A distributed feedback fibre laser made of highly Er-Yb co-doped phosphate glass fibre was demonstrated experimentally. The 45 mm long fibre laser device operated at 1540 nm with more than 50 dB side mode suppression ratio. However, the output power was still relatively lower due to un-optimized grating structure and thermal management.
Comet Lulin was discovered by Lin Chi-Sheng and Ye Quanzhi using the 16-inch telescope at Lulin Observatory in Nantou, Taiwan in 2007. According to Brian Marsden of the Smithsonian Astrophysical Observatory, it reached its perihelion on 10 January 2009 at a distance of 113 million
km from the Sun. It moves in a very nearly parabolic retrograde (‘backwards’ compared to the movement of the planets) orbit at an inclination of 1.6 degrees from the ecliptic (“Newfound Comet Lulin to Grace Night Skies”). http://www.space.com/spacewatch/090206-ns-cometlulin.html). It passed nearest to the Earth at a distance of 61 million km on 23 February 2009.
Comet 17P/Holmes was discovered by Edwin Holmes on 6 November 1892 while he was conducting regular observations of the Andromeda Galaxy (M31). Calculations using observation of its orbits established the perihelion date as 13 June and the orbital period as 6.9 years. The 1899 and 1906 appearances were observed, but the comet was only seen again in 1964. The comet has since been
observed on every subsequent return.
In this paper, the problem of steady laminar boundary layer flow of an incompressible viscous fluid over a moving thin needle is considered. The governing boundary layer equations were first transformed into non-dimensional forms. These non-dimensional equations were then transformed into similarity equations using the similarity variables, which were solved numerically using an implicit finite-difference scheme known as the Keller-box method. The solutions were obtained for a blunt-nosed needle. Numerical computations were carried out for various values of the dimensionless parameters of the problem which included the Prandtl number Pr and the parameter a representing the needle size. It was found that the heat transfer characteristics were significantly
influenced by these parameters. However, the Prandtl number had no effect on the flow characteristics due to the decoupled boundary layer equations.
A survey on the diversity of marine macrogastropoda
in Pulau Songsong, Pulau Bidan and Pulau Telor on the
Northern Straits of Malacca was conducted. Specimens
were collected on rocky shores following NaGISA protocol
and the number of marine macrogastropod were recorded.
Distances and the number of the same species were
converted into Relative Abundance unit (individuals per
100 m2
). A total of 15 species of marine macrogastropoda
were found from seven families namely Neritidae,
Trochidae, Ceriitidae, Littorinidae, Turbinidae, Muricidae
and Potamididae. Seven macrogastropoda species were
newly recorded from these three islands. Morula marginatra
was the most dominant species and Pulau Songsong had
the highest genera and species diversity among the three
islands. (Copied from article).
Fractional factorial design was utilized to evaluate the effect of combinations of nitric acid, hydrogen peroxide, hydrochloric acid and water for microwave digestion of fish muscle. Upon digestion, copper, iron and zinc were determined by flame atomic absorption spectroscopy. H2O2 and HCl volumes were found to be the most significant parameters which resulted in good metal recoveries. This is especially so for the effect of HCl on Fe recovery. The results indicated that the combination of 4 mL 65% HNO3, 2 mL 30% H2O2 and 2 mL 30% HCl gave the most satisfactory percentage recovery. There was good agreement between measured and certified values for all metals with respect to the DORM-3 fish protein.
In this study, Zn2SiO4 composite-based ceramic was synthesised using amorphous SiO2
nanoparticles as a silicon source. Different ratios of Zn:Si were prepared by mixing amorphous
SiO2 nanoparticles with aqueous zinc nitrate. Amorphous SiO2 nanoparticles were
encapsulated by the zinc source in aqueous solution, dried, and subjected to heat treatment.
The heat treatment underwent by the amorphous SiO2 nanoparticles, with zinc source mixture,
showed the changing of phases, morphology, and size with increased temperature. ZnO
phase appeared at the beginning of heat treatment and Zn2SiO4 phase started to emerge at
800◦C onwards, as shown by XRD patterns. The average crystallite size increases from 37
nm at 600 ◦C to 68 nm at 1000 ◦C. The spherical morphology was observed at 600 and 700
◦C, but at temperatures higher than 800 ◦C, the dumbbell or necking-like structures formed.
