REASSESSING THE EFFECT OF FISCAL AND MONETARY POLICIES IN IRAN: THE ST. LOUIS EQUATION REVISITED

Vefa Moayedi 중앙대학교 경제연구소 2013 Journal of Economic Development Vol.38 No.4

The purpose of this study is to observe the effect of fiscal and monetary policy actions on the Iranian economy. The famous St. Louis equation, an econometric model with lagged independent variables, is the key model for this study. Interestingly, the findings are converse to what scholars found when examining Western countries, especially the United States. With regard to Iran’s case, monetary policy is much less effective than fiscal policy in stimulating permanent economic growth. It is suggested that government interference is the reason. Furthermore, these findings support the equation’s general validity and its application, due to its parsimonious construction.

Confident Diagnosis of Bronchobiliary Fistula Using Contrast-Enhanced Magnetic Resonance Cholangiography

Nevzat Karabulut,Vefa Çakmak,Go ¨ksel Kiter 대한영상의학회 2010 Korean Journal of Radiology Vol.11 No.4

We report the utility of contrast-enhanced magnetic resonance cholangiography (MRC) using gadoxetic acid (Gd-EOB-DTPA) in the diagnosis of bronchobiliary fistula associated with liver hydatid cyst. Contrast-enhanced MRC clearly delineated the leakage of contrast agent from the biliary duct and its communication with the bronchial tree. Providing functional information about physiologic or pathologic biliary flow in addition to the display of biliary anatomy, contrastenhanced MRC stands as a robust technique in confidently detecting bronchobiliary fistula and bile leaks.

Evaluation of Internal Resistance in Asphalt Concretes

Yousef Zandi,Muhammet Vefa Akpinar 한국콘크리트학회 2012 International Journal of Concrete Structures and M Vol.6 No.4

Composites are somewhat more difficult to model than an isotropic material such as iron or steel due to the fact that each layer may have different orthotropic material properties. In finite element literature the asphalt mixes are represented by using rectangular meshes, not the actual picture of their cross-sections. Asphalt aggregate size and distribution in the asphalt concrete sample, aggregate shape, and fractured surface effects are ignored. In this research, the actual image of the sample including all these effects were directly considered in the finite element. The samples, were cut into cross-sections and were scanned. The image-processing toolbox of Labview was utilized in obtaining the rectangular gray images of the scanned images. In the rectangular sample the aggregates were white and the asphalt binders were black. The grayscale images were converted by LABVIEW into the format required by ANSYS as an input file, with the same dimensions. The nodes at the bottom of the model were constrained in both x and y directions. Left and right edges were symmetry and top was free. Certain amount of pressure was applied along the top surface to simulate the tire pressure.

Temperature Reduction of Concrete Pavement Using Glass Bead Materials

Erhan Burak Pancar,Muhammet Vefa Akpınar 한국콘크리트학회 2016 International Journal of Concrete Structures and M Vol.10 No.1

In this study, different proportions of glass beads used for road marking were added into the concrete samples to reduce the temperature gradient through the concrete pavement thickness. It is well known that decreasing the temperature gradient reduces the risk of thermal cracking and increases the service life of concrete pavement. The extent of alkali–silica reaction (ASR) produced with partial replacement of fine aggregate by glass bead was investigated and compressive strength of concrete samples with different proportion of glass bead in their mix designs were measured in this study. Ideal results were obtained with less than 0.850 mm diameter size glass beads were used (19 % by total weight of aggregate) for C30/37 class concrete. Top and bottom surface temperatures of two different C30/37 strength class concrete slabs with and without glass beads were measured. It was identified that, using glass bead in concrete mix design, reduces the temperature differences between top and bottom surfaces of concrete pavement. The study presented herein provides important results on the necessity of regulating concrete road mix design specifications according to regions and climates to reduce the temperature gradient values which are very important in concrete road design.

Evaluation of Internal Resistance in Asphalt Concretes

Zandi, Yousef,Akpinar, Muhammet Vefa Korea Concrete Institute 2012 International Journal of Concrete Structures and M Vol.6 No.4

Composites are somewhat more difficult to model than an isotropic material such as iron or steel due to the fact that each layer may have different orthotropic material properties. In finite element literature the asphalt mixes are represented by using rectangular meshes, not the actual picture of their cross-sections. Asphalt aggregate size and distribution in the asphalt concrete sample, aggregate shape, and fractured surface effects are ignored. In this research, the actual image of the sample including all these effects were directly considered in the finite element. The samples, were cut into cross-sections and were scanned. The image-processing toolbox of Labview was utilized in obtaining the rectangular gray images of the scanned images. In the rectangular sample the aggregates were white and the asphalt binders were black. The grayscale images were converted by LABVIEW into the format required by ANSYS as an input file, with the same dimensions. The nodes at the bottom of the model were constrained in both x and y directions. Left and right edges were symmetry and top was free. Certain amount of pressure was applied along the top surface to simulate the tire pressure.

