Mode transitions in DBR semiconductor lasers: Experiments, mode analysis and simulations

The performance of a multisection DBR semiconductor laser emitting around 1060 nm is experimentally and theoretically investigated. Simulations and mode analysis of the traveling wave model including temperature induced changes of the refractive index explain experimentally observed nearly-periodic transitions between neighboring cavity mode determined continuous wave states with increasing injection current

Enantioselective separation of ofloxacin by ligand exchange chromatography

A ligand exchange HPLC method for enantioseparation of ofloxacin enantiomers was developed by a using C8 stationary phase. Chromatographic separation was performed on a Zorbax-300SB-C8 column eluted with the mobile phase consisting of 15 % methanol in water containing 10mM phenylalanin and 5 mM CuSO4 at flow rate of 0.8 mL/min. The method was simple, rapid and suitable for routine analytical studies of ofloxacin enantiomers

On the performance of NOMA in SWIPT systems with power-splitting relaying

This paper presents a decode-and-forward (DF) relaying protocol, namely power-splitting relaying (PSR), employed at relay nodes in NOMA technique. The PSR is considered for simultaneous wireless information and power transfer (SWIPT) systems. The relaying node is both energy harvesting from the received radio frequency (RF) signal and information forwarding to the destination. The outage performance and ergodic rate of the PSR are analyzed to realize the impacts of energy harvesting time, energy harvesting efficiency, power splitting ratio, source data rate, and the distance between the source and relay nodes. The simulation results show that NOMA schemes have the lower outage probability compared to the that of the conventional orthogonal multiple access (OMA) schemes at the destination node. Numerical results are provided to verify the findings

Electronic structure and optoelectronic properties of strained InAsSb/GaSb multi quantum wells

A study of the optical properties of a set of InAsxSb1-x/Al0.15In0.85As0.77Sb0.23/GaSb multiple quantum-wells (for x between 0.82 and 0.92) with build-in strains in the -0.62% to +0.05%-range is presented. The energy of the lowest quantum-confined optical transition is calculated by kp perturbation theory and experimentally determined by absorption measurements. Stokes shift of photoluminescence, photocurrent and of the emission from light emitting devices against the absorption edge of the quantum-well are quantified. The impact of the decreasing carrier confinement in the InAsxSb1-x quantum well system with increasing mole fraction is analyzed theoretically, and experimentally demonstrated by photoluminescence measurement. Our results allow for the improvement of optoelectronic devices, in particular for tailoring emission spectra of light emitting diodes

A community participatory intervention model to reduce the health risks from biogas wastewater in Hanam Province, Vietnam

In Vietnam, using biogas to treat livestock waste is common, in particular on small holder farms. However, most small holder farms do not know how to use biogas correctly and wastewater can affect health and the environment. Using a participatory approach with farmers and other stakeholders we developed and implemented a set of interventions in Hanam province to reduce health risks from biogas wastewater. Twenty-four pig farmers were selected as a "core group" to be instrumental in developing the interventions and training other farmers to correctly use biogas. The intervention model was piloted for 6 months. Several outputs were obtained including i) approval and enforcement of a "huong uoc - village law" on environmental protection; ii) training of 24 farmers from the core group in communication skills to share information on using biogas; iii) development of a 6-step program of pig cage cleaning to limit waste loaded to biogas to improve the efficiency of biogas production; iv) a health monitoring books for humans and animals for use by families in the community. The results provided evidence that applying the participatory approach can lead to improved knowledge and practices of farmer using biogas and can reduce the health risks from biogas wastewater

Arbitrary Form Plasmonic Structures: Optical Realization, Numerical Analysis and Demonstration Applications

Surface plasmon resonance has attracted more and more attention thanks to its wide range of applications in numerous fields (physics, chemistry, biology, etc.). In this chapter, we present different aspects, from theoretical calculation and experimental fabrication to applications demonstration, related to arbitrary shape plasmonic nanostructures. First, numerical calculations based on finite-difference time-domain method were realized to investigate the plasmonic properties of gold nanostructures having various size and shapes. Then the direct laser writing method was demonstrated as an excellent tool for fabrication on demand of arbitrary nanostructures. Plasmonic structures were obtained indirectly by a standard lift-off method from a polymeric template and directly by tightly focusing a continuous-wave laser beam onto a metallic thin film. Finally, demonstration of various applications of fabricated plasmonic structures, namely plasmonic-based data storage, color nanoprinter, tunable filters, and plasmonic-magneto-optics sensors will be shown

Static and free vibration analyses of laminated composite shells by cell-based smoothed discrete shear gap method (CS-DSG3) using three-node triangular elements

A cell-based smoothed discrete shear gap method (CS-DSG3) using three-node triangular elements was recently proposed to improve the performance of the discrete shear gap method (DSG3) for static and free vibration analyses of isotropic Reissner-Mindlin plates and shells. In this paper, the CS-DSG3 is further extended for static and free vibration analyses of laminated composite shells. In the present method, the first-order shear deformation theory (FSDT) is used in the formulation due to the simplicity and computational efficiency. The accuracy and reliability of the proposed method are verified by comparing its numerical solutions with those of others available numerical results