18 results on '"Santiago, Isabel"'
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2. Neuro-fuzzy systems for daily solar irradiance classification and PV efficiency forecasting
- Author
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Gersnoviez, Andrés, Gámez-Granados, Juan C., Cabrera-Fernández, Marta, Santiago, Isabel, Cañete-Carmona, Eduardo, and Brox, María
- Published
- 2023
- Full Text
- View/download PDF
3. The ubiquitous catechol moiety elicits siderophore and angucycline production in Streptomyces
- Author
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van Bergeijk, Doris A., Elsayed, Somayah S., Du, Chao, Santiago, Isabel Nuñez, Roseboom, Anna M., Zhang, Le, Carrión, Victor J., Spaink, Herman P., and van Wezel, Gilles P.
- Published
- 2022
- Full Text
- View/download PDF
4. Farnesoid X receptor prevents neutrophil extracellular traps via reduced sphingosine-1-phosphate in chronic kidney disease.
- Author
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Jones, Bryce A., Myakala, Komuraiah, Guha, Mahilan, Davidson, Shania, Adapa, Sharmila, Santiago, Isabel Lopez, Schaffer, Isabel, Yang Yue, Allegood, Jeremy C., Cowart, L. Ashley, Wang, Xiaoxin X., Rosenberg, Avi Z., and Levi, Moshe
- Subjects
FARNESOID X receptor ,CHRONIC kidney failure ,SPHINGOSINE-1-phosphate ,BIOMARKERS ,SPHINGOSINE kinase - Abstract
Farnesoid X receptor (FXR) activation reduces renal inflammation, but the underlying mechanisms remain elusive. Neutrophil extracellular traps (NETs) are webs of DNA formed when neutrophils undergo specialized programmed cell death (NETosis). The signaling lipid sphingosine-1-phosphate (S1P) stimulates NETosis via its receptor on neutrophils. Here, we identify FXR as a negative regulator of NETosis via repressing S1P signaling. We determined the effects of the FXR agonist obeticholic acid (OCA) in mouse models of adenosine phosphoribosyltransferase (APRT) deficiency and Alport syndrome, both genetic disorders that cause chronic kidney disease. Renal FXR activity is greatly reduced in both models, and FXR agonism reduces disease severity. Renal NETosis and sphingosine kinase 1 (Sphk1) expression are increased in diseased mice, and they are reduced by OCA in both models. Genetic deletion of FXR increases Sphk1 expression, and Sphk1 expression correlates with NETosis. Importantly, kidney S1P levels in Alport mice are two-fold higher than controls, and FXR agonism restores them back to baseline. Short-term inhibition of sphingosine synthesis in Alport mice with severe kidney disease reverses NETosis, establishing a causal relationship between S1P signaling and renal NETosis. Finally, extensive NETosis is present in human Alport kidney biopsies (six male, nine female), and NETosis severity correlates with clinical markers of kidney disease. This suggests the potential clinical relevance of the newly identified FXR-S1P-NETosis pathway. In summary, FXR agonism represses kidney Sphk1 expression. This inhibits renal S1P signaling, thereby reducing neutrophilic inflammation and NETosis. NEW & NOTEWORTHY Many preclinical studies have shown that the farnesoid X receptor (FXR) reduces renal inflammation, but the mechanism is poorly understood. This report identifies FXR as a novel regulator of neutrophilic inflammation and NETosis via the inhibition of sphingosine-1-phosphate signaling. Additionally, NETosis severity in human Alport kidney biopsies correlates with clinical markers of kidney disease. A better understanding of this signaling axis may lead to novel treatments that prevent renal inflammation and chronic kidney disease. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
5. Design and Development of a Relational Database Management System (RDBMS) with Open Source Tools for the Processing of Data Monitored in a Set of Photovoltaic (PV) Plants.
