Temperature dependent current–voltage characteristics of the Cd/CdO/n–Si/Au–Sb structure

M. Sağlam,A. Ates,M.A. Yıldırım,B. Güzeldir,A. Astam 한국물리학회 2010 Current Applied Physics Vol.10 No.2

In this study, this is the first time, it has been employed Successive Ionic Layer Adsorption and Reaction (SILAR) method in order to prepare Cd/CdO/n–Si/Au–Sb sandwich structure. The sample temperature effect on the current–voltage (I–V) characteristics of Cd/CdO/n–Si/Au–Sb structure has been investigated in a wide temperature range by steps of 20 K. The parameters such as barrier height, ideality factor and series resistance of this structure have been calculated from the forward bias I–V characteristics as a function of sample temperature. With a decreasing temperature, a decreasing in the apparent barrier height (Øb0), an increasing in the ideality factor (n) and a nonlinearity in the activation energy plot have been seen. The experimental values of barrier height and ideality factor for this device have been calculated as 0.871 eV and 1.787 at 300 K and 0.436 eV and 2.221 at 80 K, respectively. These abnormal behaviors can be explain by the barrier inhomogeneities at the metal–semiconductor (M–S) interface. From the temperature dependent I–V characteristics of the Cd/CdO/n–Si/Au–Sb sandwich structure, Øb0 and A*are calculated as 0.790 and 1.160 eV, and 153.90 and 188.42 A/㎠ K2, respectively, by using ln(I0/T2) - q2σ2s/2k2T2 vs. 1/T plot for the two temperature regions. Deviation of experimental values of A* from known value for n–Si has been attributed to the spatial inhomogeneous barrier heights and potential fluctuations at the interface that consist of low and high barrier areas.

Earthquake response of isolated cable-stayed bridges under spatially varying ground motions

Sevket Ates,Kurtulus Soyluk,A. Aydin Dumanoglu,Alemdar Bayraktar 국제구조공학회 2009 Structural Engineering and Mechanics, An Int'l Jou Vol.32 No.1

A comprehensive investigation of the stochastic response of an isolated cable-stayed bridge subjected to spatially varying earthquake ground motion is performed. In this study, the Jindo Bridge built in South Korea is chosen as a numerical example. The bridge deck is assumed to be continuous from one end to the other end. The vertical movement of the stiffening girder is restrained and freedom of rotational movement on the transverse axis is provided for all piers and abutments. The longitudinal restraint is provided at the mainland pier. The A-frame towers are fixed at the base. To implement the base isolation procedure, the double concave friction pendulum bearings are placed at each of the four support points of the deck. Thus, the deck of the cable-stayed bridge is isolated from the towers using the double concave friction pendulum bearings which are sliding devices that utilize two spherical concave surfaces. The spatially varying earthquake ground motion is characterized by the incoherence and wavepassage effects. Mean of maximum response values obtained from the spatially varying earthquake ground motion case are compared for the isolated and non-isolated bridge models. It is pointed out that the base isolation of the considered cable-stayed bridge model subjected to the spatially varying earthquake ground motion significantly underestimates the deck and the tower responses.

Earthquake response of isolated cable-stayed bridges under spatially varying ground motions

Sevket Ates,Kurtulus Soyluk,A. Aydin Dumanoglu,Alemdar Bayraktar 국제구조공학회 2009 Structural Engineering and Mechanics, An Int'l Jou Vol.31 No.6

A comprehensive investigation of the stochastic response of an isolated cable-stayed bridge subjected to spatially varying earthquake ground motion is performed. In this study, the Jindo Bridge built in South Korea is chosen as a numerical example. The bridge deck is assumed to be continuous from one end to the other end. The vertical movement of the stiffening girder is restrained and freedom of rotational movement on the transverse axis is provided for all piers and abutments. The longitudinal restraint is provided at the mainland pier. The A-frame towers are fixed at the base. To implement the base isolation procedure, the double concave friction pendulum bearings are placed at each of the four support points of the deck. Thus, the deck of the cable-stayed bridge is isolated from the towers using the double concave friction pendulum bearings which are sliding devices that utilize two spherical concave surfaces. The spatially varying earthquake ground motion is characterized by the incoherence and wavepassage effects. Mean of maximum response values obtained from the spatially varying earthquake ground motion case are compared for the isolated and non-isolated bridge models. It is pointed out that the base isolation of the considered cable-stayed bridge model subjected to the spatially varying earthquake ground motion significantly underestimates the deck and the tower responses.

