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Rohaya M.A.W.,UKM | Majlis B.Y.,Institute of Microengineering and Nanoelectronics
Malaysian Applied Biology | Year: 2013

Stem cells that made up of embryonic stem cells and adult stem cells are well known for their ability to self renew and differentiate into matured cells. Adult stem cells isolated from peripheral blood system were used as the study sample. The objective of this study was to determine the relationship between size and proliferation potential of stem cells from 3 different culturing terms, i.e., short (7 days), medium (14 days), and long (30 days) terms. Density gradient centrifugation was applied in isolating mononucleated cells (MNCs) from peripheral blood sample. Isolated MNCs were washed with Hank's Balanced Salt Solution and Phosphate Buffer Saline. The MNCs which cultured in complete media were then subjected to proliferation analysis every day for a time period of 30 days. RT-PCR analyses and cell size measurements were carried out at day 7, 14, and 30. Activation of KIT and SLAMF1 marker genes during RT-PCR analyses indicated that the isolated MNCs were stem cells. Analyses of proliferation rate and cell size showed that short term stem cells have the largest cell size with the lowest proliferation potential. While, medium term stem cells gave rise to a smaller stem cell population with higher proliferation potential compared to short term stem cells. Long term stem cells have smallest cell size with highest proliferation potential. In conclusion, each culturing term cell population had their own sizes and can be isolated based on those sizes.

Hanim A.R.,University Technical Malaysia Melaka | Mardiana B.,University Technical Malaysia Melaka | Hazura H.,University Technical Malaysia Melaka | Saari S.,IMEN | Saari S.,Institute of Microengineering and Nanoelectronics
2010 International Conference on Photonics, ICP2010 | Year: 2010

This paper highlights the study of carrier injection effect on silicon waveguide with p-i-n diode structure integrated on Silicon-on-Insulator (SOI). The device performance is predicted using 2D Silvaco CAD software under different applied voltages at wavelength 1.3 and 1.55 μm. Lπ and VπLπ is minimized at a greater applied voltage. Operating at 1.55 μm is proven to be more efficient in terms of length of the modulator, Lπ and modulation phase efficiency. At 0.75V, Lπ and VπLπ are 0.527711 cm and 0.39578 Vcm respectively. Meanwhile, at IV, Lπ and VπLπ are 0.01303 cm and 0.013029Vcm respectively. Therefore, a greater voltage is suggested for a shorter device length and greater modulation efficiency. © 2010 IEEE.

Mardiana B.,University Technical Malaysia Melaka | Hazura H.,University Technical Malaysia Melaka | Hanim A.R.,University Technical Malaysia Melaka | Shaari S.,Institute of Microengineering and Nanoelectronics
2010 International Conference on Photonics, ICP2010 | Year: 2010

This paper presents the study of electrical characteristic of phase modulator in the carrier injection mode. The phase modulator device has been integrated in the silicon-on-insulator (SOI) rib waveguide by using the p-i-n diode structure. The electrical device performance is predicted by using the 2-D semiconductor package SILVACO (CAD) software under DC operation. In summary, the phase modulator device required 0.035mA drive current to get π phase shift at wavelength 1.55μm meanwhile 0.066mA drive current is required for the 1.3μm wavelength. © 2010 IEEE.

Karim A.M.,Institute of Microengineering and Nanoelectronics | Othman M.,Institute of Microengineering and Nanoelectronics
IEEE Communications Letters | Year: 2010

Proposed is an improved blind carrier frequency offset (CFO) estimator suitable for Multi-Band OFDM Ultra Wideband (MB-OFDM UWB) system. By exploiting the conjugate symmetry of the physical layer convergence protocol (PLCP) the need for training symbols can be avoided and estimation performance is improved as well. Computer simulations show that the proposed method achieves better estimation performance than existing method. © 2006 IEEE.

Ismail K.,Institute of Microengineering and Nanoelectronics | Menon P.S.,Institute of Microengineering and Nanoelectronics | Shaari S.,Institute of Microengineering and Nanoelectronics | Bakarman H.A.,Institute of Microengineering and Nanoelectronics | And 2 more authors.
IETE Technical Review (Institution of Electronics and Telecommunication Engineers, India) | Year: 2013

Semiconductor optical amplifier (SOA) is one of the commonly used amplifiers in optical networks. This paper reviews the SOA implementation in coarse wavelength division multiplexing (CWDM) systems, which includes the explanation of the fundamental concepts such as the configuration, principle of operation as amplifiers, and the performance in different CWDM topologies. Simulation using OptiSystem software was carried out to determine the gain saturation at high input power and longer wavelengths. It shows that SOA implementation in CWDM networks is capable of providing flat gain for 40 nm wavelength span. © 2013 by the IETE.

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