Abstract
Plankton is the primary food sources for many fish larvae as well as other organisms during their early stage of development. Zooplankton such as copepods play a major role in freshwater and ...marine environment as live food that offer great variety of sizes, species and nutritional value to the larvae. The aim of this study is to increase the nutritional value of copepod and its effect on
Penaeus monodon
post-larvae growth performance. The experiment was carried out 30 days and comprised with four different treatments of diets. The diets fed to copepod consisted of algal diet which is
Tetraselmis
sp. that acted as a control followed by three types of vegetable-based diet which is carrot, water spinach, and lettuce. The efficiency of the copepods enriched was further evaluate on its growth, survival and proximate composition. The outcome of the study showed that highest specific growth rate (SGR) in
P.monodon
post-larvae was obtained when fed with copepods enriched water spinach (11.28±0.38%) and the highest survival rate of
P.monodon
was obtained when being fed with copepods enriched
Tetraselmis
sp. (91.67±0.29%). Proximate analysis composition for enriched copepods and
P
.
monodon
fed with enriched copepods showed the water spinach produce highest protein and lipid content compared to other enrichment. The current result showed that vegetable based are able to replace the microalgae, hence it also can gave an advantages to the economy in aquaculture and higher yields.
Commercially available oral rinses, containing chlorhexidine are effective in treating and preventing oral infections but they can cause unpleasant taste and staining of teeth and are not advocated ...for long- term oral care. Hence comes the need for an alternative remedy with reduced side effects that is suitable for daily regime. Coleus blumei has been reported to contain phytochemicals that are active against oral bacteria. The objective of this study is to determine the phytochemicals content of C. blumei leaves extract and its potential as an antibacterial agent to treat oral infection as alternative to chlorhexidine. C. blumei extract was first screened for its phytochemicals content and was later screened for its antibacterial activity against Staphylococcus aureus and Streptococcus mitis using disc diffusion method. The extract was tested to find the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) for both bacteria. The phytochemicals screenings showed that the extract contains flavonoid, terpenoid, tannin and saponin. At a concentration of 100 mg/ml, the extract showed antibacterial activity against both bacteria, S. aureus (14.56 mm) and S. mitis (13 mm), with Percentage of Relative Inhibition Zone Diameter (% RIZD) of 35% (S. aureus) and 65% (S. mitis). The extract was shown to have similar effects as Oradex oral rinse (0.12% chlorhexidine), with 15.67 mm inhibition zone and % RIZD of 38% for S. aureus, and 15mm with % RIZD of 75% for S. mitis. The MIC results shows that the extract was most effective against S. aureus, as the MIC was determined at the lowest concentration of 1.5625 mg/ml and the MBC was determine at the concentration of 100 mg, 50 mg/ml, 25 mg/ml, 12.5 mg/ml, 6.25 mg/ml and 3.125 mg/ml. For S. mitis, the MIC was determined at the concentration of 25 mg/ml, with MBC value at the highest concentration of 100 mg/ml. These results suggest that C. blumei extract possesses antibacterial effects against oral bacteria similar to Oradex and therefore has the potential to be used as an oral rinse in the future.
Lift enhancement by using passive vortex trapping technique offers great advantage in small aircraft design as it can improve aerodynamics performance and reduce weight of the wing. To achieve this ...aim, a qualitative study on the flow structures across wing models with cavities has been performed using smoke wire visualisation technique. An experiment has been conducted at low Reynolds number of 26,000 with angle of attack (α) = 0°, 5°, 10° and 15° to investigate the vortex trapping capability of semi-circular leading edge (SCLE) flat-plate wing model and elliptical leading edge (ELE) flat-plate wing model with cavities, respectively. Results from the qualitative study indicated unique characteristics in the flow structures between the tested wing models. The SCLE wing models were able to trap stable rotating vortices for α ≤ 10° whereas the ability of ELE wing models to suppress flow separation allowed stable clockwise vortices to be trapped inside the cavities even at α > 10°. The trapped vortices found to have the potential to increase lift on the unconventional wing models.
In this work, hydrate liquid vapor equilibrium conditions for methane (CH4) gas is measured in the absence and presence of different aqueous TEACl concentrations. The temperature cycle (T-cycle) ...method has been used for the hydrate equilibrium temperature of CH4 + H2O + TEACl system measurement within the pressure ranges of 3.90 - 8.30 MPa. Results reveal that, for 10 wt% aqueous TEACl average of suppression temperature (ΔT) (inhibition effect) appeared of 0.9 K for CH4 hydrate. Additionally, the enthalpy of dissociation for methane gas hydrate with and without the present of inhibitor is calculated using Clausius-Clapeyron equation.
