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991.
Paulo Ronaldo Sousa Teixeira Ana Siqueira do Nascimento Marreiro Teixeira Emanuel Airton de Oliveira Farias Durcilene Alves da Silva Lívio César Cunha Nunes Cleide Maria da Silva Leite Edson Cavalcanti da Silva Filho Carla Eiras 《Journal of Polymer Research》2018,25(5):127
The babassu coconut is a plant very abundant in northeast of Brazil and other countries, and any part of plant and fruit becomes residue. In this study, babassu mesocarp (Orbignya sp) (BM) was chemically modified with phthalic anhydride (BMPA) to increase its solubility in an aqueous medium, and thus facilitate its processing in the form of thin films. The reaction of modification of the babassu mesocarp with phthalic anhydride (PA), obtaining BMPA, was confirmed by FTIR, XRD, TG/DTG, Zeta Potential and SEM analysis, from the differences in the bands of the FTIR spectra, increase in crystallinity, new thermal profile, changes in zeta potential value and morphology, respectively. The thin monolayer films of BM and BMPA were produced by the self-assembly monolayer (SAM) technique, and adsorbed onto conductive glass substrates (tin-doped indium oxide, ITO). The electroactive properties of these thin films were evaluated by cyclic voltammetry (CV). BM exhibited a pair redox pair process of +0.57 V(oxidation) and?+?0.19 V (reduction) for BM. In BMPA these redox processes were observed at +0.37 V (oxidation) and 0.24 V vs. ECS (reduction), verifying that both BM and BMPA are electroactive materials that can be used in the construction of sensor platforms, without the necessity of being conjugated with other electroactive materials, such as conductive polymers, metal phthalocyanines, or dyes. Furthermore, under the experimental conditions used, the BMPA presented a more reversible redox process and higher electrochemical stability in comparison to BM. This effect occurs because BMPA has higher solubility in aqueous media, which favors the preparation of films with smaller grain sizes compared to BM films, as observed by Atomic Force Microscopy (AFM). This study showed that BMPA is a new material with potential for applications in electrochemical sensors. 相似文献
992.
Xavi Masip-Bruin Marcelo Yannuzzi Rene Serral-Gracia Jordi Domingo-Pascual Jose Enriquez-Gabeiras Maria Angeles Callejo Michel Diaz Florin Racaru Giovanni Stea Enzo Mingozzi Andrzej Beben Wojciech Burakowski Edmundo Monteiro Luís Cordeiro 《Communications Magazine, IEEE》2007,45(2):96-103
EuQoS is the acronym for "end-to-end quality of service support over heterogeneous networks", which is a European research project aimed at building an entire QoS framework, addressing all the relevant network layers, protocols, and technologies. This framework, which includes the most common access networks (xDSL, UMTS, WiFi, and LAN) is being prototyped and tested in a multidomain scenario throughout Europe, composing what we call the EuQoS system. In this article we present the novel QoS routing mechanisms that are being developed and evaluated in the framework of this project. The preliminary performance results validate the design choices of the EuQoS system, and confirm the potential impact this project is likely to have in the near future 相似文献
993.
Laura Menabò Alessandra Sansavini Antonella Brighi Grace Skrzypiec Annalisa Guarini 《Journal of Computer Assisted Learning》2021,37(6):1566-1577
Background: The rapid spread of COVID-19 forced many countries to adopt severe containment measures, transferring all didactic activities into virtual environments. However, the integration of technology in teaching may present difficulties, especially in some countries, such as Italy. Objectives: The present study analyzed how the two main factors of the Technology Acceptance Model (TAM), namely perceived usefulness and perceived ease of use, combined with online teaching self-efficacy, were associated with the intention to use technology to teach. We posited a moderated moderation model in which perceived usefulness represented the main predictor, with self-efficacy and perceived ease of use as moderators of intention to use technology to teach. Method: The model was tested through multiple regressions, using the PROCESS macro on SPSS 26 with a sample of 178 upper secondary school teachers in Italy. Results and conclusions: Regressions showed that each variable significantly predicted the intention to use technology. In addition, a moderation effect of self-efficacy on the perceived usefulness of using technology was found for medium and high-level of perceived ease of use of technology. Implications: The present study provides targeted implications for distance education policy and practice to promote its adoption (or the blended modality) in Italian upper schools. 相似文献
994.
