NR-GCE) was prepared for simultaneous and selective determination of hydroquinone (HQ) and catechol (CT). Surface morphology and crystallinity of Co3O4NR were investigated employing field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) analysis. The structure (16 nm) of the Co3O4 nanorod was observed in the FESEM image. A sharp peak pattern in the XRD survey revealed the following crystal planes in Co3O4NR material: (111), (220), (311), (222), (400), (422), (511), and (440). Electrochemical characterization of modified Co3O4NR-GCE was carried out performing cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Selective and simultaneous detection of HQ and CT was carried out by performing CV and differential pulse voltammetry (DPV) analysis. In both studies, modified Co3O4NR-GCE showed well defined oxidation and reduction peaks f... [more]
3565. LAPSE:2023.3053
Bio-Based Synthesis of Silver Nanoparticles from Waste Agricultural Biomass and Its Antimicrobial Activity
February 21, 2023 (v1)
Subject: Materials
Keywords: bacteria, bio-based synthesis, disinfection, disk diffusion test, nanosilver, waste
The problem of cleaning and disinfecting surfaces has become extremely important in the context of the ongoing SARS-CoV-2 coronavirus pandemic. However, it should be considered that, in everyday life, we come into contact with many other viruses, as well as pathogenic bacteria and fungi, that may cause infections and diseases. Hence, there is a continuous need to search for new and more effective methods of fighting pathogens. Due to their documented antimicrobial activity, silver nanoparticles may be an interesting alternative to the commonly used surface cleaners and disinfectants. Therefore, the present study aimed to evaluate the bactericidal properties of silver nanoparticles obtained with the use of nontoxic plant waste biomass against bacteria isolated from the environment. Silver nanoparticles with the desired physicochemical characteristics were obtained by a simple and rapid chemical reduction method using plant waste such as unused parsley stems and potato peels (the biogeni... [more]
3566. LAPSE:2023.3051
Green Process for the Synthesis of 3-Amino-2-methyl-quinazolin-4(3H)-one Synthones and Amides Thereof:DNA Photo-Disruptive and Molecular Docking Studies
February 21, 2023 (v1)
Subject: Materials
Keywords: 3-Amino-quinazolin-4(3H)-ones, 3-Arylamido-quinazolin-4(3H)-ones, 6-Nitro-Quinazolinone, aerobic and anaerobic DNA photo-cleavage, benzoxazinones, DNA photocleavers, microwave-assisted synthesis, molecular docking, photodynamic effects, privileged structures
Eleven 3-amino-2-methyl-quinazolin-4(3H)-ones have been synthesized, in good to excellent yields, via their corresponding benzoxazinones using an efficient tandem microwave-assisted green process. Representative acetamides have been thermally derived from their functional free 3-amino group, whereas for the synthesis of various arylamides, a novel green microwave-assisted protocol has been developed, which involved the attack of hydrazides on benzoxazinones. Eight out of the eleven 3-amino-2-methyl-quinazolin-4(3H)-ones were found photo-active towards plasmid DNA under UVB, and four under UVA irradiation. Amongst all acetamides, only the 6-nitro derivative retained activity both under UVB and UVA irradiation, whereas the 6-bromo-substituted one was active only under UVB. 3-arylamido-6-bromo derivatives exhibited dramatically decreased photo-activity; however, all 3-arylamido-6-nitro compounds developed extraordinary activity, even at concentrations as low as 1μM, which was enhanced com... [more]
3567. LAPSE:2023.3019
A Molecular Investigation of the Solvent Influence on Inter- and Intra-Molecular Hydrogen Bond Interaction of Linamarin
February 21, 2023 (v1)
Subject: Materials
Keywords: hydrogen bonding, linamarin, molecular dynamics, solvation free energy, solvents
Linamarin has been reported to have anticancer activities; however, its extraction and isolation using different solvents yield a low amount. Therefore, understanding the physical properties, such as solvents’ solubility, membrane permeability and lipophilicity and how they are associated with different solvents, is a paramount topic for discussion, especially for its potential as a drug. Linamarin has a sugar moiety with many polar groups responsible for its physical properties. Following current trends, a molecular dynamics simulation is performed to investigate its physical properties and how different solvents, such as water, methanol (MeOH), dimethyl sulfoxide (DMSO) and dichloromethane (DCM), affect such properties. In this work, we have investigated the influence of intermolecular and intramolecular hydrogen bonding and the influence of polar and non-polar solvents on the physical properties of linamarin. Furthermore, solvation free-energy and electronic structure analysis are p... [more]
3568. LAPSE:2023.3017
Catalytic Decomposition of n-C7 Asphaltenes Using Tungsten Oxides−Functionalized SiO2 Nanoparticles in Steam/Air Atmospheres
February 21, 2023 (v1)
Subject: Materials
Keywords: asphaltenes, Catalysis, nanomaterials, silica, sodium tungstate, tungsten oxide, wet combustion
A wide range of technologies are being developed to increase oil recovery, reserves, and perform in situ upgrading of heavy crude oils. In this study, supported tungsten oxide nanoparticles were synthesized, characterized, and evaluated for adsorption and catalytic performance during wet in situ combustion (6% of steam in the air, in volumetric fraction) of n-C7 asphaltenes. Silica nanoparticles of 30 nm in diameter were synthesized using a sol−gel methodology and functionalized with tungsten oxides, using three different concentrations and calcination temperatures: 1%, 3%, 5% (mass fraction), and 350 °C, 450 °C, and 650 °C, respectively. Equilibrium batch adsorption experiments were carried out at 25 ℃ with model solutions of n-C7 asphaltenes diluted in toluene at concentrations from 100 mg·L−1 to 2000 mg·L−1, and catalytic wet in situ combustion of adsorbed heavy fractions was carried out by thermogravimetric analysis coupled to FT-IR. The results showed improvements of asphaltenes d... [more]
3569. LAPSE:2023.3013
Wood-Sourced Polymers as Support for Catalysis by Group 10 Transition Metals
February 21, 2023 (v1)
Subject: Materials
Keywords: cellulose, lignin, nickel, palladium, platinum, supported catalyst
Despite providing interesting solutions to reduce the number of synthetic steps, to decrease energy consumption or to generate less waste, therefore contributing to a more sustainable way of producing important chemicals, the expansion of the use of homogeneous catalysis in industrial processes is hampered by several drawbacks. One of the most important is the difficulty to recycle the noble metals generating potential high costs and pollution of the synthesized products by metal traces detrimental to their applications. Supporting the metals on abundant and cheap biosourced polymers has recently appeared as an almost ideal solution: They are much easier to recover from the reaction medium and usually maintain high catalytic activity. The present bibliographical review focuses on the development of catalysts based on group 10 transition metals (nickel, palladium, platinum) supported on biopolymers obtained from wood, such as cellulose, hemicellulose, lignin, and their derivatives. The... [more]
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