End-of-life oriented product design (design for recycling, disassembly, remanufacturing) is considered an emerging area in modern approach to product lifecycle. Numerous tools aiding the design process have been developed, but many of them work as independent computer applications. The presented solution is strictly integrated with typical design environment: CAD 3D and PLM systems. This paper presents the application of agent technology operating in the PLM environment to support the design process. The architecture of the proposed solution is shown. A method of product assessment, based of three indicators, is described. The example analysis of real household appliance is presented

Radiation of sound waves from a semi-infinite cylindrical duct with perforated end whose outer wall is coated with acoustically absorbent material is investigated by using the Wiener-Hopf technique in conjunction with the mode matching technique. A semi-infinite duct with a perforated screen can be used as a model for many engineering applications, such as noise reduction in exhausts of automobile engines, in modern aircraft jet, and turbofan engines. In particular, we aim to find the effects of outer lining and perforated end to sound pressure level for the underlying problem by using the standard Wiener-Hopf and mode matching techniques. We also present some numerical illustrations by determining the sound pressure level for different parameters such as soft and rigid outer surface, with and without perforated end, etc. Such investigations are useful in the reduction of noise effects generated through variety of sources.

This paper deals with the modelling of traction linear induction motors (LIMs) for public transportation. The magnetic end effect inherent to these motors causes an asymmetry of their phase impedances. Thus, if the LIM is supplied from the three-phase symmetrical voltage, its phase currents become asymmetric. This effect must be taken into consideration when simulating the LIMs’ performance. Otherwise, when the motor phase currents are assumed to be symmetric in the simulation, the simulation results are in error. This paper investigates the LIM performance, considering the end-effect induced asymmetry of the phase currents, and presents a comparative study of the LIM performance characteristics in both the voltage and the current mode.

This paper describes the simulation, exergy analysis and comparison of two commonly applied liquefaction of technologies natural gas, namely: propane precooled mixed refrigerant process (C3MR) and dual mixed refrigerant process (DMR) alongside two modifications of each employing end flash systems. The C3MR and DMR process schemes were simulated using the commercial software to mathematically model chemical processes. These schemes were then analysed using energy and exergy calculations to determine their performances. The exergy efficiency for the C3MR processes without end flash system, with simple end flash system and extended end flash system were evaluated as 29%, 31%, and 33%, respectively, while the exergy efficiency for the DMR processes without end flash system, with simple end flash system, and extended end flash system were evaluated as 26%, 25.5%, and 30%, respectively. The results achieved show that the extended end flash system versions of the schemes are most efficient. Furthermore, the exergy analysis depicted that the major equipment that must be enhanced in order to improve the cycle exergy efficiencies are the compressors, heat exchangers, and coolers.

The problem of uniqueness and representativeness of steel frame fire resistance assessment is considered in this paper. The thesis, that the selection of analysis method determines the result in both qualitative and quantitative terms is given scrutiny. It is also shown, that the differences between computed values may be significant. The selection of an appropriate computational model for an analysis of this type seems to be especially important, as the possible overestimation of the fire resistance determined during computation is equivalent to an unjustified optimism of the user with respect to the safety level warranted. In the considerations presented here the critical temperature determined for the whole bearing structure is considered as the measure of sought resistance. The determined temperature is associated with the bearing structure reaching the bearing capacity limit state subject to fire conditions, treated as accidental design situation. Two alternative computational methods have been applied during calculations: the first one – classical, based on 1st order statics and using the buckling length concept for members of the considered frame, and the second one – taking account of 2nd order phenomena via simple amplification of the horizontal loads applied to the frame. Special attention has been paid to the influence exerted on the final fire resistance of the considered structure by the real joint rigidity, decreasing with increasing temperature of the structural members. The obtained results differ not only in the value of determined temperature but also in the indicated location of the weakest frame component, determining its safety.