Makine Mühendisliği Bölümü Yayın Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/263
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Article Citation - WoS: 7Citation - Scopus: 7Experimental Investigation Into the Effect of Magnetorheological Fluid Damper on Vibration and Chatter in Straight Turning Process(Elsevier Sci Ltd, 2023) Nasab, Vahid Hasan; Akar, Samet; Batako, Andre; Emami, MohsenMagneto-Rheological (MR) dampers have received a great deal of attention in recent years due to the potential of offering semi-active control. MR dampers have been successfully applied in the vibration control of several machining processes. However, the effect of the material of the damper's fluid chamber on its magnetic prop-erties has not been studied much. In this study, an MR damper has been designed to control the chatter vibration of the straight turning operation. The magnetic properties of the MR damper are simulated in the FEM software COMSOL Multiphysics with two types of steel AISI 410 and AISI 1018, and the material with the best perfor-mance for constructing the fluid chamber is determined. Then, the MR damper with an assembly to hold the cutting tool was fabricated and experimentally tested during straight turning operation and its effect on the tool vibration, and work surface roughness was analyzed. From the result, it was observed that the MR damper reduced tool vibration and chatter effectively. The results obtained in this research confirm that the application of the MR damper in the straight-turning process can either suppress the chatter or greatly reduce the frequency amplitude of the chatter. The reduction of the tool's acceleration amplitude with the MR damper was more intense in the condition of chatter suppression and reached up to 89.42 %. Moreover, the MR damper reduced the roughness of the machining surface. This reduction was higher in cases where the chatter was suppressed and it was observed up to 29 %.Article Citation - WoS: 45Exploring the Relationship Between Software Process Adaptive Capability and Organisational Performance(Ieee Computer Soc, 2015) O'Connor, Rory V.; Leavy, Brian; Yilmaz, Murat; Clarke, PaulSoftware development is a complex socio-technical activity, with the result that software development organisations need to establish and maintain robust software development processes. While much debate exists regarding the effectiveness of various software development approaches, no single approach is perfectly suited to all settings and no setting is unchanging. The capability to adapt the software process is therefore essential to sustaining an optimal software process. We designed an exploratory study to concurrently examine software process adaptive capability and organisational performance in 15 software development organisations, finding that companies with greater software process adaptive capability are shown to also experience greater business success. While our exploratory study of the complex relationship between these phenomena is limited in some respects, the findings indicate that software process adaptive capability may be worthy of further integration into software process engineering techniques. Software process adaptive capability may be an important organisational strength when deriving competitive advantage, and those responsible for the creation and evolution of software process models and methodologies may want to focus some of their future efforts in this area.Article Citation - WoS: 22Citation - Scopus: 22Phaseguide Assisted Liquid Lamination for Magnetic Particle-Based Assays(Royal Soc Chemistry, 2014) Yildirim, Ender; Tarn, Mark D.; Trietsch, Sebastiaan J.; Hankemeier, Thomas; Pamme, Nicole; Vulto, Paul; Phurimsak, ChayakomWe have developed a magnetic particle-based assay platform in which functionalised magnetic particles are transferred sequentially through laminated volumes of reagents and washing buffers. Lamination of aqueous liquids is achieved via the use of phaseguide technology; microstructures that control the advancing air-liquid interface of solutions as they enter a microfluidic chamber. This allows manual filling of the device, eliminating the need for external pumping systems, and preparation of the system requires only a few minutes. Here, we apply the platform to two on-chip strategies: (i) a one-step streptavidin-biotin binding assay, and (ii) a two-step C-reactive protein immunoassay. With these, we demonstrate how condensing multiple reaction and washing processes into a single step significantly reduces procedural times, with both assay procedures requiring less than 8 seconds.Article Citation - WoS: 29Citation - Scopus: 33Phaseguides as Tunable Passive Microvalves for Liquid Routing in Complex Microfluidic Networks(Royal Soc Chemistry, 2014) Trietsch, Sebastiaan J.; Joore, Jos; van den Berg, Albert; Hankemeier, Thomas; Vulto, Paul; Yildirim, EnderA microfluidic passive valving platform is introduced that has full control over the stability of each valve. The concept is based on phaseguides, which are small ridges at the bottom of a channel acting as pinning barriers. It is shown that the angle between the phaseguide and the channel sidewall is a measure of the stability of the phaseguide. The relationship between the phaseguide-wall angle and the stability is characterized numerically, analytically and experimentally. Liquid routing is enabled by using multiple phaseguide with different stability values. This is demonstrated by filling complex chamber matrices. As an ultimate demonstration of control, a 400-chamber network is used as a pixel array. It is the first time that differential stability is demonstrated in the realm of passive valving. It ultimately enables microfluidic devices for massive data generation in a low-cost disposable format.