Robust identification and fault diagnosis based on uncertain multiple input–multiple output linear parameter varying parity equations and zonotopes

We present a robust fault diagnosis method for uncertain multiple input–multiple output (MIMO) linear parameter varying (LPV) parity equations. The fault detection methodology is based on checking whether measurements are inside the prediction bounds provided by the uncertain MIMO LPV parity equations. The proposed approach takes into account existing couplings between the different measured outputs. Modelling and prediction uncertainty bounds are computed using zonotopes. Also proposed is an identification algorithm that estimates model parameters and their uncertainty such that all measured data free of faults will be inside the predicted bounds. The fault isolation and estimation algorithm is based on the use of residual fault sensitivity. Finally, two case studies (one based on a water distribution network and the other on a four-tank system) illustrate the effectiveness of the proposed approach.     

Characterisation of an Egyptian coal by Mossbauer and FT-IR spectroscopy

Six coal samples collected from Maghara Coal Mine, North Sinai, Egypt, at different depths (52-87 m) were characterised by Mossbauer (MS) and Fourier Transform Infrared (FT-IR) spectroscopy. The moisture and ash content and the ultimate analysis are given. The iron minerals were studied by MS. Jarosite (ferric sulphate) and pyrite have been found in the sample taken at 52 m. However, ferrous sulphate and pyrite are present in the other samples. On the other hand, several structural parameters such as H_ar/H_al and H_ar/C_ar were calculated from FT-IR spectra as a function of depth. These parameters give a quantitative determination of the aromaticity, which was found in the range between 0.46 and 0.59, similar to that reported in the literature for subbituminous coals.     

Structural topology optimization for multiple load cases using a dynamic aggregation technique

A series of techniques is presented for overcoming some of the numerical instabilities associated with SIMP materials. These techniques are combined to create a robust topology optimization algorithm designed to be able to accommodate a large suite of problems that more closely resemble those found in industry applications. A variant of the Kreisselmeier–Steinhauser (KS) function in which the aggregation parameter is dynamically increased over the course of the optimization is used to handle multi-load problems. Results from this method are compared with those obtained using the bound formulation. It is shown that the KS aggregation method produces results superior to those of the bound formulation, which can be highly susceptible to local minima. Adaptive mesh-refinement is presented as a means of addressing the mesh-dependency problem. It is shown that successive mesh-refinement cycles can generate smooth, well-defined structures, and when used in combination with nine-node elements, virtually eliminate checkerboarding and flexural hinges.     

Microglia Response and In Vivo Therapeutic Potential of Methylprednisolone‐Loaded Dendrimer Nanoparticles in Spinal Cord Injury

The control and manipulation of cells that trigger secondary mechanisms following spinal cord injury (SCI) is one of the first opportunities to minimize its highly detrimental outcomes. Herein, the ability of surface‐engineered carboxymethylchitosan/polyamidoamine (CMCht/PAMAM) dendrimer nanoparticles to intracellularly deliver methylprednisolone (MP) to glial cells, allowing a controlled and sustained release of this corticosteroid in the injury site, is investigated. The negatively charged MP‐loaded CMCht/PAMAM dendrimer nanoparticles with sizes of 109 nm enable a MP sustained release, which is detected for a period of 14 days by HPLC. In vitro studies in glial primary cultures show that incubation with 200 μg mL^?1 nanoparticles do not affect the cells' viability or proliferation, while allowing the entire population to internalize the nanoparticles. At higher concentrations, microglial cell viability is proven to be affected in response to the MP amount released. Following lateral hemisection lesions in rats, nanoparticle uptake by the spinal tissue is observed 3 h after administration. Moreover, significant differences in the locomotor output between the controls and the MP‐loaded nanoparticle‐treated animals one month after the lesion are observed. Therefore, MP‐loaded CMCht/PAMAM dendrimer nanoparticles may prove to be useful in the reduction of the secondary injury following SCI.     

Chromium recovery from tannery sludge with saponin and oxidative remediation

Two new methods for treatment of tannery sludge were studied to achieve cost-effective and environmentally acceptable remediation solutions for high chromium containing tannery sludge. Quillaja bark saponin, a plant derived biosurfactant, was applied to dewatered tannery sludge for chromium recovery and a comparative assessment with H(2)O(2) oxidative treatment method is presented. Tannery sludge samples were treated on a laboratory scale with saponin in the pH range 2-3. The effects of various factors like time, concentration of saponin, pH, and temperature on the extraction of chromium were studied. The treatment with saponin extracted 24% of Cr from tannery sludge at a pH around2, performing multiple wash of 6h, at 33 °C. On the other hand, the H(2)O(2) treatment, which include Cr(III) oxidation to Cr(VI) and extraction with sulfuric acid solution at pH 2, enabled to extract 70% of chromium within less than 4h at room temperature (21 °C). The results indicate that the extraction efficiency of saponin was strongly dependent on the organic matter content of the sample, which affects chromium mobility by its high adsorption capacity. On the other hand hydrogen peroxide treatment is effective and the duration of the process is short and requires cheap chemicals and moderate conditions.     

