The P* model as a general identity to analyze and forecast the behavior of the inflation rate in the economy of Puerto Rico

In this work the P* model is used to analyze and forecast the inflation rate in the economy of Puerto Rico. This model is based on two essential points: the first one is to identify the inflationary potential of an economic system through the estimation of the price level to which the inflation tends to adjust in the long run. The second, points that the price level will be adjust, in the long run, to the forecast of the model. Given the way in which the monetary sector in Puerto Rico its constituted, the model needs to complement with U.S.A. monetary variables , such as, monetary supply, to forecast the inflation. The results indicate a long run relationship between the monetary supply of United States (M1) and the price level, the real production and the islands preferential interest rate. The final model is a good representation of the generating process of information (GPI) and it could be used for forecasting purposes. The same predicts the development of inflation better than the two ARIMA models previously selected

Diavideos: a Diabetes Health Video Portal

Diavideos1 is a web platform that collects trustworthy diabetes health videos from YouTube and offers them in a easy way. YouTube is a big repository of health videos, but good content is sometimes mixed with misleading and harmful videos such as promoting anorexia [1].Diavideos is a web portal that provides easy access to a repository of trustworthy diabetes videos. This poster describes Diavideos and explains the crawling method used to retrieve these videos from trusted channels

Análisis de la economía de Puerto Rico con un modelo de vectores autorregresivos y cointegración.

This paper analyses the behaviour of the economy of Puerto Rico through a vector autorregresive and cointegration model. The obtained results point out that the economy of Puerto Rico has the general behaviour of an IS-LM model with market imperfections, which means that, for the economy of Puerto Rico, the rate of interest, the price index, the real production and the money supply of the United States maintain a long-run equilibrium relation. These variables could be used like a strategic axle for the construction of any macroeconometric model.Este trabajo analiza el comportamiento de la economía de Puerto mediante un modelo de vectores autorregresivos y cointegración. Los resultados obtenidos señalan que la economía de Puerto Rico tiene el comportamiento general de un modelo IS-LM, con imperfecciones en los mercados. Esto significa que, para la economía de Puerto Rico, la tasa de interés, el índice de precios, la producción real de Puerto Rico, así como la oferta monetaria de los Estados Unidos mantienen una relación de equilibrio a largo plazo. Estas variables pueden utilizarse como eje estratégico en la construcción de cualquier modelo macroeconométrico para la economía de Puerto Rico

Mathematical Model of Bridge-Linked Photovoltaic Arrays Operating Under Irregular Conditions

Este artículo presenta un procedimiento matemático para modelar un arreglo fotovoltaico (N filas y M columnas) en configuración puente-vinculado operando en condiciones regulares o irregulares. Dicho procedimiento usa el modelo ideal de un diodo para representar cada modulo fotovoltaico y la ecuación de Shockley para representar cada diodo de desviación. Para plantear el sistema de NxM ecuaciones no lineales requerido para obtener los voltajes de cada modulo, el modelo propuesto aplica la ley de corrientes de Kirchhoff a cada nodo interno del arreglo y la ley de voltajes de Kirchhoff a: cada lazo creado en la parte superior de una conexión entre dos columnas consecutivas y a cada columna con respecto al voltaje del arreglo. Además, el modelo provee un procedimiento para obtener la matriz Jacobiana para reducir el tiempo de solución del sistema de ecuaciones. El modelo circuital de dos arreglos (pequeño: 3x3 y mediano: 20x3) fue implementado en Simulink para validar el modelo. La exactitud y mejora en la velocidad de cálculo del modelo propuesto permite su uso para realizar evaluaciones energéticas de arreglos en puente vinculado o su comparación con otras configuraciones típicas, lo cual puede ser útil en el diseño de plantas fotovoltaica.This paper presents a mathematical procedure to model a photovoltaic array (N rows and M columns) in bridge-linked configuration operating under regular and irregular conditions. The proposed procedure uses the ideal single-diode model representation for each photovoltaic module and the Shockley equation to represent each bypass diode. To pose the system of NxM non-linear equations required to obtain the voltages of each module of the array, the proposed model apply the Kirchhoff current law to each internal node of the array and the Kirchhoff voltage law to: each loop created in the upper part of each connection of two consecutive strings and each string with respect to the output voltage of the array. Moreover, the model provide a procedure to obtain the Jacobian matrix to reduce the solution time of the equation system. The circuital model of two arrays (small: 3x3 and medium: 20x3) were implemented in Simulink to validate the proposed model. The accuracy and improved calculation speed of the proposed model allow its use to perform energetic evaluations of bridge-linked arrays or its comparison with other typical array configurations, which can be useful in the designing of photovoltaic plants

