A Passivity-Based High-Bandwidth Voltage Control for Grid-Forming Inverters

The increasing number of power electronic devices connected to the power system is leading it to new stability challenges. The uncertainty of the grid-model may complicate the controller design and compromise stability. As a countermeasure, LQR and pole-placement techniques can be re-oriented to design for passivity, which is leading to new controller design paradigms. Nevertheless, as a general rule, all the variables of the system are considered in the full bandwidth, which may become unfeasible or costly in the industrial scenario. An original controller design technique for LC or LCL filter which accomplishes passivity in a wide range of frequency is proposed. Besides, it reduces the voltage sensor needs, even controlling it, being suitable for Grid-Forming. As consequence, the complexity of the software, hardware and price are reduced. Experimental verification is provided: impedance of the converter from the grid side and response against a changes in the reference/load

Experimental artifact in MOKE measurements when using paramagnetic sample holders

We describe here an artifact that may affect to magneto-optical Kerr measurements. When paramagnetic sample holders (SH) with non-negligible susceptibilities are used, the inhomogeneity of the applied magnetic field can induce forces and torques on it, shifting the reflected beam, and altering its intensity at the photodetector. The effect is even and can be avoided using low susceptibility paramagnetic or diamagnetic SH We also present a detailed analytical description of the magnetic forces involved and provide some estimated values of the SH shifting, showing that they might distort the magneto-optical Kerr effect signal. Moreover, in this paper we show how the artifact can be removed from the experimental curves with an appropriated data analysis.Fil: Munoz-Noval, Alvaro. Comunidad de Madrid; EspañaFil: Bonin, Claudio Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; ArgentinaFil: Bonetto, Fernando Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; ArgentinaFil: Garcia, Miguel Angel. Institute For Ceramic And Glass; Españ

Removal of urothelium affects bladder contractility and release of ATP but not release of NO in rat urinary bladder

<p>Abstract</p> <p>Background</p> <p>The objective of our work was to investigate both the contractile function and the release of ATP and NO from strips of bladder tissue after removal of the urothelium.</p> <p>Methods</p> <p>The method of removal was a gentle swabbing motion rather than a sharp surgical cutting to separate the urothelium from the smooth muscle. The contractile response and ATP and NO release were measured in intact as well as on swabbed preparations. The removal of the urothelial layer was affirmed microscopically.</p> <p>Results</p> <p>After the swabbing, the smaller contractions were evoked by electrical as well as by chemical stimulation (50 μM carbachol or 50 μM α, β meATP). Electrical stimulation, carbachol and substance P (5 μM) evoked lower release of ATP in the swabbed strips than in intact strips. Although release of NO evoked by electrical stimulation or substance P was not changed, release of NO evoked by carbachol was significantly less in the swabbed preparations.</p> <p>Conclusion</p> <p>Since swabbing removes only the urothelium, the presence of the suburothelial layer may explain the difference between our findings and those of others who found an increase in contractility. Evoked release of ATP is reduced in swabbed strips, indicating that ATP derives solely from the urothelium. On the other hand, electrical stimulation and substance P evoke identical degrees of NO release in both intact and swabbed preparations, suggesting that NO can be released from the suburothelium. Conversely, carbachol-induced release of NO is lower in swabbed strips, implying that the cholinergic receptors (muscarinic or nicotinic) are located in the upper layer of the urothelium.</p

Internet-based training of coronary artery patients: the Heart Cycle Trial

© 2016, Springer Japan. Low adherence to cardiac rehabilitation (CR) might be improved by remote monitoring systems that can be used to motivate and supervise patients and tailor CR safely and effectively to their needs. The main objective of this study was to evaluate the feasibility of a smartphone-guided training system (GEX) and whether it could improve exercise capacity compared to CR delivered by conventional methods for patients with coronary artery disease (CAD). A prospective, randomized, international, multi-center study comparing CR delivered by conventional means (CG) or by remote monitoring (IG) using a new training steering/feedback tool (GEx System). This consisted of a sensor monitoring breathing rate and the electrocardiogram that transmitted information on training intensity, arrhythmias and adherence to training prescriptions, wirelessly via the internet, to a medical team that provided feedback and adjusted training prescriptions. Exercise capacity was evaluated prior to and 6 months after intervention. 118 patients (58 ± 10 years, 105 men) with CAD referred for CR were randomized (IG: n = 55, CG: n = 63). However, 15 patients (27 %) in the IG and 18 (29 %) in the CG withdrew participation and technical problems prevented a further 21 patients (38 %) in the IG from participating. No training-related complications occurred. For those who completed the study, peak VO 2 improved more (p = 0.005) in the IG (1.76 ± 4.1 ml/min/kg) compared to CG (−0.4 ± 2.7 ml/min/kg). A newly designed system for home-based CR appears feasible, safe and improves exercise capacity compared to national CR. Technical problems reflected the complexity of applying remote monitoring solutions at an international level

