Response of a completely free beam on a tensionless Pasternak foundation subjected to dynamic load

Celep, Z.,Guler, K.,Demir, F. Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.37 No.1

Static and dynamic responses of a completely free elastic beam resting on a two-parameter tensionless Pasternak foundation are investigated by assuming that the beam is symmetrically subjected to a uniformly distributed load and concentrated load at its middle. Governing equations of the problem are obtained and solved by paying attention on the boundary conditions of the problem including the concentrated edge foundation reaction in the case of complete contact and lift-off condition of the beam ina two-parameter foundation. The nonlinear governing equation of the problem is evaluated numerically by adopting an iterative procedure. Numerical results are presented in figures to demonstrate the non-linear behavior of the beam-foundation system for various values of the parameters of the problem comparatively by considering the static and dynamic loading cases.

Symmetrically loaded beam on a two-parameter tensionless foundation

Celep, Z.,Demir, F. Techno-Press 2007 Structural Engineering and Mechanics, An Int'l Jou Vol.27 No.5

Static response of an elastic beam on a two-parameter tensionless foundation is investigated by assuming that the beam is symmetrically subjected to a uniformly distributed load and concentrated edge loads. Governing equations of the problem are obtained and solved by pointing out that a concentrated edge foundation reaction in addition to a continuous foundation reaction along the beam axis in the case of complete contact and a discontinuity in the foundation reactions in the case of partial contact come into being as a direct result of the two-parameter foundation model. The numerical solution of the complete contact problem is straightforward. However, it is shown that the problem displays a highly non-linear character when the beam lifts off from the foundation. Numerical treatment of the governing equations is accomplished by adopting an iterative process to establish the contact length. Results are presented in figures to demonstrate the linear and non-linear behavior of the beam-foundation system for various values of the parameters of the problem comparatively.

Forced vibrations of an elastic circular plate supported by unilateral edge lateral springs

Zekai Celep,Mustafa Gençoğlu 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.83 No.4

The present study deals with forced vibrations of an elastic circular plate supported along its circular edge by unilateral elastic springs. The plate is assumed to be subjected to a uniformly distributed and a concentrated load. Under the combination of these loads, equations of motion are explicitly derived for static and dynamic response analyses by assuming a series of the displacement functions of time and other unknown parameters which are to be determined by employing Lagrangian functional. The approximate solution is sought by applying the Lagrange equations of motions by using the potential energy of the external forces that includes the contributions of the edge forces and the external moments, i.e., those of the effects of the boundary condition to the analysis. For the numerical treatment of the problem in the time domain, the linear acceleration procedure is adopted. The tensionless character of the support is taken into account by using an iterative process and, the coordinate functions for the displacement field are selected to partially fulfill the boundary conditions so that an acceptable approximation can be achieved faster. Numerical results are presented in the figures focusing on the nonlinearity of the problem due to the plate lift-off from the unilateral springs at the edge support.

Antioxidant and anticancer activities of gallic acid loaded sodium alginate microspheres on colon cancer

Sagdicoglu Celep A. Gulcin,Demirkaya Aslihan,Solak Ebru Kondolot 한국물리학회 2022 Current Applied Physics Vol.40 No.-

Polyphenols found in fruits and vegetables are of great interest due to their health benefits. Gallic acid (GA) is an antioxidant with cytotoxic effects. Microspheres are drug carrier systems, where the active substance is trapped in matrix. A controlled release profile is aimed at the target region by preserving the loss of substance and activity. In this study, GA containing microspheres were formed with sodium alginate (NaAlg) in formulations with different ratios. The arrest efficiencies ranged between 11.26 and 72.64%. Release studies were performed at pH 7.4. Optimum conditions were determined as GA/NaAlg ratio 1/8. The microspheres were found to arrest GA and exhibit a controlled release profile. Microspheres were characterized by scanning electron microscope (SEM), differential scanning calorimetry (DSC), X-Ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR) analysis. GA retained its antioxidant activity determined by DPPH (2,2-diphenyl-1-picrylhydrazyl) method and anticancer activity on Caco-2 cells. Further studies are necessary on GA-loaded NaAlg microspheres which have high potential to be used in adjunct and complementary therapies.

