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You searched for publisher:("University of Malaya"). Showing records 1 – 3 of 3 total matches.

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1. Asman, Saliza. Adsorption behaviour of molecularly imprinted-beta-cyclodextrin polymers prepared by reversible additionfragmentation chain transfer (RAFT) polymerization for selective recognition of benzylparaben.

Degree: PhD, Department of chemistry, faculty of science, 2015, University of Malaya

Molecularly imprinted polymers (MIPs) are kinds of powerful materials with promising selective molecule recognition abilities. However, the conventional MIPs have relatively low binding capacity. In order to improve this characteristic of MIPs, the modification monomer based on β-cyclodextrin (β-CD) and the essential of reversible additionfragmentation chain transfer (RAFT) polymerization process were studied to generate potential MIPs. The study focuses on the characterization and adsorption behaviour of MIPs for selective recognition of benzylparaben (BzP) analyte. The potential of β-CD in MIP was investigated by synthesizing a reversible addition-fragmentation chain transfer molecularly imprinted methacrylic acid functionalized β-cyclodextrin polymer; RAFTMIP( MAA-β-CD) based on methacrylic acid functionalized β-cyclodextrin (MAA-β-CD) monomer, which was then compared to a reversible addition-fragmentation chain transfer molecularly imprinted methacrylic acid polymer; RAFT-MIP(MAA) synthesized without β-CD. Both MIPs were prepared by the RAFT polymerization process in bulk polymerization method. The resulting MIPs were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Field Scanning Electron Microscope (FESEM) and Brunauer-Emmett-Teller (BET) analysis. The batch adsorption study that includes studying of the pH, kinetic, isotherm and thermodynamic was conducted. The essential of RAFT polymerization on MIP was studied by comparing RAFT-MIP(MAA-β-CD) with the molecularly imprinted methacrylic acid functionalized β-cyclodextrin polymer; MIP(MAA-β-CD) was synthesized without RAFT agent, and characterized by using FTIR, elemental analysis, FESEM and BET. The binding experiments demonstrated that the RAFT-MIP(MAA-β-CD) has a higher binding capacity and higher accessibility compared to RAFT-MIP(MAA) and MIP(MAA-β-CD) for selective of BzP, respectively. The β-CD and RAFT polymerization process improved the MIP’s physical properties and iv enhanced its recognition capacity, thus affecting the adsorption behaviour of RAFTMIP( MAA-β-CD). The effects of RAFT polymerization process were also investigated by a reversible addition-fragmentation transfer molecularly imprinted hydroxylethyl methacrylate functionalized β-cyclodextrin polymer; RAFT-MIP(HEMA-β-CD). The RAFT-MIP(HEMA-β-CD) was synthesized based on the hydroxylethyl-methacrylate functionalized β-cyclodextrin (HEMA-β-CD) monomer and was prepared by the RAFT polymerization process in bulk polymerization method. The molecularly imprinted hydroxylethyl-methacrylate functionalized β-cyclodextrin polymer; MIP(HEMA-β-CD) without a RAFT agent was synthesized as comparison. A similar study to RAFTMIP( MAA-β-CD) had also been carried out for RAFT-MIP(HEMA-β-CD).The effects of RAFT polymerization on RAFT-MIP(HEMA-β-CD) were contrasted with RAFTMIP( MAA-β-CD). The compact and non-porous morphology of RAFT-MIP(HEMA-β- CD) reduces its binding capacity performance compared to MIP(HEMA-β-CD). Thus, this directly affected the RAFT-MIP(HEMA-β-CD) adsorption behaviour…

Subjects/Keywords: QD Chemistry

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Asman, S. (2015). Adsorption behaviour of molecularly imprinted-beta-cyclodextrin polymers prepared by reversible additionfragmentation chain transfer (RAFT) polymerization for selective recognition of benzylparaben. (Doctoral Dissertation). University of Malaya. Retrieved from http://eprints.uthm.edu.my/7841/

Chicago Manual of Style (16th Edition):

Asman, Saliza. “Adsorption behaviour of molecularly imprinted-beta-cyclodextrin polymers prepared by reversible additionfragmentation chain transfer (RAFT) polymerization for selective recognition of benzylparaben.” 2015. Doctoral Dissertation, University of Malaya. Accessed August 08, 2020. http://eprints.uthm.edu.my/7841/.

