Papers by Noor Adila Aluwi Shakir
Optimization of spinning conditions plays a key role in the development of high performance asymm... more Optimization of spinning conditions plays a key role in the development of high performance asymmetric hollow fiber membranes. However, from previous studies, in solving these spinning condition optimization problems, they were handled mostly by using an experimentation that varied one of the independent spinning conditions and fixed the others. The common problem is the preparation of hollow fiber membranes that cannot be performed effectively due to inappropriate settings of the spinning conditions. Moreover, complexities in the spinning process have increased where the interaction effects between the spinning conditions with the presence of multiple objectives also affect the optimal spinning conditions. This is one of the main reasons why very little work has been carried out to vary spinning conditions simultaneously. Hence, in order to address these issues, this study focused on a non-dominated sorting genetic algorithm-II (NSGA-II) methodology to optimize the spinning conditi...
... pretreatment, diamond coating, surface roughness, chemical etching. Subjects: Q Science &... more ... pretreatment, diamond coating, surface roughness, chemical etching. Subjects: Q Science > Q Science (General). Kulliyyahs/Centres/Divisions/Institutes: Kulliyyah of Engineering > Department of Manufacturing and Materials Engineering. Depositing User: Dr Mohamed Konneh. ...
This study attempts to optimize the spinning process used for fabricating hollow fiber membranes ... more This study attempts to optimize the spinning process used for fabricating hollow fiber membranes using the response surface methodology (RSM). The spinning factors considered for the experimental design are the dope extrusion rate (DER), air gap length (AGL), coagulation bath temperature (CBT), bore fluid ratio (BFR), and post-treatment time (PT) whilst the response investigated is rejection. The optimal spinning conditions promising the high rejection performance of polyethersulfone (PES) ultrafiltration hollow fiber membranes for oily wastewater treatment are at the dope extrusion rate of 2.13 cm 3 /min, air gap length of 0 cm, coagulation bath temperature of 30 ˝ C, and bore fluid ratio (NMP/H 2 O) of 0.01/99.99 wt %. This study will ultimately enable the membrane fabricators to produce high-performance membranes that contribute towards the availability of a more sustainable water supply system.
Countries generally experience continuous growth in population, living standards and industrial d... more Countries generally experience continuous growth in population, living standards and industrial development. These have resulted in an increase in water consumption. Any harmful discharge into the water supply system needs to be treated. Membrane separation technology is an effective technology for wastewater or water treatment. This study attempts to model the spinning process used for fabricating the hollow fiber membrane using the design of experiment methodology. Spinning factors investigated are the dope extrusion rate, air gap length, coagulation bath temperature, bore fluid ratio and post-treatment time whilst the response investigated is rejection. Among the common significant process factors identified are bore fluid ratio, dope extrusion rate, coagulation bath temperature and air gap length. Several 2-factor interactions are also significant. The regression model obtained can be subsequently used for determining the optimum spinning conditions. This study will ultimately enable the membrane fabricators to produce high-performance membranes that contribute towards the availability of a sustainable water supply system.
kajian ini, kami telah membangunkan satu model untuk membantu memperuntukkan bilangan pekerja sok... more kajian ini, kami telah membangunkan satu model untuk membantu memperuntukkan bilangan pekerja sokongan tetap, kontrak dan sementara di dalam sektor kerajaan. Berbanding kaedah peruntukan pekerja yang sedia ada, kajian ini menggunakan kaedah pengaturcaraan linear untuk menentukan jumlah optimum pekerja yang perlu diambil. Kajian menunjukkan bahawa kos untuk mengupah pekerja kontrak dan sementara berbanding mengambil pekerja tetap adalah hampir sama. Namun, dalam kajian sebelumnya, tiada pendekatan khusus dibuat untuk menentukan kuota pelantikan pekerja dan sistem yang digunakan sekarang hanya bergantung kepada kekosongan sesesuatu jawatan. Oleh kerana itu, ramai pekerja sementara dan kontrak gagal diserap ke status tetap kerana terpaksa bersaing dengan pengambilan pekerja secara tetap. Kajian juga turut mengambil kira pekerja kontrak yang diserap ke status tetap apabila berkhidmat melebihi tempoh masa tertentu.