Earthquake response of isolated cable-stayed bridges under spatially varying ground motions

Ates, Sevket,Soyluk, Kurtulus,Dumanoglu, A. Aydin,Bayraktar, Alemdar Techno-Press 2009 Structural Engineering and Mechanics, An Int'l Jou Vol.31 No.6

A comprehensive investigation of the stochastic response of an isolated cable-stayed bridge subjected to spatially varying earthquake ground motion is performed. In this study, the Jindo Bridge built in South Korea is chosen as a numerical example. The bridge deck is assumed to be continuous from one end to the other end. The vertical movement of the stiffening girder is restrained and freedom of rotational movement on the transverse axis is provided for all piers and abutments. The longitudinal restraint is provided at the mainland pier. The A-frame towers are fixed at the base. To implement the base isolation procedure, the double concave friction pendulum bearings are placed at each of the four support points of the deck. Thus, the deck of the cable-stayed bridge is isolated from the towers using the double concave friction pendulum bearings which are sliding devices that utilize two spherical concave surfaces. The spatially varying earthquake ground motion is characterized by the incoherence and wave-passage effects. Mean of maximum response values obtained from the spatially varying earthquake ground motion case are compared for the isolated and non-isolated bridge models. It is pointed out that the base isolation of the considered cable-stayed bridge model subjected to the spatially varying earthquake ground motion significantly underestimates the deck and the tower responses.

The protective effect of Myrtus communis L. against experimental kidney stone in rats

Halil Yılmaz,Nihat Ekinci,Ayşe Ömerli,Mehtap Nisari,Arzu Hanım Yay,Harun Ülger,Karatoprak Gökçe Şeker,Seher Yımaz,Şükrü Ateş,Mustafa aştan 경희대학교 융합한의과학연구소 2023 Oriental Pharmacy and Experimental Medicine Vol.23 No.1

The aim of this study is to investigate the protective effect of 70% methanolic extract of Myrtus communis L. leaves (300 mg/kg) against the kidney stone modeling created by (0.75%) ethylene glycole. Twenty-eight, 10 week’s Sprague Dawley male rats were divided into four groups (n = 7) as the control group, ethylene glycol (EG) group, M. communis (MC) group and protective (EG + MC) group. For 28 days, while 0.75% EG was given by adding it to drinking water to occur kidney stone model, MC was given by gavage to test the protective effect. 24 h’ urine samples were taken, and calcium, creatinine, uric acid, magnesium, citrate and oxalate were evaluated. On the 28th day, the rats were sacrificed, and their kidneys were removed. Kidney tissues were examined with hematoxylin eosin (HE) staining and kidney stones formed with Pizzolato’s (PZ) staining technique were shown. M. communis extract brought abnormal urine parameter values closer to the control group. Additionally, it was concluded that the tissue degeneration and number of stones decreased in the protective group. M. communis extract has a protective effect against the kidney stone modeling which created by EG.

Gröbner-Shirshov bases and embedding of a semigroup in a group

E. G. Karpuz,A. S. Cevik,F. Ates,J. Koppitz 장전수학회 2015 Advanced Studies in Contemporary Mathematics Vol.25 No.4

The main goal of this paper is to show that if a group G has a Gröbner-Shirshov basis that satisfies the condition R+, then the semigroup P having positive rules in < as a dening relation embeds in this group G. As a corollary of our result, we obtain that the semigroup B+ n+1 of braids can be embedded in the braid group. The main goal of this paper is to show that if a group G has a Grobner-Shirshov basis that satisfies the condition R+, then the semigroup P having positive rules in < as a dening relation embeds in this group G. As a corollary of our result, we obtain that the semigroup B+ n+1 of braids can be embedded in the braid group.