scholarly journals Effect of Dissipative and Dispersive DNG Material Coating on the Scattering Behavior of Parallel Nihility Circular Cylinders

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Shakeel Ahmed ◽  
Muhammad Naveed ◽  
Abdul Ghaffar ◽  
Aqeel A. Syed ◽  
Q. A. Naqvi
Keyword(s):  
Plane Wave ◽  
Electromagnetic Scattering ◽  
Iterative Procedure ◽  
Coating Layer ◽  
Circular Cylinders ◽  
Double Negative ◽  
Double Positive ◽  
Different Types ◽  
Coating Layers ◽  
Expansion Coefficients

Electromagnetic scattering from coated nihility circular cylinders, illuminated byE-polarized plane wave, is investigated using an iterative procedure. Cylinders are infinite in length. The boundary conditions are applied on the surface of each cylinder in an iterative procedure in order to solve for the field expansion coefficients. The effect of different types of the coating layers including double positive (DPS) and double negative (DNG) on the alteration of the forward and backward scattering has been observed. Specially, the effect of dispersive and dissipative DNG coating layer has been focused. Numerical verifications are presented to prove the validity of this formulation by comparison with the published literature.

Extraordinary Electromagnetic Scattering of Plane Wave by Double Negative Coated Sphere

2012 ◽  
Vol 571 ◽  
pp. 626-630
Author(s):  
Yan’e Shi ◽  
Zhen Sen Wu ◽  
Hong Fei Tian ◽  
Zheng Jun Li
Keyword(s):  
Plane Wave ◽  
Electromagnetic Scattering ◽  
Mie Theory ◽  
Degree Of Polarization ◽  
Core Shell ◽  
Double Negative ◽  
Scattered Intensity ◽  
Double Positive ◽  
Isotropic Sphere ◽  
Scattering Characteristic

Based on generalized Lorenz-Mie theory and Ricatti-Bessel Derivation functions, a theoretical analysis of electromagnetic scattering of a plane wave by an isotropic sphere coated by double negative metamaterial (DNM) is investigated. The extraordinary scattering characteristic of an isotropic sphere coated by DNM is numerically discussed, which is different from those by double positive material (DPM). The effects of the refractive index of inner sphere material and core-shell ratio on the scattered intensity and degree of polarization are numerically studied and analyzed.

Effects of Microcracks in CVD Coating Layers on Cemented Carbide and Cermet Substrates on Residual Stress and Transverse Rupture Strength

1997 ◽  
Vol 119 (1) ◽  
pp. 50-54 ◽  
Author(s):  
Sakae Katayama ◽  
Masayuki Hashimura
Keyword(s):  
Residual Stress ◽  
Coating Layer ◽  
Rupture Strength ◽  
Cemented Carbide ◽  
Tensile Residual Stress ◽  
Transverse Rupture Strength ◽  
Beneficial Effects ◽  
Thermal Expansion Coefficients ◽  
Coating Layers ◽  
Expansion Coefficients

Microcracks were mechanically induced in the CVD coating layers on two types of cemented carbides with different thermal expansion coefficients, and one type of cermet. The microcracks were found to have beneficial effects on residual stress, transverse rupture strength, and chipping resistance during interrupted cutting. Residual stress in the coating on cemented carbide is tensile. Tensile residual stress decreases with increasing microcrack width and decreasing microcrack distance. Induction of 20 μm-distant and 0.025 μm-wide cracks relieves tensile residual stress by about 0.5 GPa, increases transverse rupture strength by about 0.70 GPa, and almost doubles the chipping resistance. Residual stress in the coating on cermet is compressive. Microcracks in the coating layer do not change residual stress or transverse rupture strength.

scholarly journals Electromagnetic Scattering of Inhomogeneous Plane Wave by Ensemble of Cylinders

