The thermophysical properties of nanofluids must be determined to evaluate their thermal performances like heat transfer, convection heat transfer coefficient, Nusselt number. The purpose of this study is to obtain the thermophysical properties of nanofluids. Al2O3, TiO2, and ZnO are used as a nanoparticle, while deionized water is used as base fluid. The solutions included nanoparticles in a way to be each with 0.5%, 0.7%, and 1.0% volumetric concentration were prepared. SDS was added to the solutions as a surfactant to prevent instability that occurred due to agglomeration and sedimentation. For thermal conductivity measurement, the device that works by the transient hot-wire method was used between 30-60?C temperatures. Also, for viscosity measurement, the device that works as based on the vibrating plate method was used between 20-50?C temperatures. Density and specific heat values are obtained with the help of the well-known equations while thermal conductivity and viscosity are measured. Thanks to this study, it is emphasized how thermophysical properties of nanofluids change according to temperature and volumetric concentration. Moreover, their curve fitting equations are obtained. All of the thermophysical properties compared with the studies in the literature. It is established that the thermal conductivity of nanofluids is proportional to temperature, and viscosity of it is proportional to volumetric concentrations but inversely with temperature. Finally, the effects of the augmentation in dynamic viscosity on pumping power were considered as well as the increase in thermal conductivity; thus, no abnormal heat transfer enhancement was observed.

Elevators have an important place in human life just after uprising demands in high rise buildings, skyscraper and luxury residence concepts have surged. Steel wire ropes provide permanent working safety and reliability in the elevator installations. Due to this reason steel wire ropes are one of the vital components of elevators. In this study, effects of discard criteria such as wire breaks, abrasive wear and corrosion where extents of those failures are defined by ISO 4344 standard on the tensile endurance of 6×19 Seale and 8×19 Warrington elevator ropes have been investigated theoretically and experimentally. Tensile endurances of rope samples that have different extents of failure have been determined by using tensile testing machine and comparison is made by undamaged samples for each rope separately. In addition, stress and strain values occurred on the elevator ropes investigated have also been presented. The most critical failure type has been found to be 24 wire breaks for 6×19 Seale rope with fiber core where lifting capacity reduced by 25.99 %. The most critical failure type has been found to be abrasive wear which is 0.1 mm in depth along 100 mm length for 8×19 Warrington rope with independent wire rope core where lifting capacity reduced by 7.93 %.

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Asansörlerde kullanılan çelik tel halatlar, zaman içerisinde işletme koşullarına bağlı olarak farklı hasar türlerine, farklı derecelerde maruz kalırlar. Bu çalışmada, hasar görmüş halat numunelerinin eksenel kaldırma kapasitelerindeki değişimler incelenmiştir. Asansör halatlarını servis dışına bırakma kriterleri göz önüne alınarak, laboratuvar ortamında halat numunelerine 3 farklı hasar verilmiştir. Halat numunelerine çekme testleri yapılarak, halatların çekme mukavemetlerindeki düşüş miktarları tespit edilmiştir. Bu çalışmada, asansör sistemleri için de uygun olan 6x19 Standart bağımsız tel halat özlü tel halat kullanılmıştır. Elde edilen veriler, asansörler için halat seçimi, halatların periyodik bakımı ve gerekirse halatları servis dışı bırakma gibi konularda yardımcı olacak deneysel sonuçlara dayalı bir kaynak oluşturmuştur. İncelenen halat için en kritik hasar tipi, 16 saat süresince korozyona maruz kalma olarak tespit edilmiştir.

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