A New Refinement Method for Registration of Range Images Based on Segmented Data

Received November 21, 2000; revised July 17, 2001     

Systolic time intervals during isometric exercise in supine position should be corrected also for arterial pressure

In this paper we have studied the relationship between the systolic time intervals (STI) and the heart rate (HR) and systolic arterial pressure (SAP) in a group of 24 healthy subjects at three different effort levels during an isometric exercise in supine position and in basal conditions. We observed a decrease of the non corrected STI values during the exercise. Then we corrected STI using the regression equations obtained by plotting STI values versus the corresponding HR values at rest and during the exercise. We showed an increase of corrected left ventricular ejection time (LVET) during the whole exercise, and an increase of corrected total electromechanical systole (QS2c) at 50% effort level and then a return to the basal values. We also derived the multiple regression equations correlating QS2 and LVET with HR and SAP. Notwithstanding these equations show a significant positive correlation between the two STI considered and SAP only at the maximum effort, we corrected LVET and QS2 values by these equations assuming that the relationship between these parameters exists also in basal conditions and during the remaining stages of the exercise. By this correction we found a decrease of LVETc and QS2c in accordance with hemodynamic data reported by other authors. We may conclude that it seems useful to correct the STI obtained during isometric exercise in supine position both for HR and SAP.     

A multiple shutdown method for managing evacuation in case of major fire accidents in chemical clusters

This paper may be regarded as the second part of a larger article. The basic decision model developed in the first part of the article by Reniers et al. [G.L.L. Reniers, N. Pauwels, A. Audenaert, B.J.M. Ale, K. Soudan, Management of evacuation in case of fire accidents in chemical industrial areas, J. Hazard. Mater., 147 (2007) 478-487] is extended to determine both the optimal time and the optimal mode to stop the ongoing activities in case of a major fire possibly giving rise to an escalating event. Chemical plants have multiple modes to stop their production processes, differing with respect to the resulting costs, and with respect to the required time and personnel to complete the shutdown operations. The existence of an additional and more economic (but slower) shutdown mode might encourage the decision maker to stop the production processes earlier, in a less intervening manner, whereas the availability of an additional faster (but less economic) shutdown procedure might stimulate the decision maker to stop the production processes later, in a more intervening manner.     

Reliability and risk treatment centered maintenance

We propose a new methodology for application of well-known tools — RCM, RBI and SIFpro — with the aim to treat risks by means of suitable maintenance. The basis of the new methodology is the complex application of all three methods at the same time and not separately as is typical today. The proposed methodology suggests having just one managing team for reliability and risk treatment centred maintenance (RRTCM), employing existing RCM, RBI, and SIFpro tools concurrently. This approach allows for significant reduction of engineering activities’ duration. In the proposed methodology these activities are staged into five phases and structured to eliminate all duplication resulting from separate application of the three tools. The newly proposed methodology saves 45% to 50% of the engineering workload and adequate significant financial savings.     

Sorption and Drying Characteristics of Xylite

The wood from which xylite is formed in a long-term process undergoes numous changes while still retaining the character of a hygroscopic porous material. To plan the optimal drying schedule of xylite, the permeability coefficient, diffusion coefficient, and surface emission coefficient were determined. The porosity of xylite is low due to the demolished capillary structure; concurrently with the blocked pits, the permeability of xylite is very low, with a permeability coefficient not higher than 2.12 × 10^?10 m²/Pa s. The capillary flow of free water is insignificant, allowing the diffusion transport of water to prevail. The diffusion coefficient is considerably influenced by the xylite's density. We confirm a significant increase in the bound water diffusion coefficient as the temperature increased (from 5.5 × 10^?12 m²/s at 20°C to 46.3 × 10^?12 m²/s at 40°C), and we predict that the activation energy will increase as the moisture content of xylite decreases (approx. 0.63 to 1.05%/% MC changes). As a consequence of the low surface resistance, the surface emission coefficient barely influences the moisture transport below the fiber saturation point.With an appropriate drying schedule, quality dried xylite can be used for various products as an equivalent substitute for dark-colored, high-density woods like ebony.     

Behaviour of cod liver oil during the autoxidation process

Prostaglandin‐like compounds, called isoprostanes, are generated by free enzyme‐independent radical peroxidation of the acids arachidonic (AA), eicosapentaenoic (EPA) and docosahexaenoic (DHA). Up to now, isoprostanes have been largely studied only in men and biological systems, but never in food. In this research, cod liver oil was used as a model system to study the oxidation mechanism in food containing high amounts of EPA and DHA. For comparison, under similar oxidation conditions, also the behaviour of a sunflower seed oil and an n‐3 long‐chain polyunsaturated fatty acid capsule supplement oil were studied. It was ascertained that EPA‐ and DHA‐derived compounds were formed during oxidation. These compounds were polar and easily isolatable by methanol from oxidised transmethylated oil. EPA and DHA oxidation derivatives showed maximal absorbance at 200 nm and were very potent pro‐oxidants at high temperatures. In oxidised sunflower oil, similar compounds did not form. Unfortunately, the chemical structures of the EPA and DHA oxidation derivatives were not discovered, but it is a realistic hypothesis that they could be isoprostane‐like compounds.     

Heat-oxidation stability of palm oil blended with extra virgin olive oil

Rancimat induction time of palm oil (PO), several extra virgin olive oils (EV) and their binary blends have been determined at three different temperatures (120, 130 and 140°C). Analytical composition and oxidation stability of PO/EV blends were found to be a linear combination of the oil partners. Induction time of pure PO was always higher than those of EV oils and blends, in which induction time increased proportionally with the percentage of PO. However, induction time of 80% PO blend was similar to that of pure PO. Fatty acid composition appeared to be the most important factor affecting heat-oxidation stability and a saturated/unsaturated ratio near 1 was the optimally stable composition. Conversely, total phenols had a zero or negative role on the oxidative stability of the blends. Finally, in heat-oxidised oils significant losses of polyunsaturated fatty acids and formation of short-chain fatty acids were recorded.