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 study polymer electrolytes composed of poly(methyl methacrylate) (PMMA) as a host polymer and ethylene carbonate (EC) as a plasticizer complexed with different lithium salts, i.e. lithium tetrafluoroborate (LiBF4) and lithium triflate (LiCF3SO3) were prepared by the solution casting technique. The conductivities of the films were characterized by impedance spectroscopy. At room temperature, the highest conductivities were 4.07 × 10–7S cm–1 and 3.40 × 10–5 S cm–1 achieved, respectively from the films containing 30 wt% LiBF4 in the PMMA-EC-LiBF4 system and 35 wt% LiCF3SO3 in the PMMA-EC-LiCF3SO3 system. The conductivity-temperature dependence of the films seemed to obey the Arrhenius equation in which the ion transport in these materials was thermally assisted. Scanning electron microscopy analysis showed that the surface of PMMA-EC-LiCF3SO3 film was smooth and homogeneous, hence lithium ions could traverse through the PMMA-EC-LiCF3SO3 film more easily compared to the PMMA-EC-LiBF4 film. X-Ray diffraction studies revealed that complexation had occurred and the complexes formed were amorphous.
Herein, we report the synthesis of a thiosemicarbazide derivatives, namely 4-(2-
fluorophenyl) thiosemicarbazide from the reaction between 2-fluorophenyl isothiocyanate and
hydrazine hydrate. The isolated solid compound was elucidated from micro-elemental analysis
and IR spectroscopy. The structure of the molecule in the ground state was calculated
using density functional theory (DFT) method and basic set of 6-311G (d,p) was used to
calculate the energy gap (4Egap), hardness (η), softness (σ) and the global electronegativity
(χ). Its electrostatic potential mapping and frontier orbital energy analysis were also
discussed. The interaction of the molecule with selected proteins are investigated using
SwissTargetPrediction database.
Results of a biodiversity study of Antarctic microfungi from ornithogenic soils are presented in this paper. A wide range of soil habitats within and adjacent to active and abandoned penguin rookeries were sampled in order to examine relationships between environmental factors and the biodiversity of soil microfungi. Soil samples were collected from two contrasting Antarctic locations: (1) Beaufort Island (Ross Sea, Continental Antarctica), which is largely ice- and snow-covered, isolated, difficult to access and infrequently visited, and (2) Barrientos Island (maritime Antarctica) which is mostly ice-free during summer and is often visited by scientists and tourists. Soil sampling at Beaufort and Barrientos Islands was completed during the austral summer seasons of 2004/05 and 2006/07, respectively. Warcup’s soil method was used for fungi cultivation. A total of 27 fungal taxa were isolated from the two study sites, consisting of 11 ascomycetes, 13 hyphomycetes
and three yeasts. Only three taxa — Geomyces sp., a pink and a white yeast — occurred on both sites. The isolated fungi were classified according to their thermal characteristics in culture, with seven psychrophilic, 10 psychrotrophic and 10 mesophilic fungi being isolated. Thelebolus microspores, Thelebolus sp., Geomyces sp. and Antarctomyces sp., were the most frequently isolated fungi. A total of 10 taxa were isolated from the 20 soil samples from Beaufort Island, consisting of five psychrophilic, four psychrotrophic and one mesophilic fungi. Thelebolus microsporus, Thelebolus sp., Asco BI8 and Phoma sp. were the most frequently obtained fungi
(20%–27% of isolates). A total of 22 fungal taxa were isolated from 23 soil samples from Barrientos Island, consisting of four psychrophilic, six psychrotrophic and 12 mesophilic fungi. Geomyces sp. and Antarctomyces sp. were the most frequently isolated taxa. Thus, the fungal diversity of Beaufort Island was dominated by Ascomycetes while that of Barrientos Island was dominated by hyphomycetes.
Computational chemistry is a discipline that concerns the computing of physical and chemical properties of atoms and molecules using the fundamentals of quantum mechanics. The expense of computational chemistry calculations is significant and limited by available computational capabilities. The use of high-performance computing clusters alleviate such calculations. However, as high-performance computing (HPC) clusters have always required a balance between four major factors: raw computing power, memory size, I/O capacity, and communication capacity. In this paper, we present the results of standard HPC benchmarks in order to help assess the performance characteristics of the various hardware and software components of a home-built commodity-class Linux cluster. We optimized a range of TCP/MPICH parameters and achieved a maximum MPICH bandwidth of 666 Mbps. The bandwidth and latency of GA put/get operations were better than the corresponding MPICH send/receive ones. We also examined the NFS, PVFS2, and Lustre parallel filesystems and Lustre provided the best read/write bandwidths with more than 90% of those of the local filesystem.
