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Article Citation - WoS: 4Citation - Scopus: 4Fixed Point Theorems for Generalized Weak Contractions Satisfying Rational Expression on a Ordered Partial Metric Space(Maik Nauka/interperiodica/springer, 2013) Karapinar, Erdal; Marudai, M.; Pragadeeswarar, V.The purpose of this manuscript is to present a fixed point theorem using a generalized weak contraction condition of rational type in the context of partial metric spaces.Article Citation - WoS: 1Citation - Scopus: 2Design of a Ratio Control Algorithm for a Fluid Catalytic Cracking System in an Universal Oil Product Context(Maik Nauka/interperiodica/springer, 2024) Atiyah, Safa Khalaf; Aljanabi, Ahmed Yaseen Ali; Ahmed, Mohammed S.; Al-Timimi, Buthainah Ali; Mhmood, Ali H.This paper delves into the intricate dynamics of industrial fluid catalytic cracking, a pivotal process in refining universal oil products (UOP). At the core of this investigation is the endeavor to derive a comprehensive mathematical model that captures the essence of mass and energy balances within a UOP fluid catalytic cracking unit. The study's central objective is to explore and apply a ratio control algorithm in two distinct operational scenarios. In the first scenario, the ratio controller is strategically positioned after the control valve for the regenerator's input air, while in the second, it precedes the control valve. The primary focus here is the meticulous control of outlet temperatures for both the riser and regenerator reactors. Leveraging the capabilities of MATLAB software, the research methodically simulates the fluid catalytic cracking process. It introduces variables such as the gas oil feed rate, along with the temperatures of the gas oil feed and air, to rigorously test the efficacy of the proposed ratio control algorithm. The results of this investigation reveal a notable superiority of the ratio control in case one over case two. In the riser and regenerator reactors, this advantage is demonstrated by improved stability and operational efficiency, as evidenced by lower integral absolute error (IAE) readings and a quicker approach to the intended setpoint temperatures.Article Citation - WoS: 13Citation - Scopus: 13Surface Characterization and Corrosion Resistance of Boron Nitride Coated Titanium Dental Implants(Maik Nauka/interperiodica/springer, 2019) Cakal, G. O.; Gokmenoglu, C.; Kaftanoglu, B.; Ozmeric, N.Surface modifications of dental implants are of vital importance to enhance osseointegration and improve their corrosion resistance. This study characterized the surface properties of boron nitride (BN) coated titanium implants and their corrosion behaviors. Pretreated implant surfaces were coated successfully with BN by RF-magnetron sputtering system. Surface morphology and elemental composition of uncoated and BN-coated implant surfaces were examined by using X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) coupled with energy dispersive X-ray spectrometer (EDS). The corrosion tests were performed by use of artificial saliva. The tri-dimensional topography of the uncoated sandblasted, large-grit, acid-etched (SLA) implant surface showing sponge-like characteristics, revealed characteristic differences at micro level after BN-coating. It had more holes and peaks in addition to the sponge-like characteristics which further improved its surface microroughness. Boron-to-nitrogen ratio of the coated surface was obtained in the range of 0.8-1.6. The BN-coated SLA implant had no weight loss in the corrosion test. However, the surface characteristics of implants before coating had an impact on corrosion behavior of other implant types. The results demonstrated that titanium implants can be coated with BN successfully and this coating improves the surface properties of dental implants.
