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Sylhet, Bangladesh

Leading University or LU is a private university of Bangladesh. It was established in 2001 by the Private University Act 1992. The outreach campus of LU is located in Surma & Rangmahal Tower, Sylhet. Sylhet. Wikipedia.

Rabbi M.F.,Leading University
2013 International Conference on Electrical Information and Communication Technology, EICT 2013 | Year: 2013

MIMO-OFDMA has become an efficient method characterizing diversity to multi-user transmission over doubly selective fading channels with high spectral efficiency. In this paper we develop a Basis Expansion Model (BEM) based MIMO-OFDMA system and we analyze the channel capacity for the system. It is shown that, by using BEM based channel approximation for MIMO-OFDMA system we can achieve diversity without any space-time coding. Specifically, BEM based system inherently exploits the receive diversity and maximizes channel capacity similar to existing diversity technique like Maximal Ratio Combining (MRC). © 2014 IEEE. Source

Bari S.H.,Leading University | Rahman M.T.U.,Shahjalal University of Science and Technology | Rahman M.T.U.,Bangladesh Institute of Technology | Hoque M.A.,Shahjalal University of Science and Technology | Hussain M.M.,Shahjalal University of Science and Technology
Atmospheric Research | Year: 2016

The aim of the present study was to investigate 50 years (1964-2013) of seasonal and annual rainfall trends and their fluctuation over time in northern Bangladesh. After testing the autocorrelation, non-parametric Mann-Kendall test along with Sen Slope estimator was used to examine rainfall trends and their magnitudes. The sequential Mann-Kendall test was used to identify any fluctuations in the trends over time and to detect the possible points of change in the rainfall series. We found that pre-monsoon and post-monsoon rainfall is increasing in most of the rainfall stations. The only decrement in pre-monsoon rainfall was found for Ishurdi (1.28 mm/year). However, the sequential Mann-Kendall test detected decreasing pre-monsoon rainfall trend after early the 1990s. Monsoon rainfall showed a decreasing trend in the majority of the area studied. The maximum decrement in monsoon rainfall was found for Sylhet station (8.10 mm/year) and minimum in Mymensingh (1.53 mm/year). An upward monsoon rainfall trend was found for Rangpur (2.02 mm/year). Annual rainfall followed the monsoon rainfall trend. However, all of the positive and negative trends were found statistically non-significant at 95% confidence limit with the only exception for monsoon and annual rainfall at Rajshahi station. Rajshahi station was the only region where the monsoon and annual rainfall has a significant negative trend at 95% confidence limit. The sequential Mann-Kendall test detected several non-significant points of change for seasonal and annual rainfall at most of the stations. Periodic fluctuations were also detected. We observed that there were decreasing seasonal rainfall trend after early the 1990s for the majority of the stations. © 2016 Elsevier B.V. Source

Haque M.A.,Leading University
Chemical Product and Process Modeling | Year: 2016

In this research, landfill solid waste was solidified as cement-waste matrix to protect the environment from excessive intrusive contaminants like Fe, Cu and Ni and minimize the waste load. Within this context, ingredients of cement-waste mortar were characterized to determine their physical properties. Long-term feasibility study was conducted to examine the metal contents stabilization by employing the standard mass transfer-leaching test. The cumulative leaching concentration of Fe, Cu and Ni were found to be 1.29 mg/l, 0.18 mg/l and 0.63 mg/l respectively up to 180 days static leaching test period that satisfied the surface water quality standard. Mechanical strength test was also conducted to characterize the solidification technique. Five well-established non-linear mathematical Models were conducted to evaluate the mechanisms of Fe, Cu and Ni migration. Goodness of fit statistical parameter analysis and visual examination indicated that polynomial equation Model is better for explaining the experimentally generated data. Moreover, parameter of polynomial equation was extended from five to nine for examining the best calibration profile to the observations. In context of slope-intercept and visual observation analysis resulted that polynomial equation based Model bearing five parameters with 0.5 power interval of each parameter describes the leaching phenomena quite similar with the experimental observations whereas goodness of fit parameters and information criterion shows reverse. It was found that the studied immobilized landfill waste mortar have acceptable mechanical performance that confirms to be used as construction material. © 2016 by De Gruyter. Source

Aminul M.,Shahjalal University of Science and Technology | Aminul M.,Leading University | Hoque M.A.,Shahjalal University of Science and Technology
Journal of Solid Waste Technology and Management | Year: 2016

To reduce the solid waste load and minimize the contaminant like heavy metals migration to the surrounding environment at landfill sites, solid waste was incorporated in paving mortar block by following the solidification/stabilization treatment technique. Two well established nonlinear methods such as diffusion equation derived for a plane source model and empirical method employing a polynomial equation were used for the better understanding of the heavy metals like Fe, Cu and Ni migration phenomena. Experimental data representing the releasing heavy metal from paving block were used for non-linear models for calibration. The accuracy of the models was statistically evaluated followed by models parameter estimation. The study showed that polynomial equation is better than diffusion equation for explaining experimental observation. Moreover, in this current study, polynomial equation was extended further three different longer terms namely Model 1, Model 2 and Model 3 respectively using the least squares procedure for examining the best fit profile with the observations. All the three extended models were justified against statistical point of view. Calibration results shows that the polynomial equation with 2.5 degree (Model 2) explains better leaching behavior of Fe and Cu, whereas the Model 3 having third degree polynomial equation is found to be perfect for representing Ni release pattern from the solid waste block. Apart from the calibration approach, the accuracy of Model 2 and Model 3 were validated with respective experimental observation followed by the model parameters estimation with 95% confidence interval. Source

Bari S.H.,Leading University | Hussain M.M.,Bangladesh University of Engineering and Technology | Husna N.-E.-A.,Bangladesh University of Engineering and Technology
Theoretical and Applied Climatology | Year: 2016

This paper aimed at the analysis of rainfall seasonality and variability for the northern part of South-Asian country, Bangladesh. The coefficient of variability was used to determine the variability of rainfall. While rainfall seasonality index (SI ) and mean individual seasonality index ((Formula presented.)) were used to identify seasonal contrast. We also applied Mann-Kendall trend test and sequential Mann-Kendall test to determine the trend in seasonality. The lowest variability was found for monsoon among the four seasons whereas winter has the highest variability. Observed variability has a decreasing tendency from the northwest region towards the northeast region. The mean individual seasonality index (0.815378 to 0.977228) indicates that rainfall in Bangladesh is “markedly seasonal with a long dry season.” It was found that the length of the dry period is lower at the northeastern part of northern Bangladesh. Trend analysis results show no significant change in the seasonality of rainfall in this region. Regression analysis of (Formula presented.) and SI, and longitude and mean individual seasonality index show a significant linear correlation for this area. © 2016 Springer-Verlag Wien Source

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