Track-based self-supervised classification of dynamic obstacles

This work introduces a self-supervised architecture for robust classification of moving obstacles in urban environments. Our approach presents a hierarchical scheme that relies on the stability of a subset of features given by a sensor to perform an initial robust classification based on unsupervised techniques. The obtained results are used as labels to train a set of supervised classifiers. The outcomes obtained with the second sensor can be used for higher level tasks such as segmentation or to refine the within-clusters discrimination. The proposed architecture is evaluated for a particular realization based on range and visual information which produces track-based labeling that is then employed to train supervised modules that perform instantaneous classification. Experiments show that the system is able to achieve 95% classification accuracy and to maintain the performance through on-line retraining when working conditions change.     

The thermal conductivity of liquid 1,1,1,2-tetrafluoroethane (HFC 134a)

The thermal conductivity of HFC 134a was measured in the liquid phase with the polarized transient hot-wire technique. The experiments were performed at temperatures from 213 to 293 K at pressures up to 20 MPa. The data were analyzed to obtain correlations in terms of density and pressure. This study is part of an international project coordinated by the Subcommittee on Transport Properties of Commission 1.2 of IUPAC, conducted to investigate the large discrepancies between the results reported by various authors for the transport properties of HFC 134a, using samples of different origin. Two samples of HFC 134a from different sources have been used. The thermal conductivity of the first sample was measured along the saturation line as a function of temperature and the data were presented earlier. The thermal conductivity of the second one, the round-robin sample was measured as a function of pressure and temperature. These data were extrapolated to the saturation line and compared with the data obtained, previously in order to demonstrate the importance of the sample origin and their real purity. The accuracy of the measurements is estimated to be 0.5%. Finally, the results are compared with the existing literature data.     

The thermal conductivity of liquid argon for temperatures between 110 and 140 K with pressures to 70 MPa

The paper presents new experimental measurements of the thermal conductivity of liquid argon for four temperatures between 110 and 140 K with pressures to 70 MPa and densities between 23 and 36 mol · L ^–1. The measurements were made with a transient hot-wire apparatus. A curve fit of each isotherm allows comparison of the present results to those of others and to correlations. The results are sufficiently detailed to illustrate several features of the liquid thermal conductivity surface, for example, the dependence of its curvature on density and temperature. If these details are taken into account, the comparisons show the accuracy of the present results to be 1 %. The present results, along with several other sets of data, are recommended for selection as standard thermal conductivity data along the saturated liquid line of argon, extending the standards into the cryogenic temperature range. The results cover a fairly wide range of densities, and we find that a hard-sphere model cannot represent the data within the estimated experimental accuracy.     

Effect of processing conditions on proteolysis and taste of dry-cured sausages

 This paper deals with the influence of industrial practices such as use of starters (Lactobacillus sake and Staphylococcus carnosus), preripening (3 days at 5°C) and drying temperatures (8 and 16°C) on proteolysis, ammonia production and the taste of “salchichón”, a traditional Spanish dry-cured sausage lacking surface mould. pH dropped more sharply in the presence of a starter and at a high drying temperature (16°C); preripening did not affect the pH. The highest value for non-protein nitrogen (NPN), 16% of total nitrogen, was observed to occur in samples with the lowest pH (4.7–4.8). Total volatile basic nitrogen (TVBN) increased during drying due to the deaminase activity of internal microbial flora, which was not great (0.5–1.0% of total nitrogen) enough to affect the pH, and significantly in samples showing a larger decrease of pH. The greater proteolysis in samples with starter did not affect the assessors’ taste preference. Assessors clearly preferred those samples without starter that were dried at low temperature (8°C); however, samples with starter showed excellent commercial appearance since they dried more homogeneously. An equilibrium point must be found between acid production and taste. Received: 12 February 1996/Revised version: 24 May 1996     

Influence of contact loss between workpiece and grinding wheel on the roundness errors in centreless grinding

The objective of this paper is the study of certain non-linear phenomena in the centreless grinding process and their effect on roundness quality. These phenomena arise as a consequence of contact loss between workpiece and grinding wheel. A simplified analysis of the problem is carried out to determine the main parameters involved. A qualitative assessment of the effect of these parameters is undertaken by means of a time simulation based on a non-linear bi-dimensional model of the centreless grinding process. Two situations are analysed: the steady process, and the transient spark-out process. The results, which are generalised in graphics form provide an estimation of roundness errors resulting from working under linearly unstable conditions. Finally, a correlation between theoretical and experimental results is presented.     