- Author
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Trillo-Montero, David, Cosano-Lucena, Samuel, Gonzalez-Redondo, Miguel, Luna-Rodriguez, Juan Jesus, and Santiago, Isabel
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DATABASES ,RELATIONAL databases ,DATABASE design ,ELECTRONIC data processing ,PHOTOVOLTAIC power systems - Abstract
The objective of this work has been to implement an orderly, accessible, fast and space-saving storage system that allows the transfer to a Relational Database Management System (RDBMS) of all the data corresponding to the monitoring of a set of photovoltaic (PV) systems whose behaviour is to be analysed. The RDBMS consists of a series of linked databases, enabling all PV system information to be stored, and it is scalable so it can be expanded depending on the number of installations to be studied. The data recorded in the plants are found in a large number of very disaggregated files, and with different measured parameters, different formats, nomenclatures, or units of measurement, so the developed system is responsible for homogenising all the information for storage. For this purpose, a procedure has been developed to carry out the automatic transfer of all the data recorded in their corresponding databases. In addition, in this work, a web application called S·lar 2 has been developed to facilitate selective access to all the data once stored in the corresponding tables. This application, which is connected to the designed databases, allows the storage and management of the information coming from the PV plants, in order to determine, among other things, the operation mode of each of the components of these facilities. Using the data already organised, it has also been possible to establish a system for comparing the production of inverters within the same plant in order to have a tool that allows the quick and visual detection of possible deviations between them and thus detect malfunctions in any of the components. The whole procedure has been carried out using free software, such as Maria DB and Python. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
6. Measurement of metastable atom populations along an argon plasma column generated at atmospheric pressure
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Santiago, Isabel and Calzada, Maria Dolores
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Atoms -- Properties ,Atoms -- Measurement ,Atmospheric pressure -- Influence ,Metastability -- Research ,Argon -- Properties ,Plasma (Ionized gases) -- Properties ,Spectrum analysis -- Methods ,Spectrum analysis -- Usage ,Collisions (Physics) -- Models ,Radiation -- Models ,Business ,Chemistry ,Electronics ,Electronics and electrical industries - Abstract
This paper describes a procedure for experimental determination of metastable and resonant populations along a surface wave argon plasma column at atmospheric pressure. As modeling work progresses extensively, an experimental database is necessary to confirm these models. Obtained results, within the range of values reported in literature, indicate that densities of metastable and resonant levels grow along the plasma column for positions near the energy coupler device, where the energy of the surface wave which creates discharge is the highest. This behavior is also found for electron density and temperature; however, it is not the same for gradient. Therefore, at atmospheric pressure, populations of 4s levels are not only controlled by collision with electrons from ground state, but the dissociative recombination mechanism is also important, in agreement with results found by other authors using collisional-radiative models. Index Terms--Argon, atmospheric pressure, metastable atoms, optical spectroscopy, plasmas, self-absorption.
- Published
- 2009
7. Analysis of Some Power Quality Parameters at the Points of Common Coupling of Photovoltaic Plants Based on Data Measured by Inverters.
- Author
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Santiago, Isabel, García-Quintero, Javier, Mengibar-Ariza, Gonzalo, Trillo-Montero, David, Real-Calvo, Rafael J., and Gonzalez-Redondo, Miguel
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PHOTOVOLTAIC power systems ,POWER plants ,RENEWABLE energy sources ,VOLTAGE ,ELECTRICITY - Abstract
With the increasing implementation of renewable energies, the impact that this type of installation can have on the electricity supply grid is of great importance. In this context, the aim of this work is to analyse how the production and injection of electricity generated by a series of small photovoltaic (PV) installations influence some parameters of the electricity grid in the low-voltage (LV) distribution networks to which they are connected, by analysing the basic data provided by the inverters of these installations. The presence of a slight rise in the grid voltage values in the Point of Common Coupling (PCC) as the production of the PV plants increases has been verified, with maximum slopes between 0.95 and 0.00027 V/kW, but which do not result in voltage values close to the limits set by the regulations. In addition to assessing this impact, the results obtained made it possible to determine the hosting capacity that the networks into which these installations inject their energy would have for this type of installation so as not to have a detrimental effect on the voltage values of the grid. The possible influence of the production of PV installations on the voltage imbalance between phases or on the frequency of the grid has also been analysed in this work. Although the values recorded by the inverters have limitations in their measurements that do not make them valid for assessing events such as the presence of harmonics or flickers, they do allow a first analysis to be made of the influence of PV plant production on some grid parameters, without the need to incorporate additional measurement systems in these renewable installations. However, it is important to be aware of the limitations of the measurements of this equipment and, as far as possible, to choose inverter models that carry out this type of measurement as completely as possible. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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8. Stochastic Optimization of Microgrids With Hybrid Energy Storage Systems for Grid Flexibility Services Considering Energy Forecast Uncertainties.
