Ammonia Removal using Organic Acid Modified Activated Carbon from Landfill Leachate

This study was conducted to enhance the ability of activated carbon to remove ammonia by modifying its surface as ion exchanger. The study involved the determination of the capabilities of modified activated carbon to remove ammonia from leachate using fixed bed column. Adsorption capability was determined based on the percentage of ammonia removal. Thomas and Yoon and Nelson models were used to determine the adsorption capacity for both modified and bare activated carbon. Results indicated that modified activated carbon has higher removal ability for ammonia with the maximum removal up to 94.30% compared to bare activated carbon with maximum removal of 64.05%. Based on Yoon and Nelson model, the maximum capacity value, qo was found to be 3.063 mg/g using modified activated carbon which is higher than bare activated carbon with the value of 1.478 mg/g. It can be concluded that the modified activated carbon has a higher ion-exchange capacity for removing ammonia removal compared to bare activated carbon

The structural efficiency of tapered steel section with perforation under lateral torsional buckling behaviour

Purpose - Tapered section can resist maximum stress at a single location while the stresses are considerably lower at the rest of the member and therefore it could have higher structural efficiency compared to conventional section. It could also satisfy functional requirements while reducing weight and cost in many fields of civil construction. Perforation in the steel section also eases the integration of Mechanical and Electrical (M&E) services such as ventilation pipes and electrical cables within the structural depths of the beam. In this analysis, the structural efficiency of tapered steel section with perforation under lateral-torsional buckling behaviour is investigated

Effect of Triangular Web Profile on the Shear Behaviour of Steel I-Beam

Shear buckling occurred in the instability modes of steel beams when it slender. This paper developsa three-dimensional finite element model using LUSAS 14.3 to study on the effect ofthe triangularsteel beamwebprofile (T WP) inshearbuckling behaviourof differentthicknesscompared RI to that of thenormalflatbeam (FW).All specimens are cantilever beam which are fixedat one ends. The flange is constant with variable webthickness. Eigenvalue buckling analysis was used in analysing the buckling load of the flat plate model andtriangular web profile (TRIWP). Results showed that the web thickness gave a significant impact on the shearbuckling of the TRIWP. In addition, the corrugation thickness of web was also effective in increasing the shearbuckling capacity of the profile

Finite Element Analysis of Lateral Torsional Buckling Behaviour of Tapered Steel Section with Perforation

This paper presents the finite element analysis of lateral torsional buckling of tapered steel section with perforation. The numerical analysis consists of four main models with a ratio of tapering 0.3 for 3.5m and 5.5m span and ratio of tapering 0.5 for 3.5m and 5.5m span. This study has 94 models in order to investigate the effect of thickness and the openings on the buckling moment. LUSAS software was used to carry out the finite element analysis to study the effect of web opening on the buckling behavior which had five variables such as thickness of web and flange, opening size, ratio of tapering, and opening arrangement. The opening size from 0.2D to 0.4D is recommended because buckling moment capacity difference only around 2% was observed for the opening size exceeds 0.4D. Ratio of tapering 0.3 and ratio of tapering 0.5 was observed increase with the web opening area. The deformation patterns are almost similar for the different sizes of web openings and ratio of tapering. Based on the finite element results, tapered steel section without perforation has higher buckling moment capacity. The comparison of the buckling moment between non-perforated sections with the recommended section is around 2% to 4%

Finite Element Analysis of Lateral Torsional Buckling Behaviour of Tapered Steel Section with Perforation

This paper presents the finite element analysis of lateral torsional buckling of tapered steel section with perforation. The numerical analysis consists of four main models with a ratio of tapering 0.3 for 3.5m and 5.5m span and ratio of tapering 0.5 for 3.5m and 5.5m span. This study has 94 models in order to investigate the effect of thickness and the openings on the buckling moment. LUSAS software was used to carry out the finite element analysis to study the effect of web opening on the buckling behavior which had five variables such as thickness of web and flange, opening size, ratio of tapering, and opening arrangement. The opening size from 0.2D to 0.4D is recommended because buckling moment capacity difference only around 2% was observed for the opening size exceeds 0.4D. Ratio of tapering 0.3 and ratio of tapering 0.5 was observed increase with the web opening area. The deformation patterns are almost similar for the different sizes of web openings and ratio of tapering. Based on the finite element results, tapered steel section without perforation has higher buckling moment capacity. The comparison of the buckling moment between non-perforated sections with the recommended section is around 2% to 4%

The influence of palm oil fuel ash and metakaolin on the strength of concrete and crack resistance of reinforced concrete beam: a review

Purpose The purpose of this study is to know the influence of palm oil fuel ash and metakaolin on the strength of concrete and crack resistance of reinforced concrete beam. An ordinary portland cement has been used in the concretes production where it is an important material to be considered due to its nature that reacts with every substance present. During the cement production, a significant amount of carbon dioxide is emitted from the clinker in rotary kiln and lot of energy is required in the production processes. Such an event can be prevented by replacing the part of cement with metakaolin (MK) and palm oil fuel ash (POFA). Aside from being a cementitious alternative, the materials can also contribute to a greener environment and more sustainable building, as POFA is available in Malaysia and may be used to substitute cement and minimize pollution. Design/methodology/approach This study assesses the effect of MK and POFA on the concrete in terms of compressive strength and cracks pattern of the reinforced concrete beam based on the relevant previous studies. Findings From this study, the compressive strength of concrete containing MK and POFA was higher than the control mix with the percentage of improvement in the range of 0.8%–78.2% for MK and 0.5%–14%, respectively. The optimum content of MK and POFA is between the range of 10% and 15% and 10% and 20%, respectively, to achieve high strength of concrete. Other than that, the inclusion of MK to the concrete mix improves the strength of reinforced concrete beams and reduces cracks on the surface of reinforced concrete beams, whereas the inclusion of POFA to the concrete mix increases the cracks on reinforced concrete beams. The cracks appeared within the flexure zone of every beam containing the MK and POF