With the final phase of the European Monetary Union underway, concern has been raised over the regional implications of the European Central Bank (ECB) Monetary Policy. Departing from the standard ...approach utilized by the ECB, this book provides a comprehensive theoretical framework to explore the ways through which money and monetary policy may affect regions. Carlos Rodriguez Fuentes, the rising star of Spanish economics, has produced a work of impressive clarity which analyzes the effects of regional monetary policy - with particular reference to European Monetary Union. Here, he examines the role that the banking system and the liquidity preference of economic agents play in the transmission of central banks monetary policy decisions to regions within a country or countries within a currency union. Rodriguez Fuentes utilizes a unique framework built upon the basic principle of the Post-Keynsian monetary theory which enables the identification of a new way for money and monetary policy to have a regional impact; the behavioural effect. This book, with it’s combination of literary and empirical approach will prove essential reading for all students of economics and politics, as well as readers who interested in the development of the European Union.
Summary
In this article, an analysis of chattering in systems driven by Lipschitz continuous sliding‐mode controllers (LCSMC) is performed using the describing function approach. Two kinds of LCSMC ...are considered: the first one is based on a linear sliding variable (LSV) and the second one on a terminal sliding variable (TSV). Predictions of amplitude, frequency, and average power of self‐excited oscillations, are used to compare such LCSMC respect to the supertwisting controller (STC) in systems with fast‐actuators. Theoretical predictions and simulations allow the following conclusions: (i) LCSMC still may induce fast‐oscillations (chattering) of smaller amplitude and average power, than ones caused by the STC in the absence of the measurement noises. (ii) The level of chattering with LSV‐LCSMC could be smaller than one produced by TSV‐LCSMC. (iii) The zero (sliding) dynamics of the LSV‐LCSMC cannot be arbitrarily fast or the closed‐loop system may lose even practical stability, unlike the TSV‐LCSMC whose trajectories are finally bounded.
Wettability of a Single Carbon Fiber Qiu, Si; Fuentes, Carlos A; Zhang, Dongxing ...
Langmuir,
09/2016, Letnik:
32, Številka:
38
Journal Article
Recenzirano
Wettability as determined from contact angle measurements is a suitable parameter for characterizing the physical bonding of a polymer matrix and reinforcing fibers, but it is very challenging to ...measure the capillary force exerted by a probe liquid on a fiber accurately for very fine fibers such as single carbon fibers. Herein, we propose an innovative method for measuring dynamic contact angles with a tensiometer, considering both the intrinsic variability of the carbon fiber diameter and the extremely small amplitude of the capillary forces, allowing the measurement of reliable dynamic contact angles over a large range of contact line velocities. The analysis of the contact angle dynamics by the molecular-kinetic theory permits us to check the relevancy of the measured contact angles and to obtain the static contact angle value, improving the prospect of employing tensiometry to better understand the wetting behavior of carbon fibers.
For large-scale photovoltaic (PV) systems, the multistring configuration is becoming more and more attractive compared with the classical central inverter, since it results in better energy yield by ...realizing distributed maximum power point tracking. Among the existing solutions, an attractive topology consists in a single dc bus bar collector cascaded H-bridge (CHB) inverter. Through the use of a single dc bus bar collector, the CHB inverter presents inherent balanced operation while the multistring PV-system is fully decoupled from the grid-tie inverter. This paper proposes the experimental validation of this structure on a reduced-size single-phase laboratory prototype. Results confirm the interest of the proposed PV multistring architecture.
Wettability of carbon nanotube fibers Zhang, Luman; Wang, Jian; Fuentes, Carlos A. ...
Carbon (New York),
October 2017, 2017-10-00, 20171001, Letnik:
122
Journal Article
Recenzirano
Carbon nanotube (CNT) fibers are interesting alternatives to carbon fibers as fibrous reinforcement. However, good interfacial adhesion between the fibers and the matrix is difficult to control. ...Wetting of the fiber reinforcement with the matrix strongly determines the interfacial strength. Therefore, accurate characterization of the wettability of CNT fibers is one of the most important cornerstones to improve the interfacial adhesion. In this work, dynamic contact angle measurements were conducted on individual CNT fibers by using a modified tensiometric method based on the Wilhelmy method combined with a synchronized optical observation. The CNT fiber-liquid interactions were monitored in-situ, and accurate measurements of the contact angles were achieved. Contact angles on CNTs were estimated through a modified Cassie-Baxter model on the basis of the experimental contact angle values of CNT fibers. Subsequently, the non-polar and polar surface energy components of the CNTs were obtained. Then, the wetting parameters (work of adhesion, spreading coefficient and wetting tension) were predicted by using the surface energy values of both the CNTs and a series of polymers (PP, MAPP, PET, PVDF, and PVA). The results indicate that PVA is in terms of wetting the most suitable matrix for the preparation of CNT fiber polymer composites.
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Anisotropic NMR spectroscopy, revealing residual dipolar couplings (RDCs) and residual chemical shift anisotropies (RCSAs) has emerged as a powerful tool to determine the configurations of synthetic ...and complex natural compounds. The deduction of the absolute in addition to the relative configuration is one of the primary goals in the field. Therefore, the investigation of the enantiodiscriminating capabilities of chiral alignment media becomes essential. While RDCs and RCSAs are now used for the determination of the relative configuration routinely, RCSAs have not been measured in chiral alignment media such as chiral liquid crystals. Herein, we present this application by measuring RCSAs for chiral analytes such as indanol and isopinocampheol in the lyotropic liquid crystalline phase of an L‐valine derived helically chiral polyacetylenes. We have also demonstrated that a single 1D 13C−{1H} NMR spectrum suffices to get the RCSAs circumventing the necessity to acquire two spectra at two alignment conditions.
