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1.
In this study, we perform a series of mass-balance-type calculations, in order to estimate the minimum volume of liquid water required to dissolve completely a single methane gas bubble, located inside different types of domains that are near or under hydrate equilibrium pressure/temperature conditions. We examine the case of methane bubble dissolution in the bulk, along with the cases of methane bubble dissolution within simple/regular networks of pores, where all pores have the same size. In our calculations, we consider experimental values for the equilibrium solubilities of methane in water, along the hydrate-forming line, as well as, values obtained from predictive tools that are based on different thermodynamic models. The effect of aqueous NaCl solutions on the results is also investigated. As a result of the relatively low solubility of methane in water, large volumes of water are required for complete dissolution of a methane bubble. 相似文献
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Demeter Tzeli Ioannis D. Petsalakis Giannoula Theodorakopoulos 《International journal of quantum chemistry》2019,119(16):e25958
We study, via density functional theory and time dependent DFT calculations, the photophysical processes of a styryl-bodipy derivative, which acts as a three metal-cation-receptor fluorophore in order to (a) gain information on the appropriate computational approach for successful prediction of molecular logic gate candidates, (b) rationalize the available experimental data and (c) understand how the given combination of three different receptors with the BODIPY fluorophore presents such interesting optoelectronic responses. The fluorophore ( 1 ), its monometallic complexes ( 1-Ca 2+ , 1-Zn 2+ , and 1-Hg 2+ ), and its trimetallic complex ( 2 ) are studied. The calculated λmax values for absorption and emission are in excellent agreement with experimental data. It was found that the observed quenching of emission of 1 and of the monometallic complexes is attributed to the fact that their first excited state is a charge-transfer state whereas this does not happen for the complex 2 . It should be noted that for the correct ordering of the excited states, the inclusion of corrections to the excitation energies for nonequilibrium solvent effects is required; while in the case of 1-Ca 2+ , the additional explicit inclusion of the solvent is necessary for the quenching of the emission spectra. 相似文献
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Nikos Karanikolopoulos Ioannis Choinopoulos Marinos Pitsikalis 《Journal of polymer science. Part A, Polymer chemistry》2020,58(11):1582-1600
A series of well-defined poly{dl -lactide-b-[oligo(ethylene glycol) methyl ether (meth)acrylate)]} (PDLLA-b-POEG[M]A) functional amphiphilic diblock copolymers was synthesized by employing a multistep procedure involving: (a) ring-opening polymerization of dl -lactide using n-decanol and stannous octoate as the initiating system, (b) esterification reaction of the PDLLA hydroxyl end groups with 2-bromoisobutyryl bromide, (c) atom transfer radical polymerization of OEG(M)A with the newly created bromoisobutyryl initiating site, and (d) incorporation of biotin or folic acid at the POEGA chain ends using click chemistry. The products were characterized by NMR spectroscopy and SEC analysis. The aggregation behavior of the synthesized block copolymers was investigated by dynamic light scattering at 25°C in aqueous solutions. The hydrophobic model compounds Nile red and pyrene were efficiently incorporated into the copolymer aggregates in aqueous solutions. High partition coefficient values were determined by fluorescence spectroscopy. 相似文献
6.
Nikolaos Gialelis Ioannis G. Stratis 《Mathematical Methods in the Applied Sciences》2019,42(15):4939-4956
We show local existence of certain type of solutions for the Cauchy problem of the defocusing nonlinear Schrödinger equation with pure power nonlinearity, in various cases of open sets, unbounded or bounded. These solutions do not vanish at the boundary or at infinity. We also show, in certain cases, that these solutions are unique and global. 相似文献
7.
Stefania Corsaro Ioannis Kyriakou Daniele Marazzina Zelda Marino 《European Journal of Operational Research》2019,272(3):1082-1095
In this paper, we present a transform-based algorithm for pricing discretely monitored arithmetic Asian options with remarkable accuracy in a general stochastic volatility framework, including affine models and time-changed Lévy processes. The accuracy is justified both theoretically and experimentally. In addition, to speed up the valuation process, we employ high-performance computing technologies. More specifically, we develop a parallel option pricing system that can be easily reproduced on parallel computers, also realized as a cluster of personal computers. Numerical results showing the accuracy, speed and efficiency of the procedure are reported in the paper. 相似文献
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Xiaoli Liu Michelle M. T. Jansman Peter W. Thulstrup Ana C. Mendes Ioannis S. Chronakis Leticia Hosta‐Rigau 《Macromolecular bioscience》2020,20(2)
Despite all the attempts to create advanced hemoglobin (Hb)‐based oxygen carriers (HBOCs) employing an encapsulation platform, major challenges including attaining a high Hb loading and long circulation times still need to be overcome. Herein, the fabrication, for the first time, of nanoparticles fully made of Hb (Hb‐NPs) employing the electrospray technique is reported. The Hb‐NPs are then coated by antioxidant and self‐polymerized poly(dopamine) (PDA) to minimize the conversion of Hb into nonfunctional methemoglobin (metHb). The PDA shell is further functionalized with poly(ethylene glycol) (PEG) to achieve stealth properties. The results demonstrate that the as‐prepared Hb‐NPs are hemo‐ and biocompatible while offering antioxidant protection and decreasing the formation of metHb. Additionally, decoration with PEG results in decreased protein adsorption onto the Hb‐NPs surface, suggesting a prolonged retention time within the body. Finally, the Hb‐NPs also preserve the reversible oxygen‐binding and releasing properties of Hb. All in all, within this study, a novel HBOCs with high Hb content is fabricated and its potential as an artificial blood substitute is evaluated. 相似文献
10.
Konstantinos Petrotos Ioannis Giavasis Konstantinos Gerasopoulos Chrysanthi Mitsagga Chryssoula Papaioannou Paschalis Gkoutsidis 《Molecules (Basel, Switzerland)》2021,26(1)
Orange pomace (OP) is a solid waste produced in bulk as a byproduct of the orange juice industry and accounts for approximately 50% of the quantity of the fruits processed into juice. In numerous literature references there is information about diverse uses of orange pomace for the production of high-added-value products including production of natural antioxidant and antimicrobial extracts rich in polyphenols and flavonoids which can substitute the hazardous chemical antioxidants/antimicrobials used in agro-food and cosmetics sectors. In this work and for the first time, according to our knowledge, the eco-friendly aqueous vacuum microwave assisted extraction of orange pomace was investigated and optimized at real industrial scale in order to produce aqueous antioxidant/antimicrobial extracts. A Response Surface Optimization methodology with a multipoint historical data experimental design was employed to obtain the optimal values of the process parameters in order to achieve the maximum rates of extraction of OP total polyphenols and/or total flavonoids for economically optimum production at industrial scale. The three factors used for the optimization were: (a) microwave power (b) water to raw pomace ratio and (c) extraction time. Moreover, the effectiveness and statistical soundness of the derived cubic polynomial predictive models were verified by ANOVA. 相似文献