Optical band gap analysis of Zn2SiO4 composite was determined to be within the range of
3.12 ± 0.04 to 3.17 ± 0.04 eV. The photoluminescence of treated samples showed emission
peaks at 411 and 455 nm wavelengths from ZnOs blue band and at 528 nm wavelength from
Zn2SiO4
0
s green band. The diffusion of zinc ions into Zn2SiO4 composite with high surface
area will favour the diffusion at a much lower temperature compared to a conventional solid
state method.
The aim of this work was to investigate the effect of glycerol concentration on mechanical
and physical properties of gellan gum (GG) biofilm. The biofilm was prepared using solvent
casting method and the effective glycerol concentration was found to be within 30-50%
w/w (based on GG weight). At 60 and 70 w/w% of glycerol, the films started to distort
because the films was flexible and brittle. As glycerol concentration was increased the tensile
strength (TS) and Youngs modulus (E) of films decreased. Somehow, elongation at break
(EAB), water vapor transmission rate (WVTR) and swelling of films was increased. Glycerol
plasticized GG biofilm was thermally stable and flexible, proposed its can be exploited as
film-forming material and with optimized glycerol concentration it has good mechanical and
physical properties for edible biofilm.
The genus Streptomonospora is a group of extremely halophilic filamentous actinomycetes that form a distinct branch in the 16S rRNA gene phylogenetic tree adjacent to the genera Nocardiopsis and Thermobifida, family Norcadiopsaceae. To date, genus Streptomonospora only contain two validly described species which are Streptomonospora salina and Streptomonospora alba. During a biodiversity study on halophilic filamentous actinomycetes from 18 co-ordinates in Barrientos Island, Antarctic, numerous actinomycetes strains were isolated. To identify whether these isolates were members of the genus Streptomonospora, a genus specific primer that allow the rapid detection of the genus Streptomonospora by means of PCR amplification was used. Furthermore molecular cloning was performed to make identical and multiple copies of the target gene. In addition, morphological characteristic identification was performed to validate isolates with positive amplification during PCR.
This paper reviews the advances made on studies related to bank erosion. Bank erosion has been an area of interest by researchers in geological, geotechnical, hydraulic, hydrology and river engineering disciplines. With anticipated global challenges from climate change impacts, bank erosion studies could support challenges faced in ensuring sustainable environmental management. The evolution in the theoretical and laboratory findings have led to the advances in bank erosion and contributed to new knowledge in the said field. This review summarises the findings of previous investigators including measurements approach and prediction of rates of bank erosion through the use of physical models and numerical approach.
The incidences of breast cancer have been rising at an alarming rate. Mass breast screening programmes involving mammography and ultrasound in certain parts of the world have also proven their benefits in early detection. However, radiologists may be confronted with increased workload. An attempt has been made in this paper to rectify part of the problems faced in this area. Expert systems based on the interpretation of mammographic and ultrasound images for classifying patient cases could be utilized by doctors (expert and non-expert) in screening. These softwares consist of MAMMEX (for mammogram) and SOUNDEX (for breast ultrasound) could be used to deduce cases according to Breast Imaging Recording and Data System (BI-RADS), based on patients’ history, physical and clinical assessment, mammograms and breast ultrasound images. A total of 179 retrospective cases from the Radiology Department, hospital of the University of Science Malaysia, Kubang Kerian, Kelantan were used in this study. A receiver operating characteristic (ROC) curve analysis was implemented, based on the usage of a two-class forced choice of classifying suspicious and malignant findings as positive with normal, benign and probably benign classified as negative. Results yielded an area under the curve (AUC) of 0.997 with the least standard error value of 0.003 for MAMMEX while an AUC of 0.996 with the least standard error of 0.004 was accomplished for SOUNDEX. A system which very closely simulated radiologists was also successfully developed in this study. The ROC curve analysis indicated that the expert systems developed were of high performance and reliability.
Polycrystalline samples of YBa2Cu3O7−δ added with small amounts (x = 0.0 - 1.0 wt%)
of Sm2O3 nanoparticles were synthesized via co-precipitation process. The effects of addition
of Sm2O3 nanoparticles on the superconducting properties and crystal structure of
YBa2Cu3O7−δ were thoroughly elucidated. The superconducting transition temperature
(Tc) of each sample was measured by a standard four point probe method. As the addition
of nano-Sm2O3 increases, the reduction of Tc occur from 92 K for x = 0.0 to 80 K for x =
1.0 wt% attributable to oxygen vacancy disorder. The crystal lattice parameters of all samples
were determined by X-ray diffraction (XRD) with the Rietveld refinement technique. It
was found that the samples are predominantly single phase perovskite structure Y-123 with
orthorhombic, small amount of Y-211 and unreacted Sm2O3 secondary phases for samples
x = 0.2 - 1.0 wt%. Besides, the structure from SEM images showed that the structure becomes
more porous than the pure sample and the grain sizes are getting slightly decrease
as the addition of Sm2O3 nanoparticles increase. The addition of nano-Sm2O3 disrupts the
grain growth of YBCO (123), therefore resulting in the degradation of microstructure and
superconducting properties of the samples.
