نتایج جستجو برای: simultaneous variations of permeability and permittivity

تعداد نتایج: 24073783  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید چمران اهواز - دانشکده مهندسی علوم آب 1393

drought is transient phenomenon , slow , repetitive and integral part of the climate of each region. drought begins with a substantial reduction in precipitation over the long-term average rainfall and over time, reduced soil moisture and surface and ground water resources will continue to decrease. this phenomenon is the most important in bakhtegan basin because of its importance in strategic ...

Journal: :journal of petroleum science and technology 2015
farhad khoshbakht mohammad mohammadnia ali akbar rahimibahar yousef beiraghdar

permeability can be directly measured using cores taken from the reservoir in the laboratory. due to high cost associated with coring, cores are available in a limited number of wells in a field. many empirical models, statistical methods, and intelligent techniques were suggested to predict permeability in un-cored wells from easy-to-obtain and frequent data such as wireline logs. the main obj...

2011
I. Zivkovic A. Murk

This work presents new method, retrieved results and validation for complex and frequency dependent permittivity and permeability parameter extraction of two composite, homogeneous and isotropic magnetically loaded microwave absorbers. Permittivities and permeabilities are extracted from free space transmission measurements for frequencies from 22 up to 140 GHz. For validation of the results re...

2010
Kirk T. McDonald Joseph Henry

In 1967 Veselago considered the possibility of materials with (relative) permittivity and (relative) permeability μ both negative [1]. Building on the long history of artifical dielectrics for high-frequency applications (see, for example, [2, 3, 4]), in 1999 Pendry et al. proposed a technique for fabrication of metamaterials with both negative and negative μ within a certain frequency range [5...

2014
Ke Bi Yunsheng Guo Xiaoming Liu Qian Zhao Jinghua Xiao Ming Lei Ji Zhou

Electromagnetic materials with tunable permeability and permittivity are highly desirable for wireless communication and radar technology. However, the tunability of electromagnetic parameters is an immense challenge for conventional materials and metamaterials. Here, we demonstrate a magnetically tunable Mie resonance-based dielectric metamaterials. The magnetically tunable property is derived...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده ادبیات و علوم انسانی 1391

the purpose of this two-phase, sequential mixed methods study was to find out whether there were any decencies between male and female ma students’ theses regarding the common features of academic writing such as syntactic complexity, means of integrating cited information, and organizing arguments. i chose 10 male written theses and 15 female written theses in tefl and linguistics. in the firs...

2004
Ricardo A. Depine Akhlesh Lakhtakia

Non–dissipative mediums with both simultaneously negative permittivity and permeability were first investigated by Veselago [1] in 1968. These mediums support electromagnetic wave propagation in which the phase velocity is antiparallel to the direction of energy flow, and other unusual electromagnetic effects such as the reversal of the Doppler effect and Cerenkov radiation. After the publicati...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تبریز 1381

deposite the different criticisms on contrastive analysis it has been proved that the results of it(when processed)can be usuful in a tefl environment,specially at the level of phonology.this study is an attempt to compare and contrast the sound systems of kurdish and english for pedagogical aims. the consonants,vowels,stress and intonation of the twolanguages are described by the same model-ta...

2008
Yaroslav A. Urzhumov Gennady Shvets

In this review we describe the challenges and opportunities for creating magnetically active metamaterials in the optical part of the spectrum. The emphasis is on the sub-wavelength periodic metamaterials whose unit cell is much smaller than the optical wavelength. The conceptual differences between microwave and optical metamaterials are demonstrated. We also describe several theoretical techn...

Journal: :Optics letters 2014
Yen-Kai Chang Chih-Wei Chang

We show that employing localized surface plasmon resonators to probe environmental media will always lead to dissimilar optical sensitivities to permittivity and permeability. We find that while the permittivity sensitivities of diverse plasmonic structures display a geometry-independent universal scaling relation, the permeability sensitivities are highly dependent on the metals' geometries an...

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