- Author
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Garcia-Torres, Felix, Bordons, Carlos, Tobajas, Javier, Real-Calvo, Rafael, Santiago, Isabel, and Grieu, Stephane
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GRID energy storage ,ENERGY storage ,POWER resources ,STOCHASTIC control theory ,QUADRATIC programming - Abstract
This paper presents a stochastic framework for the optimization of microgrids that has the functionality of providing flexibility services to System Operators (SOs) considering uncertainties in the energy forecast. The methodology is developed with the aim of being applied to complex microgrids composed of different distributed energy resources and hybrid energy storage systems (ESS). The associated optimization problem is operated in two stages: the first one performs a stochastic optimization of the microgrid in order to reserve an up/down regulation capacity with which to deal with the energy forecast uncertainties of the microgrid. The different microgrid devices are optimized by considering their operational costs in order to achieve their optimal operation in the Day-Ahead Market (DM). The second stage is used to re-schedule the initial planning according to the signal request and an economic offer from the SO. The control problem is developed using Stochastic Model Predictive Control (SMPC) techniques and Mixed-Integer Quadratic Programming (MIQP), owing to the presence of logic, integer, mixed and probabilistic variables. The simulation results show that the proposed methodology reduces the risk of undergoing up/down-penalty deviations in the Regulation Service Market (RM), also being able to provide flexibility services to the SOs, despite being subject to uncertainties in the energy forecast carried out for the microgrid. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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9. Monitoring of Energy Data with Seamless Temporal Accuracy Based on the Time-Sensitive Networking Standard and Enhanced µPMUs.
- Author
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Pallarés-López, Víctor, Real-Calvo, Rafael Jesús, del Rio Jiménez, Silvia, González-Redondo, Miguel, Moreno-García, Isabel, and Santiago, Isabel
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PHASOR measurement ,SUCCESSIVE approximation analog-to-digital converters ,RENEWABLE energy sources ,COMPUTER network protocols ,REAL-time control ,TIMESTAMPS - Abstract
In the energy sector, distributed synchronism and a high degree of stability are necessary for all real-time monitoring and control systems. Instantaneous response to critical situations is essential for the integration of renewable energies. The most widely used standards for clock synchronisation, such as Network Time Protocol (NTP) and Precision Time Protocol (PTP), do not allow for achieving synchronised simultaneous sampling in distributed systems. In this work, a novel distributed synchronism system based on the Time-Sensitive Networking (TSN) standard has been validated for its integration in an architecture oriented towards the high-resolution digitisation of photovoltaic (PV) generation systems. This method guarantees a time stamping with an optimal resolution that allows for the analysis of the influence of fast-evolving atmospheric fluctuations in several plants located in the same geographical area. This paper proposes an enhanced micro-phasor measurement unit (µPMU) that acts as a phasor meter and TSN master controlling the monitoring system synchronism. With this technique, the synchronism would be extended to the remaining measurement systems that would be involved in the installation at distances greater than 100 m. Several analyses were carried out with an on-line topology of four acquisition systems capturing simultaneously. The influence of the Ethernet network and the transducers involved in the acquisition process were studied. Tests were performed with Ethernet cable lengths of 2, 10, 50, and 75 m. The results were validated with 24-bit Sigma-Delta converters and high-precision resistor networks specialised in high-voltage monitoring. It was observed that with an appropriate choice of sensors and TSN synchronism, phase errors of less than ±1 µs can be guaranteed by performing distributed captures up to 50 kS/s. Statistical analysis showed that uncertainties of less than ±100 ns were achieved with 16-bit Successive Approximation Register (SAR) converters at a moderate cost. Finally, the requirements of the IEEE C37.118.1-2011 standard for phasor measurement units (PMU) were also satisfied. This standard establishes an uncertainty of ±3.1 μs for 50 Hz systems. These results demonstrate the feasibility of implementing a simultaneous sampling system for distributed acquisition systems coordinated by a µPMU. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
10. Classification of Daily Irradiance Profiles and the Behaviour of Photovoltaic Plant Elements: The Effects of Cloud Enhancement.
