Now showing 1 - 10 of 36
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Remazol orange dye sensitized solar cell

2017-01-03 , Siti Salwa Mat Isa , Muhammad Mahyiddin Ramli , Nor Azura Malini Ahmad Hambali , Muda M.R. , Shahrir Rizal Kasjoo , Muammar Mohamad Isa , Nurul Izza Mohd Nor , Norhawati Ahmad , Nazuhusna Khalid , Nur M. Selamat , Nur Asyikin Mohd Anhar

Water based Remazol Orange was utilized as the dye sensitizer for dye sensitized solar cell. The annealing temperature of TiO2 working electrode was set at 450 °C. The performance of the device was investigated between dye concentrations of 0.25 mM and 2.5 mM at three different immersion times (3, 12 and 24 hours). The adsorption peak of the dye sensitizer was evaluated using UV-Vis-Nir and the device performance was tested using solar cell simulator. The results show that the performance was increased at higher dye concentration and longer immersion time. The best device performance was obtained at 0.2% for dye concentration of 2.5 mM immersed at 24 hours.

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Effect of Ni on the suppression of sn whisker formation in Sn-0.7Cu solder joint

2021 , Aimi Noorliyana Hashim , Mohd Arif Anuar Mohd Salleh , Andrei Victor Sandu , Muhammad Mahyiddin Ramli , Khor Chu Yee , Noor Zaimah Mohd Mokhtar , Jitrin Chaiprapa

The evolution of internal compressive stress from the intermetallic compound (IMC) Cu6Sn5 growth is commonly acknowledged as the key inducement initiating the nucleation and growth of tin (Sn) whisker. This study investigates the effect of Sn-0.7Cu-0.05Ni on the nucleation and growth of Sn whisker under continuous mechanical stress induced. The Sn-0.7Cu-0.05Ni solder joint has a noticeable effect of suppression by diminishing the susceptibility of nucleation and growth of Sn whisker. By using a synchrotron micro X-ray fluorescence (µ-XRF) spectroscopy, it was found that a small amount of Ni alters the microstructure of Cu6Sn5 to form a (Cu,Ni)6Sn5 intermetallic layer. The morphology structure of the (Cu,Ni)6Sn5 interfacial intermetallic layer and Sn whisker growth were investigated by scanning electron microscope (SEM) in secondary and backscattered electron imaging mode, which showed that there is a strong correlation between the formation of Sn whisker and the composition of solder alloy. The thickness of the (Cu,Ni)6Sn5 IMC interfacial layer was relatively thinner and more refined, with a continuous fine scallop-shaped IMC interfacial layer, and consequently enhanced a greater incubation period for the nucleation and growth of the Sn whisker. These verification outcomes proposes a scientifically foundation to mitigate Sn whisker growth in lead-free solder joint.

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Automated monitoring system for transmission system laboratory model

2018-12 , MN Mohtar , MA Osman , Muhammad Mahyiddin Ramli

Transmission System Laboratory Model (TSLM) is a model of power transmission systems use to facilitate the studies of power system. TSLM replicates a power transmission system mimicking the real transmission line. The input and output voltage reading on the current TSLM requires a manual measurement using multimeter. The lack of real time monitoring is rectified in this work. This works propose an automated real time measurement and display system for real time voltage input and output monitoring on the TSLM. An imbedded custom made digital voltmeter and a digital display is used for real time monitoring.

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Influence of perturbations on linear and nonlinear optical properties of quantum dot

2023 , Collins Okon Edet , Emre Bahadir Al , Fatih Ungan , Etido Patrick Inyang , Norshamsuri Ali @ Hasim , Muhammad Mahyiddin Ramli , Rosdisham Endut , Syed Alwee Aljunid Syed Junid

This study focused on investigating the influence of perturbations on the linear and nonlinear optical properties of GaAs/ Ga1-xAlxAs screened modified Kratzer potential (SMKP) quantum dot (QD). The optical absorption coefficients (OACs) and refractive index changes (RICs) for GaAs/ Ga1-xAlxAs have been presented. The density matrix and iterative approaches were used to derive expressions of OACs and RICs in SMKP QD. The diagonalization method has been used to obtain energy eigenvalues and eigenfunctions of GaAs/ Ga1-xAlxAs SMKP QD under the effects of Al concentration-x, hydrostatic pressure, and temperature. Our results reveal that the Al concentration-x, hydrostatic pressure, and temperature greatly impact the position and amplitude of the resonant peaks of the linear and nonlinear OACs and RICs. Interpretations have been presented in detail. The results of this study will find applications in the optical physics of semiconductors and other systems.

