Procedimiento de descontaminación superficial de alimentos sólidos envasados

Número de publicación: 2 534 529 Número de solicitud: 201530326Procedimiento de descontaminación microbiana de alimentos sólidos envasados mediante aceites esenciales (AEs) que comprende una evaporación de los AEs a vacío, y una aplicación a vacío de los vapores de AEs sobre el alimento sólido situado en un envase abierto, en donde dichos vapores son arrastrados por aire o por una mezcla de gases de grado alimentario y conducidos hasta el recinto al vacío, en donde se encuentra el alimento envasado al que se va a descontaminar microbiológicamente.Universidad Politécnica de Cartagen

Termoformadora ultralimpia para film rígido, semirrígido y flexible

Número de publicación: 2 545 431 Número de solicitud: 201530316Máquina termoformadora ultralimpia de film rígido, semirrígido o flexible, para la obtención de envases ultralimpios de alimentos en forma de bol, bandeja, barqueta o cesta, que posee un adecuado diseño higiénico, que cumple, en su arquitectura y componentes, las normas básicas de diseño higiénico de equipos de procesado de alimentos líquidos, y que incorpora un sistema automático de limpieza y desinfección, de forma automática y sin desmontar, que actúa de forma programada, y con la frecuencia adecuada, para garantizar unas buenas condiciones de higiene, y un control seguro de la descontaminación microbiana; que posee un cerramiento donde se genera y mantiene un recinto microbiológicamente controlado (que envuelve a todas las estaciones de la termoformadora) mediante la inyección de aire que se pasa por filtros HEPA o ULPA que retienen con alta eficacia las partículas de diámetro igual o superior a 0,5 micrómetros.Universidad Politécnica de Cartagen

Predicted photoreflectance signatures on QD selective contacts for hot carrier solar cells

The CO2 emission of our present energy transformation processes, based mainly on burning fossil fuels, is possibly the main cause of global climatic change. The photovoltaic conversion of solar energy is a clean way of producing which for sustainability should (and most probably will) become a major source of electricity. The sun is a huge resource but relatively diluted and it is reasonable to expect that only high efficiency extraction can be cost effective for mass exploitation. New concepts are neccessary such as hot carrier solar cells

Evidence for an arginine-dependent route for the synthesis of NO in the model filamentous fungus Aspergillus nidulans

Nitric oxide (NO) is a signalling molecule in eukaryotic and prokaryotic organisms. NO levels transiently boost upon induction of conidiation in Aspergillus nidulans. Only one pathway for NO synthesis involving nitrate reductase has been reported in filamentous fungi so far, but this does not satisfy all the NO produced in fungal cells. Here we provide evidence for at least one additional biosynthetic pathway in A. nidulans involving l-arginine or an intermediate metabolite as a substrate. Under certain growth conditions, the addition of l-arginine to liquid media elicited a burst of NO that was not dependent on any of the urea cycle genes. The NO levels were controlled by the metabolically available arginine, which was regulated by mobilization from the vacuoles and during development. In vitro assays with protein extracts and amino acid profiling strongly suggested the existence of an arginine-dependent NO pathway analogous to the mammalian NO synthase. Addition of polyamines induced NO synthesis, and mutations in the polyamine synthesis genes puA and spdA reduced the production of NO. In conclusion, here we report an additional pathway for the synthesis of NO in A. nidulans using urea cycle intermediates.Austrian Federal Ministry of Education, Science and Research P 3279

Optoelectronic Characterisation of Intermediate Band Solar Cells by Photoreflectance Comparison to Other Advanced Architectures.

The fabrication and design of novel materials and devices for advanced photovoltaics, like the intermediate-band solar cell (IBSC), requires the use of specific characterization tools providing information about their optoelectronic properties. We have tested the suitability of photoreflectance for the characterization of IBSC prototypes based on quantum dots and compared the results obtained with those predicted by the theory. Nonidealities in operative devices have been identified and detailed information has been obtained about the electronic structure of the materials. We have compared PR spectra of IBSCs with those obtained from alternative device architectures, namely a triple-junction solar cell and a multi-quantum well structure. Some general conclusions are drawn demonstrating the potential of the technique

Thin Film intermediate band chalcopyrite solar cells: Theoretical Analysis of device performance and prospects for their realisation

The feasibility of implementing the intermediate-band (IB) concept into a relevant thin-film technology has been assessed. Compounds belonging to the group of I-III-VI2 chalcopyrites, currently used as absorbers in the leading thin-film technology, appear as promising candidates for the realization of IB-devices. In this paper we first analyze the expected performance of such a thin-film intermediate band solar cell (TF-IBSC) by considering different levels of idealization. In the second part of the paper some issues relevant for the practical realization of IBs in chalcopyrites are discussed and impurities acting as potential IB-precursors in the chalcopyrite sulfide host identified

Isolation and characterization of salt-sensitive mutants of the moderate halophile Halomonas elongata and cloning of the ectoine synthesis genes