Tribological and Corrosion Behaviour of Electroless Ni-B Coating Possessing a Blackberry Like Structure

Ferhat Bülbül,Hikmet Altun,Özkan Küçük,Vefa Ezirmik 대한금속·재료학회 2012 METALS AND MATERIALS International Vol.18 No.4

This study aims to evaluate the tribological and corrosion properties of the electroless Ni-B coating deposited on AISI 304 stainless steels. The microstructure of the coating was characterized using x-ray diffraction (XRD) and scanning electron microscopy-energy dispersive spectrometry (SEM-EDS). XRD analysis revealed that the prepared coating possessed an amorphous character. SEM-EDS investigation also indicated that a non-stoichiometric Ni-B coating was deposited with a columnar growth mechanism on the stainless steel substrate and the morphology of the growth surface was blackberry-like. The hardness and tribological properties were characterized by microhardness and a pin-on-disc wear test. The electroless Ni-B coated sample had a higher degree of hardness, a lower friction coefficient and a lower wear rate than the uncoated substrate. The electrochemical potentiodynamic polarization method was used to evaluate the corrosion resistance of the coating. The electroless Ni-B coating offered cathodic protection on the substrate by acting as a sacrificial anode although it was electrochemically more reactive than the stainless steel substrate.

Compactness in soft $S$-metric spaces

Cigdem Gunduz Aras,Sadi Bayramov,Vefa Cafarli 원광대학교 기초자연과학연구소 2020 ANNALS OF FUZZY MATHEMATICS AND INFORMATICS Vol.20 No.1

The first aim of this paper is to contribute for investigating on soft $S-$ metric space which is based on soft points of soft sets and to prove some important theorems on sequential compact and totally bounded in soft $S-$ metric space. Moreover, we introduce soft uniformly continuous mapping and examine some of its properties.

Experimental and Computational Approaches to the Molecular Structure of 3-(2-Mercaptopyridine)phthalonitrile

Hasan Tanak,Yavuz Köysal,Şamil Işık,Hanifi Yaman,Vefa Ahsen 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.2

The compound 3-(2-Mercaptopyridine)phthalonitrile has been synthesized and characterized by IR, UV-vis, and X-ray single-crystal determination. The molecular geometry from X-ray determination of the title compound in the ground state has been compared using the Hartree-Fock (HF) and density functional theory (DFT) with the 6-31G(d) basis set. The calculated results show that the DFT and HF can well reproduce the structure of the title compound. The energetic behavior of the title compound in solvent media was examined using the B3LYP method with the 6-31G(d) basis set by applying the Onsager and polarizable continuum model. Using the TD-DFT and TD-HF methods, electronic absorption spectra of the title compound have been predicted and good agreement with the TD-DFT method and the experimental determination was found. The predicted nonlinear optical properties of the title compound are much greater than those of urea. Besides, molecular electrostatic potential of the title compound were investigated by theoretical calculations. The thermodynamic properties of the compound at different temperatures have been calculated and corres ponding relations between the properties and temperature have also been obtained.

Experimental and Computational Approaches to the Molecular Structure of 3-(2-Mercaptopyridine)phthalonitrile

Tanak, Hasan,Koysal, Yavuz,Isik, Samil,Yaman, Hanifi,Ahsen, Vefa Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.2

The compound 3-(2-Mercaptopyridine)phthalonitrile has been synthesized and characterized by IR, UV-vis, and X-ray single-crystal determination. The molecular geometry from X-ray determination of the title compound in the ground state has been compared using the Hartree-Fock (HF) and density functional theory (DFT) with the 6-31G(d) basis set. The calculated results show that the DFT and HF can well reproduce the structure of the title compound. The energetic behavior of the title compound in solvent media was examined using the B3LYP method with the 6-31G(d) basis set by applying the Onsager and polarizable continuum model. Using the TD-DFT and TD-HF methods, electronic absorption spectra of the title compound have been predicted and good agreement with the TD-DFT method and the experimental determination was found. The predicted nonlinear optical properties of the title compound are much greater than those of urea. Besides, molecular electrostatic potential of the title compound were investigated by theoretical calculations. The thermodynamic properties of the compound at different temperatures have been calculated and corresponding relations between the properties and temperature have also been obtained.

Glycerol and galactose substituted zinc phthalocyanines. Synthesis and photodynamic activity

Zorlu, Yunus,Ermeydan, Mahmut Ali,Dumoulin, Fabienne,Ahsen, Vefa,Savoie, Huguette,Boyle, Ross W. Korean Society of Photoscience 2009 Photochemical & photobiological sciences Vol.8 No.3

Three novel water soluble, non-ionic, zinc phthalocyanines (Pcs) have been synthesized and their spectroscopic and photodynamic properties investigated in aqueous media. One of the three compounds was shown to be significantly less aggregated, when compared to the other two compounds, and this effect was found to be related to both the nature of the substituent, and also the position at which it is attached to the macrocycle. Photodynamic activity and cellular uptake by human adenocarcinoma cells (HT-29) was shown to be linked to the aggregation state of the Pcs in water.