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Öğe PID controller design for controlling integrating processes with dead time using generalized stability boundary locus(IFAC Secretariat, 2018) Atiç, Serdal; Çökmez, Erdal; Peker, Fuat; Kaya, İbrahimThis paper proposes a method so that all PID controller tuning parameters, which are satisfying stability of any integrating time delay processes, can be calculated by forming the stability boundary loci. Processes having a higher order transfer function must first be modeled by an integrating plus first order plus dead time (IFOPDT) transfer function in order to apply the method. Later, IFOPDT process transfer function and the controller transfer function are converted to normalized forms to obtain the stability boundary locus in (KKcT, KKc(T2 / Ti)), (KKcT, KKcTd) and (KKc(T2/Ti), KKcTd) planes for PID controller design. PID controller parameter values achieving stability of the control system can be determined by the obtained stability boundary loci. The advantage of the method given in this study compared with previous studies in this subject is to remove the need of re-plotting the stability boundary locus as the process transfer function changes. That is, the approach results in somehow generalized stability boundary loci for integrating plus time delay processes under a PID controller. Application of the method has been clarified with examples.Öğe An analysis of sport managers' work stress levels in various variables(Horizon Research Publishing, 2018-12) Kılınç, Zühal; Dinçer, NevzatThis paper was conducted to measure the psychological and psychosomatic symptoms related with the sport managers’ work stress in public sector and federations. In this research, total 185 sport managers including 31 sport managers from the Central Organization of Sport General Directorate, 113 sport managers from the provincial organization, 41 sport managers from the Independent Sport Federations were included. The relevant managers were applied the work stress scale developed by Houso and Rizzo (1972). According to the results of the research, as sport managers get older, the averages of work stress seem to increase. In younger sport managers, the averages of work stress were found to be lower. When the participant sport managers’ education levels improve, their work stress points fall down. In the first period of service of sport managers, the averages of work stress were high, in next years they went down over time.Öğe Temperature dependent electrical transport in Al/Poly(4-vinyl phenol)/ p -GaAs metal-oxide-semiconductor by sol-gel spin coating method(Hindawi, 2016-03-10) Özden, Şadan; Tozlu, Cem; Pakma, OsmanDeposition of poly(4-vinyl phenol) insulator layer is carried out by applying the spin coating technique onto p-type GaAs substrate so as to create Al/poly(4-vinyl phenol)/p-GaAs metal-oxide-semiconductor (MOS) structure. Temperature was set to 80-320 K while the current-voltage (I-V) characteristics of the structure were examined in the study. Ideality factor (n) and barrier height (φ b) values found in the experiment ranged from 3.13 and 0.616 eV (320 K) to 11.56 and 0.147 eV (80 K). Comparing the thermionic field emission theory and thermionic emission theory, the temperature dependent ideality factor behavior displayed that thermionic field emission theory is more valid than the latter. The calculated tunneling energy was 96 meV.Öğe The effect of intrapreneurship and organizational factors on the innovation performance in hospital(Expert Projects, 2018-09) Ekingen, Erhan; Ekemen, Mehmet Ali; Yıldız, Ahmet; Korkmazer, FuatIn the context of environmental uncertainty and competition, organizations are trying to find new ways to improve their performance. The development of novelties based on innovation, especially in the service sector, is the departure point for many organizations. Intrapreneurship and organizational structure are important factors for organizations to improve the innovation performance. In this study, it is aimed to investigate whether intrapreneurship and organizational factors influence the innovation performance. The data were collected from a hospital by means of intrapreneurship scale, organizational factors scale and innovation performance scale. According to the results of Structural Equation Model analysis, intrapreneurship has positive influences on innovation performance. Organizational factors directly and indirectly affect innovation performance. Moreover, intrapreneurship has mediation effect between organizational factors and innovation performance. Lastly, Intrapreneurship enhances the effect of organizational factors on innovation performance.Öğe Performance and exhaust emissions of a DI diesel engine fueled with waste cooking oil and inedible animal tallow methyl esters(TÜBİTAK, 2011) Altun, ŞehmusThe performance and exhaust emissions of a direct injection diesel engine were experimentally investigated using 2 biodiesel fuels with promising economic perspective, one obtained from inedible animal tallow and the other from waste cooking oils. Inedible animal tallow, which is obtained from a mixture of slaughtered cattle and sheep fats collected from a local slaughterhouse during meat preparation process, was transesterified using methyl alcohol and an alkaline catalyst to produce the inedible animal tallow methyl ester. Biodiesel from waste cooking oil was produced from waste cooking oils and methyl alcohol via a transesterification reaction, and provided by a commercial biodiesel producer. In order to investigate the performance and exhaust emissions, the experiments were conducted at different engine speeds under the full load condition of the engine. The experimental results showed, compared with diesel fuel, that the biodiesel fuels resulted in a reduction in brake torque and in an increase in brake specific fuel consumption. Although both biodiesels caused reductions in carbon monoxide (CO), the NOx emissions were higher for waste cooking oil biodiesel and lower for inedible animal tallow biodiesel as compared to diesel fuel.