Global population is aging, particularly in developed countries and cities. Through the "Friendly Elderly Cities" and "Aging in Place" initiatives, various countries are making great efforts to improve the welfare and quality of life of the elderly, with the aim of catering to the physical and spiritual health as well as social welfare of the elderly. In this regard, the improvement of the housing environment of the elderly is one of the key factors in their quality of life and health. This study aims to effectively assess and improve the housing environment of the elderly in order to enhance their quality of life; it also aims to contribute the knowledge about improving elderly housing by applying an assessment framework using expert interviews and data collected from relevant literature. Using a mixed Multi-Criteria Decision Analysis model, a combination of the DEMATEL (Decision Making Trial and Evaluation Laboratory)-based ANP (Analytic Network Process) (DANP) and the modified VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) methods, and the investigations and assessments in the case study, this study proposes strategies and directions for improving elderly housing. The study results indicate that, as distinct from using traditional methodologies where the hypothesis criteria are mutually independent, the proposed hybrid model (examining real-life problems by considering the mutual influences of factors) identifies a priority sequence wherein emphasis is placed on improving ventilation and air quality rather than adjustment of temperature. The systemic way of thinking shifts the focus from the most apparent problems to the root cause of the problems. Doing so avoids any mismatch of resource allocation in decision-making and thus maximizes the efficiency and sustainability of the improvement.

This paper repor ts th e results of studying v arious appr oaches in non-sacrificial boundary lubrication in w hich t he deposition of a beneficial surface layer is t he result of a chemical reaction in v olvin g one or mo re com ponents in the lubr icating fluid but not th e m etal surface it self. This is in contrast to t he con v entional approach w hich invol v es th e rubbing surfaces as reactants wit h th e com ponents in th e lub ricant and usually promotes wear as th e result of chemical change of the surfaces. Th e mo st int erestin g finding s show that a reaction betwe en a molybdenum complex and a mi xture of zinc dialk ylphosphorodith ioat es produced in situ deposition of M 05 2 and som e oth er unidentified crys talline material. E ffective reductions in friction and wear were obtained. El ectron diffra ction patt erns of the w orn m etal surface established th e presence of M 05 2 ,

A new technique for visual examination of the progressive development of fretting is evolved and found to be especially useful in following the progress of fretting from the initial stage to the later stages. The qualitative investigation, co-ordinated with a quantitative study in three different atmospheres, dry air, carbon dioxide, and helium, yielded results supporting the mechanism of fretting suggested by the authors in a previous publication. Visual observation also leads to the conclusion that chemical reaction, for example, oxidation, of metal with the environment takes place when the metal is being removed, or after it has been removed, from the surface.

A new theory of metal transfer and wear is suggested in this paper. The essence of the theory is as follows: Metal transfer and wear take place at points of actual contact. The interfaces of the high spots that actually make contact are roughened as the result of plastic deformation when they carry normal load. The mechanical interlocking effect of these roughened interfaces is the primary cause of metal transfer and wear. Due to the mechanical interlocking effect of the roughened interface, and the strain-hardening that accompanies plastic deformation, the application of a tangential force will break one of the pair of the contacting high spots a certain distance away from the interface rather than at the original interface. A secondary cause of metal transfer is the adhesion or the diffusion process which takes place during the temperature flash that occurs during breakage. If the adhesive force is very weak and the diffusion process is not rapid enough to cause the sheared-off peak of the high spot to become a blob of transferred metal, the small piece of metal sheared from the high spot can leave as a loose wear particle. This proposed theory explains the welding of the sheared-off peak to its opponent high spot as the consequence of friction, whereas, in the ``welding'' theory of friction, welding is considered as the cause of friction. Most metallic surfaces in ordinary atmosphere are always covered by a surface film. The effect of surface contamination on metal transfer, wear, and the shear component of friction is discussed. Difficulties encountered in applying the ``welding'' theory to explain the friction of and metal transfer between contaminated surfaces where metallic adhesion is absent, are obvious. Experimental support of this new theory is given here. It includes as direct evidence (1) the roughening of the interface as the result of the plastic deformation, (2) the perfect matching at the roughened interface, which gives a strong mechanical interlocking effect, and (3) a definite region of severely strain-hardened metal near the interface.

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