Yazar "Ornek, Bulent Nafi" için listeleme
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Analytical investigation on Effect of Nanofluid Usage on Temperature Distribution in Double Pipe Heat Exchangers
Kursun, Burak; Ornek, Bulent Nafi; Okten, Korhan; Colak, Merve (CENTRE ENVIRONMENT SOCIAL & ECONOMIC RESEARCH PUBL-CESER, 2018)Heat exchangers are used in many industrial areas for the purpose of meeting the heat transfer requirement. The widespread use of heat exchangers has led to a number of designs for increasing the heat transfer in the heat ... -
ANALYTICAL MODEL FOR ESTIMATION OF TEMPERATURE DISTRIBUTION IN PARALLEL AND COUNTER FLOW DOUBLE PIPE HEAT EXCHANGERS
Kursun, Burak; Ornek, Bulent Nafi; Okten, Korhan (YILDIZ TECHNICAL UNIV, 2017)Heat exchangers are a widely used as a device for meeting the heat transfer requirement in industrial applications. Many types of innovative heat exchanger designs have been implemented with the aim of increasing heat ... -
APPLICATIONS OF JACK'S LEMMA FOR CERTAIN SUBCLASSES OF HOLOMORPHIC FUNCTIONS ON THE UNIT DISC
Catal, Batuhan; Ornek, Bulent Nafi (KOREAN MATHEMATICAL SOC, 2019)In this paper, we give some results on zf' (z)/f(z) for the certain classes of holomorphic functions in the unit disc E = {z : vertical bar z vertical bar< 1} and on partial derivative E {z : vertical bar z vertical bar = ... -
Applications of the Jack's lemma for the meromorphic functions
Aydinoglu, Selin; Ornek, Bulent Nafi (Springernature, 2021)In this paper, we give some results on zf'(z)/f(z) for the certain classes of f(z) meromorphic functions. For the function f(z) = 1/z + c(0) + c(1)z + c(2)z(2)+ ... defined in the punctured disc U = {z : 0 -
BEHAVIOR OF HOLOMORPHIC FUNCTIONS ON THE BOUNDARY OF THE UNIT DISC
Ornek, Bulent Nafi (KOREAN SOC MATHEMATICAL EDUCATION, 2017)In this paper, we establish lower estimates for the modulus of the non tangential derivative of the holomorphic function f (z) at the boundary of the unit disc. Also, we shall give an estimate below vertical bar f ''(b)vertical ... -
Behavior of Meromorphic Functions at the Boundary of the Unit Disc
Ornek, Bulent Nafi (UNIV NIS, FAC SCI MATH, 2017)In this paper, a boundary version of the Schwarz lemma for meromorphic functions is investigated. The modulus of the angular derivative of the meromorphic function I-n f(z) = 1/z + 2(n)c(0) + 3(n)c(1)z+4(n)c(2)z(2) +... ... -
Bound Estimates for the Derivative of Driving Point Impedance Functions
Ornek, Bulent Nafi; Duzenli, Timur (UNIV NIS, FAC SCI MATH, 2018)In this paper, a boundary analysis is carried out for the derivative of driving point impedance functions, which is mainly used for synthesis of networks containing RL, RC and RLC circuits. It is known that driving point ... -
Boundary Analysis for the Derivative of Driving Point Impedance Functions
Ornek, Bulent Nafi; Duzenli, Timur (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2018)Four theorems are presented in this brief by performing boundary analysis of the derivative of driving point impedance functions evaluated at the origin. Also, the circuits corresponding to these driving point impedance ... -
Boundary Schwarz Lemma for Holomorphic Functions
Ornek, Bulent Nafi; Gok, Burcu (UNIV NIS, FAC SCI MATH, 2017)In this paper, a boundary version of Schwarz lemma is investigated. We take into consideration a function f (z) holomorphic in the unit disc and f (0) = 0 such that vertical bar R-f vertical bar < 1 for vertical bar z ... -
Estimates Concerned with Hankel Determinant for M (?) Class
Aydinoglu, Selin; Ornek, Bulent Nafi (Univ Nis, Fac Sci Math, 2022)In this paper, we give an upper bound of Hankel determinant of (H2(1)) for the classes of M (alpha), alpha is an element of C. Also, for M (alpha), we obtain a sharp estimate for the classical Fekete-Szego center dot ... -