Pretreatment on tungsten carbide (WC-Co) surface is critical for obtaining perfectly adherent dia... more Pretreatment on tungsten carbide (WC-Co) surface is critical for obtaining perfectly adherent diamond coatings by chemical vapor deposition (CVD). The carbide surface should have high roughness to facilitate diamond nucleation and adhesion. The presence of cobalt-common binder for tungsten carbide-on the surface to be coated should be made minimum since it has negative influence on the diamond deposition process. In this study, surface pretreatment on tungsten carbide using sulfuric acid was evaluated in terms of the resulted cobalt removal and the surface roughening. The variables included were acid concentration, reaction temperature, and reaction time. The resulted surface roughness was 29% higher than initial, averaged at 1.07 µm. The acid pretreatment was also found effective in eliminating surface cobalt.
In this paper, simulation model was developed for forecasting of permanent, contract and temporar... more In this paper, simulation model was developed for forecasting of permanent, contract and temporary supporting workers in government sector. The objective of the study is to determine the number of workers that should be hired by comparing to current allocations of workers intake methods by applying the simulation approach. Based on previous studies, show that the costs to hire contract and temporary workers compared to bring on full-time workers are quite same or just slightly less. However, in previous research, there is no particular way to determine the quota of workers' appointment and the current system fully depends on the available vacancies to hire worker. Due to this scenario, a lot of temporary and contract worker missed to be absorbed into permanent status due to competition with the future permanent worker who hired due to availability. By considering about the status of contract workers that supposed to be converted into permanent status after they are working more than certain period, the proposed simulation model has successfully provided a quota to allocate optimal numbers of each categories of worker in order to reduce the permanent worker intake by adding the number of contract and temporary worker and the same time increase the number of workers who converted to permanent status.
Countries generally experience continuous growth in population, living standards and industrial d... more Countries generally experience continuous growth in population, living standards and industrial development. These have resulted in an increase in water consumption. Any harmful discharge into the water supply system needs to be treated. Membrane separation technology is an effective technology for wastewater or water treatment. This study attempts to model the spinning process used for fabricating the hollow fiber membrane using the design of experiment methodology. Spinning factors investigated are the dope extrusion rate, air gap length, coagulation bath temperature, bore fluid ratio and post-treatment time whilst the response investigated is rejection. Among the common significant process factors identified are bore fluid ratio, dope extrusion rate, coagulation bath temperature and air gap length. Several 2-factor interactions are also significant. The regression model obtained can be subsequently used for determining the optimum spinning conditions. This study will ultimately enable the membrane fabricators to produce high-performance membranes that contribute towards the availability of a sustainable water supply system.
Adhesive strength is a critical issue for super hard diamond coatings on tungsten carbide (WC-Co)... more Adhesive strength is a critical issue for super hard diamond coatings on tungsten carbide (WC-Co). The presence of Co in the cemented tungsten carbide substrate has a negative influence on the diamond deposition process. High Co content in the substrates has proved to be very deteriorating for the adhesion of diamond coatings. The surface treatments (single step pretreatment) leading to both Co removal and the roughening of the substrate surface can ensure adequate adhesion levels of the diamond coatings deposited onto WC-Co substrates. The factors investigated were acid temperature, etching time, concentration of H2O2 and concentration H2SO4. The Co content and surface roughness were the response variables investigated. The experimental plan was based on the face central composite design (CCD). The experimental results indicate that the proposed mathematical models suggested could adequately describe the performance indicators within the limits of the factors that are being investigated. The acid temperature is the most significant factor that influences the surface roughness and the Co content. The etching time provided secondary contribution to the responses investigated. Additionally, the square of the acid temperature also provided secondary contribution to the surface roughness. The reduced quadratic model developed using RSM were reasonably accurate and can be used for prediction within the limits of the factor investigated.
Abstract Car cabin acoustical comfort is one of the factors which attract the buyer prospective ... more Abstract Car cabin acoustical comfort is one of the factors which attract the buyer prospective buyer on purchasing a new vehicle. Basically the amount of discomfort depends to magnitude, frequency, direction and also the duration of exposed vibration in the cabin. ...
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Papers by Noor Adila Aluwi Shakir