Publications by authors named "S Darmawan"

The data presented here is the characteristics of biopellets and its raw materials. The raw materials of lignocellulosic waste (coffee skin, corncob, patchouli waste) and shrubs ( and ) were collected from certain districts in Indonesia which provided quite abundant stocks of these raw materials. The raw material preparation and pelletization at room temperature (25 °C) using a manual press machine were carried out at Hasanuddin University, Makassar, Indonesia.

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In this study, we examined activated and non-activated carbon nanoparticles (CNPs) derived from oil palm empty fruit bunch (OPEFB) fibers for their nanomaterial characteristics and their potential effectiveness in heavy metal removal. To investigate these properties, transmission electron microscopy, scanning electron microscopy (SEM), EDX, Fourier transform infrared spectroscopy, particle size analysis, X-ray diffraction, and atomic absorption spectrophotometry were employed. This study shows that both the activated and the non-activated CNPs were in the form of well-dispersed and aggregated particles.

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Coupling induced effects are higher order effects inherent in waveguide evanescent coupling that are known to spectrally distort optical performances of integrated optics devices formed by coupled resonators. We present both numerical and experimental studies of coupling-induced phase shift in various basic integrated optics devices. Rigorous finite difference time domain simulations and systematic experimental characterizations of different basic structures were conducted for more accurate parameter extraction, where it can be observed that coupling induced wave vector may change sign at the increasing gap separation.

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We experimentally demonstrate coupled-resonator-induced-transparency (CRIT) phenomenon in ring-bus-ring (RBR) geometry synergistically integrated with Mach-Zehnder interferometer (MZI). The RBR consists of two detuned resonators indirectly coupled through a center bus waveguide. The transparency is obtained by increasing the light intercavity interaction through tailoring the RBR phase response while ensuring balanced MZI operation.

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We experimentally study the effects of the coupling-induced phase shift (CIPS) in silicon-on-insulator microring-coupled Mach-Zehnder interferometer (MZI) devices for the flat-top filter application. Excellent agreement is obtained between the theoretical modeling and the experiment. It is demonstrated that width offset of the uncoupled MZI arm can compensate the CIPS and approximate a box-like filter with only 0.

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