ESTIMATES FOR A CERTAIN SUBCLASS OF HOLOMORPHIC FUNCTIONS
Ornek, Bulent Nafi; Akyel, Tugba (KOREAN SOC MATHEMATICAL EDUCATION, 2019)In this paper, a version of the boundary Schwarz Lemma for the holomorphic function belonging to N(alpha) is investigated. For the function f(z) = z + c(2)z(2) + c(3)z(3) + ... which is defined in the unit disc where f(z) ... -
ESTIMATES FOR ANALYTIC FUNCTIONS ASSOCIATED WITH SCHWARZ LEMMA ON THE BOUNDARY
Kaynakkan, Aysan; Ornek, Bulent Nafi (Kangwon-Kyungki Mathematical Soc, 2022)In this paper, we will introduce the class of analytic functions called R (alpha, lambda) and explore the different 5properties of the functions belonging to this class. -
ESTIMATES FOR HOLOMORPHIC FUNCTIONS CONCERNED WITH JACK'S LEMMA
Ornek, Bulent Nafi (PUBLICATIONS L INSTITUT MATHEMATIQUE MATEMATICKI, 2018)We investigate a boundary version of the Schwarz lemma for classes H(alpha). Also, we estimate a modulus of the angular derivative of f(z) function at the boundary point b with f (b) = b/ (beta)root 2, 0 < beta <= 1. The ... -
ESTIMATES FOR SECOND NON-TANGENTIAL DERIVATIVES AT THE BOUNDARY
Gok, Burcu; Ornek, Bulent Nafi (KOREAN MATHEMATICAL SOC, 2017)In this paper, a boundary version of Schwarz lemma is investigated. We take into consideration a function f(z) holomorphic in the unit disc and f (0) = 0, f'(0) = 1 such that R f'(z) > 1-alpha/2, -1 < alpha < 1, we estimate ... -
AN IMPROVED LOWER BOUND FOR SCHWARZ LEMMA AT THE BOUNDARY
Ornek, Bulent Nafi; Akyel, Tugba (KOREAN SOC MATHEMATICAL EDUCATION, 2016)In this paper, a boundary version of the Schwarz lemma for the holomrophic function satisfying f (a) = b, vertical bar a vertical bar < 1, b is an element of C and Rf (z) > alpha, 0 <= alpha < vertical bar b vertical bar ... -
INEQUALITIES FOR THE ANGULAR DERIVATIVES OF CERTAIN CLASSES OF HOLOMORPHIC FUNCTIONS IN THE UNIT DISC
Ornek, Bulent Nafi (KOREAN MATHEMATICAL SOC, 2016)In this paper, a boundary version of the Schwarz lemma is investigated. We take into consideration a function f (z) - z+c(p+1)z(p+1)+c(p+2)z(p+2)+... holomorphic in the unit disc and vertical bar f (z)/lambda f(z)+(1-lambda)z ... -
NEW ESTIMATES FOR MEROMORPHIC FUNCTIONS
Ornek, Bulent Nafi (Publications L Institut Mathematique Matematicki, 2021)A boundary version of the Schwarz lemma for meromorphic functions is investigated. For the function I-n f(z) = 1/z + Sigma(infinity)(k=2) k(n)c(k-2)z(k-2), belonging to the class of W, we estimate from below the modulus ... -
A novel version of slime mould algorithm for global optimization and real world engineering problems Enhanced slime mould algorithm
Ornek, Bulent Nafi; Aydemir, Salih Berkan; Duzenli, Timur; Ozak, Bilal (Elsevier, 2022)The slime mould algorithm is a stochastic optimization algorithm based on the oscillation mode of nature's slime mould, and it has effective convergence. On the other hand, it gets stuck at the local optimum and struggles ... -
ON A CLASS OF ANALYTIC FUNCTION RELATED TO SCHWARZ LEMMA
Ornek, Bulent Nafi (Korean Soc Mathematical Education, 2022)In this paper, we plan to introduce the class of the analytic functions called P (b) and to investigate the various properties of the functions belonging this class. The modulus of the second coefficient c(2) in the expansion ... -
On boundary analysis for derivative of driving point impedance functions and its circuit applications
Ornek, Bulent Nafi; Duzenli, Timur (INST ENGINEERING TECHNOLOGY-IET, 2019)In this study, a boundary analysis is carried out for the derivative of driving point impedance (DPI) functions, which is mainly used for the synthesis of networks containing resistor-inductor, resistor-capacitor and ...
