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121.
David Evangelista Diogo A. Gomes 《Journal of Dynamics and Differential Equations》2018,30(4):1365-1388
Mean-field games (MFGs) are models of large populations of rational agents who seek to optimize an objective function that takes into account their location and the distribution of the remaining agents. Here, we consider stationary MFGs with congestion and prove the existence of stationary solutions. Because moving in congested areas is difficult, agents prefer to move in non-congested areas. As a consequence, the model becomes singular near the zero density. The existence of stationary solutions was previously obtained for MFGs with quadratic Hamiltonians thanks to a very particular identity. Here, we develop robust estimates that give the existence of a solution for general subquadratic Hamiltonians. 相似文献
122.
Pablo R. Cortez Tornello Gabriela E. Feresin Alejandro Tapia Teresita R. Cuadrado 《Soft Materials》2018,16(1):51-61
Polymeric electrospun meshes are highly attractive as versatile platforms for numerous biomedical applications, tissue engineering, biosensors, and controlled release of bioactive agents. Herein, we describe the preparation and characterization of multilayered nanofibrous poly(ε-caprolactone) scaffolds with different embelin content by electrospinning technique. In vitro release in physiological and acidic pH and kinetic analysis were performed. The results show that it is possible to modulate the release profile depending on the number and thickness of layers added to drug-loaded scaffold that acts as an embelin reservoir. Electrospun multilayered scaffolds present characteristics, morphology and release profiles that could be very attractive for use as embelin controlled release systems. 相似文献
123.
Tatiane Melina Guerreiro Diogo Noin de OliveiraMônica Siqueira Ferreira Rodrigo Ramos Catharino 《Analytica chimica acta》2014
Balsamic vinegar (BV) is a typical and valuable Italian product, worldwide appreciated thanks to its characteristic flavors and potential health benefits. Several studies have been conducted to assess physicochemical and microbial compositions of BV, as well as its beneficial properties. Due to highly-disseminated claims of antioxidant, antihypertensive and antiglycemic properties, BV is a known target for frauds and adulterations. For that matter, product authentication, certifying its origin (region or country) and thus the processing conditions, is becoming a growing concern. Striving for fraud reduction as well as quality and safety assurance, reliable analytical strategies to rapidly evaluate BV quality are very interesting, also from an economical point of view. This work employs silica plate laser desorption/ionization mass spectrometry (SP-LDI-MS) for fast chemical profiling of commercial BV samples with protected geographical indication (PGI) and identification of its adulterated samples with low-priced vinegars, namely apple, alcohol and red/white wines. 相似文献
124.
Rui L. Aguiar Diogo Gomes João Paulo Barraca Nuno Lau 《Wireless Personal Communications》2014,76(2):231-244
Mobile robotics is a transforming field that presents a varying set of challenges. The discussion on the autonomy of (self-powered) robots is not settled, and as the communication infrastructure evolves, centralized concepts become more attractive over distributed concepts. This paper presents the CloudThinking architecture applied to intelligent cloud-based robotic operation. CloudThinking offloads most of complex robotic tasks to a central cloud, which retrieves inputs from the environment as a whole in order to instruct the robots to perform its actions. CloudThinking is a natural approach to the orchestration of multiple specialized robotic systems, defining the best mechanisms for reaching a goal. Furthermore, this architecture provides a set of automatic features which can be useful for application developers. These features can fully exploit novel cloud tools development as it becomes available, providing a time-resilient infrastructure of easy upgrade. The resulting approach has the potential to create a different set of market for robotic application developers. 相似文献
125.
Mafalda Cortez Gijs Roelofs Said Hamdioui Giorgio Di Natale 《Journal of Electronic Testing》2014,30(5):581-594
Design for test is an integral part of any VLSI chip. However, for secure systems extra precautions have to be taken to prevent that the test circuitry could reveal secret information. This paper addresses secure test for Physical Unclonable Function based systems. It investigates two secure Built-In Self-Test (BIST) solutions for Fuzzy Extractor (FE) which is the main component of PUF-based systems. The schemes target high stuck-at-fault (SAF) coverage by performing scan-chain free functional testing, to prevent scan-chain abuse for attacks. The first scheme reuses existing FE blocks (for pattern generation and compression) to minimize the area overhead, while the second scheme tests all the FE blocks simultaneously to minimize the test time. The schemes are integrated in FE design and simulated; the results show that for the first test scheme, a SAF fault coverage of 95 % can be realized with no more than 47.1k clock cycles at the cost of a negligible area overhead of only 2.2 %; while for the second test scheme a SAF fault coverage of 95 % can be realized with 3.5k clock cycles at the cost of 18.6 % area overhead. Higher fault coverages are possible to realize at extra cost (i.e., either by extending the test time, or by adding extra hardware, or a combination of both). 相似文献
126.