2020 ◽  
Vol 3 ◽  
pp. 1-7 ◽  
Author(s):  
Lorenzo Dina ◽  
Fabio Mangini ◽  
Fabrizio Frezza
Keyword(s):  
Mathematical Model ◽  
Finite Element Method ◽  
Plane Wave ◽  
Electromagnetic Scattering ◽  
Circular Cylinders ◽  
The Finite Element Method ◽  
Matlab Code ◽  
Inhomogeneous Plane ◽  
Inhomogeneous Plane Wave ◽  
Cylindrical Harmonics

The interaction between an ensemble of cylinders and an inhomogeneous plane wave is introduced and is determined, in the present paper, through a rigorous theoretical approach. Scattered electromagnetic field generated by an indefinite number of infinite circular cylinders is analyzed by the application of the generalized vector cylinder harmonics (VCH) expansion. The exact mathematical model relied upon to represent this scenario considers the so-called complex-angle formalism reaching a superposition of vectorial cylindrical-harmonics and Foldy-Lax Multiple scattering equations (FLMSE) to account for the multiscattering process between the cylinders. The method was validated by comparing the numerical results obtained with the use of the finite element method and a homemade Matlab code

scholarly journals Critical and Multiple Roles for the CD3ε Intracytoplasmic Tail in Double Negative to Double Positive Thymocyte Differentiation

2009 ◽  
Vol 182 (8) ◽  
pp. 4844-4853 ◽  
Author(s):  
Jean-Francois Brodeur ◽  
Samantha Li ◽  
Maria da Silva Martins ◽  
Louise Larose ◽  
Vibhuti P. Dave
Keyword(s):  
Multiple Roles ◽  
Double Negative ◽  
Double Positive ◽  
Double Positive Thymocyte ◽  
Thymocyte Differentiation

Pre-TCR signaling regulates IL-7 receptor α expression promoting thymocyte survival at the transition from the double-negative to double-positive stage

2003 ◽  
Vol 33 (7) ◽  
pp. 1968-1977 ◽  
Author(s):  
Cesar Trigueros ◽  
Katsuto Hozumi ◽  
Bruno Silva-Santos ◽  
Ludovica Bruno ◽  
Adrian C. Hayday ◽  
...  
Keyword(s):  
Double Negative ◽  
Tcr Signaling ◽  
Double Positive

scholarly journals Distinct contracted conformations of the Tcra/Tcrd locus during Tcra and Tcrd recombination

2010 ◽  
Vol 207 (9) ◽  
pp. 1835-1841 ◽  
Author(s):  
Han-Yu Shih ◽  
Michael S. Krangel
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Three Dimensional ◽  
Double Negative ◽  
Thymocyte Development ◽  
Double Positive ◽  
Long Distance ◽  
Large Pool ◽  
Antigen Receptor Loci

Studies have suggested that antigen receptor loci adopt contracted conformations to promote long-distance interactions between gene segments during V(D)J recombination. The Tcra/Tcrd locus is unique because it undergoes highly divergent Tcrd and Tcra recombination programs in CD4−CD8− double negative (DN) and CD4+CD8+ double positive (DP) thymocytes, respectively. Using three-dimensional fluorescence in situ hybridization, we asked whether these divergent recombination programs are supported by distinct conformational states of the Tcra/Tcrd locus. We found that the 3′ portion of the locus is contracted in DN and DP thymocytes but not in B cells. Remarkably, the 5′ portion of the locus is contracted in DN thymocytes but is decontracted in DP thymocytes. We propose that the fully contracted conformation in DN thymocytes allows Tcrd rearrangements involving Vδ gene segments distributed over 1 Mb, whereas the unique 3′-contracted, 5′-decontracted conformation in DP thymocytes biases initial Tcra rearrangements to the most 3′ of the available Vα gene segments. This would maintain a large pool of distal 5′ Vα gene segments for subsequent rounds of recombination. Thus, distinct contracted conformations of the Tcra/Tcrd locus may facilitate a transition from a Tcrd to a Tcra mode of recombination during thymocyte development.

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