A neural network-based scheme coupled with the RPV model inversion package

A hybrid scheme for the inversion of the Rahman-Pinty-Verstraete (RPV) model is presented. It combines the inversion technique described by Lavergne et al. (Lavergne, T., Kaminski, T., Pinty, B., Taberner, M., Gobron, N., Verstraete, M.M., Vossbeck, M., Widlowski, J.L., Giering, R. (2007). Application to MISR land products of an RPV model inversion package using adjoint and Hessian codes. Remote Sensing of Environment, 107, 362-375.) and a multilayer backpropagation feedforward neural network. The RPV inversion package is applied to a sample set of pixels within the satellite scene. Subsequently the pairs of bidirectional reflectance factors (BRF) and model parameters estimated from the sample set of pixels are used to train the neural network. Since the mathematical formulation of the RPV model is embedded in these training data variables, the neural network can efficiently retrieve the model parameters for the whole satellite scene. This scheme has been tested for a MISR L2 BRF scene, MISR L1B2-derived BRF data corresponding to two different dates and a mosaic of MISR L2 BRF scenes acquired over Southern Africa covering a large extent of Miombo woodland. The results show this strategy retrieves the RPV model parameters and uncertainties with high accuracy and considerable speed over large areas.     

Numerical modeling and design of supercritical CO2 pre-cooler for fusion nuclear reactors

One of the key issues of fusion technology is the efficient recovery of the fusion power extracted by heat transfer fluids in the breeding blanket. The Spanish National Program TECNO_FUS is exploring a dual-coolant breeding blanket design concept and its plant auxiliary systems for a future power reactor (DEMO), with liquid lead–lithium as main primary nuclear power recovering fluid. Supercritical CO₂ is chosen for the secondary circuit, since its high efficiency at significantly lower required temperatures than for the Brayton helium cycle, due to low compression work near the critical point and also because its additional major benefits in terms of tritium control. Use of printed circuit heat exchangers (PCHE) is suggested in literature due to its highly compact design and robustness for the high pressures found. This work deals with the heat exchanger devoted to release the thermal energy of the power cycle to the thermal sink. The aim of this work is analyzing how the nearness of the CO₂ to its critical point affects the performance of the heat exchanger. Computer Fluid Dynamics (CFD) simulations that include the complex thermal behavior of CO₂ properties at supercritical conditions are used in order to achieve an accurate approach to the design of this heat exchanger. These results are compared with others obtained through correlations found in the open literature. The behavior of CO₂ close to its critical point results in an inefficient use of the exchange area, giving a temperature profile in CO₂ which remembers a condensation process and an overall heat transfer coefficient 1.4 times higher than the one achieved with literature correlations design.     

Gene clustering for time-series microarray with production outputs

The identification of coexpressed genes from microarray data is a challenging problem in bioinformatics and computational biology. The objective of this study is to obtain knowledge about the most important genes and clusters related to production outputs of real-world time-series microarray data in the industrial microbiology area. Each sample in the microarray data experiment is complemented with the measurement of the corresponding production and growth values. A novel aspect of this research refers to considering the relation of coexpression patterns with the measured outputs to guide the biological interpretation of results. Shape-based clustering models are developed using the pattern of gene expression values over time and further incorporating knowledge about the correlation between the change in the gene expression level and the output value. Experiments are performed for time-series microarray of bacteria, and an analysis from a biological perspective is carried out. The obtained results confirm the existence of relationships between output variables and gene expressions. Moreover, the shape-based clustering methods show promising results, being able to guide metabolic engineering actions with the identification of potential targets.     

Physical and Tribological Properties Degradation of Silicone Rubber Using Jatropha Biolubricant

This article aims to investigate the degradation of physical and tribological properties (friction coefficients and wear resistance) of a dynamic sealing material (silicone rubber [VMQ]) exposed to Jatropha oil (JO), engine mineral oil (EMO), and a blend (B20; 80% EMO–20% JO), separately. JO has demonstrated better lubricating properties than EMO in various mechanical applications; however, the degradation of elastomers by using this oil has not been studied yet, nor have its effect on their tribological properties. The physical degradation was evaluated by conducting static immersion tests (670 h at 25 °C) based on ASTM-D471 and ASTM-D7216 methods. Hence, the changes in mass, volume, tensile and tear strengths, and hardness of VMQ were measured. In addition, creep compliance tests were conducted to determine the changes in viscoelastic properties and the changes in morphology and topography were measured by scanning electron microscopy (SEM) and optical profilometry, respectively. In addition, the compositional changes were determined by Fourier transform infrared (FTIR) analyses to complement the degradation examination. Changes in the friction coefficients were determined by ball-on-disk tests and changes in wear resistance were obtained by accelerated wear tests (microabrasion tests). Finally, VMQ exhibited no significant physical and compositional degradation due to immersion in the three lubricants. However, considerable changes in the friction coefficients and wear resistance were observed; the change in the friction coefficients was minimal using JO. In addition, the coefficients using JO were 50% lower than those for EMO and the changes in wear resistance were lowest after immersion in JO.     