Deposition reactors for solar grade silicon: a comparative thermal analysis of a Siemens reactor and a fluidized bed reactor

Polysilicon production costs contribute approximately to 25–33% of the overall cost of the solar panels and a similar fraction of the total energy invested in their fabrication. Understanding the energy losses and the behaviour of process temperature is an essential requirement as one moves forward to design and build large scale polysilicon manufacturing plants. In this paper we present thermal models for two processes for poly production, viz., the Siemens process using trichlorosilane (TCS) as precursor and the fluid bed process using silane (monosilane, MS). We validate the models with some experimental measurements on prototype laboratory reactors relating the temperature profiles to product quality. A model sensitivity analysis is also performed, and the effects of some key parameters such as reactor wall emissivity and gas distributor temperature, on temperature distribution and product quality are examined. The information presented in this paper is useful for further understanding of the strengths and weaknesses of both deposition technologies, and will help in optimal temperature profiling of these systems aiming at lowering production costs without compromising the solar cell quality.Peer ReviewedPostprint (published version

Deposition reactors for solar grade silicon: a comparative thermal analysis of a Siemens reactor and a fluidized bed reactor

Polysilicon production costs contribute approximately to 25-33% of the overall cost of the solar panels and a similar fraction of the total energy invested in their fabrication. Understanding the energy losses and the behaviour of process temperature is an essential requirement as one moves forward to design and build large scale polysilicon manufacturing plants. In this paper we present thermal models for two processes for poly production, viz., the Siemens process using trichlorosilane (TCS) as precursor and the fluid bed process using silane (monosilane, MS).We validate the models with some experimental measurements on prototype laboratory reactors relating the temperature profiles to product quality. A model sensitivity analysis is also performed, and the efects of some key parameters such as reactor wall emissivity, gas distributor temperature, etc., on temperature distribution and product quality are examined. The information presented in this paper is useful for further understanding of the strengths and weaknesses of both deposition technologies, and will help in optimal temperature profiling of these systems aiming at lowering production costs without compromising the solar cell quality

Sessile Biofouling on Electrolytic Carbonated Structures: Stages of Colonization and Succession

The ecological succession has been widely studied by means of biofouling assemblages among different substrates, and mainly targeted in early stages on artificial ones. The present study focuses on biofouling that colonizes carbonated structures, a material similar to the natural substrate produced by the electrolysis of seawater, which is relatively very little studied. We have observed the colonization of sessile macrofouling of the port of Alicante (SE Spain, Western Mediterranean) on two types of substrates (electrolytic carbonated and steel) over 12 months of succession. The assemblages of both substrates have been analyzed by means of diversity indexes and multivariate analysis (PERMANOVA and SIMPER) in order to see the differences over time. The carbonated substrate has presented a community with higher values of biological diversity, structure and complexity, although the differences in species composition between substrates are not evident during all immersion periods. Thus, these results seem to indicate that, even after 12 months of immersion, communities are still in a dynamic successional stage.This research forms part of the ThinkInAzul program and was funded by Ministerio de Ciencia e Innovación with funding from European Union NextGenerationEU (PRTR-C17.I1) and by Generalitat Valenciana (THINKINAZUL/2021/014)

Early colonization of sessile megabenthos on electrolytic carbonated structures (Alicante's harbor, Western Mediterranean)

