|
Archives |
Volume 2, Issue No 1, June 2015 <<Previous Volume II Next Volume>>
Issues in Volume 2 Cover Page and Table of Contents Full Articles
Variations in suspended sediment yield and dynamics in catchments of differing land-use in Sabah
Anand Nainar; Kawi Bidin; Rory P. D. Walsh; Robert M. Ewers; Glen Reynolds. 2015. Transactions on Science and Technology, 2(1), 1 - 19 Abstract Variations in suspended sediment dynamics in different land-use were observed over the period of 2011 to 2014 in the SAFE Project area (www.safeproject.net). Five catchments of different land-use namely primary forest (PF), old regrowth-virgin jungle reserve (VJR), twice-logged regenerating forest (LFE), thrice-logged regenerating forest (0 m) and oil palm (OP) were instrumented with Campbell data loggers and sensors to record at five-minute intervals water level, turbidity, electrical conductivity and water temperature. Turbidity is converted to suspended sediment concentration (SSC) using algorithms derived from calibration experiments. This paper focuses mainly on duration of high discharge, peak SSC, duration of high SSC and sediment yield during selected storm events. It was found that the primary forest has longer duration of high discharge which points to good infiltration and better water-holding capacity. The oil palm has a short duration of peak flow. The highest peak SSC and duration of high SSC was almost always found in the oil palm. The peak SSC and duration of high SSC of the thrice-logged forest is lower than that of the primary forest in medium to large storms indicating the important role of understory vegetation for erosion protection. Sediment yield is the highest in the oil palm catchment and the lowest in the thrice-logged forest therefore highlighting the role of forests (even disturbed forests) in the regulation of sediment export. View article
Mini review on efficient data structure for 3D modelling of polygonal mesh
Nurhamiezrah Midin; Abdullah Bade. 2015. Transactions on Science and Technology, 2(1), 20 - 32 Abstract 3D graphics has become an increasingly important part in geometric modelling visualization. 3D model is mainly represented by polygonal mesh. Highly complex meshes result in expensive rendering cost, exceeding the memory storage, difficulty to transmit data and unable to be edited. The development of data structure to store meshes information and handling those problems have begun since 30 years ago. This paper aims to highlight the major approaches of various types of algorithm used to address specific problems in storing mesh data over a decade. Trend has shown that remeshing, random access and streaming representation are the methods that been used widely recently. We believe this paper will help other researchers to be familiar with polygonal mesh and their connotation. View article
Fractionation and crystallization of isotactic polypropylenes prepared using homogenous metallocene catalyst
Ismael Amer; Touhami Mokran; Albert Van Reenen. 2015. Transactions on Science and Technology, 2(1), 33 - 41 Abstract A series of polypropylenes were prepared using rac-ethylene-bis(4,5,6,7-tetrahydro-1-indenyl) zirconium dichloride (Et(H4Ind)2ZrCl2 (EI(4H)) as a homogeneous metallocene catalyst. The molecular weight of the polypropylene polymers was controlled using molecular hydrogen which was used as a transfer agent. To obtain materials with differing molecular weight and tacticities, polymers were fractionated with prep-TREF. Polypropylene polymers and fractions were fully characterized using various analytical techniques: differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), 13C nuclear magnetic resonance spectroscopy (13C-NMR) and high temperature gel permeation chromatography (HT-GPC). It was found that the addition of molecular hydrogen to propylene polymerizations catalyzed using EI(4H) catalyst system resulted in a reduction in polymer molecular weight and isotacticity. Furthermore, the molecular weight, the isotacticity and the degree of crystallinity of the TREF fractions increased significantly with increasing elution temperature for all samples. Also, only the ? crystal form existed in all TREF fractions of different samples. View article
An experimental study on evacuated tube solar collector using nanofluids
Sabiha Monny Akter; Saidur Rahman; Saad Mekhilef. 2015. Transactions on Science and Technology, 2(1), 42 - 49 Abstract The present study aims to investigate the energy efficiency of an evacuated tube solar collector containing water based single walled carbon nanotube nanofluids. The effect of various parameters such as volume concentration of nanofluid, inlet and outlet fluid temperature, solar radiation and ambient temperature on the collector efficiency is investigated. According to the results, higher efficiency is achieved for higher volume concentration of single walled carbon nanotube nanofluids. The energy efficiency also increased with increasing solar radiation value. The highest collector efficiencies are observed for 84.24% and 94.73% using 0.05 and 0.25 vol% single walled carbon nanotube nanofluids respectively at a mass flow rate of 1.5kg/min. View article
