Characterization of multiwalled carbon nanotubes by DC ARC discharge in methane under magnetic field influence

Carbon nanotubes (CNTs) have gained many interest among researchers over the last two decades due to its remarkable mechanical, electrical, optical and thermal properties. High quality CNTs are in demand especially for application in nano electronics where CNTs are required to be in high crystallinity, straight and aligned orientation, having uniform diameter and less impurities to achieve the best performance. Literally, hydrogen gas is reported as the best buffer gas in producing high crystallinity and less impurities attached to CNTs by arc discharge method. However, it is not suitable for large scale CNTs synthesis due to unstable plasma formation. Recently, methane gas which contains hydrogen atoms is being studied in producing multiwalled carbon nanotubes (MWCNTs). This leads to the opportunity of investigating methane as buffer gas in producing high quality CNTs. On the other hand, the usage of magnetic field in arc discharge has been reported to have the ability to enhance the quality of CNTs in terms of narrow and uniform diameter as well as reducing impurities. Thus, this work presents a comparative study on the effect of three different arc discharge configurations to the yield of MWCNTs in methane environment. The first configuration known as Configuration A where no magnetic field assistance during CNTs arc discharge synthesis. Configuration B utilises four (4) magnets which are placed surrounding inter electrode gap while two (2) magnets are placed at anode for Configuration C. Arc discharge is generated at fixed 750 mbar of chamber pressure and fixed current about 60 A in the voltage range of 30 ~ 32 V. As a result, needle like shapes with straight orientation of individual MWCNTs for all configurations is observed under Scanning Electron Microscope. Narrow diameters are observed in configuration B with standard deviation of 2.71 mm followed by configuration C of 5.7 mm and configuration A of 8.05 mm. The results show the influence of magnetic field in producing MWCNTs with narrow and uniform diameter compared to no magnetic field assistance. The diameter distribution trend is confirmed by X-Ray powder diffraction results. High crystalline MWCNTs is confirmed by Transmission Electron Microscope images for configuration B with uniform MWCNTs inner diameter at average 2 nm. Raman spectrum shows low ratio of D band intensity over G band intensity at 0.53 for configuration B while configuration A at 0.79 which suggest fewer wall defects of MWCNTs produced in configuration B. Therefore, magnetic field assistance in methane arc discharge is proved to produce smaller and uniform diameter of MWCNTs with less wall defects. MWCNTs produced in this study can be further investigated in nanoelectronics applications such as nanowires and conductive nanofille

The Assessment of Children's Performance at Child Care Centre

AbstractThe study aims to examine children's performance through their behaviour and the relationship between children's performance and children's profile at child care centre. Data were collected through 43 children using questionnaires filled by teachers who supervise children aged between 2 - 4 years at three child care centre in Shah Alam, Selangor. Fifty-two variables which were generated from children's performance that include three behavioural categories (movement, interaction and attention) have been analyzed. The result indicated only three out of fifty-two children's behavioural elements have high performance level which were happy to go home, physical activity, and happy to watch television. They scored > 0.75 for Cronbach's alphas coefficient which indicated with high level of internal consistency

The Converts and Zakat Distribution in State of Selangor

The knowledge about zakat distribution method is a vital issue because it leaves an impact to the converts regarding fairness and satisfaction. The aim of the study is to analyze the zakat distribution method in the state of Selangor. In addition, the study is to delve the statisctics in the form of assistance programs received by the converts in Selangor. The study employs mixed method which adopts both quantitative and qualitative studies. The quantitative study employs the questionnaire instrument to 454 converts in Selangor. Meanwhile, the qualitative study employs the library study. The finding of the study indicates that there are twelve zakat distribution methods. The study also shows the statistics in the form of assistance program received by converts.There are fifteen forms of aid received by converts. In the one hand, the highest form of assistance program received by converts are hari raya allowance and monthly financial assistance which are amounted to 54.4% and 47.6% respectively. On the other hand, the lowest form of assistance program is printing and publication assistance which is amounted to 7%. The implication signifies that the zakat distribution method is dessiminated either in the form of money as well as services. Thus, the study finds that the zakat authority in Selangor has fairly distributed the funds into 1/8 of the right of zakat recipients

CNC PCB drilling machine using novel natural approach to euclidean TSP

Nowadays, many industries use the Computerized Numerical Control (CNC) for Printed Circuit Board (PCB) drilling machines in industrial operations. It takes a long time to find optimal tour for large number of nodes (up to thousands). To achieve more effective results, optimization systems approach is required to be equipped in drilling machine. Euclidean Traveling Salesman Problem (TSP) is one of optimization method that gives fast near optimal solution for the drilling machine movement using novel friendly techniques. This paper describes the development of that CNC PCB drilling machine with novel approach to Euclidean TSP. This design can be widely applied to various CNC PCB drilling machines in small and medium scale manufacturing industries

Study On the Uniformity Aluminum Nitrate Thin Film On 2-Inch Silicon Substrate Prepared by RF Magnetron Sputtering