Biofouling in different artificial substrata was done to determine the differences in biofouling assemblages among different substrates. However, studies on biofouling on natural substrates like electrolytic carbonated ones are lacking. These substrates have a great potential for coral reef restoration in tropical areas and for biofilter construction. Thus, this study was done to examine the colonization of sessile macrofouling in the port of Alicante (SE Spain, Western Mediterranean) on two types of substrata: electrolytic carbonated and bare steel (as control) over three months of immersion (October 2019–January 2020). The community diversity was studied through different biotic parameters and abundance of assemblages, and preference of organisms according to their status and functional group (active filter feeders). Univariate and multivariate analyses (PERMANOVA and SIMPER) were also done to examine the differences between carbonate and control substrata. The carbonated substrate had a more structured community and higher abundance, recruitment, and diversity indexes than the bare steel. Moreover, filter feeders (Porifera, Bivalvia, and Ascidiacea) were more abundant, and most of them only appeared in the carbonated substrate. These results show the potential of carbonated structures as biofilters.This study forms part of the ThinkInAzul program and was supported by Ministerio de Ciencia e Innovación with funding from European Union NextGenerationEU (PRTRC17.I1) and by Generalitat Valenciana (THINKINAZUL/2021/014)

Streptomyces as a host for the secretion of heterologous proteins for the production of biopharmaceuticals

The commercial production of therapeutic or diagnostic proteins in recombinant microorganisms is of considerable interest. Several microbial protein production systems have been developed. So far, Escherichia coli have been the commonly employed host. However, proteins expressed in this host remain intracellular and often precipitate as inclusion bodies, which may seriously complicate downstreamprocessing. Faced with this problem, several genera of Gram-positive bacteria are being tested as host for the production of heterologous proteins due to their ability to efficiently secrete proteins in the culture medium. Among them is the genus Streptomyces since several of its species are known to secrete high amounts of proteins. Due to the absence of an extensive restriction-modification system, limited protease activity and the availability of suitable vector systems, Streptomyces lividans is the host of choice for the secretory production of heterologous proteins. The presented results show, that S. lividans can act as an interesting host to produce a number of proteins useful in several disease areas important in the worldwide pharmaceutical sales: i.e. oncology, immunology, cardiovascular diseases and infectious diseases

Photovoltaic battery charger with sliding mode control and charging current derivative limitation

En los sistemas fotovoltaicos (PV) aislados, los cargadores de baterías son importantespara garantizar el suministro de energía cuando la luz solar no está disponible. Dichoscargadores necesitan realizar el seguimiento del punto de máxima potencia (MPPT) ylimitar la derivada de corriente de carga de las baterías para extender su vida útil. Esteartículo propone un sistema cargador de baterías compuesto por un convertidor Buck, uncontrol en cascada de la corriente de las baterías y la tensión del panel PV, y la técnica deMPPT Perturbar y Observar (P&O). El P&O genera la referencia de tensión del panel parael lazo externo del control en cascada, implementado con un regulador P, cuya acción decontrol es la referencia de la corriente de carga de las baterías. Dicha referencia de corrientepasa por un limitador de derivada antes de llegar al lazo interno de control de corriente delas baterías, el cual es implementado con un control por modos deslizantes (SMC). Elartículo incluye el análisis de transversalidad y alcanzabilidad del SMC, así como elprocedimiento de diseño del regulador P. El sistema propuesto se valida por medio desimulaciones en el software PSIM mostrando la capacidad de realizar el MPPT y limitar laderivada de corriente de carga de las baterías al mismo tiempo.In stand-alone photovoltaic (PV) systems, battery chargers are important to guaranteethe energy supply when sunlight is not available. Such chargers need to track the maximumpower point (MPPT) and limit the derivative of the batteries’ charging current to extendtheir lifetime. This paper proposes a battery charging system composed of a Buck converter,a cascade control of the battery current and the PV panel voltage, and the Perturb andObserve (P&O) MPPT technique. P&O generates the reference of the panel voltage for theexternal loop of the cascade control implemented with a P regulator, whose control action isthe reference of the batteries’ charging current. Such current reference passes through aderivative limiter before reaching the internal current control loop, which is implementedby a sliding-mode controller (SMC). This paper includes transversality and reachabilityanalyses of the SMC, as well as the procedure to design the P regulator. The proposedsystem is validated by simulations in PSIM software to show its capacity to perform MPPTand limit the battery’s charging current derivative at the same time