The Phenomena of Spreading of Hydrotalcite Sol on A Porous Silica Surface Governed by Marangoni Effect

Wetting phenomena plays a crucial role in a wide range of technological applications. Spreading of liquids on solids involving phase change is encountered in many areas ranging from biological systems to industrial applications such as coatings, printing, painting and spraying. The fundamental study on wetting of membrane precursors namely hydrotalcite sols on a porous silica surface with different types of precursor material was successfully carried out. Relationship between the contact angle of a hydrotalcite droplet on silica surface and the Marangoni effect was also investigated. The presence of PVA in hydrotalcite sols was found to influence the rheological properties of the sols significantly, resulting in higher viscosity and ultimately leading to lower contact angle on solid surfaces. The degree of hydrotalcite's philicity on a substrate was improved by the addition of PVA solution. In this study, the spreading of a liquid droplet on a solid surface controlled by a surface tension gradient, due to Marangoni effect was found to drive better spreading of the liquid droplet. Marangoni Number, Ma was found to be proportionally related with the surface tension of the sols but inversely proportional to contact angles of the sols. Marangoni forces that decreased the contact angle, promoted spreading of hydrotalcite droplets on the selected glass substrates.Keywords: contact angle, hydrotalcite, marangoni effect, spreading, wetting evolutio

Mismatch between school furniture and anthropometric measurements of primary school children in Mersing, Johor, Malaysia.

This study is a cross-sectional study with the objective to determine mismatch between school furniture and anthropometric measurement among primary school children in Mersing. The sample consisted of 91 primary school children (46 male and 45 female) from Year 2 and Year 5 in two schools in Mersing District, Malaysia. Seven anthropometric measurement (height, weight, popliteal height, buttock-popliteal length, hip breadth, shoulder height and elbow height while sitting) as well as 5 furniture dimensions (seat height, seat depth, seat width, backrest height and seat to desk height) were taken. Instruments used were Martyn type anthropometer set, ruler, height scale and weighing scale. Differences between genders in anthropometric measurements were also investigated in this study. Findings showed 100% high mismatch for seat height, seat depth, desk height respectively while 56% match and only 44% mismatch for backrest height among Year 2 children. Year 5 students reported contrary result with 79% mismatch for seat height, 91% for backrest height and 100% for both seat depth and desk height. There was no significant difference between genders for both age groups. In conclusion, there was a mismatch between furniture and children's anthropometric measurements. It is recommended that school furniture be redesigned so as to conform to the children's physiological measurement. The use of adjustable furniture can be taken into consideration in designing new furniture for school environments in order to meet all the differences in children anthropometry

Debinding process of ss316L metal injection moulding under argon atmosphere

Solvent and thermal debinding acted as binder in removing Restaurant Waste Lipid (RWL) and Polypropylene (PP) from the stainless steel 316L. This investigation was carried out to determine the effect of thermal debinding variables on density, shrinkage and surface morphology of the brown parts other than to remove the binder from the SS316L under the Argon atmosphere with flow rate of 5 ml/min. The parameter used for solvent debinding process was solvent temperature at 60°C for six hours, while thermal debinding process was conducted at various temperature of 400°C, 500°C and 600°C, heating rate of 10 °C/min, 20 °C/min and 30 °C/min, dwell time of 30 min, 60 min and 90 min, and cooling rate of 5 °C/min, 10 °C/min and 15 °C/min. Analysis of weight loss percentage was done on the brown part after the solvent debinding and thermal debinding processes. Scanning Electron Microscope (SEM) was used to confirm the removal of RWL and PP from the compacts based on the porosity form, and attachment of PP in the powder particles. This investigation showed that debinding parameters were important in terms of their effects on the physical properties. Based on the observation through SEM and consideration of the factors that affected the physical properties of the parts, it was found that RWL was completely extracted out at 60°C for six hours, while the thermal temperature of 500°C with heating rate of 10 °C/min, dwell time of 60 min and cooling rate of 15 °C/min were the optimal thermal debinding parameters in PP removal

The impact of Sharia compliance on the adjustment to target debt maturity of Malaysian firms

This paper investigates the speed of adjustment to target debt maturity for a sample of Malaysian firms based on the sample period of 2007 to 2016. We examine the impact of Sharia compliance on the speed of adjustment to target debt maturity structure by grouping companies based on nature of compliance to Sharia requirements which is categorised by the Securities Commission of Malaysia. In line with our expectations, the analysis shows that firms classified as Sharia compliant tend to adjust at more rapid rates to target debt maturity when below target levels suggesting that compliant firms are able to issue long-term debt at cheaper levels relative to non-compliant counterparts. In addition, the reverse is observed when evaluating firms above target levels where non-compliant firms adjust at more rapid rates. Our findings indicate that compliant firms are able to raise long-term debt at cheaper rates relative to non-compliant firms given the captive market situation observed in the Islamic capital markets in Malaysia. This does however indicate the potential for higher agency costs as well as greater levels of information asymmetry for compliant firms relative to non-compliant firms given that non-compliant firms are more willing to reduce maturity structures to reach target levels when above target levels.peer-reviewe

Community structure, diversity and biomass of trees in two forest subtypes of Pekan Forest Reserve, Pahang, Malaysia.

