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I. K. Erabee,A. Ahsan,Bipin Jose,M. Manniruzzaman A. Aziz,A. W. M. Ng,S. Idrus,N. N. N. Daud 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.4
Activated Carbon (AC) is an adsorbent having high surface area which makes the process of removing heavy metals fromwastewater (such as landfill leachate) very effective. This study explored the utilization of three methods of modification of ACproduced from coconut shell by treating it with nitric acid (HNO3), potassium permanganate (KMnO4) and heating at 600oC toimprove the adsorption capacity. The AC can remove multi-pollutants in the filtration process which was used to treat landfillleachate. The water quality parameters such as pH, TSS, Ammonia-Nitrogen and a few heavy metals were considered in the presentstudy. Results showed that the removal of these parameters was proportional with the increase of contact time and the bed depth ofAC. The isotherm analysis of the adsorption of modified AC showed the best Removal Efficiency (RE) can be achieved when ACtreated with KMnO4 for NH3-N, zinc, TSS and sulphide. The morphology of the AC was studied through Scanning ElectronMicroscopy (SEM), Energy Dispersive X-ray spectroscopy (EDX) pattern analysis and Fourier Transform Infrared (FTIR) analysis. It was found that various types of oxygen functional groups were introduced onto the surface of coconut shell derived AC throughoxidation using HNO3. FTIR was used to characterize the surface oxygen functional groups. The surface functional groups such asN-H and C-H stretching played a significant role in heavy metals adsorption. Hence, it can be concluded that the hybrid technique byusing electrolysis process with AC adsorption be an effective way to remove the suspended solids and heavy metals from landfillleachate and thus able to reduce environmental pollution.
Full Dimension MIMO (FD-MIMO): Demonstrating Commercial Feasibility
Xu, Gary,Yang Li,Jin Yuan,Monroe, Robert,Rajagopal, Sridhar,Ramakrishna, Sudhir,Young Han Nam,Ji-Yun Seol,Jaeweon Kim,Gul, Malik Muhammad Usman,Aziz, Ahsan,Jianzhong Zhang IEEE 2017 IEEE journal on selected areas in communications Vol.35 No.8
<P>Massive multi-input multi-output (MIMO) is shown to significantly increase spectral efficiency by exploiting a large number of antennas to support high-order multiuser MIMO. In 3GPP Release-13, a full-dimension MIMO (FD-MIMO) technology was introduced to address practical aspects for massive MIMO in cellular systems; extensive simulations show 2-4 times capacity gain compared with current LTE systems. FD-MIMO has been identified as one of the key 5G technologies and is being continuously improved in 3GPP new radio standards. However, several practical challenges such as interference mitigation among MIMO streams for a large number of users with limited channel feedback, hardware limitations, such as calibration errors that limit the precoding capabilities need to be addressed carefully. A proof of concept (PoC) base-station and user equipment (UE) prototype has been designed to validate the potential of FD-MIMO technology and demonstrate commercial implementation feasibility. In this paper, we present theory and architecture behind an FD-MIMO prototype and share the field test results with LTE-based UEs in a multi-user MIMO setup. We also analyze the impact of transmitter and receiver calibration errors on the performance of the FD-MIMO system.</P>