Effect of calcium chloride on the volatile pattern and sensory acceptance of dry-fermented sausages

The effect of calcium chloride addition used in combination with starter cultures (lactic acid bacteria and staphylococci) was studied in the development of dry-fermented sausage aroma and final sensory acceptance. Volatile compounds were extracted by solid-phase micro extraction and analysed by gas chromatography-mass spectrometry. A paired comparison test was done to determine which sausage was preferred. The addition of calcium chloride 0.05% showed an important effect on volatile generation during ripening by inhibiting the generation of lipid oxidation products and promoting the generation of methyl branched alcohols and ethyl esters that contribute to proper sausage aroma. However, other compounds such as 3-methyl-butanoic acid and acetic acid, detected in high quantities in the 0.05% calcium added batch, may impart rancid and cheese-like notes that can negatively affect the final aroma. Moreover, the amount of calcium chloride used is important because larger amounts (0.5%) favoured the lipid oxidation producing a rejection from consumers.     

Bimetallic catalysts for continuous catalytic wet air oxidation of phenol.

Catalytic wet oxidation has proved to be effective at eliminating hazardous organic compounds, such as phenol, from waste waters. However, the lack of active long-life oxidation catalysts which can perform in aqueous phase is its main drawback. This study explores the ability of bimetallic supported catalysts to oxidize aqueous phenol solutions using air as oxidant. Combinations of 2% of CoO, Fe2O3, MnO or ZnO with 10% CuO were supported on gamma-alumina by pore filling, calcined and later tested. The oxidation was carried out in a packed bed reactor operating in trickle flow regime at 140 degrees C and 900 kPa of oxygen partial pressure. Lifetime tests were conducted for 8 days. The pH of the feed solution was also varied. The results show that all the catalysts tested undergo severe deactivation during the first 2 days of operation. Later, the catalysts present steady activity until the end of the test. The highest residual phenol conversion was obtained for the ZnO-CuO, which was significantly higher than that obtained with the 10% CuO catalyst used as reference. The catalyst deactivation is related to the dissolution of the metal oxides from the catalyst surface due to the acidic reaction conditions. Generally, the performance of the catalysts was better when the pH of the feed solution was increased.     

Simple and Efficient Generation of White Light Emission From Organophosphorus Building Blocks

This paper describes a structure–property study using two dithieno[3,2‐b;2′,3′‐d]phosphole building blocks for the generation of white light emission and the incorporation of these units in a single polystyrene material. The emission of one of the light‐emitting organophosphorus building blocks can efficiently be switched from orange to green by simple protonation of the amino functional groups that are part of the π‐conjugated scaffold. The resulting three components (blue, green, and orange) exhibit photophysical properties that allow for an efficient fluorescence resonance energy transfer (FRET) in the mixture/polymer and provide intense white fluorescence upon excitation of the blue component; the fluorescence is close to pure white in solution and similar to the emission of an incandescent light bulb in the thin film. The results nicely illustrate the intriguing features that can be obtained by exclusively using organophosphorus‐based organic electronic materials.     

Optimal haulage routing of off-road dump trucks in construction and mining sites using Google Earth and a modified least-cost path algorithm

This study presents new software, called Google Earth-based Optimal HAulage RouTing System (GEOHARTS), to improve the functionality of Google Earth for optimal haulage routing of off-road dump trucks in construction and mining sites. A modified least-cost path algorithm, which is applicable to working areas with both paved and unpaved temporary roads and can consider the effects of terrain relief and curves along a route on the route planning, was proposed and utilized for the software development. GEOHARTS can determine optimal haulage routes between loaders and dumps that ensure the least travel time or fuel consumption of off-road dump trucks and can visualize the results using an embedded 3D render window of Google Earth. The application to the Pasir open-pit coal mine in Indonesia demonstrates that GEOHARTS could provide a rational solution to support the truck haulage operations.