Öğe Plantago major protective effects on antioxidant status after administration of 7,12-dimethylbenz(a)anthracene in rats(Asian Pacific Organization for Cancer Prevention, 2011) Oto, Gökhan; Ekin, Suat; Özdemir, Hülya; Demir, Halit; Yaşar, Semih; Levent, Abdulkadir; Berber, İsmet; Kaki, BarışAim: The present study was designed to evaluate effects of Plantago major extract on oxidative status in Wistar albino rats administrated 7,12-dimethylbenz(a)anthracene (DMBA). Methods: Rats were divided into three equal groups of 6 animals each: Group 1 controls, group 2 treated with DMBA (100 mg/kg, single dose) and group 3 receiving the DMBA and the aqueous extract at 100 mg/kg/d for 60 days. Results: Significant decrease in catalase (P<0.05), carbonic anhydrase (p≤0.01), reduced glutathione (GSH) (P<0.01) and total protein (P<0.01) values was observed in the DMBA group compared with the healthy controls and DMBA + Plantago major groups. Conclusion: The results suggest preventive effects of Plantago major on DMBA induced oxidative damage in Wistar albino rats that might be due to decreased free radical generation.Öğe Design, preparation and application of a Pirkle-type chiral stationary phase for enantioseparation of some racemic organic acids and molecular dynamics studies(ACG Publications, 2017-11) Çakmak, Reşit; Ercan, Selami; Sünkür, Murat; Yılmaz, Hayrullah; Topal, GirayThis study consists of two parts. In the first part of the study; a Pirkle-type chiral stationary phase was prepared by synthesizing an aromatic amine derivative of (R)-2-amino-1-butanol as a chiral selector and binding to L-tyrosine-modified cyanogen bromide (CNBr)-activated Sepharose 4B and then, packed into the separation column. The chromatographic performance of the separation column was evaluated with racemic mandelic acid and 2-phenylpropionic acid by using phosphate buffers at three different pHs as mobile phase. In the resolution processes, the prepared solutions were loaded onto the separation column at two different concentrations and at three different pHs for each racemic organic acid, separately. Enantiomeric excess (ee%) of the eluates was determined on CHIRALPAK AD-H chiral analytical column by HPLC. The maximum ee% for mandelic acid and 2-phenylpropionic acid was determined to be 60.84 and 27.4, respectively. Separation factors (k1 ’ , k2 ’ , α, and Rs) were calculated for each acid. The structures of the obtained compounds were characterized using the spectroscopic methods (NMR, and elemental analysis). In the second part of the study; enantioselective interactions between the prepared CSP and the analytes have been widely studied by docking, molecular dynamics simulation and quantum mechanical computation methods. The reason of column eluation of rac-2-phenylpropionic acid with lower enantiomeric yield was explained by these techniques.Öğe Exhaust emissions of methanol and ethanol-unleaded gasoline blends in a spark ignition engine(VINCA Institute of Nuclear Sciences, 2013) Altun, Şehmus; Öztop, Hakan Fehmi; Öner, Cengiz; Varol, YasinIn this study, the effect of unleaded gasoline and unleaded gasoline blended with 5% and 10% of ethanol or methanol on the performance and exhaust emissions of a spark-ignition engine were experimentally investigated. The engine tests were performed by varying the engine speed between 1000 and 4000 rpm with 500 rpm period at three-fourth throttle opening position. The results showed that brake specific fuel consumption increased while brake thermal efficiency, emissions of carbon monoxide and hydrocarbon decreased with methanol-unleaded gasoline and ethanol-unleaded gasoline blends. It was found that a 10% blend of ethanol or methanol with unleaded gasoline works well in the existing design of engine and parameters at which engines are operating.Öğe Mesogenic properties of PAA/6BA binary liquid crystal complexes(Elsevier, 2018-09-19) Okumuş, Mustafa; Eskalen, Hasan; Sünkür, Murat; Özgan , ŞükrüA novel supramolecular liquid crystal complex has been designed and formed from pure liquid crystalspara-azoxyanisole (PAA) and 4-hexylbenzoic acid (6BA). Thermal and microstructural properties offormed PAA/6BA binary liquid crystal complex system are investigated by differential scanning calo-rimeter (DSC), polarized optical microscopy (POM) and X-ray diffractometer (XRD). Fourier transformedinfrared spectroscopy (FTIR) is used to confirm the formation of hydrogen bond between the PAA and6BA molecules. The XRD results show that the molecular ordering of the hydrogen bonded PAA/6BAcomplex is arranged in the orthorhombic structure. The DSC and POM results clearly indicate that thePAA/6BA binary complex exhibits liquid crystalline properties due to the hydrogen bonds formed be-tween the PAA and 6BA molecules. The PAA/6BA complex shows the phase transition peaks indicatingCr/N/I and I/N/SmA/Cr phase sequence during continuous heating and cooling, respectively, byDSC. These phase sequences have also been confirmed by POM observations. Furthermore, the effect ofthe heating rate on the phase transition temperature values is investigated. As the heating rate increases,the phase transition temperature values increase as well. Moreover, the activation energies for the phasetransitions of the PAA/6BA liquid crystal complex are calculated by using Kissinger, Ozawa and Takhormethods. The calculated results clearly show that the phase transitions are regular.Öğe First boundary value problem for cordes-type semilinear parabolic equation with discontinuous coefficients(Hindawi, 2020-06-19) Harman, Aziz; Harman, EzgiFor a class of semilinear parabolic equations with discontinuous coefficients, the strong solvability of the Dirichlet problem is studied in this paper. The problem ∑i,j=1naijt,xuxixj-ut+gt,x,u=ft,x,uΓQT=0, in QT=Ω×0,T is the subject of our study, where Ω is bounded C2 or a convex subdomain of En+1,ΓQT=∂QT\∖t=T. The function gx,u is assumed to be a Caratheodory function satisfying the growth condition gt,x,u≤b0uq, for b0>0,q∈0,n+1/n-1,n≥2, and leading coefficients satisfy Cordes condition b0>0,q∈0,n+1/n-1,n≥2.