The residual chemical shift anisotropy can be acquired from enantiomers employing biphasic helically chiral polyacetylene liquid crystal from a single 1D carbon spectrum. The chiral environment of the liquid crystal facilitates diastereomorphous interactions of enantiomers and leads to two different sets of RCSAs. On the basis of two chiral molecules, it has been demonstrated that enantiodiscrimination is feasible
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Measuring contact angles made by liquids around individual carbon fibers (CFs) using the Wilhelmy technique is a conventional method to evaluate their surface properties. However, ...despite its apparent simplicity, inaccurate measurements of capillary forces and wetted lengths, due to the fineness of the CFs, as well as an improper selection of probe liquids can lead to incorrect contact angle and surface energy calculations, leading to an erroneous characterization of their surface properties.
In this study, dynamic wetting experiments of individual CFs were performed in ethylene glycol, diiodomethane, and formamide based on the Wilhelmy method. Capillary forces exerted on the CFs were recorded and analyzed in detail to calculate reliable dynamic contact angles at different contact-line velocities. The molecular-kinetic theory (MKT) and hydrodynamic approach (HD) were then used to model the experimental data and to obtain static contact angles.
The analysis shows that the experimental data are in good agreement with the linear MKT suggesting that the dominant channel of energy dissipation at the contact line is the contact-line friction. From the predicted static advancing contact angle values, the surface energy components of the CFs could be obtained thus providing a way to characterize their interfacial properties and predict their compatibility with polymer matrices. This study furthermore points out the importance of choosing the correct combination of test fluids to obtain reliable surface energy results.
•PLC-5 is adequate to detect probable PTSD cases after a natural disaster in Mexicans.•The 8-item PCL-5 is recommended for screening and monitoring PTSD symptoms.•The 8-item PCL-5 showed more ...consistent diagnostic utility across time.
Posttraumatic stress disorder (PTSD) is a common and disabling condition developing in one of four survivors after an earthquake. Brief and self-reported validated measures for assessing PTSD symptom severity are necessary to improve care access and assess disorder progress and treatment response. Therefore, we evaluated the psychometric properties of the PTSD-Checklist for the DSM-5 (PCL-5) of 20-, 8- and 4-item in patients that sought specialized mental health services after a catastrophic earthquake that stroke Mexico on September 19th, 2017. The internal consistency of 20-, 8- and 4-item PCL-5 was adequate (≥.7). Using the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) as a reference, signal detection analyses revealed a PCL-5 score of 27 as optimal (sensitivity = .96, specificity = .73) for identifying probable PTSD cases. The shortened versions highly correlated with the full PCL-5 and had comparable diagnostic utility. Our results indicate that the 20-item PCL-5 and the abridged versions can effectively identify possible PTSD cases. The 8-item version has better psychometric properties and more consistent diagnostic utility across time and civil populations. These measures must be evaluated in independent samples to corroborate their utility in different populations and regarding diverse traumatic events.
The aim of this study is the deduction of an analytic representation of the optimal irrigation flow depending on the border length, hydrodynamic properties, and soil moisture constants, with high ...values of the coefficient of uniformity. In order not to be limited to the simplified models, the linear relationship of the numerical simulation with the hydrodynamic model, formed by the coupled equations of Barré de Saint-Venant and Richards, was established. Sample records for 10 soil types of contrasting texture were used and were applied to three water depths. On the other hand, the analytical representation of the linear relationship using the Parlange theory of infiltration proposed for integrating the differential equation of one-dimensional vertical infiltration was established. The obtained formula for calculating the optimal unitary discharge is a function of the border strip length, the net depth, the characteristic infiltration parameters (capillary forces, sorptivity, and gravitational forces), the saturated hydraulic conductivity, and a shape parameter of the hydrodynamic characteristics. The good accordance between the numerical and analytical results allows us to recommend the formula for the design of gravity irrigation.
Suicide is a major public health problem in Mexico and around the world. Genetic predisposition for major depressive disorder (MDD) has been associated with increased risk for suicidal behaviors (SB) ...in populations of European ancestry (EA). Here, we examine whether MDD polygenic risk scores (MDD PRS), derived from a genome‐wide association study involving EA individuals, predict SB, including ideation, planning, and attempt, among Mexican youth using a longitudinal design. At baseline, participants (N = 1,128, 12–17 years, 55% women) were interviewed and genotyped as part of a general population survey on adolescent mental health. Eight years later, they were recontacted for a follow up visit (N = 437, 20–25 years, 63% women). At both assessments, individuals reported on their engagement in SB within the past year. MDD PRS were significantly positively associated with SB, particularly suicide ideation and planning during adolescence, accounting for ~4–5% of the variance in these outcomes. In contrast, associations between MDD PRS and SB during young adulthood did not reach statistical significance. Our results suggest that increased genetic liability for depression increased risk for SB, particularly during adolescence, expanding our knowledge of the genetic underpinnings of SB.
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