Enhanced encapsulation of actives in self-sealing microcapsules by precipitation in capsule shells

Microcapsules with core-shell structures are excellent vehicles for the encapsulation of active ingredients; however, the actives often leak out of these structures over time, without observable damage to them. We present a novel approach to enhancing the encapsulation of active ingredients inside microcapsules. We use two components that can form solid precipitates upon mixing and add one each to the microcapsule core and to the continuous phase. The components diffuse through the shell in the same manner as the actives, but upon meeting, they precipitate to form solid particles within the shell; this significantly reduces leakage through the shell of the microcapsules. We show that the reduction in the leakage of actives is due to the blockage of channels or pores that exist in the shell of the capsules by the solid precipitates.     

Single SOA based all-optical adder assisted by optical bandpass filter: Theoretical analysis and performance optimization

A simple and compact configuration of all-optical adders implemented with a single semiconductor optical amplifier (SOA) and optical bandpass filter (OBF) is presented in this paper. A comprehensive SOA model is put forward to investigate the output characteristics of the all-optical adders. The numerical simulation results demonstrate the influence of these key parameters, including input pulse peak power, pulsewidth, repetition rate, and OBF characteristics. Moreover some design rules are extracted for the proper selection of these parameters so as to ensure optimum performance. The obtained results confirm the feasibility of our configuration.     

Noise Like Ultra-Short Bound Solitons Train

Asymmetrical bound solitons train with pulsewidth of 103fs and separation of 585.5fs without any CW components are observed from Figure-8 passive mode locked fiber laser, the separation and pulsewidth keep unchanged even after 1.2Km SMF.     

Coupling Considerations for Fabrication of Acoustooptic Tunable Filter

Induced acoustic wave to bare fiber through various types of horn are examined. The center wavelength and extinction ratio of the notch filter are dynamically tunable and dependent on the RF signals.     

Splicing on Condensed Photonic Crystal Fiber Using CO2 Laser

Condensation in the air-holes of photonic crystal fiber results in bubble development during the electric arc splicing is first reported. The condensation can be removed by laser splicing; and 1.4dB splice loss has been achieved.     

Widely Tunable Fiber Ring Laser with High Concentration Erbium-Doped Fiber

We report a high power and widely tunable erbium-doped fiber (EDF) ring laser using 1480nm pump and high concentration EDF. Large tuning range up to 105nm (1513-1618 nm) has been obtained by optimizing of the EDF length.     

On the divisibility of power LCM matrices by power GCD matrices

Let S = {x ₁, ..., x _n } be a set of n distinct positive integers and e ⩾ 1 an integer. Denote the n × n power GCD (resp. power LCM) matrix on S having the e-th power of the greatest common divisor (x _i , x _j ) (resp. the e-th power of the least common multiple [x _i , x _j ]) as the (i, j)-entry of the matrix by ((x _i , x _j ) ^e ) (resp. ([x _i , x _j ] ^e )). We call the set S an odd gcd closed (resp. odd lcm closed) set if every element in S is an odd number and (x _i , x _j ) ∈ S (resp. [x _i , x _j ] ∈ S) for all 1 ⩽ i, j ⩽ n. In studying the divisibility of the power LCM and power GCD matrices, Hong conjectured in 2004 that for any integer e ⩾ 1, the n × n power GCD matrix ((x _i , x _j ) ^e ) defined on an odd-gcd-closed (resp. odd-lcm-closed) set S divides the n × n power LCM matrix ([x _i , x _j ] ^e ) defined on S in the ring M _n (ℤ) of n × n matrices over integers. In this paper, we use Hong’s method developed in his previous papers [J. Algebra 218 (1999) 216–228; 281 (2004) 1–14, Acta Arith. 111 (2004), 165–177 and J. Number Theory 113 (2005), 1–9] to investigate Hong’s conjectures. We show that the conjectures of Hong are true for n ⩽ 3 but they are both not true for n ⩾ 4. Research is partially supported by Program for New Century Excellent Talents in University, by SRF for ROCS, SEM, China and by the Lady Davis Fellowship at the Technion, Israel Research is partially supported by a UGC (HK) grant 2160210 (2003/05).     

Surfactant aggregates at rough solid-liquid interfaces

We demonstrate improved atomic force microscopic imaging of surfactant surface aggregates, featuring an increase in the topography contrast by several hundred percent with respect to all previous studies. Surfactant aggregates on rough gold surfaces, which could not be imaged previously because of low resolution, display substantially different morphologies when compared with atomically smooth materials.     

Flexible chirp control using the linearly inherent chirped phase mask with the equivalent chirp design

The design of fiber Bragg grating to achieve different chirp amount in the selective transmission channel is presented. The method depends on the combination effect of introduced equivalent chirp with the linearly inherent chirp provided by the phase mask. Since these two chirps can be incorporated, or be counteracted, the different chirp amount can be easily obtained.