Saari's homographic conjecture for planar equal-mass three-body problem in Newton gravity

Saari's homographic conjecture in N-body problem under the Newton gravity is the following; configurational measure \mu=\sqrt{I}U, which is the product of square root of the moment of inertia I=(\sum m_k)^{-1}\sum m_i m_j r_{ij}^2 and the potential function U=\sum m_i m_j/r_{ij}, is constant if and only if the motion is homographic. Where m_k represents mass of body k and r_{ij} represents distance between bodies i and j. We prove this conjecture for planar equal-mass three-body problem. In this work, we use three sets of shape variables. In the first step, we use \zeta=3q_3/(2(q_2-q_1)) where q_k \in \mathbb{C} represents position of body k. Using r_1=r_{23}/r_{12} and r_2=r_{31}/r_{12} in intermediate step, we finally use \mu itself and \rho=I^{3/2}/(r_{12}r_{23}r_{31}). The shape variables \mu and \rho make our proof simple

Various Doping Concentration Effect on Silicon-on-Insulator (SOI) Phase Modulator

This paper reports the effect of doping concentration to the electrical characteristic performance of the phase modulator in the carrier injection mode at wavelength 1.55μm. The phase modulator device has been integrated in the silicon-on-insulator (SOI) rib waveguide with the p-i-n diode structure. The electrical device performance is predicted using the 2-D semiconductor package SILVACO (CAD) software under DC operation. The least doping concentration of p+ and n+ region produces the least change of refractive index of the modulator. Meanwhile, results show that by increasing the doping concentrations, the value of I decreases. This means that the phase modulator performance is better with increased doping concentrations

Phase modulator based on Silicon-on-Insulator (SOI) rib waveguide

This paper presents the study of electrical characteristic of phase modulator in the carrier injection mode. The phase modulator device has been integrated in the silicon-oninsulator (SOI) rib waveguide by using the p-i-n diode structure. The electrical device performance is predicted by using the 2-D semiconductor package SILVACO (CAD) software under DC operation. In summary, the phase modulator device required 0.035mA drive current to get phase shift at wavelength 1.55μm meanwhile 0.066mA drive current is required for the 1.3μm wavelength

2x2 Optical Switch Based on Silicon-On-Insulator Microring Resonator

In near future, silicon-on-insulator (SOI) microring resonator are expected to be basic components for wavelength filtering and switching due to their compact size and wide free spectral range (FSR). In this paper, a 2X2 optical switch by using active microring resonator is proposed. The switch is consists of second order serially cascaded microring coupled to a pair of waveguide. The ON/OFF state of the design is control by electric signal which will vary the refractive index. The device is design to operate at 1.55μm wavelength. With a 500nm x 200nm rib dimensions, the design is proven to have single mode behaviour. Finite-Difference Time-Domain (FDTD) method simulation by RSOFT software is use to characterize the device performance. The results show that the 2X2 optical switch proposed can be an efficient device to be functioning in WDM application

Reactive oxygen species induced structural alterations of substance P

Substance P (SP1-11) was exposed to a continuous flux of superoxide ( O 2 - ) or hydroxyl radicals (.OH) in a hypoxanthine (HX)/xanthine oxidase (86 mU) system in the presence of 1 mM deferoxamine and 40 mM D-mannitol or 50 μM FeCI3. 6H2O and 50 μM EDTA, respectively. O 2 - caused fragmentation between the Phe7 and Phe8, whereas .OH induced cleavage also between the Phe8 and Gly9. Reactive oxygen species H2O2 and HCIO did not cause fragmentation, but modification of the amino acid side chains and/or aggregation with altered hydrophobicity in reverse phase high performance liquid chromatography compared to native SP1-11. Furthermore, exposure of SP1-11 to phorbol myristate acetate preactivated neutrophils resuited in products similar to those observed upon exposure to superoxide or hydroxyl radicals in a cell-free HX/xanthine oxidase system. This study suggests that, in contrast to rigid proteins, fragmentation is relatively easily induced in a small peptide like SP1-11, perhaps due to strain on the peptide and t-carbon bonds caused by the movable, random coil configuration acquired by SP1-11 in an aqueous solution. Oxidative modification might modulate paracrine actions of SP1-11 at site of inflammation