Measurement of low magnetic field has played an important role in many electronics applications such as navigation, military, non-destructive test, traffic detection as well as medical diagnosis and treatment. The presence of magnetic field, particularly its strength and direction, can be measured using magnetometer. There are many types of magnetometers being investigated through the years and one of the prominent types is fluxgate magnetometer. The main components of fluxgate magnetometer consisting of driving coils, sensing coils and magnetic core are developed by MEMS silicon processing technology. In this paper, an investigation on physical characteristics of the three-dimensional coil structure for a micro-scaled fluxgate magnetometer is presented. The physical characteristics such as width of the coil, distance between successive coils, and gap between the top and bottom coils which would influence the magnetic energy in magnetometer is discussed. In this work, finite-element method simulations to investigate the physical characteristics of the sensing coils were carried out, where the parameter of interest is the coils’ inductance as well as the magnetic flux density. Based on the simulation results, the varying of physical characteristics of the coils had its effects particularly in coil inductance, magnetic flux density, and magnetic energy. It could also be seen that the simulated results agreed with the theoretical aspects of magnetism in a coil. From the investigations, suitable coil dimensions were proposed.
The laser technology laboratory (LTL) of the Physics Department, University of Technology Malaysia was established in 1989 to support research and development activities. The laboratory provides activities for short- and long-term projects to serve final year undergraduate and post-graduate students in masters and PhD programmes.
In this project, a Geographic Information System (GIS) was used to collect and compile various field data in the Pedro Vicente Maldonado Ecuadorian Scientific Station Antarctica Base area. The main source of data was obtained from a global positioning system (GPS) survey using kinematic GPS (GPS-RTK) which allowed continuous point mapping in the terrain. GPS units were utilized in the collection of spatial data for all field work. The co-ordinates obtained were used to produce a point map which was then exported into GIS software where the proximity of cartographic phenomena and boundaries were mapped. All the collected data were subsequently gathered to develop the GIS database which was then used to generate and compile different maps to test for spatial and temporal relationships. The output of the project comprises a GIS database, spatial maps and 3D terrain model of the area. The developed GIS database can be used with other ecological datasets to provide biogeographical information, potential range distribution and sampling adequacy. The database is also applicable to geographical management and multi-disciplinary research projects.
Hydraulics simulation can be used as a supporting tool for planning and developing a framework, such as Integrated Flood Management for river management. To demonstrate this, a hydraulics model for the Sarawak River Basin was run using InfoWorks RS software by Wallingford Software, UK. InfoWorks River Simulation (RS) was chosen because its applicability has been proven and widely used to model Malaysian rivers. The extraction of computed floodwater level and flood maps for different time intervals would produce the rate of floodplain submergence from river bank level. This information could be incorporated into a logical framework to support decisions on flood management measures. Thus, hydraulics models can be used as tools to provide the necessary decision parameters for developing logical frameworks which would act as to guide the planning when it involved various stakeholders’ participation.
