Now showing 1 - 10 of 58
  • Publication
    The influence of selenium amount added into the graphite box during the selenization of solution deposited CIGSe thin films.
    ( 2021)
    G M Albalawneh
    ;
    M M Ramli
    ;
    M ZM Zain
    ;
    AbstractCu(In,Ga)Se2 (CIGSe) semiconductor is an efficient light absorber material for thin-film solar cell technology. The sequential evaporation of precursor solution, followed by the selenization process, is a promising non-vacuum and low-cost approach for CIGSe thin-film fabrication. The main properties of CIGSe thin films are strongly affected by the post-selenization step. Hence, thorough control of selenization parameters is essential for achieving pure crystalline, large grain films needed for high-performance solar cell devices. In this study, the impact of selenium (Se) amount added during the selenization step was evaluated. The structural, morphological, and compositional properties of the selenized thin films were investigated. The CIGSe precursor film was deposited by a spin-coating technique using a thiol/amine-based solution, followed by annealing with different Se amounts (100, 200, and 300 mg) within a partially closed small round graphite container. In all cases, uniform films of 1.2–1.5 µm thickness with a well-defined single chalcopyrite phase were obtained. It was observed that the grain size and Se content increased with increasing Se mass added. Moreover, the sample selenized with 200 mg Se resulted in higher surface coverage, thinner fine-grained layer, and less MoSe2 formation than the excess Se samples.
  • Publication
    Kinetics, mass transport characteristics, and structural changes during air-drying of purple yam (Dioscorea Alata L.) at different process conditions
    ( 2017)
    Flordeliza C. De Vera
    ;
    Leif Anthony B. Comaling
    ;
    Iya Ray Alyanna M. Lao
    ;
    Alvin R. Caparanga
    ;
    This experiment was designed to follow the 2k factorial design to study the effects of the three drying parameters on the drying characteristics and effective moisture diffusivity and to fit each run performed on the best thin-layer drying kinetics model. Raw purple yam samples were pre-treated and undergone the designed drying procedures at which the weight of the samples were recorded every minute until such time that the sample weights become constant. Scanning Electron Microscopy (SEM) is utilized for qualitative analysis of the dried samples. The number of pores per unit area and the overall aesthetics of the surface of the dried samples were compared also using SEM. Considering the qualitative analysis conducted on the samples from the images of SEM, dried samples from run 2 has the most desirable conditions such as high temperature and low air velocity for drying because the samples from this run have large pore diameters with minimal cell breakages.
  • Publication
    Digital fringe projection for hand surface coordinate variation analysis caused by osteoarthritis
    ( 2017) ;
    Cheek Hau Tan
    ;
    Vithyacharan Retnasamy
    ;
    Rajendaran Vairavan
    ;
    Muhammad Hafiz Ab Aziz
    ;
    ; ; ;
    Hand osteoarthritis is one of the most common forms of arthritis which impact millions of people worldwide. The disabling problem occurs when the protective cartilage on the boundaries of bones wear off over time. Currently, in order to identify hand osteoarthritis, special instruments namely X-ray scanning and MRI are used for the detection but it also has its limitations such as radiation exposure and can be quite costly. In this work, an optical metrology system based on digital fringe projection which comprises of an LCD projector, CCD camera and a personal computer has been developed to anticipate abnormal growth or deformation on the joints of the hand which are common symptoms of osteoarthritis. The main concept of this optical metrology system is to apply structured light as imaging source for surface change detection. The imaging source utilizes fringe patterns generated by C++ programming and is shifted by 3 phase shifts based on the 3 steps 2 shifts method. Phase wrapping technique and analysis were applied in order to detect the deformation of live subjects. The result has demonstrated a successful method of hand deformation detection based on the pixel tracking differences of a normal and deformed state.
  • Publication
    Interrogation of surface roughness and bond force effect
    In the macro world surface roughness is a feature undoubtedly not to be ignored. In the current trend towards the nano-scale feature in the devices related to the semiconductor and other various niche, surface roughness is being propelled as an important element. In this work the surface roughness at nano level is investigated for the adhesion interaction and influence. The samples for the roughness feature and ranges were prepared using controlled plasma etching. The wire bonding bond force parameter was chosen as the factor to be tested and shear test as the response. The shear value ranged from 13g to 22g for the low to high bond force respectively for the lower range surface roughness, for the higher surface roughness the value ranged 5g to 9g respectively. The interaction shows surface roughness has tangible effect on adhesion for a more thorough detailed investigation.
  • Publication
    Analysis on square and circular inductor for a high Q-factor inductor
    This paper presents the high-quality (Q) factor inductors using Silicon-on-sapphire (SOS) for the 10GHz to 20GHz frequency band. Inductors are designed on SOS because of their advantages, including high resistivity and low parasitic capacitance. This paper compares square and circular inductor topologies for high-quality (Q) factor inductors using HFSS software for the high-frequency band. Both inductors have been designed with the same width and thickness to make them comparable with each other. The comparison shows that a circular inductor achieves the highest Q-factor. Furthermore, the circular and square inductor's Q-factor, inductance, and resistance are analyzed. As a result, the circular inductor has the maximum Q-factor of 89.34 at 10.6GHz for 0.29nH, while the square inductor has obtained a maximum Q-factor of 80.72 at 10GHz for 0.40nH inductance.