A pivotal year for Bolivian conservation policy

Non peer reviewe

Contenido de la causal de termino de contrato de trabajo por caso fortuito o fuerza mayor

44 p. La siguiente tesis no es autorizada por el autor para su difusión en formato digitalEl término de contrato de trabajo se presenta como una de las ramas del derecho laboral más discutidas y abiertas al debate. Dentro de las causales anteriores es que surge el despido por caso fortuito o fuerza mayor, consagrado en el artículo 159 nº 6 del Código del Trabajo. Para aplicarla, se deben reunir los siguientes requisitos, que se desprenden del Código Civil, donde sí ha sido consagrado: que sea imprevisible, que sea inimputable a las partes y que sea irresistible en cuanto a sus efectos. El derecho del trabajo agrega un cuarto requisito, cual es la causalidad del hecho. La presente memoria analiza doctrina y jurisprudencia, con el fin de conocer el contenido de la causal. Esto, con el fin de delimitar los requisitos de su aplicación, para no ir en desmedro del trabajador, el cual quedaría sin las indemnizaciones legales respectivas./ Abstract. The employment contract termination is presented as a branch of labour law more discussed and open to debate. Within the previous grounds is that arises the dismissal by unforeseeable circumstances or force majeure, enshrined in article 159 n°6 of the Labour. To be applied, must meet the following requirements arising from the civil code, where it has been consecrated: it’s unpredictable, being not subject to prosecution to the parties, and be irresistible in terms of their effects. The labour law adds a fourth requirement, which is the causality of the fact. This report analyzes doctrine and jurisprudence, to acquaint the causal. This, in order to delimit the requirements of it’s application, to not be at the detriment of the worker, who would not receive the respective legal compensation

Habitat differences filter functional diversity of low dispersive microscopic animals (Acari, Halacaridae)

We are starting to appreciate that microscopic animals are not as widespread as previously thought, but we still ignore to what extent and through which mechanisms the environment selects for specific communities or traits in microscopic animals. We here analyse the functional diversity of marine mite communities living in a seagrass meadow across two habitats: the leaves and the matte. The strictly benthic lifestyle and the conserved morphology of mites allow for unambiguous characterisation of their functional traits, while the discrete nature of the two habitats alleviates the uncertainty in their ecological characterisation. Our results show that habitat filters the distribution of certain traits favouring a higher diversity, dispersion, and evenness of functional traits in the matte than in the leaves. We further observed temporal variations in the functional diversity of communities, following the changes in biomass and structure of seagrass leaves. However, despite the stark differences between the two habitats, the filtering effect is partial and affects mostly relative species abundances. Our study emphasises the need of moving from a taxonomical towards a functional view of ecological studies of microscopic organisms. This integrative approach is key to achieve a mechanistic understanding of their habitat and distribution patterns.Peer reviewe

Stated benefits from air quality improvement through urban afforestation in an arid city – A contingent valuation in Mexicali, Baja California, Mexico

Cities in drylands are expected to experience increasing challenges when it comes to air pollution. Currently, concentrations of particulate matter in these cities frequently reach dangerous levels. Urban afforestation represents an alternative to increase human health in arid cities via air-filtering and dry deposition. By simulating a non-existing market through a contingent valuation protocol, this study estimates the willingness to contribute monetarily to an urban afforestation scenario in Mexicali -an arid city located at the US-Mexico border. We estimate an average annual willingness to pay (WTP) of (2019) USD 88 per household. Variations in WTP are associated with the respondent's perception of air quality and the presence of respiratory symptoms in the respondent's household. The smallest WTP (USD 75) is reported by those perceiving poor air quality in their neighborhood and with no household members affected by respiratory symptoms. Respondents perceiving good air quality and with at least one household member facing respiratory symptoms report a WTP of USD 99. The highest WTP represents around 0.8 % of the annual household income. This WTP, when extrapolated to and aggregated over the total number of households in Mexicali, justifies the implementation of an urban afforestation program supplying 30 thousand tree seedlings annually