Two one-ha ecological plots representing Kempas-Ramin-Durian and Durian-Nyatoh forest subtypes were established in Compartment 156 and Compartment 200, respectively at Pekan Forest Reserve, Pahang to determine community structure, diversity and biomass of trees. All trees of 10 cm diameter at breast height and above were enumerated in the plots. Results showed that although tree stocking was almost similar in the two forest subtypes, the basal area, volume and total tree biomass were higher in the Kempas-Ramin-Durian subtype. Shannon-Weiner diversity index, H′ obtained in the Durian-Nyatoh subtype was however, significantly higher (p<0.05) than Kempas-Ramin Durian subtype. Morisita's Index of Dispersion (Id) showed a random distribution pattern for both forest subtypes

Highly Efficient Cladding Pumped Dual-Wavelength Thulium Ytterbium Co-Doped Fiber Laser

This paper describes the all-fiber dual-wavelength thulium ytterbium co-doped fiber laser by using a newly developed octagonal shaped double-clad thulium-ytterbium co-doped fiber as gain medium in conjunction with spatial filtering effect. The thulium ytterbium co-doped fiber laser operates at wavelengths of 1990.64 nm and 1998.92 nm with a signal to noise ratio of more than 34 dB as the 980 nm multimode pump power is increased above a threshold value of 1.5 W. The slope efficiency of the dual-wavelength laser is measured to be around 26.16%, which is comparable with the conventional thulium laser pumped by 800 nm single mode pump

Predicting youth participation in urban agriculture in Malaysia: insights from the theory of planned behavior and the functional approach to volunteer motivation

This study examines factors associated with the decision of Malaysian youth to participate in a voluntary urban agriculture program. Urban agriculture has generated significant interest in developing countries to address concerns over food security, growing urbanization and employment. While an abundance of data shows attracting the participation of young people in traditional agriculture has become a challenge for many countries, few empirical studies have been conducted on youth motivation to participate in urban agriculture programs, particularly in non-Western settings. Drawing on the theories of planned behavior and the functional approach to volunteer motivation, we surveyed 890 students from a public university in Malaysia about their intention to join a new urban agriculture program. Hierarchical regression findings indicated that the strongest predictor of participation was students’ attitude toward urban agriculture, followed by subjective norms, career motives and perceived barriers to participation. The findings from this study may provide useful information to the university program planners in Malaysia in identifying mechanisms for future students’ involvement in the program

Factors influencing students’ intention to use internet for academic purposes

This study aimed to investigate the factors influencing students’ intention to use the Internet for academic purposes amongst 204 final year business students in public universities in Malaysia.This study integrated theory of planned behavior (TPB) and theory of acceptance model (TAM) as the base model toward that purpose.The research model employs the variables from both theories namely attitudes, subjective norms, perceived behavioral control, perceived usefulness, perceived ease of use, intention, and behavior.A multiple regression analysis provides empirical support for the applicability of integration of TPB and TAM in predicting students’ intention to use the Internet for academic purposes.Results of the study show that attitudes, perceived behavioral control, and perceived usefulness are statistically significant in influencing intention to use the Internet for academic purposes.Based on the results, it can be concluded that students’ intention to use the Internet for academic purposes could be predicted from their attitudes, perceived behavioral control, and perceived usefulness at 49% level.In view of the results, several implications and recommendations are discussed

A review of the systematic biology of fossil and living bony-tongue fishes, Osteoglossomorpha (Actinopterygii: Teleostei)

The bony-tongue fishes, Osteoglossomorpha, have been the focus of a great deal of morphological, systematic, and evolutionary study, due in part to their basal position among extant teleostean fishes. This group includes the mooneyes (Hiodontidae), knifefishes (Notopteridae), the abu (Gymnarchidae), elephantfishes (Mormyridae), arawanas and pirarucu (Osteoglossidae), and the African butterfly fish (Pantodontidae). This morphologically heterogeneous group also has a long and diverse fossil record, including taxa from all continents and both freshwater and marine deposits. The phylogenetic relationships among most extant osteoglossomorph families are widely agreed upon. However, there is still much to discover about the systematic biology of these fishes, particularly with regard to the phylogenetic affinities of several fossil taxa, within Mormyridae, and the position of Pantodon. In this paper we review the state of knowledge for osteoglossomorph fishes. We first provide an overview of the diversity of Osteoglossomorpha, and then discuss studies of the phylogeny of Osteoglossomorpha from both morphological and molecular perspectives, as well as biogeographic analyses of the group. Finally, we offer our perspectives on future needs for research on the systematic biology of Osteoglossomorpha