An application-oriented,optimization-based methodology for interactive design of engineering systems†

Motivated by a control system example, a new methodology is proposed for tackling optimal design of engineering systems. This methodology emphasizes designer's intuition and man-machine interaction. It includes a classification of specifications into various types and a scaling of specification space and parameter spaces based on the designer's knowledge of the particular application. An algorithm is proposed for solving the resulting constrained ‘minimax’ optimization problem and its convergence is proved. Finally, an application-oriented user front-end is presented. The methodology discussed in this paper has been implemented in the DELIGHT system and has been successfully used in various types of applications.     

Evaluating π-π-Interactions as a Method for Isolation of Polycyclic Aromatic Hydrocarbons from Solution

The polycyclic aromatic hydrocarbon (PAH), chrysene, was linked to the solid support TentaGel S-NH₂ via a linker by means of synthesis. The resulting product 4-(chrysene-1-yloxy)-N-(TentaGel S)butanamide (4) was then evaluated for its ability to isolate PAHs from solution by means of π-π-interactions.     

Effects of carbide-forming elements on the response to thermal treatment of the X45Cr13 martensitic stainless steel

The effects of carbide-forming elements on the response to thermal treatment of the X45Cr13 martensitic stainless steel have been investigated. Heat treatments consisted of austenitizing for 60 s at temperatures ranging from 1000–1250 °C. The higher is the solution treatment temperature, the less M23C6 carbide is left out of solution in the austenite. As a result, the concentration of carbon and alloying elements in the martensite increases and, therefore, an increase in the hardness until a maximum value of 710 HV was found at austenitizing temperatures of 1120 and 1130 °C for the steels X45Cr13 and X45CrMoV14, respectively. At higher austenitizing temperatures, the presence of retained austenite was observed, which leads to a lowering of the hardness value. The higher amount of carbide-forming elements in the X45CrMoV14 determines an increase in retained austenite from 3 vol% to about 30 vol%. Thus, a drop in the hardness value from 710 to 680 and 585 for the steels X45Cr13 and X45CrMoV14, respectively, was found. © 1998 Kluwer Academic Publishers     

Experimental Investigation of the Mixing Between Hot and Cold Gas in Two Cooling Processes

The mixing between a hot turbulent flow and a cold fluid, injected through a porous plate or using a discrete injection, is experimentally investigated. The blowing is shown to dramatically modify the dynamic and thermal fields, whereas the discrete injection has a weaker effect. The influence on the average quantities and fluctuating parts are found to be different. The effect of the main flow temperature is addressed and a discussion for the mixing in the blowing and discrete injection cases is proposed.     

EFFECT OF THIN KNbO3 SEED LAYERS ON PULSED LASER DEPOSITED FERROELECTRIC KTa0.65Nb0.35O3 FILMS FOR MICROWAVE TUNABLE APPLICATION

ABSTRACT

Ferroelectric KTa_0.65Nb_0.35O₃ thin films were grown by pulsed laser deposition on R-plane sapphire substrates. The potassium enriched ceramic targets were used for compensating potassium losses. In order to improve the KTa_0.65Nb_0.35O₃ film growth on sapphire, a thin KNbO₃ layer was introduced as seed layer. The experimental results show that the crystalline quality is lowered when increasing the K-excess. Simultaneously, phase purity, orientation and crystalline quality of perovskite (h00)-oriented KTa_0.65Nb_0.35O₃ are greatly improved by the use of the KNbO₃ seed layer. In particular, the presence of the latter effectively suppresses any pyrochlore secondary phase formation.     

Optimization of a quantitative method for muscle histology assessment

Optical microscopy offers the simplest way to obtain magnified images of biological tissues. The assessment of the muscle destructuration level can be performed by a method called Meat Destruction Indicator (MDI), which combines optical microscopy and image analysis. MDI can be used for evaluation of food quality and for considering mechanically separated meat (meat raw material with an MDI value above 58.1% contained muscle fibres sufficiently destructured). This paper is particularly focused on the metrological optimization of a quantitative image analysis method around the example of MDI measurement by microscopy, especially on the digital acquisition calibration focusing and analysis work‐flow. Ten different samples (45 sections) were examined with variable settings of microscope and camera to define the optimal configuration. The tests were performed with different observers to define rules and criteria for results validation. Based on the obtained results, we suggest choosing objective rules to set the light and colour of the camera and the microscope focus. To control the results of the automatic segmentation emerged also as a key step, and objective rules for observers to select or discard wrong segmented images should be defined. The adjusted MDI measurement by microscope can be used as a reliable method with good repeatability, thanks to this metrological assessment, which could and should be applied to all image analysis applications whatever the application.     

SOLUBILITY AND DIFFUSIVITY OF GASES IN AN ORGANIC SOLUTION OF AMINE

Solubilities and diffusivities of carbon dioxide and nitrous oxide in a mixture of toluene and isopropanol organic solution of cyclohexylamine were measured at 20°C in the range of pressures of solute from 1 to 3 bars. This was performed with an original chromatographic technique taking into account the presence of the product of the reaction.