Affordable and greener materials were extensively studied in electrode fabrication for Liion
based batteries but less interest was shown to proton battery. Hence, in this work,
a methodology on preparing a natural based binder for proton battery was reported. 2-
Hydroxyethyl Cellulose (2HEC) was chosen to replace PVDF commercial binder in electrode
for ZnSO4|MnO2 proton battery configuration. SEM image shows good surface formation
for both anode and cathode with good porous structure. OCV result shows that the cell
improved the stable voltage of reference cell of 0.7 V to 0.9 V after 24 hours. The first
discharge of the cell took 6 hours and 49 minutes at 0.005mA and shows good potential for
rechargebility test.
A 2.4 GHz variable-gain low noise amplifier (VGLNA) intended for use in a Wide-band Code Division
Multiple Access receiver was designed in 0.18 um CMOS process for low voltage and low power applications. Rivaling classical designs using voltage mode approach, this design used the current mode approach, utilizing the current mirror principle to obtain a controllable gain range from 8.26 dB to 16.95 dB with good input and output return losses. By varying the current through the widths of transistors and a bias resistor, the VGLNA was capable of exhibiting 8 dB gain tuning range without degrading the noise figure. Therefore, higher gain was possible at lower current and thus at lower power consumption. Total power consumption simulated was 4.63 mW from a 1 V supply and this gave a gain/power quotient of 3.66 dB/mW. Comparing this with available published data, it was observed that this work demonstrated a good gain tuning range and the lowest noise figure with such power consumption.
Nowadays, construction and demolition waste has become a major issue to environmental problems faced by many countries. This concern comes from the inefficiencies of waste management which includes the waste generated from construction and demolition activities. In Malaysia, there is a lack of database records on construction waste and this has affected proper management planning of the waste. As there is a lack of policy on construction waste management, control on construction waste disposal is very hazy and this has aggravated environmental problems and exhausted landfill usage and increased illegal dumping. This paper reviews the critical issues on construction waste management and also discusses several estimation models on construction waste generation from several countries. Based on the review, most of the countries faced problems regarding construction waste management and the models developed were considered as one of the methods which could be adopted for better management of construction wastes.
This study investigated the thermal properties of three room temperature curing adhesives containing nano particles which were thixotropic and shear thinning which allowed injection into overhead holes when exposed to different environmental conditions. Viscosity and shear stress of the adhesives were measured as a function of shear rate. The thermal behaviour of the adhesives were measured using dynamic mechanical thermal anylisis following exposures to different temperatures and humidities which included temperatures of 20 degrees Celcius, 30 degrees Celcius and 50 degrees Celcius, relative humidities of 65% RH, 75% RH 95% RH soaked in water at 20 degrees Celcius and placed in the oven at 50 degrees Celcius. The dynamic thermal properties reported include storage and loss modulus, the loss tangent and the glass transition temperature ( Tg ). For nano- and micro-particles filled adhesives, the Tg increased with the temperature increase, even though the adhesives was subjected to high humidity and this was due to further cross-linking. The results showed that room temperature cured epoxies were only partially cured at room temperature.
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).
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.
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.
The effects of topical application of Orthosiphon stamineus leaf extract on the rate of wound healing and histology of the healed wound were assessed. Four groups of adult male Sprague Dawley rats were experimentally wounded in the posterior neck area. A thin layer of blank placebo was applied topically to wounds of Group 1 rats. Wounds of experimental animals (Group 2 and 3) were dressed with placebo containing 5% and 10% O. stamineus extract, respectively. A thin layer of Intrasite gel® was applied topically to wounds of Group 4 animals as reference. Macroscopically, wounds dressed with placebo containing 5% (healed on day 14.50 ± 0.43) and 10% (healed on day 13.83 ± 0.21) O. stamineus extract each or Intrasite gel® (healed on day 13.13 ± 0.42) significantly accelerated the rate of wound healing compared to wounds dressed with blank placebo. Histological analysis of healed wounds confirmed the results. Wounds dressed with placebo containing 5%, 10% O.stamineus or Intrasite gel® showed markedly less scar width at wound enclosure and granulating tissue contained markedly more collagen, proliferating fibroblast with angiogenesis, and no inflammatory cells compared to wounds dressed with blank placebo. In conclusion, placebo containing 5% or 10% O. stamineus on extract-dressed wounds significantly accelerated the rate of wound healing in rats.
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.
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.