Affine parameter estimation from the trace transform 总被引:2,自引:0,他引:2
Kadyrov A Petrou M 《IEEE transactions on pattern analysis and machine intelligence》2006,28(10):1631-1645
In this paper, we assume that we are given the images of two segmented objects, one of which may be an affinely distorted version of the other, and wish to recover the values of the parameters of the affine transformation between the two images. The images may also differ by the overall level of illumination. The multiplicative constant of such difference may also be recovered. We present a generic theoretical framework to solve this problem. In terms of this framework, other proposed methods may be interpreted. We show how, in this framework, one can recover the affine parameters in a way that is robust to various effects, such as occlusion and illumination variation. The proposed method is generic enough to be applicable also to matching two images that do not depict the same scene or object. 相似文献
995.
Comparative adsorption and precipitation squeezes carried out on field core materials demonstrate that significant lifetime enhancement is achievable for precipitation squeeze with respect to more conventional adsorption squeeze. Coreflood tests have been carried out under reservoir conditions (135°C) employing a poly-phosphinocarboxylate (PPCA) as the scales inhibitor. Field treatment simulations, carried out starting from coreflood data and considering the characteristics of a North Sea formation taken as the reference, confirmed the higher performance, in term of squeeze lifetime, of the precipitation squeeze with respect to adsorption. The results pointed out the importance of choosing the appropriate formulation once the operative conditions are known, in order to promote the inhibitor precipitation into the formation. Some implications of these results for the optimization of the precipitation squeeze technology for field applications, with particular emphasis to formation damage, are also discussed. 相似文献
996.
Martina Gensini Dr. Maria Altamura Dr. Tula Dimoulas Dr. Valentina Fedi Dr. Danilo Giannotti Dr. Sandro Giuliani Dr. Antonio Guidi Dr. Nicholas J. S. Harmat Dr. Stefania Meini Dr. Rossano Nannicini Franco Pasqui Manuela Tramontana Dr. Antonio Triolo Dr. Carlo Alberto Maggi Dr. 《ChemMedChem》2010,5(1):65-78
Herein we describe the synthesis of a series of new potent tachykinin NK2 receptor antagonists by the modulation of the C‐ and N‐terminal moieties of ibodutant (MEN 15596, 1 ). The N‐terminal benzo[b]thiophene ring was replaced by different substituted naphthalenes and benzofurans, while further modifications were evaluated at the C‐terminal tetrahydropyran moiety. Most compounds demonstrated a high affinity for the human NK2 receptor and high in vitro antagonist potency, indicating that a wide range of substituents at both termini can be incorporated in the molecule without detrimental effects on the interactions with the NK2 receptor. Selected compounds were tested in vivo confirming their activity as NK2 antagonists. In particular, after both iv and id administration to guinea pig, compound 61 b was able to antagonize NK2‐induced colonic contractions with a potency and duration‐of‐action fully comparable to the reference compound 1 (MEN 15596, ibodutant). 相似文献
997.
Gouveia Paula F. Mesquita-Guimarães Joana Galarraga-Vinueza Maria E. Souza Júlio C. M. Moreira Anderson C. Silva Filipe S. Fredel Márcio C. Henriques Bruno 《Journal of Materials Science》2021,56(20):11682-11697
Journal of Materials Science - The objective of this study was to develop a replica method for producing zirconia-reinforced bioactive glass (ZRBG) porous structures for bone... 相似文献
998.
999.
1000.
Maria Laura Di Lorenzo 《应用聚合物科学杂志》2010,116(3):1408-1413
The isothermal and nonisothermal crystallization kinetics of cis‐1,4‐polybutadiene has been investigated with respect to the content of cis units and the linearity of the main chain. The rate of spherulite growth increases with chain regularity as the presence of branches as well as segments with different configurations slows the crystallization rate. The major parameter that determines the crystallization rate is the presence in the formulation of heterogeneities that favor the formation of primary nuclei and determine an anticipated onset of crystallization. As the activity of the heterogeneous nuclei depends more on the type and number of foreign particle than on any chain parameter, no straightforward information on the influence of the chain structure on the crystallization rate can be derived by mere calorimetric analysis, at least for analyzed samples. It is only with combined analysis by optical microscopy that comprehensive information on the crystallization kinetics of cis‐1,4‐polybutadiene can be derived. The results reported in this contribution point out the importance, in polymer science, of preferring complementary instrumentation and not limiting experimental investigations to a single technique of analysis. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献