Aluminum nitrate (AlN) has attracted the researcher's interest due to its unique properties in the semiconductor material and other high-performance devices. This results in numerous techniques to investigate the uniformity of AlN thin film. The deposition in this study is carried out on an AlN on a 2-inch silicon substrate using a magnetron sputtering technique. The RF magnetron sputtering can also produce better film quality and deposit a wide variety of insulators, metals, alloys and composites. In this study, the AlN film was deposited using the RF magnetron sputtering by using three different parameters for the growth of the AlN on the 2-inch Si substrate for uniformity analysis. The uniformity of AlN thin film includes analyses of  the structural, thickness, topology and surface morphology by using the characterization of X-ray diffraction (XRD), atomic force microscopy (AFM), surface profiler and field emission scanning electron microscopy (FE-SEM). Based on the result from three parameters that have been done, parameter one shows the best results. For the crystalline structure results, the peak (100) AlN indicates the highly textured phases similar to a single crystal, and the cross-section result in FE-SEM shows the homogenous thickness

Production of herbal shampoo from Madagascar periwinkle

Recently, the society interest in using herbal shampoos has increased significantly. Big companies have started to produce herbal shampoo to meet the market demands. However, most of these shampoos contain chemicals that could be harmful to human health. The main purpose of this study are to produce homemade herbal shampoo from Madagascar Periwinkle plant without harmful chemicals and have additional benefits to consumers. By using stem and leaf extract from the plant and cold press machine, we analysed the quantitative aspect of the extracts and use it as a main ingredient to produce homemade herbal shampoo. The extracts are then used as ingredients in production of the shampoo. Several tests were conducted to determine the performance of the shampoos. The Fourier Transform Infrared Spectroscopy (FTIR) analysis shows presence oh -OH groups and C=O bond to indicate the presence of vinca alkaloids. The performance tests result inconsistent to one extract only. This study provided an information to future researchers regarding the study of Madagascar Periwinkle and effectiveness of this plant in herbal shampoos production

Motif kesukarelawan remaja muslimah di Terengganu / Wan Asri Wan Aziz… [et al.]

Motivasi dan penglibatan golongan wanita dalam aktiviti kesukarelawan telah lama wujud dalam kalangan masyarakat Islam. Oleh itu, kajian ini bertujuan untuk adalah mengenal pasti faktor motivasi utama yang mempengaruhi penglibatan sukarelawan remaja muslimah Terengganu. Seramai 67 responden daripada 240 dalam kalangan siswi Kor Sispa UiTM dipilih melalui kaedah persampelan bertujuan. Data diperolehi dengan menggunakan borang soal selidik yang ditadbir sendiri oleh responden. Volunteer Functions Inventory (VFI) telah digunakan untuk mengukur motivasi sukarelawan dan tahap kepuasan dalam aktiviti sukarelawan. Hasil kajian menunjukkan motif utama penglibatan responden dalam aktiviti sukarela adalah motif nilai, diikuti oleh motif pemahaman dan motif kerjaya. Selain itu, kajian turut mendapati tahap motivasi responden adalah tinggi, manakala tahap kepuasan dalam aktiviti kerja sukarela adalah sederhana tinggi

Preliminary characteristic of electrical non-linearity Co doped CMO-ZnO based varistor ceramic

Zinc oxide based varistor are widely used as circuit protective devices by literally absorbs these dangerous surge and spikes or grounding this unwanted magnitudes. In this research, zinc oxide is added with 20 mol% calcium manganite (CaMnO3) as an additive and Cobalt oxide (CoO) as doping material. Citrate-gel method is used as fabrication method compared to conventional solid-state method. This compound (ZnO-CaMnO3 -CoO) undergoes pre-sintering at 500 °C for 2 hours. In the sintering process, sintering temperature at 1300 °C, while the sintering time are setting at 1.5 hours. X-ray diffraction (XRD) patterns shows the components and phases of the compounds. The change of functional group was observed by Furrier transform infra-red (FTIR). I-V characteristic shows the value of nonlinear coefficient in the range of 1.0-2.0

Structural and Optical properties of Multiwalled Carbon Nanotubes Modified by DBD Plasma at Atmospheric Pressure

Structure, chemical, and physical properties of Multiwalled Carbon Nanotubes (MWCNTs) after modification by dielectric barrier discharge (DBD) at atmospheric pressure is investigated using Transmission Electron Microscopy (TEM), Raman and Uv-vis-NIR spectroscopy. Effects of plasma treatment time on MWCNTs are analyzed. TEM result shows that during the short period of plasma treatment time of 5 minutes, the tube surface experienced a few damages. With increase in plasma treatment time, the tube surface is damaged to a certain extent. Intensity ratio, ID/IG through Raman analysis shows a good agreement with TEM. The values of ID/IG of the modified MWCNTs are larger than those of pristine MWCNTs. An increase of ID/IG indicates that considerable defects are produced on the surfaces of MWCNTs. The treated MWCNTs has energy band gap compared to zero band gap of untreated MWCNTs. It is believed that the defect site of MWCNTs can modify the electronics properties of MWCNTs from being metallic to semiconducting structure, which is applicable for almost all electronics device applications

Lubricity of bio-based lubricant derived from different chemically modified fatty acid methyl ester

In this research, polyol ester was used as the source of a biolubricant. The trimethylolpropane (TMP) and pentaerythritol ester (PE) were produced from palm oil methyl ester; they are biodegradable and have high lubricity properties. Two different conditions of lubrication were investigated. Under these test conditions, the wear and friction characteristics of different ester samples were measured and compared. The esters derived from PE and TMP had comparable characteristics to the fully formulated lubricant (FFL) in terms of the coefficient of friction (CoF). In terms of the mixed lubrication condition, the PE ester has the lowest CoF