[신간안내] Computational Electrodynamics (the finite difference time - domain method)

Preface 1. Wave Theory of Optical Waveguides 2. Planar Optical Waveguides 3. Optical Fibers 4. Couple Mode Theory 5. Nonlinear Optical Effects in Optical Fibers 6. Finite Element Method 7. Beam Propagation Method 8. Staircase Concatention Method 9. Planar Lightwave Circuits 10. Theorems and Formulas Appendix

Fundamentals of optical waveguides

We have observed a darkening effect and the formation of permanent volume gratings in CdSSe semiconductor-doped glasses, both phenomena being certainly due to the same photochemical mechanism. This allowed us to reconcile contradictory results concerning the speed of their nonlinear response. We also studied the frequency dependence of X (3) below the gap and the intensity dependence of the reflectivity of these phase-conjugate mirrors. Our results can be interpreted in terms of the band-filling model with Boltzmann statistics. Finally, frequency- and. time-resolved luminescence measurements helped us to interpret various results.

New results on optical phase conjugation in semiconductor-doped glasses

Biogas is a relatively mature renewable energy technology but still most commercial biogas power plants require significant financial incentives. Additionally, local shortages of very cheap digestible feedstocks limit biogas productivity, especially for larger biogas power plants (>1 MWe). Innovations that could improve cost-effectiveness and resource efficiency of biogas energy technology are therefore required. Over the last few years a number of potential process innovations for biogas technology have been proposed and investigated. However, the majority of these novel concepts has minimal or no impact on technology development. Disruptive innovations are very rare, but only they really matter for the economy. Therefore review reports that systematically compare, analyze and evaluate the suitability of these emerging methods with emphasis on technological excellence and realistic commercial potential are needed. This study presents potential process innovations from most recent patent and academic literature proposed for biogas (i) production, (ii) conditioning, (iii) utilization and (iv) industrial symbiosis. Within these four highly interdisciplinary categories the review attempts to provide short practical comments on selected methods and briefly analyzes their perspectives and constraints. Further, relevant biogas process innovation criteria are designed and multiple-criteria assessment of pre-selected potential process innovations is made. The paper concludes with the characterization of innovativeness of selected solutions and suggests future research needs for biogas energy technology that could bring new innovations in near term.

A review of potential innovations for production, conditioning and utilization of biogas with multiple criteria assessment

The engine, which uses both conventional diesel fuel and LPG fuel, is referred to as ‘LPG–diesel dual fuel engines’. LPG dual fuel engines are modified diesel engines which use primary fuel as LPG and secondary fuel as diesel. LPG dual fuel engines have a good thermal efficiency at high output but the performance is less during part load conditions due to the poor utilization of charges. This problem can be overcome by varying factors such as pilot fuel quantity, injection timing, composition of the gaseous fuel and intake charge conditions, for improving the performance, combustion and emissions of dual fuel engines. This article reviews about the research work done by the researchers in order to improve the performance, combustion and emission parameters of a LPG–diesel dual fuel engines. From the studies it is shown that the use of LPG in diesel engine is one of the capable methods to reduce the PM and NOx emissions but at same time at part load condition there is a drop in efficiency and power output with respect to diesel operation.

LPG diesel dual fuel engine – A critical review

Effect of hydrogen and LPG addition on the efficiency and emissions of a dual fuel diesel engine

Investigations on the combustion parameters of a dual fuel diesel engine with hydrogen and LPG as secondary fuels

Laser induced nonlinear absorption coefficient of Brilliant Green solution was measured by single beam open aperture Z-scan technique using a continuous wave He–Ne laser at the wavelength of 632.8 nm. It was found that the material exhibits multiphoton absorption type optical nonlinearity. Significant optical nonlinearity is an indicative that Brilliant Green dye is prominent material for low power nonlinear applications. Ultraviolet–visible and photoluminescence (PL) spectra of Brilliant Green solutions are also recorded. A strong linear absorption band with a peak at 625 nm has been observed, while the PL intensity was found to decrease due to quenching effect on increasing the concentration.

Sarang Medhekar

Papers

Effect of hydrogen and LPG addition on the efficiency and emissions of a dual fuel diesel engine

Investigations on the combustion parameters of a dual fuel diesel engine with hydrogen and LPG as secondary fuels

Study of nonlinear optical properties of organic dye by Z-scan technique using He–Ne laser

All-optical NOT and AND gates using counter propagating beams in nonlinear Mach–Zehnder interferometer made of photonic crystal waveguides

Solitons in Optical Metamaterials with Trial Solution Approach and Bäcklund Transform of Riccati Equation