Md. Ruhul Amin

Dr. Md. Ruhul Amin

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Research Focus & Metrics

Academic Career Length

35Years (1992-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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21 May 2021 in IEEE Sensors Journal
Verified
Journal Article
Closed access
MHMd. Farhad Hassan
Md. Farhad Hassan
RSRakibul Hasan Sagor
Rakibul Hasan Sagor
MAMd. Ruhul Amin
Md. Ruhul Amin
MIMohammad Rakibul Islam
Mohammad Rakibul Islam
SAShah Alam
Shah Alam
To satisfy the requirements of label-free detection, low cost, fast response of a lab-on-chip biosensor, a nanodot enhanced metal-insulator-metal (MIM) waveguide based refractive index sensor coupled with three rectangular cavities, is proposed in this work. Numerical investigation of the transmission spectra, employing the finite element method (FEM), exhibits a linear correspondence with the refractive index, which is used to sense the unknown materials. Imposing a sequential optimization of the structural parameters and enhancing light-matter interaction by loading nanodots at the high E-field confined areas, desired sensitivity (S) and figure of merit (FOM) are upgraded to 7564 nmRIU-1 and 120, respectively. Additionally, the maximum temperature sensitivity of 3.40 nm°C-1 operating from 20°C to 70°C is also recorded for ploydimethylsiloxane (PDMS) sensing media. Prior to the selective detection of Na+, K+, and glucose concentration in the human blood, a sample preparation model combining purification, molecular separation, and concentration enhancement is proposed. Furthermore, a refractive index model is developed that exposes a maximum shift of 0.83 nm, 1.23 nm, and 8.72 nm of the transmittance peak for the concentration variation of 1 mgdL-1 in Na+, K+, and glucose solution easily differentiable by the modern spectrometer. With such excellent performance metrics, compact size, and simple to use features, the proposed sensor is expected to bring a notable solution in the point-of-care detection.

6 March 2019 in Energies
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Journal Article
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Ahmed Al MansurAhmed Al Mansur
Ahmed Al Mansur
MAMd. Ruhul Amin
Md. Ruhul Amin
KIKazi Khairul Islam
Kazi Khairul Islam
The mismatch in current-voltage (I-V) characteristics of photovoltaic (PV) modules causes significant power loss in a large PV array, which is known as mismatch power loss (MML). The PV array output power generation can be improved by minimizing MML using different techniques. This paper investigates the performance of different module arrangement techniques to minimize MML both for long series string (LSS) and long parallel branch (LPB) in series-parallel (SP) array configurations at uniform irradiance condition. To investigate the significance of MML LSS-SP configuration with dimensions: 1 × 40, 2 × 20, 4 × 10, 5 × 8 and LPB-SP configuration with dimensions: 40 × 1, 20 × 2, 10 × 4, 8 × 5 were used. A comparative analysis is made to find the effectiveness of MML reduction techniques on PV arrays with three different power ratings. Simulation results show that the PV modules arrangement obtained by the genetic algorithm (GA) and current based arrangement (Im) performed better than the arrangements obtained by all other techniques in terms of PV array output power and MML minimization. The performance of the proposed technique was analyzed for both LSS-SP and LPB-SP array configurations in 400 W, 3400 W, and 9880 W arrays. To substantiate the simulation results experiment was performed using a 400 W PV array in outdoor weather condition and obtained similar results. It was also observed that the percentage of recoverable energy (%RE) obtained by arranging the modules using the GA method was higher than Im based method for both LSS-SP and LPB-SP array configurations. A maximum %RE of 4.159 % was recorded for a 5 × 8 LSS-SP array configuration by applying the GA based MML reduction method.

1 March 1996 in Physical Review E
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Journal Article
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KOK. Ogura
K. Ogura
MAMd. Ruhul Amin
Md. Ruhul Amin
KMK. Minami
K. Minami
XZX. D. Zheng
X. D. Zheng
YSY. Suzuki
Y. Suzuki
VGV. L. Granatstein
V. L. Granatstein
A slow-wave electron cyclotron maser consisting of an oversized corrugated waveguide and an axially injected electron beam has been demonstrated experimentally. At resonance, the output rf power is strongly enhanced. Maximum output power of 200 kW with an electronic efficiency of 4% at 19.5 GHz is obtained for an electron beam with voltage of 35 kV and current of 150 A. The oscillation is observed to be a periodic TM01 mode. The enhancement of microwave radiation is estimated to be caused by the combined resonance of Cherenkov interactions and an anomalous Doppler shifted electron cyclotron interaction. © 1996 The American Physical Society.

5 March 2021 in Molecular Physics
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Journal Article
Closed access
SSSharmin Sultana
Sharmin Sultana
MRMohammad Majibur Rahman
Mohammad Majibur Rahman
MAMd. Ruhul Amin
Md. Ruhul Amin
SRShahed Rana
Shahed Rana
MHMd. Anamul Hoque
Md. Anamul Hoque
MAM. Alfakeer
M. Alfakeer
The TTAB surfactant micelle formation in presence of PVA was detected by the evaluation of CMC from the conductivity plot against the concentration of surfactant. Micellar parameters, such as critical micelle concentration (CMC), the extent of counter ion binding (β), and thermodynamic properties (ΔG0m, ΔH0m and ΔS0m) of PVA + TTAB systems have been estimated. Values of CMC of the PVA + TTAB mixed system was achieved and found to reduce with enhancing PVA concentrations which designate the survival of interactions between TTAB and PVA. The values of CMC were found to undergo an increase in the mixed solvents in comparison to the values obtained in aqueous media, which might be attributed to the reduction of the dielectric constant as well as water cohesive energy. The values of free energy of micellisation ( ΔGmo) are negative for the PVA + TTAB system, suggesting a spontaneous aggregation phenomenon. The negative values of ΔGmo in H2O and 9% (w/w) mixed solvents follow the order: ΔGmo (H2O) > ΔGmo (water + AN) > ΔGmo (water + DO) > ΔGmo (water + DMF). The thermodynamic properties of transfer were also estimated for the move of PVA+ TTAB mixed system from water to aqua-organic mixture of solvents. GRAPHICAL ABSTRACT

1 April 1995 in IEEE Transactions on Microwave Theory and Techniques
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Journal Article
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MAMd. Ruhul Amin
Md. Ruhul Amin
KOK. Ogura
K. Ogura
HKH. Kitamura
H. Kitamura
KMK. Minami
K. Minami
TWT. Watanabe
T. Watanabe
VGV.L. Granatstein
V.L. Granatstein

1 January 2012 in Applied Mathematics and Computation
Verified
Journal Article
Closed access
Md. Alal HosenMd. Alal Hosen
Md. Alal Hosen
MRM. Saifur Rahman
M. Saifur Rahman
MAM. Shamsul Alam
M. Shamsul Alam
MAMd. Ruhul Amin
Md. Ruhul Amin