MLA Handbook (7th Edition):

Asman, Saliza. “Adsorption behaviour of molecularly imprinted-beta-cyclodextrin polymers prepared by reversible additionfragmentation chain transfer (RAFT) polymerization for selective recognition of benzylparaben.” 2015. Web. 08 Aug 2020.

Vancouver:

Asman S. Adsorption behaviour of molecularly imprinted-beta-cyclodextrin polymers prepared by reversible additionfragmentation chain transfer (RAFT) polymerization for selective recognition of benzylparaben. [Internet] [Doctoral dissertation]. University of Malaya; 2015. [cited 2020 Aug 08]. Available from: http://eprints.uthm.edu.my/7841/.

Council of Science Editors:

Asman S. Adsorption behaviour of molecularly imprinted-beta-cyclodextrin polymers prepared by reversible additionfragmentation chain transfer (RAFT) polymerization for selective recognition of benzylparaben. [Doctoral Dissertation]. University of Malaya; 2015. Available from: http://eprints.uthm.edu.my/7841/

2. Syed Abu Bakar, Sharifah Adzila. Development of metal dopedhydroxyapatite for bone implant application.

Degree: PhD, Faculty of Engineering, 2014, University of Malaya

Hydroxyapatite (HA) powder with nanosize particles was successfully synthesized by mechanochemical method in a dry state at 170 rpm, 270 rpm and 370 rprn rotation speeds in 15 hours respectively. The research revealed that among the three rotation speeds employed, 370 rpm synthesized powder showed better characteristics as determined by X-ray Diffraction (XRD), Fourier Transform Infra Red (FTIR) and Field Emission Scanning Electron Microscopy (FESEM) analyses. Similarly, the sintering properties of these powders showed maximum densification, Vickers hardness and fracture toughness with values of 96.8%, 5.29 GPa and 1.49 M~a.m"~re,s pectively were obtained when sintered at 1250°C. The rotation speed of 370 rpm was subsequently employed to prepare the Na-doped HA and Mg-doped HA. The study found that the decrease of the XRD peak intensities and the decrease of FTIR adsorption bands corresponded to HA phase were related to the increase of Na' and M~io~ns' concentration. The substitution of the ions also changed the lattice parameters, the unit cell volumes and the crystal size of HA. Sintering and ion doping also influenced the stability of the HA phase where the decomposition occurred between 1000°C-1300°C sintering temperature and with increasing Na' and M~io~ns c+on centration in the HA lattice. This has led to the increase of HA phase decomposition due to Na+ and Mg2' replacing the ~a'+ sites. Increasing sintering temperature has led to the decrease of relative densities, Vickers hardness and fracture toughness of undoped HA, Na-doped HA and Mg-doped HA. The 1% Na-doped HA was found to have maximum densification and Vickers hardness of 99.2% and 5.47 GPa, respectively when sintered at 1250°C. The 1% Na-doped HA also exhibited a high fracrure toughness of 1.84 ~~a-rnw'h"e n sintered at 1300°C. Na' doping was more effective in enhancing the mechanical perforn~ance of HA compared to ~g'+ doping. Na-doped HA and Mgdoped HA increased the biocompatibility of HA as the maximum growth of calcium phosphate was significantly shown in the 7% Na-doped HA after 7 days of exposure. However. osteoblast cell culture showed that increasing Na' and M~"co ncentration to 7% - 9% molar concentration induced the formation of dead cells near to the samples. The study found that Na' and M~"in higher molar concentration particularly 9% doping was detrimental as it affected the mechanical properties as well as the biocompatibility of the hydroxyapatite ceramic.