Removal of causative factors for sick building syndrome using air plants
Yasuhiko Koike; Yozo Mitarai. 2015. Transactions on Science and Technology, 2(1), 50 - 55 Abstract The ability of the air plant Tillandsia brachycaulos (a CAM plant) to remove one of the factors responsible (formaldehyde) for sick building syndrome was investigated. A C3 plant (Sparthiphyllum Schott) was also used for comparison. Results showed that the T. brachycaulos reduced formaldehyde concentration more during the night than the day, and Sparthiphyllum reduced it more during the day than the night. View article
Rapid detection of Allura Red (E129) based on chitosan/nanoparticles/MWCNTs modified gold electrode in food products
Rovina Kobun; Shafiquzzaman Siddiquee; Sharifudin Md Shaarani. 2015. Transactions on Science and Technology, 2(1), 56 - 64 Abstract Allura Red AC (E 129) is a mono azo dye that is able to form of powder or granules. It is used to make foods more attractive and appetizing for over centuries. However, excessively intake of food containing synthetic food coloring can caused toxicity and pathogenicity to human. Therefore, there is needed a simple, faster and effective method for the analysis of Allura Red in food products. Herein, an electrochemical sensor for rapid and simple detection of Allura Red was developed based on combination of nanomaterials of chitosan, nanoparticles and multiwall carbon nanotubes (MWCNTs) sensing film. Methylene blue was used as a redox indicator for increasing the electron transfer in electrochemical cell. The electrochemical behavior of modified gold electrode in the presence of Allura Red was studied by using cyclic voltammetries and differential pulse voltammetries. The morphological characteristics of modified electrode were observed under scanning electron microscope and transmission electron microscope. Under optimal conditions, this electrochemical method was found a wide linear Allura Red concentrations range from 10 to 0.5 ppm, with a detection limit are as low as 0.4 ppm. Finally, the proposed sensor method was successfully used to detect Allura Red in different sample food products. View article
Copper toxic stress on Aloe barbadensis and its antioxidant response
Ghim Hock Ong; Mustafa Omer Aya Omer; Subramaniam Geetha. 2015. Transactions on Science and Technology, 2(1), 65 - 73 Abstract Toxic levels of copper (Cu) can cause deleterious effects such as protein denaturation and oxidative stress. Plants could respond to heavy metal tolerance through various mechanisms including alteration of their enzymatic antioxidant activity which acts as a toxicity tolerance mechanism. The aim of this study was to investigate the relationship between Aloe barbadensis enzymatic antioxidants and its response to different concentrations of Cu (control, 1ppm, 3ppm and 5ppm). A. barbadensis were treated with different concentrations of Cu on a 4 days cycle for a period of 21 days. Activity of the antioxidant enzymes namely superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and guaiacol peroxidase (GPX) were determined after 21 days. SOD exhibited changes in activity in response to increased Cu concentration and showed significantly higher (P<0.05) at 3ppm and 5ppm Cu compared to 1ppm. CAT exhibited changes in activity as Cu concentration increased and showed no significant difference among the three levels of Cu. APX exhibited changes in activity as Cu concentration increased and showed significantly higher (P<0.05) at 1ppm when compared to 3ppm and 5ppm. GPX exhibited changes in activity as Cu concentration increased and showed no significance within three levels of Cu. In conclusion, the enzymatic antioxidant exhibited relationship in activity. SOD antioxidant was found to be the most effective in scavenging the reactive oxygen species as it increases during copper stress and shows consistency in activity. View article
Dust fall in the residential air environment of northern part of Thailand: Chiang Mai, Lampang and Phitsanulok province
Pajaree Thongsanit; Witchaya Imkrajang. 2015. Transactions on Science and Technology, 2(1), 74 - 79 Abstract This research aims to study the concentration of dust fall samples collected from three provinces, Chiang Mai, Lampang and Pitsanulok in northern part of Thailand. The dust fall samples were collected by a dust fall jar container adapted from the environmental sampling manual of Pollution Control Department. The sampling period was set to be 30 days for each sample according to the sampling from October 2014 to February 2015. Studies parameters and sample analysis, the concentration of the dust fall 30 days was analysed by weight measurement or Gravimetric Method. It was found that the dust value of 20 - 62 microgram per square meter per day, recorded at residential are in Chiang Mai area. The dust value of 18 - 75 microgram per square meter per day, recorded at residential are in Lampang area. The dust value of 24 - 64 microgram per square meter per day, recorded at residential are in Phitsanulok area. The mostly of dust fall sample (90%) were not exceeded the residential standard value of 65-130 microgram per square meter per day. View article |