SUCCESS POSSIBILITIES OF GRID PARITY IN PARTICULAR CASES IN THE NEW SPANISH REGULATORY FRAMEWORK

ABSTRACT: During the last 10 years the Spanish photovoltaic market has experienced one of the most important increases worldwide. The continuous raise on the price of the electricity in Spain, as in other European countries, USA and Japan, as well as the decrease of the cost of solar photovoltaic systems along this decade is opening a new way to reach grid parity point in some particular scenarios. A new Spanish legislation is being performed toward selfconsumption, and it is in this new context where the grid parity in a wide sense could be achieved. This work will study different cases in Spain, in order to determine whether grid parity would be possible along 2012

Early degradation of silicon PV modules and guaranty conditions

The fast growth of PV installed capacity in Spain has led to an increase in the demand for analysis of installed PV modules. One of the topics that manufacturers, promoters, and owners of the plants are more interested in is the possible degradation of PV modules. This paper presents some findings of PV plant evaluations carried out during last years. This evaluation usually consists of visual inspections, I–V curve field measurements (the whole plant or selected areas), thermal evaluations by IR imaging and, in some cases, measurements of the I–V characteristics and thermal behaviours of selected modules in the plant, chosen by the laboratory. Electroluminescence technique is also used as a method for detecting defects in PV modules. It must be noted that new defects that arise when the module is in operation may appear in modules initially defect-free (called hidden manufacturing defects). Some of these hidden defects that only appear in normal operation are rarely detected in reliability tests (IEC61215 or IEC61646) due to the different operational conditions of the module in the standard tests and in the field (serial-parallel connection of many PV modules, power inverter influence, overvoltage on wires, etc.

RET signalling provides tumorigenic mechanism and tissue specificity for AIP-related somatotrophinomas

International audienceIt is unclear how loss-of-function germline mutations in the widely-expressed co-chaperone AIP , result in young-onset growth hormone secreting pituitary tumours. The RET receptor, uniquely co-expressed in somatotrophs with PIT1, induces apoptosis when unliganded, while RET supports cell survival when it is bound to its ligand. We demonstrate that at the plasma membrane, AIP is required to form a complex with monomeric-intracellular-RET, caspase-3 and PKCδ resulting in PIT1/CDKN2A-ARF/p53-apoptosis pathway activation. AIP-deficiency blocks RET/caspase-3/PKCδ activation preventing PIT1 accumulation and apoptosis. The presence or lack of the inhibitory effect on RET-induced apoptosis separated pathogenic AIP variants from non-pathogenic ones. We used virogenomics in neonatal rats to demonstrate the effect of mutant AIP protein on the RET apoptotic pathway in vivo. In adult male rats altered AIP induces elevated IGF-1 and gigantism, with pituitary hyperplasia through blocking the RET-apoptotic pathway. In females, pituitary hyperplasia is induced but IGF-1 rise and gigantism are blunted by puberty. Somatotroph adenomas from pituitary-specific Aip -knockout mice overexpress the RET-ligand GDNF, therefore, upregulating the survival pathway. Somatotroph adenomas from patients with or without AIP mutation abundantly express GDNF, but AIP -mutated tissues have less CDKN2A-ARF expression. Our findings explain the tissue-specific mechanism of AIP-induced somatotrophinomas and provide a previously unknown tumorigenic mechanism, opening treatment avenues for AIP -related tumours

Cinéticas de la deshidratación de zanahorias (Daucus carota L.) en procesos osmóticos y de secado convectivo con aire