Photodeposition of Pt nanoparticles on TiO2-carbon xerogel composites

Carbon xerogels synthesized from polycondensation of resorcinol with formaldehyde, having specific surface areas in the range 650 to 990 m² g⁻¹ and variable degrees of surface oxidation, are used to prepare TiO₂-carbon xerogel composites by sol-gel methods. These composite materials are used to support Pt nanoparticles (5 wt.%) by the photodeposition technique. After a high temperature reduction treatment at 773 K, the obtained materials were characterized in order to assess the interactions between the phases Pt, TiO₂ and carbon xerogel. It is observed that the carbon xerogel acts as an adhesive agent of the TiO₂ and Pt particles, enhancing the interaction between the metal and the composite support.     

Nutrition of infants and young children (one to three years) and its effect on later health: A systematic review of current recommendations (EarlyNutrition project)

Background. EarlyNutrition (www.project-earlynutrition.eu) is an international research project investigating the effects of early nutrition on metabolic programming.

Objective. To summarize, by performing a systematic review, current standards, recommendations, guidelines, and regulations (hereafter, referred to as documents) on the nutrition of children up to three years of age. Special emphasis was placed on long-term effects of early nutrition, such as the risk of cardiovascular disease, hypertension, overweight, obesity, metabolic syndrome, diabetes, or glucose intolerance.

Methods. MEDLINE, selected databases, and websites were searched for documents published between 2008 and January 2013.

Results. Forty two documents met the inclusion criteria. The strongest and most consistent evidence for a protective, long-term effect was documented for breastfeeding. Also, limiting the intake of sodium and rapidly absorbed carbohydrates, use of a specific meal pattern, reducing the consumption of saturated fatty acids by replacing them with polyunsaturated fatty acids, and lowering the intake of trans fatty acids, seems beneficial. Many documents did not evaluate long-term outcomes of interest to us, or reported insufficient or imprecise data. Inconsistency in recommendations for some outcomes and research gaps were identified.

Conclusions. Our findings may serve as a helpful tool in planning further research, preventive actions against important diet-related diseases, and guidelines improvement.     

Establishing safety distances for wildland fires

In wildland fires, safety zones should be considered concerning people who are intervening in the emergency or attempting evacuation. To establish such zones, the solid flame model, together with the view factor calculated from a previously selected equation, was used to estimate the thermal radiation emitted by the flame front of a wildland fire. After determining the flame heights yielded by the 13 fuel types in the Rothermel classification for surface fires, and for crown fires in various Mediterranean forests, the thermal radiation was calculated for each scenario as a function of the distance. These data, together with threshold values for the vulnerability of people (protected or unprotected) and houses to thermal radiation, allowed for a set of safety distances for different situations to be obtained. These safety distances can be applied both in territory planning and in emergency situations.     

Broadband ultrasound attenuation in the calcaneal region: a comparative study of single-position versus scanning systems

This work describes a system developed to measure the broadband ultrasound attenuation (BUA) in the calcaneal region. The patient's calcanei were inspected using a microcomputer-controlled X-Y axis displacement unit with two 500-kHz, central-frequency, ultrasound transducers. The transducers facing each other are submerged in a small water tank with a support for the patient's foot between them. The system allows data to be collected from a single position or by scanning the calcaneal region to obtain a BUA map. Tests were carried out on 201 patients (110 using the single-position method, and 91 using the scanning method). The results were compared with those of densitometry tests performed using the dual energy X-ray absorptiometry (DEXA) technique (single position: r=0.50; P<0.0001; scanner: r=0.75; P<0.0001). It was concluded that the single position method is more susceptible to errors due to the difficulty in positioning the transducers relative to the calcaneus. The scanning method provides better results and can be used to screen patients before referring them for DEXA.     

Assessing the Efficiency of CFRP Discrete Confinement Systems for Concrete Cylinders

Concrete columns requiring strengthening intervention always contain a certain percentage of steel hoops. Applying strips of wet layup carbon fiber-reinforced polymer (CFRP) sheets inbetween the existent steel hoops might, therefore, be an appropriate confinement technique with both technical and economic advantages, when full wrapping of a concrete column is taken as a basis of comparison. To assess the effectiveness of this discrete confinement strategy, circular cross-sectional concrete elements confined by distinct arrangements of strips of CFRP sheet are submitted to a direct compression load up to the failure point. The influence of the width of the strip, distance between strips, number of CFRP layers per strip, CFRP stiffness, and concrete strength class on the increase of the load carrying capacity and ductility of concrete columns, is evaluated. An analytical model is developed to predict the compressive stress-strain relationship of concrete columns confined by discrete and continuous CFRP arrangements. The main results of the experimental program are presented and analyzed and used to assess the model performance.