- Author
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Santiago, Isabel, Esquivel-Martin, Jorge Luis, Trillo-Montero, David, Real-Calvo, Rafael Jesús, and Pallarés-López, Víctor
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MACHINE learning ,AUTOMATIC classification ,CLASSIFICATION ,LOW temperatures ,MAXIMUM power point trackers - Abstract
In this work, the automatic classification of daily irradiance profiles registered in a photovoltaic installation located in the south of Spain was carried out for a period of nine years, with a sampling frequency of 5 min, and the subsequent analysis of the operation of the elements of the installation on each type of day was also performed. The classification was based on the total daily irradiance values and the fluctuations of this parameter throughout the day. The irradiance profiles were grouped into nine different categories using unsupervised machine learning algorithms for clustering, implemented in Python. It was found that the behaviour of the modules and the inverter of the installation was influenced by the type of day obtained, such that the latter worked with a better average efficiency on days with higher irradiance and lower fluctuations. However, the modules worked with better average efficiency on days with irradiance fluctuations than on clear sky days. This behaviour of the modules may be due to the presence, on days with passing clouds, of the phenomenon known as cloud enhancement, in which, due to reflections of radiation on the edges of the clouds, irradiance values can be higher at certain moments than those that occur on clear sky days, without passing clouds. This is due to the higher energy generated during these irradiance peaks and to the lower temperatures that the module reaches due to the shaded areas created by the clouds, resulting in a reduction in its temperature losses. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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11. Comunicação em Saúde Pública na Prevenção do Consumo Excessivo de Álcool e Drogas na População Escolar de São Tomé e Príncipe: Protocolo Científico.
- Author
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DE SANTIAGO, Isabel, NICOLAU, Leonor Bacelar, MARINHO, Rui Tato, and PEREIRA-MIGUEL, José
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- 2020
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12. Consumption of Alcohol and Drugs in the School Population of Sao Tome and Principe.
- Author
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DE SANTIAGO, Isabel, RIBEIRO, Ruy, NICOLAU, Leonor Bacelar, MARINHO, Rui Tato, and PEREIRA-MIGUEL, José
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- 2020
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13. Graphical Diagnosis of Performances in Photovoltaic Systems: A Case Study in Southern Spain.
- Author
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Santiago, Isabel, Montero, David Trillo, Luna Rodríguez, Juan J., Moreno Garcia, Isabel M., and Palacios Garcia, Emilio J.
- Subjects
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PHOTOVOLTAIC power generation , *PHOTOVOLTAIC power systems , *FAULT indicators (Electricity) , *SUPERVISION - Abstract
The starting point of the operation and maintenance tasks in photovoltaic plants is the continuous monitoring and supervision of its components. The great amount of registered data requires a major improvement in the ways this information is processed and analyzed to rapidly detect any potential fault, without incurring additional costs. In this paper, a procedure to perform a detailed graphical supported analysis of the operation of photovoltaic installations, based on inverter data, and using a self-developed application, is presented. The program carries out the automated processing of the registered data, providing their access and visualization by means of color maps. These graphs allow a large volume of data set to be simultaneously represented in a readable way, enabling operation and maintenance operators to quickly detect patterns that would require any type of intervention. As a case study, the operation of a grid-connected photovoltaic plant located in southern Spain was studied during a period of three years. The average daily efficiency values of the PV modules and inverters were in the range of 7.6-14.6%, and 73.5-94% respectively. Moreover, the presence of shadings, as well as the hours and days mainly affected by this issue, was easily detected. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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14. PV Hosting Capacity Analysis and Enhancement Using High Resolution Stochastic Modeling.
- Author
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Palacios-Garcia, Emilio J., Moreno-Muñoz, Antonio, Santiago, Isabel, Moreno-Garcia, Isabel M., and Milanés-Montero, María I.
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PHOTOVOLTAIC power systems ,AIR pollution emissions prevention ,STOCHASTIC models ,CARBON dioxide ,SMART power grids - Abstract
Reduction of CO
2 emissions is a main target in the future smart grid. This goal is boosting the installation of renewable energy resources (RES), as well as a major consumer engagement that seeks for a more efficient utilization of these resources toward the figure of 'prosumers'. Nevertheless, these resources present an intermittent nature, which requires the presence of an energy storage system and an energy management system (EMS) to ensure an uninterrupted power supply. Moreover, network-related issues might arise due to the increasing power of renewable resources installed in the grid, the storage systems also being capable of contributing to the network stability. However, to assess these future scenarios and test the control strategies, a simulation system is needed. The aim of this paper is to analyze the interaction between residential consumers with high penetration of PV generation and distributed storage and the grid by means of a high temporal resolution simulation scenario based on a stochastic residential load model and PV production records. Results of the model are presented for different PV power rates and storage capacities, as well as a two-level charging strategy as a mechanism for increasing the hosting capacity (HC) of the network. [ABSTRACT FROM AUTHOR]- Published
- 2017
- Full Text
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15. Real-Time Monitoring System for a Utility-Scale Photovoltaic Power Plant.