Oil palm frond is known to be the largest contributor to the oil palm residues, providing
up to 50.3% of the total residues. Since it has a very limited utility, an initiative was taken
by this study to investigate its suitability for bio-oil production. Hence, slow pyrolysis was
conducted in an experimental setup equipped with a fixed bed reactor and a liquid collection
system. From the experiments, the effect of reaction temperature on the bio-oil yield was
examined. The characteristics of the obtained bio-oil were also investigated to study its
potential as a substitute of phenol. It was found that at reaction temperature of 375oC,
highest yield of bio-oil was obtained at 38.4 wt%. Meanwhile, the characteristics of oil palm
frond and its bio-oil were found to be approximately similar to the characteristics of typical
softwoods and their bio-oil. Most softwood biomass has been successfully used as a phenol
substitute. Therefore, the potential of this bio-oil to be used as a phenol substitute was
enhanced.
The government’s science and technology (S&T) apparatus is now in active consultation to formulate the third national S&T policy (NSTP3) and I have been involved in some of these meetings and have benefitted from them. In an earlier article (New Straits Times, 9 July 2011, p. 18) I had briefly described the two previous policies and given some thought on what the essentials of the NSTP3 should be. I am now offering some further thoughts on the subject. (Copied from article).
Ozone generator system using discharge coronas was fabricated to produce ozone gas and
ozonated water of varying concentration. The generated ozone air emitted to the water
through bubble diffuser or venturi injection depending on the input air mass transfer rate.
The concentration of ozonated water was examined using both ozone test strip and Schoenbein
paper. It is found that the production of ozone water by using bubble diffuser technique
facilitates the production of higher concentration of ozonated water with higher ozone transfer
efficiency. The efficiency of ozone gas in microorganism treatment is verified through the
lowest number of microorganism’s colony available compared with other treatment methods.
The half-life of ozonated water in this study was improved by increasing the transfer rate
of water and solubility of ozone in water. The concentration of ozonated water was found
increased through the application of pressurised oxygen input gas.
Corrosion is a natural deterioration process that destructs metal surface. Metal of highly
protected by passivation layer such as Stainless Steel 316L also undergoes pitting corrosion
when continuously exposed to aggressive environment. To overcome this phenomenon, application
of epoxy based coating with addition of zinc oxide- poly (3,4-ethylenedioxythiophene)
doped with poly (styrene sulphonate) hybrid nanocomposite additive was introduced as
paint/metal surface coating. The compatibility between these two materials as additive
was studied by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD),
Field Emission Scanning Electron Microscopy/Energy-Dispersive X-ray spectroscopy (FESEM/EDX)
and Transmission Electron Microscopy (TEM) analysis. The effect of nanocomposite
wt.% in epoxy based coating with immersion duration in real environment on corrosion
protection performance was analyzed through potentiodynamic polarization analysis. The
main finding showed that addition of hybrid nanocomposite had increased corrosion protection
yet enhanced corrosion process when excess additives was loaded into epoxy coating.
Addition of 2 wt.% ZnO-PEDOT:PSS was found significantly provided optimum corrosion
protection to stainless steel 316L as the corrosion rate for 0 day, 15 days and 30 days of
immersion duration is 0.0022 mm/yr, 0.0004 mm/yr and 0.0015 mm/yr; respectively.
Oxidative stress (OXS) has been associated with many diseases such as neurodegenerative diseases, cancer, diabetes and osteoporosis as it can alter cellular components in the body. Oxidative stress can be neutralised by anti-oxidative compounds found in many natural products such as berries, turmeric and figs. The objective of this paper is to evaluate the anti-oxidative and anti-inflammatory properties of figs. Fig, or its scientific name Ficus carica (F. carica), is one of the fruits mentioned in the Quran and is known among the Malays as ‘buah tin’. Electronic databases used were Scopus, Ovid, Proquest and Science Direct. The inclusion criteria were studies that utilised the fresh, dried, juice, extract of F. carica, written in English, published within 2007 to 2017, studies carried out in tissue culture and animal studies. Anti-oxidative effect, lipid peroxidation inhibition and anti-inflammatory were the key outcomes in this review. A total of 19 studies met all the criteria. The results showed that treatment with F. carica increased anti-oxidative enzymes such as catalase, superoxide dismutase, glutathione peroxidase and decreased lipid peroxidation activity. F. carica also reported to reduce pro-inflammatory cytokines such as interleukin-1 (IL-1), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) in acute and chronic inflammation. In conclusion, F. carica exhibited anti-oxidative and anti-inflammatory properties.
Transition metals play an important role in the growth of carbon nanotubes (CNTs). Series of unsupported hybrid catalysts consisting of Ni:Cu, Ni:Cr, and Ni:Mn doped with Nd catalyst, respectively were synthesized by impregnation method. The catalytic performance of the catalyst for the production of CNTs was measured in the pyrolysis process of hydrocarbon source by catalytic chemical vapour deposition method. Acetylene gas was used as the source of carbon in the pyrolysis process. The decomposition of acetylene was carried out at 700ºC. The bulk properties of the catalysts were investigated by X-ray diffraction. Field emission scanning electron microscopy and thermal analysis were used to observe the morphology and thermal stability of the as-synthesized CNTs, respectively. Hybrid catalyst of Ni:Mn/Nd and Ni:Cr/Nd in 3:1 atomic ratio gave high percentage of carbon yield which was assigned for the high production of CNTs with the mass of yield 18 times greater than the initial mass of the catalyst used.
