Peanut testae are potent sources of polyphenols. When the water extracts and acid hydrolysates of five different-colored testae were analyzed by HPLC, chromatograms monitored at 280 nm varied remarkably, whereas two major peaks in the chromatograms monitored at 530 nm were detected only in kernels having completely or partially black color. After acid hydrolysis of the extracts, cyanidin was detected in each of the hydrolysates. By respectively subjecting the black testae of raw and roasted (175 degrees C for 20 min) kernels of a black colored cultivar to water extraction and HPLC analysis, a prominent peak was detected in both extracts. The structure of the substance under those peaks was identified by mass and NMR spectrometry as cyanidin 3-sambubioside in peanut testae for the first time. Subjection of cyanidin 3-sambubioside to antioxidation and anti-inflammation assessments revealed that it was a potent antioxidant and inhibitor of nitric oxide production.

Multimode interference (MMI) couplers with a width of arbitrary-exponent binomial function are proposed. The proposed structure includes the conventional, butterfly, and parabolic structure such that the proposed MMI device can be used for equal and unequal power splitting. With a proper choice of the exponent of a binomial function, several equal and unequal optical powers splitting ratio can be obtained. For comparison, the optical power splitting ratios, total transmission, and coupler length of the proposed MMI couplers are discussed.

Cyclic arrayed waveguide grating (AWG) devices with flat-top passband and uniform spectral response are proposed. Each access waveguide of the proposed cyclic AWG consists of a multimode interference region and a taper waveguide. Simulation results show that the 1-dB bandwidth of the proposed device is larger than 0.44 times the channel spacing and the corresponding nonuniformity is smaller than 1 dB.

A wideband criterion for multimode interference (MMI) splitter is proposed. The basic principle is based on reducing the interference length difference and making it shorter than the spot size for constructive mode interference. Simulation results show the spectra of proposed MMI splitter is wide enough (1.26-1.70 m) to cover the fiber communication band and the size of the splitter is more compact than that of the conventional MMI or Y-branch splitter.

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