The moderate halophile Halomonas elongata Deustche Sommlung fur Mikroorganismen 3043 accumulated ectoine, hydroxyectoine, glutamate, and glutamine in response to osmotic stress (3 M NaCl). Two Tn1732-induced mutants, CHR62 and CHR63, that were severely affected in their salt tolerance were isolated. Mutant CHR62 could not grow above 0.75 M NaCl, and CHR63 did not grow above 1.5 M NaCl. These mutants did not synthesize ectoine but accumulated ectoine precursors, as shown by 13C NMR and mass spectroscopy. Mutant CHR62 accumulated low levels of diaminobutyric acid, and mutant CHR63 accumulated high concentrations of N-γ-acetyl-diaminobutyric acid. These results suggest that strain CHR62 could be defective in the gene for diaminobutyric acid acetyltransferase (ectB), and strain CHR63 could be defective in the gene for the ectoine synthase (ectC). Salt sensitivity of the mutants at 1.5-2.5 M NaCl could be partially corrected by cytoplasmic extracts of the wild-type strain, containing ectoine, and salt sensitivity of strain CHR62 could be partially repaired by the addition of extracts of strain CHR63, which contained N-γ-acetyldiaminobutyric acid. This is the first evidence for the role of N-γ-acetyldiaminobutyric acid as osmoprotectant. Finally, a cosmid from the H. elongata genomic library was isolated which complemented the Ect- phenotype of both mutants, indicating that it carried at least the genes ectB and ectC of the biosynthetic pathway of ectoin

Demonstration and Analysis of the Photocurrent by absorption of two sub-bandgap photons in a quantum dot intermediate band solar cell

In order to surpass the efficiency limit of single gap solar cells, intermediate band solar cells (IBSC) have to fulfill two requirements: the production of extra photocurrent by absorption of sub-bandgap photons in electronic transitions involving the intermediate band (IB) and the preservation of a high output voltage, not limited by the existence of this band. This work presents experimental evidence of the production of electron-hole pairs by absorption of two sub-bandgap photons in IBSC prototypes fabricated with InAs/GaAs QD material. The experiments were carried out at low temperatures using a specifically designed modulated photocurrent measurement set-up with two light beams. The results are analysed with the help of a simple equivalent circuit model. This analysis is also used to highlight the relevance of the two-photon mechanism demonstrated in the experiment. It is discussed that, although the absorption of sub-bandgap photons in one of the IB transitions and subsequent thermal escape of carriers is a sufficient mechanism to obtain a photocurrent enhancement, the absorption of sub-bandgap photons in both transitions involving the IB is a requisite for the voltage preservation in IBSCs

Optical Characterization of Quantum Dot Intermediate Band Solar Cells

In this paper we present an optical characterization for quantum dot intermediate band solar cells (QDIBSCs). The cells were developed by growing a stack of ten InAs/GaAs QDs layers between p and n doped GaAs conventional emitters. Electroluminescence, EL, photoreflectance, PR, and transmission electron microscopy, TEM, were applied to the samples in order to test and characterize them optically. The results, derived from the application of the different techniques, showed a good correlation. TEM images revealed a very good structural quality of the QDs, which seem to evolve in shape-strain from the bottom to the top of the stack. Corresponding to the quality observed by TEM, strong signals from EL and PR resolved unambiguously the energy band diagram of the QDIBSCs. By fitting PR data we were able to indentify the coexistence of bands and discrete energy levels coming from the IB material. The PR data evidenced also a strong electric field over the dots, attributed to the space charge region created between the p-n emitters sandwiching the IB material. From EL results, we identified the predominantly radiative nature of the IB material related energy transition

Optoelectronic evaluation of the nanostructuring approach to chalcopyrite-based intermediate band materials

Nanostructured chalcopyrite compounds have recently been proposed as absorber materials for advanced photovoltaic devices. We have used photoreflectance (PR) to evaluate the impact of interdiffusion phenomena and the presence of native defects on the optoelectronic properties of such materials. Two model material systems have been analyzed: (i) thin layers of CuGaSe2 (Eg=1.7 eV) and CuInSe2 (1.0 eV) in a wide/low/wide bandgap stack that have been grown onto GaAs(0 0 1) substrates by metalorganic chemical vapor deposition (MOCVD); and (ii) thin In2S3 samples (Eg=2.0 eV) containing small amounts of Cu that have been grown by co-evaporation (PVD) intending to form CuxInySz (Eg1.5 eV) nanoclusters into the In2S3 matrix. The results have been analyzed according to the third-derivative functional form (TDFF). The valence band structure of selenide reference samples could be resolved and uneven interdiffusion of Ga and In in the layer stack could be inferred from the shift of PR-signatures. Hints of electronic confinement associated to the transitions at the low-gap region have been found in the selenide layer stack. Regarding the sulphide system, In2S3 is characterized by the presence of native deep states, as revealed by PR. The defect structure of the compound undergoes changes when incorporating Cu and no conclusive result about the presence of ternary clusters of a distinct phase could be drawn. Interdiffusion phenomena and the presence of native defects in chalcopyrites and related compounds will determine their potential use in advanced photovoltaic devices based on nanostructures