1,986 research outputs found
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
KATP Channel Opener Diazoxide Prevents Neurodegeneration: A New Mechanism of Action via Antioxidative Pathway Activation
Pharmacological modulation of ATP-sensitive potassium channels has become a promising new therapeutic approach for the treatment of neurodegenerative diseases due to their role in mitochondrial and cellular protection. For instance, diazoxide, a well-known ATP-sensitive potassium channel activator with high affinity for mitochondrial component of the channel has been proved to be effective in animal models for different diseases such as Alzheimer's disease, stroke or multiple sclerosis. Here, we analyzed the ability of diazoxide for protecting neurons front different neurotoxic insults in vitro and ex vivo. Results showed that diazoxide effectively protects NSC-34 motoneurons from glutamatergic, oxidative and inflammatory damage. Moreover, diazoxide decreased neuronal death in organotypic hippocampal slice cultures after exicitotoxicity and preserved myelin sheath in organotypic cerebellar cultures exposed to pro-inflammatory demyelinating damage. In addition, we demonstrated that one of the mechanisms of actions implied in the neuroprotective role of diazoxide is mediated by the activation of Nrf2 expression and nuclear translocation. Nrf2 expression was increased in NSC-34 neurons in vitro as well as in the spinal cord of experimental autoimmune encephalomyelitis animals orally administered with diazoxide. Thus, diazoxide is a neuroprotective agent against oxidative stress-induced damage and cellular dysfunction that can be beneficial for diseases such as multiple sclerosis
Nitrate pollution in milking yard farms in Punta Indio district
El objetivo del presente trabajo es evaluar el contenido de nitratos en el agua subterránea en establecimientos tamberos del Partido de Punta Indio como así también determinar los procesos hidroquímicos que regulan la calidad del agua para abastecimiento. Para ello se realizaron muestreos en 9 tambos durante los meses de junio, agosto y noviembre de 2017 y abril de 2018. Además, se relevaron características constructivas de las perforaciones, distancia a focos de contaminación y conductividad eléctrica y pH del agua. Los resultados muestran que 6 de los 9 tambos presentan valores por encima de los límites permitidos los que permanecen relativamente constantes a lo largo del año. Los valores del contenido de nitratos se encuentran a su vez significativamente correlacionados al pH y la conductividad eléctrica. Los elevados contenidos se vinculan a efluentes sin tratar provenientes de los tambos y disminuyen con la distancia a fuentes puntuales de contaminación.Centro de Investigaciones Geológica
Nitrate pollution in milking yard farms in Punta Indio district
El objetivo del presente trabajo es evaluar el contenido de nitratos en el agua subterránea en establecimientos tamberos del Partido de Punta Indio como así también determinar los procesos hidroquímicos que regulan la calidad del agua para abastecimiento. Para ello se realizaron muestreos en 9 tambos durante los meses de junio, agosto y noviembre de 2017 y abril de 2018. Además, se relevaron características constructivas de las perforaciones, distancia a focos de contaminación y conductividad eléctrica y pH del agua. Los resultados muestran que 6 de los 9 tambos presentan valores por encima de los límites permitidos los que permanecen relativamente constantes a lo largo del año. Los valores del contenido de nitratos se encuentran a su vez significativamente correlacionados al pH y la conductividad eléctrica. Los elevados contenidos se vinculan a efluentes sin tratar provenientes de los tambos y disminuyen con la distancia a fuentes puntuales de contaminación.Centro de Investigaciones Geológica
Nitrate pollution in milking yard farms in Punta Indio district
