18 research outputs found

    Overview of wind energy conversion systems development, technologies and power electronics research trends

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    Wind energy use has shown a remarkable increase in last years. In order to achieve the highest efficiency with the best characteristics in wind turbines, it is necessary to analyze relevant factors in wind energy conversion. In this review a state of the art is presented focused on modeling, constitutive elements, structure and control of wind generation systems and the increasing use of wind energy worldwide is evidenced.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI

    Model-Based Predictive Rotor Current Control Strategy for Indirect Power Control of a DFIM Driven by an Indirect Matrix Converter

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    This paper presents a new control strategy using model-based predictive current control (MB-PCC) for a doubly fed induction machine (DFIM) driven by an indirect matrix converter (IMC). This strategy proposes the control of rotor currents, whose references are calculated from active and reactive stator power set points and the dynamic model of the DFIM. The control strategy works well in the four P-Q operating regions of the DFIM. The grid synchronization process is carried out by setting the P-Q power set points to zero. The results presented include the DFIM synchronization procedure as well as the active and reactive power control at variable shaft speed to validate the feasibility of the proposed strategy

    Industrial, Collaborative and Mobile Robotics in Latin America: Review of Mechatronic Technologies for Advanced Automation

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    Mechatronics and Robotics (MaR) have recently gained importance in product development and manufacturing settings and applications. Therefore, the Center for Space Emerging Technologies (C-SET) has managed an international multi-disciplinary study to present, historically, the first Latin American general review of industrial, collaborative, and mobile robotics, with the support of North American and European researchers and institutions. The methodology is developed by considering literature extracted from Scopus, Web of Science, and Aerospace Research Central and adding reports written by companies and government organizations. This describes the state-of-the-art of MaR until the year 2023 in the 3 Sub-Regions: North America, Central America, and South America, having achieved important results related to the academy, industry, government, and entrepreneurship; thus, the statistics shown in this manuscript are unique. Also, this article explores the potential for further work and advantages described by robotic companies such as ABB, KUKA, and Mecademic and the use of the Robot Operating System (ROS) in order to promote research, development, and innovation. In addition, the integration with industry 4.0 and digital manufacturing, architecture and construction, aerospace, smart agriculture, artificial intelligence, and computational social science (human-robot interaction) is analyzed to show the promising features of these growing tech areas, considering the improvements to increase production, manufacturing, and education in the Region. Finally, regarding the information presented, Latin America is considered an important location for investments to increase production and product development, taking into account the further proposal for the creation of the LATAM Consortium for Advanced Robotics and Mechatronics, which could support and work on roboethics and education/R+D+I law and regulations in the Region. Doi: 10.28991/ESJ-2023-07-04-025 Full Text: PD

    Global disparities in surgeons’ workloads, academic engagement and rest periods: the on-calL shIft fOr geNEral SurgeonS (LIONESS) study

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    : The workload of general surgeons is multifaceted, encompassing not only surgical procedures but also a myriad of other responsibilities. From April to May 2023, we conducted a CHERRIES-compliant internet-based survey analyzing clinical practice, academic engagement, and post-on-call rest. The questionnaire featured six sections with 35 questions. Statistical analysis used Chi-square tests, ANOVA, and logistic regression (SPSS® v. 28). The survey received a total of 1.046 responses (65.4%). Over 78.0% of responders came from Europe, 65.1% came from a general surgery unit; 92.8% of European and 87.5% of North American respondents were involved in research, compared to 71.7% in Africa. Europe led in publishing research studies (6.6 ± 8.6 yearly). Teaching involvement was high in North America (100%) and Africa (91.7%). Surgeons reported an average of 6.7 ± 4.9 on-call shifts per month, with European and North American surgeons experiencing 6.5 ± 4.9 and 7.8 ± 4.1 on-calls monthly, respectively. African surgeons had the highest on-call frequency (8.7 ± 6.1). Post-on-call, only 35.1% of respondents received a day off. Europeans were most likely (40%) to have a day off, while African surgeons were least likely (6.7%). On the adjusted multivariable analysis HDI (Human Development Index) (aOR 1.993) hospital capacity > 400 beds (aOR 2.423), working in a specialty surgery unit (aOR 2.087), and making the on-call in-house (aOR 5.446), significantly predicted the likelihood of having a day off after an on-call shift. Our study revealed critical insights into the disparities in workload, access to research, and professional opportunities for surgeons across different continents, underscored by the HDI

    Reduce tu Gasto de Luz

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    En forma de un caso ejemplo se realizó un video en donde se explican los beneficios económicos y ambientales de la instalación de paneles solares en una vivienda promedio en Monterrey

    Norfloxacin prophylaxis effect on multidrug resistance in patients with cirrhosis and bacterial infections