This paper presents a kinetic study of osmotic dehydration and air drying with and without osmotic pre-treatment of carrot. Carrot cylinders of different diameters (4.5, 7 and 9 mm) were employed and, osmotic solutions of sodium chloride of different concentrations (17, 22 and 26% w/w) at various process temperatures (25, 35 and 45 deg C) and contact times (up to 180 min). The water loss (kg/kg) and the solid gain (kg/kg) in the samples increase with temperature and solution concentration increase. These parameters also depend on size (specific area) of the samples. The drying rate (kg water/kg dry solid/h) increases with temperature and decreases with the sample diameter. Experimental drying kinetics were fitted satisfactorily to a first order (simple model) kinetics (where the parameter ks ranges from 0.1748 up to 0.6691/h) and to the Page model [where the parameters kp (h-n) and n(-) range from 0.1592 and 1.0683 up to 0.6451 and 1.300, respectively] in order to determine the kinetic constants during drying. Osmotic dehydration combined with the air drying has proven to be an interesting method to reduce water in the samples without extreme thermal processes, nevertheless, the drying rate of the samples previously treated during 1 hour with osmotic dehydration decreased about 13%.En este trabajo se ha realizado un estudio cinético de la deshidratación osmótica y del secado con aire sin y con pretratamiento osmótico de la zanahoria. Se utilizaron cilindros de zanahoria de diferentes diámetros (4,5; 7 y 9 mm) y disoluciones osmóticas de cloruro sódico de distintas concentraciones (17, 22 y 26% en peso) a varias temperaturas de proceso (25, 35 y 45 grados C) y tiempos de contacto (hasta 180 min). La pérdida de agua (kg/kg) y la ganancia de sólidos (kg/kg) en las muestras aumentaron con la temperatura y la concentración de la disolución. Estos parámetros también dependieron del tamaño (área específica) de las muestras. La velocidad de secado (kg/kg de sólido seco/h) aumentó con la temperatura y disminuyó con el diámetro de muestra. Se ajustaron los datos experimentales satisfactoriamente a una cinética de primer orden, modelo simple (donde el parámetro ks varía desde 0,1748 hasta 0,6691/h) y al modelo de Page (donde el parámetro kp (h-n) y n(-) varían desde 0,1592 y 1,0683 hasta 0,6451 y 1,300, respectivamente) para determinar las constantes cinéticas durante el secado. La deshidratación osmótica combinada con el secado con aire resulta ser un método interesante para reducir el agua de las muestras sin procesos térmicos extremos, sin embargo, la velocidad de secado de las muestras previamente tratadas con 1 hora de deshidratación osmótica disminuye en torno a un 13%

Analysis of Chestnut Cellular Tissue during Osmotic Dehydration, Air Drying, and Rehydration Processes

The analysis of changes in microstructure is very important in order to understand heat and mass transfer processes in biological systems and to evaluate physical properties and the quality of fresh and processed food materials. In this study, chestnut (Castanea sativa M.) samples were submitted to several processes such as osmotic dehydration by immersion in sucrose solution (60% w/w) at 25 degrees C, drying with hot air at 65 degrees C, and rehydration by contact with water at 25 degrees C. The surface cellular tissue of fresh and processed chestnut at different moisture contents was characterized by optical microscopy by means of size (surface area, perimeter, Feret's diameter) and shape (roundness, compactness, and elongation) parameters. The results indicated that during the osmotic dehydration the changes in microstructure can be considered practically negligible and during drying the size of chestnut cells decreased and shape parameters changed (decreasing roundness and compactness and increasing elongation). Finally, during rehydration the cells recovered their size by swelling rapidly (30min is enough to recover the size of the cells of fresh tissue), achieving at longer times greater sizes than those measured in the fresh chestnut; nevertheless, the shape parameters are not completely recovered (lower compactness and roundness values).The authors acknowledge the financial support of the Ministerio de Educacion y Ciencia of Spain and FEDER (CTQ 2007-62009/PPQ).Moreira, R.; Chenlo, F.; Chaguri, L.; Mayor López, L. (2011). Analysis of Chestnut Cellular Tissue during Osmotic Dehydration, Air Drying, and Rehydration Processes. Drying Technology. 29(1):10-18. https://doi.org/10.1080/07373937.2010.482709S101829

Overview of the legislation of DC injection in the network for low voltage small grid-connected PV systems in Spain and other countries

In recent decades there has been an increasing interest in the use of low voltage small grid-connected photovoltaic (PV) systems, conditioned by new incentives from distinct countries. An essential element in those systems is the inverter, that is, the element which converts, in an efficient way, sinusoidal AC current waveform at its output so that it may be connected and synchronized to the utility network. However, that conversion must meet some minimum quality criteria with respect to the harmonics current, DC injection and power factor. Precisely, this work studies the relation of the PV inverter with limits of DC injection in the network, in the AC side. This has been carried out by means of the compilation referring to DC injection for low voltage small grid-connected PV systems exclusively, as well as the international standards and effective legislation in six countries (the USA, Germany, Japan, Spain, Australia and the United Kingdom), where the grid-connected PV industry has experienced remarkable growth in the last 10 years.Low voltage small grid-connected PV systems Public network DC injection