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Comparative analysis of efficient diode design for terahertz wireless power transmission system

2016-07-20T05:33:54Z

Title: Comparative analysis of efficient diode design for terahertz wireless power transmission system Authors: Bhatt, Kapil; Tripathi, C C Abstract: The wireless power transmission (WPT) technology is an extension of wireless communication. The physics of WPT and wireless communication are related, but WPT is distinct from wireless transmission for transferring information (such as radio and mobile phones etc.), where the percentage of the power that is received is only important if it becomes too low to successfully recover the signal. With WPT, the efficiency is a more critical parameter and this creates important differences in these technologies. This paper presents the wireless power transmission (WPT), from past work to most recent accomplishments including recent developments, potential approaches and factors responsible for designing most critical rectifying diodes operating at terahertz/petahertz frequencies. Page(s): 827-836

Study of some amino acid based non-linear optical materials

2016-07-20T05:31:37Z

Title: Study of some amino acid based non-linear optical materials Authors: Jananakumar, Deepa; Mani, P Abstract: Non-linear optical (NLO) single crystals of L-valine l-valinium orthophosphate (LVP) and L-valine l-valinium nitrate (LVN) were grown by slow evaporation solution growth method using water as the solvent at room temperature. Purity of the crystals was increased by the method of recrystallization. The cell parameters of LVP and LVN were determined using single crystal X-ray diffraction technique. The grown crystals were characterized by measuring their thermal, optical and mechanical properties by Differential Thermal Analysis (DTA), Thermogravimetric Analysis (TGA), Powder Second Harmonic Generation (SHG) efficiency, FTIR, UV-VIS NIR, damage threshold and microhardness measurements. The dielectric constant and dielectric loss of the crystals have been studied as a function of frequency at room temperature. Our studies showed that L-valine inorganic acids emerged as most promising NLO materials having SHG efficiency, mechanical and thermal stability greater than other semi-organic NLO materials. Page(s): 819-826

Large band gaps in two-dimensional phononic crystals with Jerusalem cross slot structures

2016-07-20T05:28:59Z

Title: Large band gaps in two-dimensional phononic crystals with Jerusalem cross slot structures Authors: Li, Yinggang; Zhu, Ling; Chen, Tianning Abstract: The band gap properties in a novel two-dimensional phononic crystal with Jerusalem cross slot structures have been investigated theoretically in the present paper. The dispersion relations, the power transmission spectra and the displacement fields of the eigenmodes are calculated by using the finite element method. Numerical results show that the proposed structures with periodic Jerusalem cross slots can yield large band gaps in the low-frequency range as compared to the typical phononic crystals composed of periodic square rods embedded in a homogenous matrix. The formation mechanisms of the large low-frequency band gaps as well as the effects of the geometrical parameters on the band gaps are further explored numerically. Results show that the openings of the low-frequency band gaps are mainly attributed to the interaction between the local resonances of the square scatterers with Jerusalem cross slot structures and the traveling wave modes in the matrix. The band gaps can be significantly modulated by changing the geometrical parameters of Jerusalem cross slot structures. Page(s): 813-818

Supramolecular structure of phellopterin isolated from the roots of heracleum thomsoni: A furanocoumarin

2016-07-20T05:25:31Z

Title: Supramolecular structure of phellopterin isolated from the roots of heracleum thomsoni: A furanocoumarin Authors: Sharma, Bandhan Abstract: The crystal structure of phellopterin has been determined by X-ray diffraction method. The compound crystallizes in the triclinic space group P1 with unit cell parameters: a = 8.431(3) Å, b = 8.947(3) Å, c = 11.125(4) Å, α = 69.11(5)°, β = 71.13(5)º and γ = 78.04(5) º, Z = 2, V=737.9(4) Å³. The structure has been solved by direct methods and refined to reliability index of 0.059. The molecules of phellopterin are linked by paired C-H...O hydrogen bond. The face to face π... π stacking interactions link the planar tricyclic moiety with one another and pack in parallel arrangements. Page(s): 808-812