DI-B experiment: planning, design and performance of an in situ diffusion experiment in the Opalinus Clay formation

The DI-B experiment is a long-term, natural-scale, in situ diffusion experiment, which is being performed in the Opalinus Clay formation at the Mont Terri Underground Rock Laboratory (URL), in Switzerland, employing nonradioactive tracers. One of the key aspects to be addressed for nuclear waste repository safety assessment purposes is the understanding of the transport mechanisms of the radionuclides contained in the radioactive waste. Consolidated clay formations display very low water hydraulic conductivities, so it is expected that the predominant transport process will be diffusion.The experimental set-up has been designed to withstand the site conditions and for monitoring and recording several physicochemical parameters (pH, conductivity, oxidation–reduction potential), as well as the pressures in the circuit and for the long-distance monitoring of the data acquisition system.The tracer selection has been made based on previous investigations carried out at CIEMAT, including a literature survey, laboratory sorption experiments and hydrogeochemical modeling for determining tracer stability under the physicochemical conditions to be expected in the site. The final selection includes ⁶Li, ⁸⁷Rb, D (as D₂O) and I (as I⁻). Hydrogeochemical modeling confirmed the stability of all the tracers selected. Batch sorption experiments showed that no sorption in the rock occurred in the case of ⁶Li, D and I (conservative tracers), whereas ⁸⁷Rb was 100% sorbed. However, ⁸⁷Rb was chosen because of its analogy with Cs, a relevant radionuclide commonly present in the nuclear spent fuel.Diffusion experiments have been carried out at laboratory scale with Opalinus Clay samples to provide diffusion parameters for modeling purposes. Effective diffusion coefficients, perpendicular and parallel to the bedding planes of the rock, respectively, were (1.68± 0.42)×10⁻¹¹ and (4.02± 0.30)×10⁻¹¹ m²/s for tritium, and (2.70± 0.27)×10⁻¹² and (1.38± 0.49)×10⁻¹¹ m²/s for iodide. Additional through-diffusion experiments (parallel to the bedding) were performed with the nonsorbing tracer ³⁶Cl⁻, in order to check the results obtained for iodide. The effective diffusion coefficient measured for chloride ions was (1.18± 0.27)×10⁻¹¹ m²/s, which is practically equal to the value obtained for iodide.Preliminary diffusion calculations have been carried out using two transport codes: GIMRT and CORE^2D, with conservative and nonconservative tracers, using effective diffusion coefficients (D_e) obtained experimentally in the laboratory (through-diffusion experiments) or selected from the literature. The diffusion profiles obtained from the calculations showed slight variations, which were consistent with the different modeling approaches employed. The predictive modeling results have been used to determine the initial tracer concentration that should be added to the circuit to assure well-defined profiles at the end of the experiment.This long-term in situ diffusion experiment will also provide useful data for the interpretation of previous diffusion experiments performed at the Mont Terri URL.     

Present status of the conceptual design of the EU test blanket systems

The EU Breeding Blanket Programme aims the testing of two blankets concept in ITER in form of Test Blanket Modules. In the equatorial port #16 the two EU TBMs – a solid and a liquid blanket concept – will be exposed to the plasma and the complex system of their auxiliary systems dedicated to heat and Tritium removal will be integrated in the surrounding ITER buildings. The development of the conceptual design of the EU TBM System is the main objective of the Grant F4E-2008-GRT-09 contract launched by F4E and assigned to a European Consortium. This paper presents an overview of the results after about 20 months of activities: namely, the design of the main sub-systems of the EU TBSs and a concept of integration in ITER.     

Transfer learning and information retrieval applied to fall detection

Detecting falls in the elderly population is a very important issue that is related with the time of recovery. This study focuses on using wearable smart watches to monitor the movements of the user in order to detect patterns that might be related to fall events. The proposed solution explores Symbolic Aggregate approXimation (SAX) Time Series representation, together with two information retrieval techniques enriched with transfer learning (TL). The solution is user centred; that is, a model is developed for each specific user. Basically, the fall detection approach makes use of a finite-state machine to detect peaks; the time series window embedding these peaks are represented using SAX. Assuming the data from the public fall detection data sets are valid, a dictionary is prepared using the most relevant words. This dictionary is then introduced as previous knowledge to an online learning classifier that is trained with normal activities of daily living. The two classifiers are evaluated and compared with two classical approaches. Before this comparison, two clustering approaches are studied to produce the bag of relevant words. A complete experimentation is included, which makes use of several publicly available data sets and also with a data set developed by the research group. Comparisons are performed for all the data sets, showing how the TL stage empowers the classifier. The results show that this solution produces high detection rates and at the same time performed similarly for all the individuals tested. Furthermore, the positive effects of TL in this context are clearly remarked.     

Preliminary neutronic assessment of a helium-cooled Li8PbO6 breeding blanket design for DEMO

A preliminary neutronic assessment of the performances of a helium-cooled Li₈PbO₆ breeding blanket for the conceptual design of a DEMO fusion reactor is given. The study mainly focuses on TBR, power density responses and shielding factor optimization to estimate the feasibility of the design under the prescribed radiation deposition limits at TF-coils superconducting magnets. Computational analyses are based on three-dimensional 30° sector using the Monte Carlo code MCNPX 2.6. The scoping interest of helium-cooled Li₈PbO₆ blanket designs is based on a large potential minimization of the amount of Be required and the strong relaxation of ⁶Li enrichment requirements for this solution when compared to other solid breeder blanket options.     

Complications of intestinal transporting of cocaine packets. Study of 215 cases

BACKGROUND: To analyse clinical manifestations, diagnosis and management in the "body packer syndrome". MATERIAL AND METHODS: We collected 215 patients who had ingested packets of cocaine. RESULTS: Bowel obstruction, haemorrhagic complications and seizures were observed in 5.1, 4.2 and 2.3%, respectively. Toxic manifestations of cocaine occurred in 4 patients. CONCLUSIONS: Radiographs of abdomen are necessary for diagnosis and follow-up. Close surveillance in necessary to identify intestinal obstruction or acute intoxication by cocaine.