Coutu R.A. Jr. Reid J.R. Cortez R. Strawser R.E. Kladitis P.E. 《Components and Packaging Technologies, IEEE Transactions on》2006,29(2):341-349
This paper is the first to report on a new analytic model for predicting microcontact resistance and the design, fabrication, and testing of microelectromechanical systems (MEMS) metal contact switches with sputtered bimetallic (i.e., gold (Au)-on-Au-platinum (Pt), (Au-on-Au-(6.3at%)Pt)), binary alloy (i.e., Au-palladium (Pd), (Au-(3.7at%)Pd)), and ternary alloy (i.e., Au-Pt-copper (Cu), (Au-(5.0at%)Pt-(0.5at%)Cu)) electric contacts. The microswitches with bimetallic and binary alloy contacts resulted in contact resistance values between 1-2/spl Omega/. Preliminary reliability testing indicates a 3/spl times/ increase in switching lifetime when compared to microswitches with sputtered Au electric contacts. The ternary alloy exhibited approximately a 6/spl times/ increase in switch lifetime with contact resistance values ranging from approximately 0.2-1.8/spl Omega/. 相似文献
127.
Bernardes CE Minas da Piedade ME Amaral LM Ferreira AI Ribeiro da Silva MA Diogo HP Costa Cabral BJ 《The journal of physical chemistry. A》2007,111(9):1713-1720
The energetics of the C-F, C-Cl, C-Br, and C-I bonds in 2-haloethanols was investigated by using a combination of experimental and theoretical methods. The standard molar enthalpies of formation of 2-chloro-, 2-bromo-, and 2-iodoethanol, at 298.15 K, were determined as Delta(f)H(degree)m(CH2CH2OH, l) = -315.5 +/- 0.7 kJ.mol-1, Delta(f)H(degree)mBrCH2CH2OH, l) = -275.8 +/- 0.6 kJ.mol-1, Delta(f)H(degree)m(ICH2CH2OH, l) = -207.3 +/- 0.7 kJ.mol-1, by rotating-bomb combustion calorimetry. The corresponding standard molar enthalpies of vaporization, Delta(vap)H(degree)m(ClCH2CH2OH) = 48.32 +/- 0.37 kJ.mol-1, Delta(vap)H(degree)m(BrCH2CH2OH) = 54.08 +/- 0.40 kJ.mol-1, and Delta(vap)H(degree)m(ICH2CH2OH) = 57.03 +/- 0.20 kJ.mol-1 were also obtained by Calvet-drop microcalorimetry. The condensed phase and vaporization enthalpy data lead to Delta(f)H(degree)m(ClCH2CH2OH, g) = -267.2 +/- 0.8 kJ.mol-1, Delta(f)H(degree)m(BrCH2CH2OH, g) = -221.7 +/- 0.7 kJ.mol-1, and Delta(f)H(degree)m(ICH2CH2OH, g) = -150.3 +/- 0.7 kJ.mol-1. These values, together with the enthalpy of selected isodesmic and isogyric gas-phase reactions predicted by density functional theory (B3LYP/cc-pVTZ) and CBS-QB3 calculations were used to derive the enthalpies of formation of gaseous 2-fluoroethanol, Delta(f)H(degree)m(FCH2CH2OH, g) = -423.6 +/- 5.0 kJ.mol-1, and of the 2-hydroxyethyl radical, Delta(f)H(degree)m(CH2CH2OH, g) = -28.7 +/- 8.0 kJ.mol-1. The obtained thermochemical data led to the following carbon-halogen bond dissociation enthalpies: DHo(X-CH2CH2OH) = 474.4 +/- 9.4 kJ.mol-1 (X = F), 359.9 +/- 8.0 kJ.mol-1 (X = Cl), 305.0 +/- 8.0 kJ.mol-1 (X = Br), 228.7 +/- 8.1 kJ.mol-1 (X = I). These values were compared with the corresponding C-X bond dissociation enthalpies in XCH2COOH, XCH3, XC2H5, XCH=CH2, and XC6H5. In view of this comparison the computational methods mentioned above were also used to obtain Delta(f)H(degree)m-594.0 +/- 5.0 kJ.mol-1 from which DHo(F-CH2COOH) = 435.4 +/- 5.4 kJ.mol-1. The order DHo(C-F) > DHo(C-Cl) > DHo(C-Br) > DHo(C-I) is observed for the haloalcohols and all other RX compounds. It is finally concluded that the major qualitative trends exhibited by the C-X bond dissociation enthalpies for the series of compounds studied in this work can be predicted by Pauling's electrostatic-covalent model. 相似文献
128.
L. A. B. Cortez 《International Journal of Mathematical Education in Science & Technology》2017,48(4):630-641
Considering the important role played by mathematical derivatives in the study of physical–chemical processes, this paper discusses the different possibilities and formulations of this concept and its application. In particular, in Chemical Thermodynamics, we study exact differentials associated with the so-called state functions and inexact differentials associated with path functions. As an application, we discuss the equation of state associated with a gas. 相似文献
129.
130.
Photochemical conversions are cost-effective and environmental friendly processes that require mild experimental conditions and avoid generation of highly acidic wastes. Treated samples are then compatible with most of the analytical techniques. These characteristics become more relevant when the photoconversions are accomplished to flow analysis, thus allowing exploitation of incomplete reactions, the effective use of the photogenerated unstable radicals and in-line sample treatment. Decreasing of reagent consumption and waste generation, sample processing in a closed environment, and improvement of efficiency of the photochemical processes are other inherent advantages. These aspects are critically reviewed in this article, which emphasizes applications to fractionation and speciation analysis, photo-induced luminescence, miniaturization, and in-line waste treatment. Design of flow-through photochemical cells, use of auxiliary reagents in homogeneous and heterogeneous media, and configurations of flow manifolds are also discussed. 相似文献