In this paper, an improved method of reducing ambient noise in speech signals is introduced. The proposed noise canceller was developed using a computationally efficient (DFT) filter bank to decompose input signals into sub-bands. The filter bank was based on a prototype filter optimized for minimum output distortion. A variable step-size version of the (LMS) filter was used to reduce the noise in individual branches. The subband noise canceller was aimed to overcome problems associated with the use of the conventional least mean square (LMS) adaptive algorithm in noise cancellation setups. Mean square error convergence was used as a measure of performance under white and ambient interferences. Compared to conventional as well as recently developed techniques, fast initial convergence and better noise cancellation performances were obtained under actual speech and ambient noise.
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.
Inter-simple sequence repeats (ISSRs) are regions in the genome flanked by microsatellite sequences.
PCR amplification of these regions using a single primer yields multiple amplification products that can
be used as a dominant multilocus marker system for the study of genetic variation in various organisms.
ISSR markers are easy to use, low-cost, and methodologically less demanding compared to other
dominant markers, making it an ideal genetic marker for beginners and for organisms whose genetic
information is lacking. Here, we comment upon some of the intricacies often overlooked in designing an
ISSR experiment, clarify some misconceptions, and provide recommendations on using ISSR markers
in genetic variation studies.
Brick-and-mortar business activities are gradually being replaced by e-commerce worldwide. The number
of transactions and revenue should be correspondingly higher but due to the increase in the number of
fraudulent cases, especially unauthorised use of credit cards, the record remains unbreakable. The use
of biometrics is an optimal solution to safeguard the online user’s identity integrity. However, the best
practicable way onimplementing biometrics with e-commerce is still in progress. The online user’s identity
integrity is important because a secure transaction that increases user confidence will directly encourage
more business. Motivated by the idea “Attack is the best form of defence”, hackers and imposters should
be misled, traced and penalised accordingly in a proactive approach. In this paper, an intelligent stateof-the-art
identity integrity safeguard framework encompassing fingerprint technology, a hiddenrisk
analysis agent mechanism and real-time reporting is proposed. Since e-commerce is ubiquitous, it is
possible to determine online users’ attitudes from different countries which enables collaboration with a
French research unit. The findings would be significant to cyberlaw makers and e-commerce merchants
to promote a secured e-commerce application from the online user’s perspective and consequently
extend the findings to the m-commerce platform.
Wood density and types of shrinkage were examined in two rubberwood latex timber clones of rubber (Hevea brasiliensis) namely RRIM 2020 and RRIM 2025, planted at densities of 500, 1000, 1500, and 2000 trees/ha, within a trial plot. The mean wood density showed a low descending trend towards high planting densities in both clones. Wood density was significantly and negatively correlated with planting density. The strength of correlation was moderate. The mean longitudinal shrinkage in both clones and tangential shrinkages in clone RRIM 2020 showed no significant difference among planting densities. The tangential (in RRIM 2025), radial and volumetric shrinkages in both clones decreased from low to high planting densities and the differences were more pronounced between densities of 500 trees/ha and 2000 trees/ha. The magnitudes of correlation between these shrinkages and planting density were low. The regression models indicated that wood density could be more ascribed by planting density followed by volumetric shrinkage. This study exhibited low variations in wood density and shrinkages among clones and the respective planting densities; however, RRIM 2025 was more stable than RRIM 2020.
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.
This study examined the effect of honey in gellan gum (GG) hydrogel containing virgin
coconut oil (VCO). Their mechanical, physical, thermal properties and in-vivo healing potential
on dermal wounds were investigated. The compression performance results show that
the inclusion of honey into gellan gum incorporated VCO (GGVCOH) hydrogel improved
the compressive stress of the materials by 3-fold and workable to be applied on the different
contours of human body. Swelling ratio of GVCO hydrogels increased upon addition of
honey, and water transmission rates (WVTRs) values of all hydrogels were in the range of
112-132 g m−2 d
−1
, in which comparable to WVTRs values of commercial wound dressings.
Thermal behavior shows the inclusion of honey in GVCO hydrogels improved the thermal
stability particularly at high concentration. In-vivo healing on dermal wounds exhibits that
the inclusion of honey accelerated the wound closure and shows complete neo-epidermal
of the wounds. The GVCOH hydrogel has shown promising results to treats acute wound
treatments.
An efficient erbium/ytterbium co-doped fibre amplifier was demonstrated by using a dual-stage partial doublepass structure with a band-pass filter (BPF). The amplifier achieved the maximum small signal gain of 56 dB and the corresponding noise figure of 4.66 dB at 1536 nm with an input signal power and total pump power of –50 dBm and 140 mW, respectively. Compared with a conventional single-stage amplifier, the maximum gain enhancement of 16.99 dB was obtained at 1544 nm with the corresponding noise figure was improved by 2 dB. The proposed amplifier structure only used a single pump source with a partial double pass scheme to provide a high gain and dual-stage structure to provide the low noise figure.