On Generalized FI-extending Modules

Yucel, Canan Celep Department of Mathematics 2020 Kyungpook mathematical journal Vol.60 No.1

A module M is called FI-extending if every fully invariant submodule of M is essential in a direct summand of M. In this work, we define a module M to be generalized FI-extending (GFI-extending) if for any fully invariant submodule N of M, there exists a direct summand D of M such that N ≤ D and that D/N is singular. The classes of FI-extending modules and singular modules are properly contained in the class of GFI-extending modules. We first develop basic properties of this newly defined class of modules in the general module setting. Then, the GFI-extending property is shown to carry over to matrix rings. Finally, we show that the class of GFI-extending modules is closed under direct sums but not under direct summands. However, it is proved that direct summands are GFI-extending under certain restrictions.

Isolated penetrating gluteal stab injury with uncontrolled bleeding in Türkiye: a case report

( Ali Metehan Celep ),( Görkem Yiğit ),( Ayla Ece Çelikten ),( Kudret Atakan Tekin ),( Ufuk Türkmen ) 대한외상학회 2023 大韓外傷學會誌 Vol.36 No.4

Arterial injuries in the gluteal region caused by a knife are rare but serious, with mortality rates of up to 25%. This case report presents the management of a young male patient admitted to the emergency department in hypovolemic shock, with uncontrollable bleeding from an isolated penetrating gluteal injury. Additionally, the details of the surgical approach employed are discussed.

Radioprotective role of amifostine on osteointegration of titanium implants in the tibia of rats

Nevra Aydemir Celep,Hülya Kara,Elif Erbaş,Elif Doğan 대한수의학회 2023 Journal of Veterinary Science Vol.24 No.3

Background: Titanium is the most widely used metal for bone integration, especially for cancer patients receiving ionizing radiation. This study aimed to investigate the amifostine administration that would reduce the effects of radiation on bone healing and osseointegration in rat models. Objectives: It is aimed that the application of amifostine in rats receiving radiotherapy treatment will reduce the negative effects of ionizing radiation on the bone. Methods: Thirty-five adult male Wistar rats were randomly divided into one healthy and four experimental groups. In three consecutive days, two experimental groups of rats (AMFRT-IMP and RT-IMP) were exposed to radiation (15 Gy/3 fractions of 5 Gy each). Then the titanium implants were inserted into the left tibia. Before the radiotherapy process, a 200 mg/kg dose of amifostine (AMF) was administered to the rats in the AMF-IMP and AMF-RTIMP groups. Twenty-eight days after the screw implant, all rats were sacrificed, and their blood samples and tibia bones were collected for analysis. Results: The results indicated an accelerated bone formation and a more rapid healing process in the screw implants in the AMF-IMP, AMF-RT-IMP, and AMF-RT groups than in the RT-IMP group. Also, bone-implant contact area measurement and inflammation decreased with amifostine treatment in the implants subjected to irradiation (p < 0.05). Conclusions: The results obtained in the present study suggested that amifostine prevents the losses of bone minerals, bone integrity, and implant position from ionizing-radiation when given before exposure.

When Some Complement of an EC-Submodule is a Direct Summand

Denizli, Canan Celep Yucel,Ankara, Adnan Tercan Department of Mathematics 2010 Kyungpook mathematical journal Vol.50 No.1

A module M is said to satisfy the $EC_{11}$ condition if every ec-submodule of M has a complement which is a direct summand. We show that for a multiplication module over a commutative ring the $EC_{11}$ and P-extending conditions are equivalent. It is shown that the $EC_{11}$ property is not inherited by direct summands. Moreover, we prove that if M is an $EC_{11}$-module where SocM is an ec-submodule, then it is a direct sum of a module with essential socle and a module with zero socle. An example is given to show that the reverse of the last result does not hold.

Response of a rectangular plate-column system on a tensionless Winkler foundation subjected to static and dynamic loads

Guler, K.,Celep, Z. Techno-Press 2005 Structural Engineering and Mechanics, An Int'l Jou Vol.21 No.6

The response of a plate-column system having five-degree-of-freedom supported by an elastic foundation and subjected to static lateral load, harmonic ground motion and earthquake motion is studied. Two Winkler foundation models are assumed: a conventional model which supports compression and tension and a tensionless model which supports compression only. The governing equations of the problem are obtained, solved numerically and the results are presented in figures to demonstrate the behavior of the system for various values of the system parameters comparatively for the conventional and the tensionless Winkler foundation models.

Response of a rectangular plate-column system on a tensionless Winkler foundation subjected to static and dynamic loads

K. Guler,Z. Celep 국제구조공학회 2005 Structural Engineering and Mechanics, An Int'l Jou Vol.21 No.6