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Effect of sodium ion addition on copper selenide/chitosan film towards electrical and shielding efficiency improvement

2024-06 , Nurul Najiha Mazu , Hazeem Ikhwan Mazlan , Josephine Ying Chyi Liew , Nurul Huda Osman , Muhammad Mahyiddin Ramli , Ali Reshak

The operation of electronic devices can be disrupted by unwanted electromagnetic signals, affecting its operation. Deploying electromagnetic shielding is a viable solution to minimize the impact of electromagnetic interference (EMI). The conventional methods of electromagnetic shielding use metal gaskets to safeguard sensitive electronic components, which have drawbacks of cost and weight. Hence, electromagnetic shielding polymer can be an alternative to replace metal gaskets. This work investigates the effect of sodium ion (Na) addition to copper selenide/chitosan (CuSe/Ch) film for electromagnetic shielding applications. The shielding polymers were produced using solution casting methods, while the CuSe was synthesized using the chemical coprecipitation method. Impedance spectroscopy and two port waveguide methods were used to characterize the prepared polymer's electrical properties and shielding efficiency. The results indicate that Na incorporation in the CuSe/Ch film resulted in a 47 % decrease in bulk resistivity and increased DC conductivity from 6.07 × 10-6 S/cm to 3.69 × 10˗5 S/cm. The AC conductivity of films containing Na demonstrates a similar level of conductivity at lower frequencies, followed by a sharp increase at higher frequencies, indicating a more substantial influence of Na at higher frequencies. Higher absorption shielding efficiency (SEA) and lower reflection shielding efficiency (SER) were achieved by introducing Na into the CuSe chitosan film. The Na/CuSe/Ch film shows higher total shielding efficiency at an average of 20 dB, equivalent to 99 % of the EM power shield.

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Banana stem waste as a sustainable modifier for microstructure modification of protonic ceramic fuel cell cathode

2024-06 , Ismariza Ismail , Muhammad Mahyiddin Ramli , Norizah Abd Karim , Abdullah Abdul Samat

This study investigates the feasibility of utilizing banana stem waste (BSW) as a pore former to modify the microstructure of the PCFC composite cathode. The microstructure of the La₀.₆Sr₀.₄Co₀.2Fe₀.8O3-α-Ba(Ce₀.₆Zr₀.₄)₀.₉Y₀.1O3-δ (LSCF-BCZY64) composite cathode was modified by varying the amounts of the incorporated banana stem waste. The samples underwent sintering at 1000 ˚C, and their microstructural and physical properties were analyzed using X-ray diffraction, scanning electron microscopy, and densimeter. The results indicate that the incorporation of BSW enhances the porosity of the cathode without significantly affecting its crystalline structure. As the amount of BSW increased from 10 to 40 wt.%, the porosity level increased from 7.0% to 32.7%, and the density of the samples decreased from 1.3 to 0.9 g/cm3, thereby supporting the results of the porosity analysis. Increased cathode porosity can enhance reactant accessibility to active sites, potentially resulting in improved cell performance and durability. Moreover, the utilization of BSW as a sustainable and cost-effective pore former aligns with the growing emphasis on environmentally friendly materials in energy applications.

