PVN-CAT-031-C-006-001-CNMDL

The objective of this project is to study techniques for controlling the duration of ultrashort (femtosecond) optical pulses by using the properties of dispersive and nonlinear media.RP 60/9

A systematic review of the molecular simulation of hybrid membranes for performance enhancements and contaminant removals

Number of research on molecular simulation and design has emerged recently but there is currently a lack of review to present these studies in an organized manner to highlight the advances and feasibility. This paper aims to review the development, structural, physical properties and separation performance of hybrid membranes using molecular simulation approach. The hybrid membranes under review include ionic liquid membrane, mixed matrix membrane, and functionalized hybrid membrane for understanding of the transport mechanism of molecules through the different structures. The understanding of molecular interactions, and alteration of pore sizes and transport channels at atomistic level post incorporation of different components in hybrid membranes posing impact to the selective transport of desired molecules are also covered. Incorporation of molecular simulation of hybrid membrane in related fields such as carbon dioxide (CO2) removal, wastewater treatment, and desalination are also reviewed. Despite the limitations of current molecular simulation methodologies, i.e., not being able to simulate the membrane operation at the actual macroscale in processing plants, it is still able to demonstrate promising results in capturing molecule behaviours of penetrants and membranes at full atomic details with acceptable separation performance accuracy. From the review, it was found that the best performing ionic liquid membrane, mixed matrix membrane and functionalized hybrid membrane can enhance the performance of pristine membrane by 4 folds, 2.9 folds and 3.3 folds, respectively. The future prospects of molecular simulation in hybrid membranes are also presented. This review could provide understanding to the current advancement of molecular simulation approach in hybrid membranes separation. This could also provide a guideline to apply molecular simulation in the related sectors

Synergistic effects of catalytic co-pyrolysis Chlorella vulgaris and polyethylene mixtures using artificial neuron network: Thermodynamic and empirical kinetic analyses

The catalytic pyrolysis of Chlorella vulgaris, high-density polyethylene (Pure HDPE) and, their binary mixtures were conducted to analyse the kinetic and thermodynamic performances from 10 to 100 K/min. The kinetic parameters were computed by substituting the experimental and ANN predicted data into these iso-conversional equations and plotting linear plots. Among all the iso-conversional models, Flynn-Wall-Ozawa (FWO) model gave the best prediction for kinetic parameters with the lowest deviation error (2.28–12.76%). The bifunctional HZSM-5/LS catalysts were found out to be the best catalysts among HZSM-5 zeolite, natural limestone (LS), and bifunctional HZSM-5/LS catalyst in co-pyrolysis of binary mixture of Chlorella vulgaris and HDPE, in which the Ea of the whole system was reduced from range 144.93–225.84 kJ/mol (without catalysts) to 75.37–76.90 kJ/mol. With the aid of artificial neuron network and genetic algorithm, an empirical model with a mean absolute percentage error (MAPE) of 51.59% was developed for tri-solid state degradation system. The developed empirical model is comparable to the thermogravimetry analysis (TGA) experimental values alongside the other empirical model proposed in literatur

Static and dynamic properties of pseudomorphic quantum well lasers.

Recent development of device-quality strained layer epitaxy facilitates the creation of a new generation of semiconductor lasers--the pseudomorphic quantum well laser. A thorough survey of the literature points to the need for a comprehensive study comparing the steady-state, transient, and small-signal characteristics of such lasers. This work is undertaken, by using numerical techniques developed to solve the multimode coupled rate equations together with calculated optical gain spectra. The broad-area laser, though simpler to fabricate than the single-mode lasers, is hitherto limited to DC characterization. This is extended to the AC domain. From the laser intensity noise spectra, the resonance frequency has been successfully determined. Observed multiple resonance peaks in broad-area lasers have also been correlated with near-field measurements. Auger recombination rates in quantum well lasers are determined by analysis of the measured turn-on delay times. The extracted Auger coefficients are found to increase with strain. These are the first measurements of Auger recombination rates in InP-based strained QW lasers. Monte Carlo study of carrier relaxation in GRINSCH quantum well structures is carried out for the first time. Calculated relaxation times of 15-20 ps for L-GRINSCH structures have found good agreement with experiments. The relative performance of various structure designs are analyzed. The reverse process of the thermalization of carriers generated "cold" at the bandedge, a phenomenon found in QCSE-based devices, has also been studied for the first time. A relatively fast thermalization time of 2-3 ps has been found. Discrepancies in the well-width dependence of the carrier capture times in the literature are examined and accounted for by Monte Carlo calculations at different injection conditions. The Monte Carlo technique is combined with optical gain and laser rate equation calculations to study gain compression. The gain compression coefficient is calculated from the reduction in the optical gain due to stimulated emissions. Gain saturation is found to be more or less independent of the quantum well width. Monte Carlo simulation of femtosecond pump-probe experiments have detected the presence of spectral holeburning. These are the first investigations of gain compression in semiconductor lasers using the Monte Carlo method.Ph.D.Electrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/103630/1/9332113.pdfDescription of 9332113.pdf : Restricted to UM users only

Fabrication and characterisation of microelectronics materials and devices

To develop a suitable photonics material and a reliable fabrication process for channel waveguide and grating devices to lead to further development of other passive devices for microelectronics (photonics) applications.RGM 21/9

One-step disposable optical waveguide immunosensors

To develop one-step disposable optical waveguide immunosensors.RG 32/9

Design and construction of fiber-optic sensors

Three types of sensors are proposed, construct and characterised. They are Michelson type position sensor, Sagnac velocimeter and gradient hydrophone.RG 55/9

Development of optical pulse sources, modulators and switches for next generation lightwave systems

With the drive to provide more diverse over fiber-optic communication systems, extensive research in the constituent optoelectronics components such as laser sources, optical modulators, otpical switches and photodetectors are required. To better facilitate such research, a versatile lithography system that can meet the diverse demands of optoelectronics integrated circuits (OEICs) fabrication is developed.RG 34/9

Development of multicolor array photodetectors

The aim of this project is to establish the basic tehcnologies in the development of the photodetector element and array in NTU.RG 45/9

Development of semiconductor lasers emitting in the visible (0.6 um) to mid-infrared (2.6 um) regions

The project established the basic technologies in the development of the semiconductor laser diode in NTU. The scope includes epitaxial growth, laser device processing, as well as laser performance characterization and analysis.RG 8/9