El objetivo del presente trabajo es evaluar el contenido de nitratos en el agua subterránea en establecimientos tamberos del Partido de Punta Indio como así también determinar los procesos hidroquímicos que regulan la calidad del agua para abastecimiento. Para ello se realizaron muestreos en 9 tambos durante los meses de junio, agosto y noviembre de 2017 y abril de 2018. Además, se relevaron características constructivas de las perforaciones, distancia a focos de contaminación y conductividad eléctrica y pH del agua. Los resultados muestran que 6 de los 9 tambos presentan valores por encima de los límites permitidos los que permanecen relativamente constantes a lo largo del año. Los valores del contenido de nitratos se encuentran a su vez significativamente correlacionados al pH y la conductividad eléctrica. Los elevados contenidos se vinculan a efluentes sin tratar provenientes de los tambos y disminuyen con la distancia a fuentes puntuales de contaminación.Centro de Investigaciones Geológica
Evidence for mid-Holocene rice domestication in the Americas
The development of agriculture is one of humankind’s most pivotal achievements. Questions about plant domestication and the origins of agriculture have engaged scholars for well over a century, with implications for understanding its legacy on global subsistence strategies, plant distribution, population health and the global methane budget. Rice is one of the most important crops to be domesticated globally, with both Asia (Oryza sativa L.) and Africa (Oryza glaberrima Steud.) discussed as primary centres of domestication. However, until now the pre-Columbian domestication of rice in the Americas has not been documented. Here we document the domestication of Oryza sp. wild rice by the mid-Holocene residents of the Monte Castelo shell mound starting at approximately 4,000 cal. yr BP, evidenced by increasingly larger rice husk phytoliths. Our data provide evidence for the domestication of wild rice in a region of the Amazon that was also probably the cradle of domestication of other major crops such as cassava (Manihot esculenta), peanut (Arachis hypogaea) and chilli pepper (Capsicum sp.). These results underline the role of wetlands as prime habitats for plant domestication worldwide
Historical review of neutron spectrometry and diffraction in Brazil – 50 years
Neutron Spectrometry and Diffraction techniques began to be studied in Brazil with the construction of the first research reactors in the years 50 and 60, and were developed with the participation of national and international scientists. In particular, we note the perseverance of the Brazilian pioneer of nuclear energy, Dr. Marcello Damy de Souza Santos_, and from that time, with the involvement of some of the early pioneers, such as the physicist Roberto Stasiulevicius_, who had the privilege of working in all three Brazilian nuclear research reactors. All these scientists shared half a century of acquired knowledge, helping in the training of a number of experts who are now working in national and international nuclear institutes. The present work reviews in chronological order, the testimony of the historical facts associated with the development and application of experimental techniques using neutrons as a tool for materials analysis and studies for many areas of the sciences and also with the training of personnel. IPEN, IEN and CDTN, all institutes of the CNEN-Brazil, are important in the national and international scene as a result of the research carried out there and the large number of publications produced in the field of neutron spectrometry and diffraction from experimental work carried out using the IEA (5MW), Argonauta (5kW) and more recently, the IPR (250kW) research reactors. An extensive bibliography is also presented and this can be disseminated to everyone interested
Debugging of Web Applications with Web-TLR
Web-TLR is a Web verification engine that is based on the well-established
Rewriting Logic--Maude/LTLR tandem for Web system specification and
model-checking. In Web-TLR, Web applications are expressed as rewrite theories
that can be formally verified by using the Maude built-in LTLR model-checker.
Whenever a property is refuted, a counterexample trace is delivered that
reveals an undesired, erroneous navigation sequence. Unfortunately, the
analysis (or even the simple inspection) of such counterexamples may be
unfeasible because of the size and complexity of the traces under examination.