This paper demonstrates an erbium/ytterbium co-doped fi bre amplifi er (EYDFA) which used a pumping wavelength of 1058 nm, whereby the amplifi cation was assisted by the energy transfer between Yb and Er ions. The energy transfer increased the erbium doping concentration limit that was imposed by concentration quenching in erbium-doped fi bre. The optimum length was obtained at 4m~6m for erbium/ytterbium co-doped fi bre with Er ion concentration of 1000 p.p.m. This enabled the development of a compact amplifi er with a shorter gain medium compared to erbium-doped fi bre amplifi ers which use a gain medium of up to 15 m. A 1058 nm pumping wave-length was used for the EYDFA, as 1480 nm pumping resulted in severely degraded gain and noise fi gures because the energy transfer could not be achieved. The use of the optical isolator improved the small signal gain and noise fi gure by about 4.8 dB and 1.6 dB, respectively. Without the isolator, gain saturation and a noise fi gure penalty were observed due to the oscillating laser which was created at around 1534 nm by spurious refl ection. This showed that the usage of optical isolators was an important aspect to consider when designing an EYDFA.
The fabrication tolerance of a short and compact low refractive index grating waveguide polarisation splitter based on the principle of resonant tunnelling was analyzed in this study. The design utilised two grating waveguides with an intermediate conventional waveguide layer. The design and optimisation were conducted using the quasi 2-D effective index solver with global search algorithm. An optimum device operating at 1.55 μm wavelength was obtained at a length of 340 μm. The splitting ratios were calculated to be 36 dB and 15 dB, and the overall device transmission efficiencies, after considering the three-dimensional waveguide leakage loss, were estimated at 88% and 83% for tranverse magnetic and tranverse electric polarisation, respectively.
There are relatively little data on bacteria with antimicrobial activities from Antarctic, especially from the South Shetland Islands when compared to the other parts of the world. Hence, this project was set to isolate and characterize bacteria that produce anti-microbial compounds from Greenwich Island (one of the South Shetland Islands), Antarctica. A total of 356 strains of bacteria were isolated from Greenwich Island. They were screened for antimicrobial activities against 13 Gram-negative and one Gram-positive indicator food-borne pathogens. Two out of the 356 Antarctic bacterial strains exhibited an antagonistic effect on the indicator strains, Escherichia coli, Salmonella spp., Klebsiella pneumoniae, Enterobacter cloacae, Vibrio parahaemolyticus and Bacillus cereus. The two Antarctic bacterial strains were designated as SS157 and SR13. Biochemical and 16S rDNA analysis indicated that the strain SS157 was closely related to Pseudomonas congelans while the strain SR13 was closely related to Pseudomonas tremae. The anti-microbial compounds produced by the two Antarctic bacteria were not sensitive to temperature and were not degraded by trypsin or pronase indicating that they were likely to be chemical compounds or antibiotics. Antimicrobial compounds from strains SS157 and SR13 were broad spectrum, and targeted both Gram-positive and negative pathogens.
Recent studies by the United Nations University - Institute of Advanced Studies (UNU-IAS) demonstrate that bioprospecting is taking place in Antarctica and the Southern Ocean and that related commercial applications were being marketed. The bioprospectors’ interest in Antarctica stems from two reasons. First, the lack of knowledge surrounding Antarctic biota provides opportunities to discover novel organisms of potential use to biotechnology. Second, Antarctica’s environmental extremes, such as cold temperatures, extreme aridity and salinity present conditions in which biota have evolved unique characteristics for survival (UNU-IAS 2003). Thus bioprospecting opportunities include, inter alia, the discovery of novel bioactives in species found in cold and dry lithic habitat, novel pigments found in hyper-saline lakes and antifreezes in sea-lakes (Cheng & Cheng 1999).
Epilepsy is a neurological disorder characterized by recurrent seizures resulting from excessive abnormal electrical discharges in the brain. Medicinal plants may play an invaluable role to discover the new antiepileptic drugs. The aim of the present study was to investigate the anticonvulsant activity of α-terpineol isolated from Myristica fragrans Hountt. The α-terpineol showed a significant inhibition of the seizure episodes and spikes in absence seizures model of Genetic Absence Epilepsy Rats from Strasbourg (GAERS) rats by using electroencephalography records. It showed dose-dependent anticonvulsant activity that was comparable to the known antiepileptic drug of diazepam. It showed a rapid onset and relatively short duration of anticonvulsant effects. The present findings suggest that α-terpineol might possess antiepileptic activities against the partial seizures of human because it prevented seizures in well-established genetic absence seizure animal model of GAERS rats.
