Importance of retronasal and orthonasal olfaction for odor aversion memory in rats.

The role of odors in food memory formation, especially for aversions, has long been considered secondary to taste. However, the importance of odor ingestion in conditioned odor aversion (COA) has recently challenged this assumption (B. M. Slotnick, F. Westbrook, & F. M. C. Darling, 1997). The aim of the present study was to evaluate the respective role of orthonasal and retronasal olfactory experience in COA acquisition, long-term retention, extinction, and spontaneous recovery. To this end, the odor was presented either close to the drinking spout (orthonasal stimulation) or close to and mixed with the drinking water (eliciting both orthonasal and retronasal stimulation). The authors brought evidence that odor ingestion was crucial for COA acquisition, especially when odor presentation and gastric malaise were separated by long delays. On the contrary, once formed, a distal (orthonasal) odor recognition was sufficient for COA to be retrieved. COA was odor specific and long lasting (more than 50 days). Moreover, results brought evidence for a spontaneous recovery of odor aversion tested 57 days after its extinction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of dust particles on the hydrodynamic behavior and mass transfer in droplet column

Bubble columns are commonly used in industry for polluted gas treatment. Based on the same principle, the droplet column which is not widely known in the literature, uses much higher gas velocities, up to 14 m/s. This study concerns the hydrodynamics and mass transfer in this apparatus, in presence or absence of solid particles. Our results have demonstrated the impact of dusts on mass transfer performance giving rise to an increase in the k_L a_L coefficient with decreasing particle size. However, no influence of dust on the hydrodynamics of the column has been demonstrated within the studied particle size range. A study of liquid holdups obtained by three different methods is also carried out. Our results are comparable, thus validating the methods used.     

Micromechanical modeling of the rolling of a A1050P aluminum sheet

A micromechanical ductile fracture model, extended to take account thermal heating due to mechanical dissipation within the material, is used to study a 3D-asymmetric rolling operation. The void coalescence mechanism by intervoid material ligament necking is also considered by using an extension of the Thomason’s criteria. This formulation is implemented into ABAQUS/Explicit finite element package and applied to simulate the effects of some rolling parameters on the evolution of the voids volume fraction and voids shape of a A1050P aluminum. The confrontation with available experimental results shows the capability of this constitutive law to predict the rolling force variation for different reductions. The results show, on one hand, that optimum parameters could be found in order to reduce the rolling force and, on the other hand, that rolling parameters exert an influence on the final microstructure of the rolled metal.     

High‐Rate Continuous Synthesis of Nanocrystalline Perovskites and Metal Oxides in a Colliding Vapor Stream of Microdroplets

A high‐rate, continuous synthesis of functional nanomaterials using a home engineered reactor is reported. The reactor is able to produce low‐cost, kilogram‐scale BaTiO₃ nanopowders with a nanocrystalline particle size less than 30 nm at mild temperatures (<100 °C) and ambient pressure. Nebulization and collision of warm microdroplets (60–80 °C) of Ba(OH)₂ and Ti(O‐nBu)₄ very quickly result in total hydrolysis and subsequent conversion to BaTiO₃, yielding 1.3 kg/day of high purity, highly crystalline nanoparticles (25–30 nm). This synthesis procedure also enables high‐rate production of TiO₂ anatase (2.9 kg/day). It therefore provides a general platform for processing and scaling up of functional inorganic nanomaterials under very mild conditions.     

Assessment of the Electrohydrodynamic Drying Process

Industries using energy-intensive processes are being forced to explore ways for reducing their energy consumption. In the food industry, air drying is one of the more energy-consuming processes. To reduce the energy consumption during this operation, alternative processes should be investigated. One promising alternative consists in the electrohydrodynamic (EHD) enhancement of heat and mass transfer. This paper analyses the literature and describes the great potential of this innovative process based on the generation of an electric wind by a corona discharge. The main aspects of this technique are discussed and special emphasis is given on its benefit for food processes. The main part of this paper concerns experimental investigations carried out to assess the EHD enhancement on the drying process. An experimental set-up was designed to measure the weight losses on a food product submitted to an electrostatic field and to a cross air flow. Present results confirm that, for a low cross air velocity, the ionic wind leads to an enhancement of the drying rate. The best results are obtained for the smaller distance between the food surface and the corona electrode. Nevertheless, the process is less efficient for a high air velocity. The last part deals with a numerical model that was developed to evaluate the electric parameters and the flow field in turbulent regime. This model provides useful information on the coupled phenomena and permits to explain the experimental observations and to help in designing EHD drying processes.     

Modelling and robust FDI of steam generator using uncertain bond graph model

In this paper, a bond graph model based approach for robust FDI (Fault Detection and Isolation) in the presence of parameter uncertainties is presented. Due to the energetic and structural properties of the bond graph, the whole of nonlinear model, structural analysis, residual with adaptive thresholds generations, and sensitivity analysis of the residuals can be synthesized using this same tool. This method is applied online on an industrial steam generator. Experimental results are given to support the theoretical development.     

A study of oxygen absorption kinetics in ionic Cu(I) aqueous solutions

We developed the oxidation reaction of Cu(I) ion in aqueous hydrochloric solution by oxygen in a gas-lift capillary bubble column. The method of gas-liquid absorption with chemical reaction was used. Test data confirmed that the rate constant of the reaction is strongly affected by solution compositions, and that chloride ions induce an inhibition effect. The kinetical orders found are equal to 1 and 2 for oxygen and Cu(I) respectively. The influence of temperature on reaction rate constant showed the existence of a maximum value between 303 and 313K. The effect of gas-liquid of gas-liquid system on the liquid-side mass transfer coefficient k_L was also investigated.     

Robust Fault Diagnosis by Using Bond Graph Approach

This paper deals with the generation of fault indicators and residual thresholds in the presence of parameter uncertainties by using a bond graph representation in linear fractional transformation (LFT) form. The residuals' sensitivity analysis, which is based on the fault detectability indexes, is used for residuals evaluation. The developed algorithms are applied on an electromechanical test bench system for on-line fault detection and isolation. Simulation and experimental tests show the influence of dead zone magnitude and variations of system parameters on the residuals.