In this paper, we endow Web-TLR with a new Web debugging facility that supports
the efficient manipulation of counterexample traces. This facility is based on
a backward trace-slicing technique for rewriting logic theories that allows the
pieces of information that we are interested to be traced back through inverse
rewrite sequences. The slicing process drastically simplifies the computation
trace by dropping useless data that do not influence the final result. By using
this facility, the Web engineer can focus on the relevant fragments of the
failing application, which greatly reduces the manual debugging effort and also
decreases the number of iterative verifications.Comment: In Proceedings WWV 2011, arXiv:1108.208
Natural Docosahexaenoic Acid in the Triglyceride Form Attenuates In Vitro Microglial Activation and Ameliorates Autoimmune Encephalomyelitis in Mice
Many neurodegenerative diseases are associated, at least in part, to an inflammatory process in which microglia plays a major role. The effect of the triglyceride form of the omega-3 polyunsaturated fatty acid docosahexaenoic acid (TG-DHA) was assayed in vitro and in vivo to assess the protective and anti-inflammatory activity of this compound. In the in vitro study, BV-2 microglia cells were previously treated with TG-DHA and then activated with Lipopolysaccharide (LPS) and Interferon-gamma (IFN-γ). TG-DHA treatment protected BV-2 microglia cells from oxidative stress toxicity attenuating NO production and suppressing the induction of inflammatory cytokines. When compared with DHA in the ethyl-ester form, a significant difference in the ability to inhibit NO production in favor of TG-DHA was observed. TG-DHA inhibited significantly splenocyte proliferation but isolated CD4+ lymphocyte proliferation was unaffected. In a mice model of autoimmune encephalomyelitis (EAE), 250 mg/kg/day oral TG-DHA treatment was associated with a significant amelioration of the course and severity of the disease as compared to untreated animals. TG-DHA-treated EAE mice showed a better weight profile, which is a symptom related to a better course of encephalomyelitis. TG-DHA may be a promising therapeutic agent in neuroinflammatory processes and merit to be more extensively studied in human neurodegenerative disorders
Propuesta de Supply Chain Management y Logística para la empresa Ramo S.A.
Trabajo colaborativo del curso de Diplomado en SCM y logística del grupo 207115_42, perteneciente al programa académico del periodo 1602 del 2022.
La cadena de suministro se ha considerado como una estructura importante y necesaria en cualquier economía, su estudio permite a las organizaciones potenciar el desarrollo de la producción y comercialización de bienes y servicios, en ese sentido, conocer las relaciones y dependencias de una organización en una cadena de suministro ayuda a incrementar su competitividad y rentabilidad, además de mantener un contacto directo con cada integrante de la cadena de suministro e incorporando nuevas herramientas informáticas, de comunicación y un adecuado sistema de gestión.
Por tal razón en el trascurso de este diplomado se abordaron 11 fases que exigieron a todo el equipo de estudiantes enfocarse en los diferentes contenidos que integran una cadena de suministro y bajo la experticia y los conocimientos adquiridos proponer una mejora en el Supply Chain Management y Logística de la empresa RAMO S.A.
El presente trabajo se encuentra estructurado en 11 partes principales, dentro de los cuales se encuentra una descripción inicial de la empresa, su estructura organizacional, tanto vertical como horizontal, los proceso de enfoque básicos y los APICS-SCOR, identificación de la cadena de suministro, la posición del país frente a otras naciones, la gestión de inventarios, de aprovisionamiento hasta análisis de las mega tendencias.Collaborative work of the course of Diploma in SCM and logistics of the group 207115_42, belonging to the academic program of the period 1602 of 2022.
The supply chain has been considered as an important and necessary structure in any economy, its study allows organizations to enhance the development of production and marketing of goods and services, in that sense, knowing the relationships and dependencies of an organization in a supply chain helps to increase its competitiveness and profitability, in addition to maintaining direct contact with each member of the supply chain and incorporating new information technology tools, communication and an appropriate management system.
For this reason in the course of this diploma course 11 phases were addressed that required the entire team of students to focus on the different contents that make up a supply chain and under the expertise and knowledge acquired to propose an improvement in the Supply Chain Management and Logistics of the company RAMO SA.
This work is structured in 11 main parts, within which there is an initial description of the company, its organizational structure, both vertical and horizontal, the basic approach process and APICS-SCOR, identification of the supply chain, the position of the country compared to other nations, inventory management, procurement and analysis of mega trends
- …