Critical Current Density Estimated from the Flux Density Distribution in Bi2Sr2CaCu2Ox Polycrystals.

the effect of traffic density on the accident externality from driving the case study of tehran

در این پژوهش به بررسی اثر افزایش ترافیک بر روی تعداد تصادفات پرداخته شده است. به این منظور 30 تقاطع در شهر تهران بطور تصادفی انتخاب گردید و تعداد تصادفات ماهیانه در این تقاطعات در طول سالهای 89-90 از سازمان کنترل ترافیک شهر تهران استخراج گردید و با استفاده از مدل داده های تابلویی و نرم افزار eviews مدل خطی و درجه دوم تخمین زده شد و در نهایت این نتیجه حاصل شد که تقاطعات پر ترافیک تر تعداد تصادفا...

High Critical Current Density Superconductivity

This project was focused on a basic scientific problem, one that is at the heart of application and development of superconductivity for efficient energy usage. This is improvement in high current density which can only be achieved by learning to pin vortices to the physical structure of its underlying superconducting material. Quantized vortices are the tornado of electrical supercurrents, ubi...

Role of internal gases and creep of Ag in controlling the critical current density of Ag-sheathed Bi2Sr2CaCu2Ox wires

High engineering critical current density JE of > 500A/mm 2 at 20T and 4.2K can be regularly achieved in Ag-sheathed multifilamentary Bi2Sr2CaCu2Ox (Bi-2212) round wire when the sample length is several centimeters. However, JE(20T) in Bi-2212 wires of several meters length, as well as longer pieces wound in coils, rarely exceeds 200A/mm. Moreover, long-length wires often exhibit signs of Bi-22...

High Critical Current Density MgB

Modeling current density distribution in electrochemical systems

A numerical method was developed for predicting current density distribution in electrochemical systems of several species at steady-state. The fundamental transport equation consisted a partial differential equation (PDE) involving linear terms of diffusion and laminar convection, and nonlinear terms of ionic migration. The boundary conditions (BCs) consisted also PDEs including flux condition...