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rGO-SWCNT hybrid for counter electrode in dye sensitized solar cell

2018-12 , M. R. Muda , Siti S. Mat Isa , Muhammad Mahyiddin Ramli

Towards platinum free counter electrode in dye sensitized solar cells, some carbon-based materials like carbon nanotubes and graphene are fully utilized due to their extraordinary properties such as high aspect ratio and conductivity. In this paper, single-walled carbon nanotubes (SWCNT), reduced graphene oxide (rGO) and hybrid structure of rGO-SWCNT spray coated counter electrodes were compared with graphite as the reference material. The morphology of these materials was analyzed with FESEM and FTIR. The DSSC performance was then measured using solar simulator. The current-voltage (I-V) characteristics show that the rGO-SWCNT counter electrode result the excellent performance with efficiency of ~1.86 %, 95.2 % better than graphite. This higher performance was attributed by the complete oxygen-functional group removal during reduction process which offers large active surface area for electro-photocatalytic activity, higher conductivity, better structure and properties compared to the individual forms.

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Single wall carbon nanotubes dispersion study of different dye molecules and chitosan

2017-09-26 , Muhammad Mahyiddin Ramli , Siti Salwa Mat Isa , Mohd. Mustafa Al Bakri Abdullah , Sohiful Anuar Zainol Murad

Carbon Nanotubes (CNTs) is known for their hydrophobicity ability. However, this ability can become the bottleneck for the application of CNTs where a highly dispersion of materials are needed. In this project, different dispersing agents were investigated namely dye molecules and chitosan. Three different dyes are studied with different concentration, including 0.05 % of chitosan. The dispersion quality is determined by examining through UV-Vis-NIR. The best dispersion quality investigated here is when the concentration of dye molecules is higher, which is around 2.5 mM.

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Remazol orange dye sensitized solar cell using graphene oxide and reduced graphene oxide working electrode

2018-12 , Norhayati Sabani , Siti S. Mat isa , Muhammad Mahyiddin Ramli , N. Rosli

Dye Sensitized Solar Cell (DSSC) is said as a potential solar device which offers easy, cheaper and greener materials and preparation process. However, the efficiency of this device is still an ultimate problem and challenge. In this paper, an organic Remazol orange dye was used as the DSSC dye sensitizer which prepared with different working electrodes. The different working electrodes consist of Titanium Dioxide (TiO2) with Graphene Oxide (GO) and TiO2 with reduced Graphene Oxide (rGO). In order to analyze the adsorption characteristics of GO and rGO, the solution was tested using Ultraviolet-Visible-Near Infrared Spectrophotometry and the surface morphology of all mixed pastes was observed under Atomic Force Microscopy and Scanning Electron Microscope. Then, the device performance was tested under illumination of solar cell simulator. From overall results, the efficiency for all tested devices was quite low from expectation. For this work, the performance of TiO2-rGO DSSC at 0.138% is 84.7% higher compared to the TiO2-GO DSSC which was 0.021%. This result was obtained when the working electrode and dye less exposed to the light during dye preparation process at 24 hours soaking time.

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Physical, mechanical and electrical properties of Chitosan/Graphene Oxide composite films for Copper Ions (Cu²+) detection

2023 , Mohammad Abdull Halim Mohd Abdull Majid , Nurul Huda Osman , Nizam Tamchek , Nurul Asyikin Ahmad Sukri , Hazeem Ikhwan Mazlan , Nurul Najiha Mazu , Adilah Idris , Josephine Ying Chyi Liew , Muhammad Mahyiddin Ramli

Copper ions are one of the metal ions that contribute significantly to water pollution and threaten the ecosystem. The threat heightened the importance of the detection and removal of the contaminants. In this study, the Chitosan/Graphene Oxide (CH/GO) composite film was synthesized at different GO ratios via a direct casting technique. The structural, mechanical and film adsorption capacities were characterized along with the electrical properties. The results revealed that adding GO into CH at a 1:5 ratio produces the highest strength and adsorption capacity. The 1:5 film was then tested for its electrical properties to see the possibility of utilizing it as part of an electrical measurement system. Various electrical parameters such as permittivity (ε′, ε″), Tanδ, bulk resistivity (Rb) and DC conductivity (σDC) were studied. Results show that the 1:5 ratio chitosan film in various Cu²+ concentrations yielded significant differences in electrical properties. The Rb and σDC gave the most significant results and can be used as Cu²+ detection parameters.