- Author
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Moreno-Garcia, Isabel M., Palacios-Garcia, Emilio J., Pallares-Lopez, Victor, Santiago, Isabel, Gonzalez-Redondo, Miguel J., Varo-Martinez, Marta, and Real-Calvo, Rafael J.
- Subjects
PHOTOVOLTAIC power systems ,SOLAR power plants ,SECURITY systems ,BIOSENSORS ,DETECTORS - Abstract
There is, at present, considerable interest in the storage and dispatchability of photovoltaic (PV) energy, together with the need to manage power flows in real-time. This paper presents a new system, PV-on time, which has been developed to supervise the operating mode of a Grid-Connected Utility-Scale PV Power Plant in order to ensure the reliability and continuity of its supply. This system presents an architecture of acquisition devices, including wireless sensors distributed around the plant, which measure the required information. It is also equipped with a high-precision protocol for synchronizing all data acquisition equipment, something that is necessary for correctly establishing relationships among events in the plant. Moreover, a system for monitoring and supervising all of the distributed devices, as well as for the real-time treatment of all the registered information, is presented. Performances were analyzed in a 400 kW transformation center belonging to a 6.1 MW Utility-Scale PV Power Plant. In addition to monitoring the performance of all of the PV plant's components and detecting any failures or deviations in production, this system enables users to control the power quality of the signal injected and the influence of the installation on the distribution grid. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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16. Comunicação em Saúde: Evitar o Contágio da Doença por Vírus Ébola nos PALOP – Metodologia KISS & KEYWORDS.
- Author
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DE SANTIAGO, Isabel, MIGUEL, José Pereira, and ANTUNES, Francisco
- Published
- 2015
- Full Text
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17. CONHECIMENTO E EXPERIÊNCIA DE FISIOTERAPEUTAS SOBRE VENTILAÇÃO NÃO INVASIVA.
- Author
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de Mendonça Santiago, Isabel Cristina, Sabino Meireles, Fabíola Maria, Kuehner, Cymara Pessoa, and Alves-de-Almeida, Mirizana
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THEORY of knowledge ,HOSPITAL wards ,PHYSICAL therapists ,INTENSIVE care units - Abstract
Copyright of Revista Brasileira em Promoção da Saúde is the property of Revista Brasileira em Promocao da Saude and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2011
18. Accelerometric comparison of the locomotor pattern of horses sedated with xylazine hydrochloride, detomidine hydrochloride, or romifidine hydrochloride.
- Author
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López-Sanromán, F. Javier, Holmbak-Petersen, Ronald, Varela, Marta, del Alamo, Ana M., and Santiago, Isabel
- Subjects
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ANIMAL sedation , *HORSE paces, gaits, etc. , *VETERINARY drugs , *XYLAZINE , *DETOMIDINE , *ACCELEROMETERS , *PHARMACODYNAMICS - Abstract
Objective--To evaluate the duration of effects on movement patterns of horses after sedation with equipotent doses of xylazine hydrochloride, detomidine hydrochloride, or romifidine hydrochloride and determine whether accelerometry can be used to quantify differences among drug treatments. Animals--6 healthy horses. Procedures--Each horse was injected IV with saline (0.9% NaCI) solution (10 mL), xylazine diluted in saline solution (0.5 mg/kg), detomidine diluted in saline solution (0.01 mg/kg), or romifidine diluted in saline solution (0.04 mg/kg) in random order. A triaxial accelerometric device was used for gait assessment 15 minutes before and 5, 15, 30, 45, 60, 75, 90, 105, and 120 minutes after each treatment. Eight variables were calculated, including speed, stride frequency, stride length, regularity, dorsoventral power, propulsive power, mediolateral power, and total power; the force of acceleration and 3 components of power were then calculated. Results--Significant differences were evident in stride frequency and regularity between treatments with saline solution and each α2-adrenoceptor agonist drug; in speed, dorsoventral power, propulsive power, total power, and force values between treatments with saline solution and detomldine or romifidine; and in mediolateral power between treatments with saline solution and detomidine. Stride length did not differ among treatments. Conclusions and Clinical Relevance--Accelerometric evaluation of horses administered α2-adrenoceptor agonist drugs revealed more prolonged sedative effects of romifidine, compared with effects of xylazine or detomidine. Accelerometry could be useful in assessing the effects of other sedatives and analgesics. Accelerometric data may be helpful in drug selection for situations in which a horse's balance and coordination are important. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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