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    It is unclear whether norfloxacin predisposes to infections by multidrug-resistant organisms (MDROs). We aimed to evaluate if patients with cirrhosis receiving norfloxacin prophylaxis at the time of the diagnosis of bacterial infections were more likely to present a multidrug-resistant isolate than those without prophylaxis. This is a cross-sectional study of hospitalized patients with cirrhosis and bacterial infections from Argentina and Uruguay (NCT03919032) from September 2018 to December 2020. The outcome variable was a multidrug-resistant bacterial infection. We used inverse probability of treatment weighting to estimate the odds ratio (OR) of norfloxacin on infection caused by MDROs considering potential confounders. Among the 472 patients from 28 centers, 53 (11%) were receiving norfloxacin at the time of the bacterial infection. Patients receiving norfloxacin had higher MELD-sodium, were more likely to have ascites or encephalopathy, to receive rifaximin, beta-blockers, and proton-pump inhibitors, to have a nosocomial or health-care-associated infection, prior bacterial infections, admissions to critical care units or invasive procedures, and to be admitted in a liver transplant center. In addition, we found that 13 (24.5%) patients with norfloxacin and 90 (21.5%) of those not receiving it presented infections caused by MDROs (adjusted OR 1.55; 95% CI: 0.60–4.03; p = 0.360). The use of norfloxacin prophylaxis at the time of the diagnosis of bacterial infections was not associated with multidrug resistance. These results help empiric antibiotic selection and reassure the current indication of norfloxacin prophylaxis in well-selected patients. Study registration number: NCT03919032Fil: Marciano, Sebastián. Hospital Italiano; ArgentinaFil: Gutierrez Acevedo, Maria N.. Hospital 4 de Junio; ArgentinaFil: Barbero, Sabrina. Complejo Medico Policial Bartolome Churruca Andres Visca; ArgentinaFil: del C. Notari, Lorena. Complejo Medico Policial Bartolome Churruca Andres Visca; ArgentinaFil: Agozino, Marina. Sanatorio Guemes; ArgentinaFil: Fernandez, Jose L.. Sanatorio Guemes; ArgentinaFil: Anders, Maria M.. Hospital Alemán; ArgentinaFil: Grigera, Nadia. Hospital Alemán; ArgentinaFil: Antinucci, Florencia. Hospital Alemán; ArgentinaFil: Orozco Ganem, Orlando F.. Hospital Aleman; ArgentinaFil: Murga, Maria D.. Hospital A. C. Padilla; ArgentinaFil: Perez, Daniela. Hospital A. C. Padilla; ArgentinaFil: Palazzo, Ana. Hospital A. C. Padilla; ArgentinaFil: Martinez Rejtman, Liria. Hospital Teodoro J. Schestakow; ArgentinaFil: Duarte, Ivonne G.. Hospital 4 de Junio; ArgentinaFil: Vorobioff, Julio. Hospital Provincial del Centenario; ArgentinaFil: Trevizan, Victoria. Hospital Provincial del Centenario; ArgentinaFil: Bulaty, Sofía. Hospital Provincial del Centenario; ArgentinaFil: Bessone, Fernando. Hospital Provincial del Centenario; ArgentinaFil: Valverde, Marcelo. Hospital de Clinicas Dr. Manuel Quintela; UruguayFil: Elizondo, Martín. Hospital de Clinicas Dr. Manuel Quintela; UruguayFil: Bosia, José D.. Hospital Prof. Rodolfo Rossi, la Plata; ArgentinaFil: Borzi, Silvia M.. Hospital Prof. Rodolfo Rossi, la Plata; ArgentinaFil: Stieben, Teodoro E.. Provincia de Entre Rios. Hospital San Martin; ArgentinaFil: Masola, Adriano. Provincia de Entre Rios. Hospital San Martin; ArgentinaFil: Ramos, Agñel. Sanatorio Parque; ArgentinaFil: Pages, Josefina. Universidad Austral; ArgentinaFil: Tevez, Silvina. Sanatorio Guemes; ArgentinaFil: Gadano, Adrián Carlos. Hospital Italiano; ArgentinaFil: Giunta, Diego Hernan. Hospital Italiano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Co-limitation towards lower latitudes shapes global forest diversity gradients

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    The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we produce a high-resolution (0.025 degrees x 0.025 degrees) map of local tree species richness using a global forest inventory database with individual tree information and local biophysical characteristics from similar to 1.3 million sample plots. We then quantify drivers of local tree species richness patterns across latitudes. Generally, annual mean temperature was a dominant predictor of tree species richness, which is most consistent with the metabolic theory of biodiversity (MTB). However, MTB underestimated LDG in the tropics, where high species richness was also moderated by topographic, soil and anthropogenic factors operating at local scales. Given that local landscape variables operate synergistically with bioclimatic factors in shaping the global LDG pattern, we suggest that MTB be extended to account for co-limitation by subordinate drivers
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