Subjects/Keywords: RD Surgery

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Syed Abu Bakar, S. A. (2014). Development of metal dopedhydroxyapatite for bone implant application. (Doctoral Dissertation). University of Malaya. Retrieved from http://eprints.uthm.edu.my/7902/

Chicago Manual of Style (16th Edition):

Syed Abu Bakar, Sharifah Adzila. “Development of metal dopedhydroxyapatite for bone implant application.” 2014. Doctoral Dissertation, University of Malaya. Accessed August 08, 2020. http://eprints.uthm.edu.my/7902/.

MLA Handbook (7th Edition):

Syed Abu Bakar, Sharifah Adzila. “Development of metal dopedhydroxyapatite for bone implant application.” 2014. Web. 08 Aug 2020.

Vancouver:

Syed Abu Bakar SA. Development of metal dopedhydroxyapatite for bone implant application. [Internet] [Doctoral dissertation]. University of Malaya; 2014. [cited 2020 Aug 08]. Available from: http://eprints.uthm.edu.my/7902/.

Council of Science Editors:

Syed Abu Bakar SA. Development of metal dopedhydroxyapatite for bone implant application. [Doctoral Dissertation]. University of Malaya; 2014. Available from: http://eprints.uthm.edu.my/7902/

3. Chulan , Megat Azahari. Design and implementation a single phase bi-directional DC-DC converter.

Degree: Faculty of Engineering, 2007, University of Malaya

High frequency bi-directional dc-dc converters are currently widely used in a diversity of power electronic applications. In order to interconnect the various DC sources at different voltage levels, one requires bi-directional DC/DC converters capable of converting the voltage from one level to another whilst also able to control the direction of power flow through the converter. The use of a bi-directional dc-dc converter in motor drives devoted to Electric Vehicles (EV) allows a suitable control of both motoring and regenerative braking operations. A bi-directional arrangement of the converter is needed for the reversal of the power flow, in order to recover the vehicle kinetic energy in the battery by means of motor drive regenerative braking operations. A full-bridge, single phase inverter and converter that uses Pulse Width Modulation (PWM) to control the power switches was constructed. The concept of PWM with different strategies for converter is described. The PWM was produced with a simple circuit and using several chips and devices that are easily available in the market. The PWM signals are simulated using OrCAD simulation tools. MOSFET IRF520 is used for high frequency switching in both sides inverter and converter. An isolation transformer (ratio 1:1) is used between inverter outputs and input of bi-directional of DC-DC converter. The proposed converter has the advantages of high switching frequency, high efficiency, simple circuit, low cost and bi-directional power flow. The detailed design and operating principles are analyzed and described. The simulation and experimental waveforms for the proposed converter are shown to verify its feasibility.

Subjects/Keywords: TK Electrical engineering. Electronics Nuclear engineering

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Chulan , M. A. (2007). Design and implementation a single phase bi-directional DC-DC converter. (Masters Thesis). University of Malaya. Retrieved from http://eprints.uthm.edu.my/689/

Chicago Manual of Style (16th Edition):

Chulan , Megat Azahari. “Design and implementation a single phase bi-directional DC-DC converter.” 2007. Masters Thesis, University of Malaya. Accessed August 08, 2020. http://eprints.uthm.edu.my/689/.

MLA Handbook (7th Edition):

Chulan , Megat Azahari. “Design and implementation a single phase bi-directional DC-DC converter.” 2007. Web. 08 Aug 2020.

Vancouver:

Chulan MA. Design and implementation a single phase bi-directional DC-DC converter. [Internet] [Masters thesis]. University of Malaya; 2007. [cited 2020 Aug 08]. Available from: http://eprints.uthm.edu.my/689/.

Council of Science Editors:

Chulan MA. Design and implementation a single phase bi-directional DC-DC converter. [Masters Thesis]. University of Malaya; 2007. Available from: http://eprints.uthm.edu.my/689/

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