Two sequential statistical experimental designs were used to screen and investigate the dependence of the amount of biodegradation of Procion Red MX-8B (PR-MX8B) on the fermentation variables. Fourteen factors were screened using the Plackett-Burman design. Among these factors, the most significant variables which included yeast extract, corn steep solids and starch influencing PR-MX8B decolourisation were statistically elucidated for optimization. The optimum concentrations of 5.00 g/l yeast extract, 2.99 g/l starch and 1.89 g/l corn steep solids were predicted by applying the Box-Behnken design to the second order polynomial model fitted to the results obtained. The best predicted optimal conditions verified experimentally yielded 72.11% while the predicted value from the polynomial model was 79.17%. The experimental values were in good agreement with the predicted values with a 90.81% degree of accuracy.
Medical emergency on board is a new phenomenon that lack of attention. Despite the
presence of cabin crew who is certified to provide medical care to the passenger, failure to
acquire the non-technical skills and low level of knowledge and technical skills retention is
reported to be major challenges in developing a highly competent cabin crew in providing
effective medical care. Having the ability to design simulations, implement it into teaching,
and effectively evaluate simulated performance is starting to become a key role for educators
in health care. For most educators, a practical knowledge and skills gap resides between
the need for simulation learning and proficiencies in designing and utilising simulation. The
purpose of this model was to develop a ‘trained educators’ from the aviation industry with
the knowledge and skills to utilise simulation effectively. The steps involve identification,
development, and integration with a follow-up assessment. The implementation of the program
yielded a significant improvement on the participants’ knowledge, t (129) = -6.27, p
< .001 together with a total DASH-SV score of 6.32. The barriers, including difficulties
encountered executing the model, are discussed combined with the implication for future application.
This model is an effective approach for developing a trained educator in first aid
for aviation incorporated with simulation learning. The trained educator will then become
a pioneer and train another organisation.
A feasible production of poly (methyl methacrylate)@alloy (gold-silver) core shell has
been presented as candidate in enhanced detection of surface enhanced Raman scattering
(SERS). Free emulsifier- emulsion synthesised PMMA sphere with average size of 419 nm in
diameter were used as core material for incorporation of alloy nanoparticles (6 nm) resulting
a core-shell structure. The fabrication of PMMA@alloy SERS substrate was successfully
done via self-assembly thus the produced SERS substrate that comprise of unique optical
properties combination arising from periodic core arrangement and plasmonic activity of
alloy nanoparticles. Alloy is bimetallic nanoparticles in which the combination of silver
(Ag) and gold (Au) present an absolutely improved light resistance as compared to single
metal alone with great surface plasmon resonance. Morphology and elemental analysis was
performed through scanning electron microscope (SEM) and the analysis showing species of
both Au and Ag in single alloy nanoparticles. The alloy nanoparticles were also observed to
homogenously coating the PMMA sphere. Surface plasmon resonance activity was maximum
at 476 nm obtained from UV-Visible spectroscopy. High surface production was observed
to have periodically arranged PMMA@alloy core -shell and potentially to be used as SERS
substrate.
We had reviewed the current practice in stocks market analysis where stock is represented by its closing price, and then found that this approach may be misleading. In actuality, in the daily activity of stocks market, stock is represented by four prices, namely opening, highest, lowest, and closing prices. Thus, stock is a multivariate time series of those four prices and not a univariate time series of closing price only. In this paper all four prices will be considered. Then, the notion of multivariate time series similarity among stocks will be developed as a generalisation of univariate time series similarity. The results are used to construct stocks network in multivariate setting. To filter the economic information contained in that network, the standard tools in econophysics is used. Furthermore, the topological properties of stocks are analysed by using the most common centrality measures. As an example, Bursa Malaysia data are investigated and we show that the proposed approach can better figure out the real situation compared to the current one.
Giving zakat is the third of the five pillars of Islam and it is obligatory. The issues arose when the gantang
for zakat payment in Malaysia is converted to kilogramme, a metric unit for weight as usually used for
foods and there was no available standard for gantang used for zakat payment in Malaysia. However,
this unit is inaccurate since gantang (sa’) is not a measure of weight (mizan) but it is a measure of
volume (mikyal). Thus, the objective of this research is to study the volume of the sa’ and to calibrate it
in the correct metric unit for standardisation purpose. A qualitative method was used by calibrating the
gantang replica at Volume Laboratory, National Metrology Institute of Malaysia and the interviews with
State Islamic Council, State Zakat Centre and State Mufti Department. From the calibration, the capacity
of the gantang (sa’) was obtained, and subsequently, the respective capacities for cupak and agricultural
nisab were calculated. The finding of the research found that the volume of gantang was important in the
determination of nisab, a minimum amount of crop for a certain cropping season. Hopefully this research
would be a guideline for all states in Malaysia to be more systematic and efficient for the zakat agriculture
determination.