نتایج جستجو برای: transition

تعداد نتایج: 262109  

بهدانی, محمد, تجبر, ناصر, یزدانیان, سمیه,

In this research, YBa2Cu3O7-d (0 < d < 1) nanocrystalite superconductor was prepared by mechanochemical alloying method. We synthesized YBa2Cu3O7-d via mixing the BaCO3, Y2O3, CuO powders and milling in SPEX 8000 for 5h with weight ratio of ball to powder 10:1 and steel balls of 11mm diameter, followed by heating for 4h at 850 ˚C. The superconductor phase formation process was completed with si...

حکمت, مریم , دادرس, صدیقه , دادمهر, وحید, صفری, محمد رضا ,

  Obtaining the superconductor samples or mainly, structural phase controlling in 123 systems is a matter of special importance. As decreasing of oxygen in this structure has special effects, and mainly causing structural phase transition, by investigating the structure and thermal analysis of the system, tetragonal-orthorhombic structural phase transition was observed and optimum contents of s...

The performance of any finite element (FE) structural analysis is directly related to the global number of nodes and degrees of freedom (DOF) of the discretized structure and mesh distribution attributes. It is obvious that the appropriate numerical analysis needs finer elements in the zone of interest, e.g. zone of high stress concentration and intensity, and coarser elements for farther porti...

Supervisory control and fault diagnosis of hybrid systems need to have complete information about the discrete states transitions of the underling system. From this point of view, the hybrid system should be abstracted to a Discrete Trace Transition System (DTTS) and represented by a discrete mode transition graph. In this paper an effective method is proposed for generating discrete mode trans...

تجبر , ناصر, علی نژاد , محمدرضا, پورآرین , فایز,

  In this research. The magnetic phase transition and anisotropic magnetoelastic effects of a polycrystalline sample of Nd14Dy2Fe78B6 were studied by susceptibility and magnetostriction measurements. The composition was prepared by casting method. SEM pictures and XRD analysis showed that it was composed of polycrystalline magnetic phases with the main phase of 2-14-1. Results of ac susceptibil...

2013
Jiyoung Kim

This paper examines the questions of why and how foreign assistance was utilized successfully in South Korea but less so in Ghana, with a focus on the role of aid in the process of state building and state transition in these two countries. Before the 1960s, South Korea and Ghana shared approximately similar levels of GDP per capita. However, while South Korea achieved rapid economic developmen...

Journal: :بوم شناسی کشاورزی 0
ابوالفضل قدیری مقدم امین نعمتی

regard to increasing demand for organic agricultural products, awareness of costs and profitability of organic products can help to decision planners of agricultural sector, and particularly farmers. this study has tried to calculate cost and profitability of cotton product in two different conventional and organic ways (procedure) of production using 253 cross-sectional data from khorasan raza...

2013
Jiyoung Kim

This paper examines the questions of why and how foreign assistance was utilized successfully in South Korea but less so in Ghana, with a focus on the role of aid in the process of state building and state transition in these two countries. Before the 1960s, South Korea and Ghana shared approximately similar levels of GDP per capita. However, while South Korea achieved rapid economic developmen...

Amir Hossien Hakimyuon Farideh Hadi Reza Ghiasi

The complexes between C20 and C2 X4 , C2 X2 (X = H, F, Cl, Br) have been studied theoretically at the B3LYP/6-311G (d,p) level. The calculations include the optimized geometries, the interaction energies, aromaticity and thermodynamic. The interaction energies ranging from -60 to -101 kcal/mol and being ordered as: X = F> Cl > Br. Natural bond orbital (NBO) analysis has been performed on all ge...

M. Ghaffarian

Using Hartree-Fock Su-Sheriffer-Heeger (HF-SSH) model, we have studied the dependence of the energies of the ground (magnetic triplet state) and the first exited (nonmagnetic singlet state) states of the size-2 trigonal zigzag graphene nanoflake (size-2 NF) on the intensity of an external in plane static electric field at zero temperature. We identify a transition from the magnetic triplet stat...

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