Systems perspectives are fundamental in driving technological improvements and yield-enhancing strategies that improve agricultural productivity. These can resolve farmerʼs problems and are important pathways for sustaining food and nutritional security for human welfare in Asia. The essential determinants of this objective are the capacity to efficiently manage the natural resource base (land, crops, animals, and water) to resolve constraints to farming systems, and notably the integration of multiple research and development (R&D) issues through all levels of formal and non-formal learning systems. Both formal and informal education systems are important, with the former relating more to universities and colleges, and the latter to the intermediate level. Graduates from this level have the primary responsibility of introducing improved technologies and change to farmers, mainly along production and disciplinary pathways.The traditional research–extension–farmer model for technology delivery is no longer acceptable, due to “top down” extension functions and prescriptions, ineffectiveness to cope with the dynamics of production systems, complex interactions within the natural resources, effects of climate change and globalisation. There are also reservations on the technical capacity and skills of extension agents, constraints identification, methods for technology diffusion and dissemination, and innovative use of beneficial technological improvements that can directly respond to the needs of small farmers, and impact on subsistence agriculture. Agricultural education and systems perspectives are therefore an overriding compelling necessity which transcends prevailing limitations to waning agriculture and rural growth. Their wider recognition and applications provides an important means to maximise efficiency in the potential use; of the natural resources, increase engagement and investments in agriculture, promote ways to become more self-reliant in the development of crucial new technologies and intensification. These together can meet the challenges of the future and overcome the legacy of continuing poverty, food and nutritional insecurity. Asian farming systems, with their diversity of crops and animals, traditional methods, multiple crop-animal interactions, numerous problems of farmers present increasingly complex issues of natural resource management (NRM) and the environment. Many if not all of these can only be resolved by interdisciplinary R&D, which overcomes a major weakness of many R&D programmes presently and in the past. Improved education and training is a powerful and important driver of community-based participation aimed at enhancing sustainable food security, poverty reduction and social equity in which the empowerment of women in activities that support organising themselves is also an important pathway to enhance self-reliance and their contribution to agriculture. A vision for the future in which improved agricultural education in a systems context can provide the pathway to directly benefit the revitalisation of agriculture and agricultural development is proposed with a three-pronged strategy as follows:
Define policy for the development of appropriate curricular for formal agricultural education that provides strong multi-disciplinary orientation and improved understanding of the natural resources (land, crops, animals and water) and their interactions
Organise formal degree education and specialisation at the university level that reflects strong training in understanding of agricultural systems; systems perspectives, methodologies and their application, and
Define non-formal education and training needs that can be intensified at different levels, including the trainin of trainers as agents of change.
Throughout the years, the construction industry has made an important contribution to the Malaysian economy. Moreover, the Ninth Malaysia Plan (2006–2010) has also played a significant role in the demands of executing major residential housing project developments where it has been observed that construction waste was one of the priority waste streams. Due to the increasing number in the population that is actively involved in economic activities, and the modernization of the country, the types of construction waste that are being produced, and identifying the source such as waste are becoming more complex. Therefore, appropriate actions and approaches are needed to be taken with respect to its effective management in handling the solid waste from construction sites. This paper is intended to review the issues and the challenges enclosed within the supply chain management mechanisms in order for improving construction waste management. Throughout this review, useful information and better understanding concerning the current issues, challenges and the supply chain management mechanisms would be made inclusive in the field to be explored. The findings would also assist in improving the quality and awareness on the construction waste management that is being practiced.
The functionalization of pristine CNTs is necessary for carbon nanotubes (CNTs) to be fully utilized, with the aim of increasing the nanotube reactivity and solubility in aqueous solutions. In this study, multi-walled carbon nanotubes (MWCNTs) were functionalized with a carboxylic group as this was an important step prior to application. The carboxylic group-functionalization was conducted through acid treatment, using sulphuric and nitric acids mixed at a ratio of 3:1 (v/v) and sonication for 30 min under different temperatures and time durations. The functionalization conditions of 50ºC x 5 h and 60ºC x 3 h were identified to be most suitable for introducing a carboxylic group onto the nanotube surfaces. The percentage of total weight loss due to the carboxylic group on the MWCNTs treated at 50ºC x 5 h and 60ºC x 3 h obtained from the thermogravimetric analysis was 13.26% and 13.76%, respectively. For both samples, peaks corresponding to the carboxylic group were identified in the FT-IR spectra. The changes in the morphology of the treated MWCNTs were also observed under SEM analysis.
The role of science and technology (S&T) in preventing disasters and building resilience to climate change is featured in this paper, drawing primarily on the presentations and discussion of researchers, practitioners and policy makers from 31 institutions in 17 countries during the Workshop on Natural Disasters and Climate Change in Asia, held on 5–7 November 2012 in Bangi, Malaysia. Issues highlighted include advances in climate modelling and weather forecasts, with emphasis on information gaps; hazards and its cascading effects, focusing on current research and approaches; and the potential for land-based mitigation-adaptation strategies. Progress in mobilizing S&T to support disaster prevention and climate resilience is hindered by factors such as absence or lack of research, incomplete and non-existent scientific records, restricted access to data and capacity to innovate and transmit S&T, among others. The establishment of an Asian Network for Climate Science and Technology is proposed to provide and facilitate exchange of information and aid development of research co-ordination projects led by Asian researchers and possibly to act as a one-stop repository of global climate change related research too. The scope of the network would cover climate research with particular relevance to disaster resilience, including scientific capacity, which is all very distinct in Asia.