نتایج جستجو برای: metal element

تعداد نتایج: 395479  

2012
Zhijun Liu Philip W. C. Hon Amir A. Tavallaee Tatsuo Itoh Benjamin S. Williams

We report terahertz metamaterial waveguides based on the concept of composite right/left-handed transmission-lines. The waveguides are implemented in a metal-insulator-metal geometry fabricated with spin-coated Benzocyclobutene and contact photolithography. Angle-resolved reflection spectroscopy shows strong resonant absorption features corresponding to both right-handed and left-handed (backwa...

Journal: :international journal of advanced design and manufacturing technology 0
purushottam karthik janaswamy rvr&jc college of engineering rohith sai tunuguntla rvr & jc college of engineering sai praneeth singu rvr & jc college of engineering

gears are one of the most critical components in power transmission system of an automobile and also many rotating machinery. many studies have been conducted on optimum gear design. the main objective is to design different aluminium metal matrix composite spur gears before and after optimization. aluminium metal matrix material composites are preferred mostly due to their low density. also th...

Journal: :نشریه دانشکده فنی 0
امین صمدی قوشچی دانشگاه تهران کارن ابری نیا دانشگاه تهران محمدکاظم بشارتی گیوی دانشگاه تهران

slab method of analysis has been used for solving metal forming problems for a long time. however it has been restricted to plane strain and axisymmetric problems due to limitations in its formulations. in this paper a new formulation has been proposed so that it could be applied to three dimensional problems in metal forming. a parametric slab has been considered in this analysis and the force...

2002
Marco Limongi Alessandro Chieffi

In this review we compare the three existing sets of theoretical yields of zero metal massive stars available in the literature. We also show how each of these three different sets of yields fits the element abundance ratios observed in the extremely metal poor star CD 38 245. We find that, at present, no theoretical set of yields of zero metal massive stars is able to satisfactorily reproduce ...

Journal: :journal of modern processes in manufacturing and production 2013
vahid rikhtehgar nezami behrooz zareh abbas vafaee sefat

in recent years, in order to reducing die design and manufacturing costs, multi point forming technique has gained an increasing interest because of its high flexibility. in this process, the conventional fixed shape solid die sets are replaced with a pair of opposite matrices of controllable elements. in this paper, the fundamental principles of multi-point forming was described and the possib...

Journal: :International journal of phytoremediation 2003
S M Keeling R B Stewart C W Anderson B H Robinson

We investigated the potential of the South African high-biomass Ni hyperaccumulator Berkheya coddii to phytoextract Co and/or Ni from artificial metalliferous media. Plant accumulation of both metals from single-element substrates indicate that the plant/media metal concentration quotient (bioaccumulation coefficient) increases as total metal concentrations increase. Cobalt was readily taken up...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی (نوشیروانی) بابل - دانشکده مهندسی مکانیک 1387

چکیده ندارد.

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علم و صنعت ایران - دانشکده مهندسی موادو متالورژی 1382

با توسعه کاربرد آلومینیوم در صنایع مختلف، استفاده از آمیژان های این عنصر نیز در چند دهه اخیر توسعه فراوانی یافته است. این مواد که عمدتاً برای دستیابی به اهداف خاصی نظیر ریز کردن دانه ها، جوانه زایی، اکسیژن زدایی و تولید سایر آلیاژها و کامپوزیت های دیگر به فلزات افزوده می شوند به روش های مختلفی نظیر ریخته گری، کلوخه سازی، الکترولیز و احیا حرارتی تولید می گردند. عمده این روش ها به لحاظ هدر رفتن عن...

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