In a wastewater treatment by using membrane filtration, fouling has been one of the major problems. In this study, the anti-fouling behaviour of the fabricated thin-film composite membrane were ...studied during the treatment of water containing copper ion. The membranes were prepared from a polymer blend of 2wt.% chitosan with 10 wt.% poly(vinyl alcohol) (PVA) and then it was cross - linked with tetraethylorthosilicate (TEOS) through sol-gel method. The membrane had been evaluated for its resistance against organic fouling where humic acid had been chosen as organic foulant model which represent the natural organic matter (NOM) in water or wastewater. The dead-end filtration experiments were carried out by using 50 ppm of copper solution with and without the presence of humic acid as feed solution, which was passed through two types of thin film composite membranes. The possible reversible fouling was evaluated by using relative flux decay (RFD) and relative flux recovery (RFR) calculations. The percentage of copper ion removal was evaluated by using Atomic Absorption Spectroscopy (AAS). Based on the results, with the presence of humic acid, the membrane incorporated with silica precursor (TEOS) showed lower flux decay (3%) and higher flux recovery (76%), which show that the formulated hybrid membrane possesses the anti fouling property. The same trend was observed in the mechanical properties of hybrid membrane, where the presence of TEOS has improved the tensile strength and flexibility of the membrane. Therefore, the fabricated thin film composite with the anti-fouling properties and good physical flexibility has potential to be used in the treatment of wastewater containing heavy metal as it could result in good saving in term of operational cost.
Micro-hydrokinetic turbine (μ-HKT) technology is considered a viable option for sustainable, green and low cost power production. In recent years, there is growing number of research and development ...on this technology to replace conventional power production systems such as fossil fuel as well as to provide off-grid electrification to communities in remote areas. This paper provides an overview of μ-HKT system, the implementation of the technology and the potential of using μ-HKT in Malaysia. A review on the climate in Malaysia shows that its average annual rainfall is higher than the world's average annual rainfall. It contributes to the total hydropower resource of about 29,000 MW which is available all year-round. Currently, hydropower resource contributes only 7.4% of the total electrical power production in Malaysia but is expected to increase with the main contribution coming from μ-HKT. However, the μ-HKT technology has not been adopted in Malaysia due to some challenges that hinder the development of the system. This paper reviews the μ-HKT technology and its potential for application in Malaysia, particularly in remote areas.
Aim: Harpaticoid copepods, an important component of fauna in marine environment, play a vital role in aquatic food webs as a source of food for other member of benthic community and the juveniles of ...predator fish species. Recent data on benthic plankton and nekton composition in coastal wetland of Setiu are useful and important in understanding the interaction between these organisms at different seasons. This maintains the diversity offish in Setiu Wetland which is a majorfactor in developing the Wetland as a place for ecotourism and recreational fishing activity. The effort will directly or indirectly benefit the fisheries community living within the wetland which depends on the fisheries sector. Methodology: Meiobenthos samples were collected by Ponar grab. The samples were fixed in 10% formalin and 1% Rose Bengal. Content of each specimen bottle was filtered through 102 pm and 62 pm sieve shaker, respectively. Harpacticoid were individually hand sorted and counted under dissecting microscope. Data obtained for harpacticoid composition were analyzed using Kruskal-Wallis test. Results: Seasonal variation of harpacticoid composition for 100 pm sizes recorded the highest number during pre-monsoon with 3591.84 ind 10 cm'2followed by monsoon, 2569.68 ind 10 cm'2 and post-monsoon 1545.84 ind 10 cm-2, respectively. Salinity is the main physical parameters that can be attributed to the plankton diversity and acts as limiting factor that influences the distribution of plankton community. Significantly, harpacticiod copepod steadily increased during post-monsoon with rising trend of salinity verified the environmental influences on zooplankton abundances. Interpretation: The results of this study indicated that different season demonstrated major impact on harpacticoid composition which may effect the avaibility of food source towards the small fishes as a live feed.
The biodegradable and non-toxic Bioflocculants have attracted considerable interest as alternative to non-biodegradable chemical flocculants. However, the cost of fermentation media for bioflocculant ...production and low flocculation efficiency is a major challenge. In this study, we grow Bacillus spp isolated from sediment of local clay pot on spoilt orange juice to produce bioflocculant. The culture supernatant of the bacilli grown on spoilt orange juice were screen for bioflocculant production using Jar test method and Kaolin clay suspension as model wastewater. The effect of pH and temperature on the bioflocculant production were also studied. The effect of cations on bioflocculation rate of the bioflocculant produced were tested via hybridization of the bioflocculant with the cations. The bioflocculation efficiency of the bioflocculant on sample wastewaters were also determined. The bacilli isolated initially had flocculation rate between 31.1±1.6 % to 76.4±1.2% when cultured on screening media. Bioflocculation rate peaked to 77.9% at 40 oC while the lowest flocculation rate (55.41%) was obtained at 25 oC. The optimum bioflocculant production (about 78%) was recorded at pH 6 – 7 while the highest bioflocculant production (84.2%) was achieved at 96th hour of incubation. Na+ and Fe3+ had serious inhibitory effect on the bioflocculant while K+, Ca2+, Mg2+ and Al3+ had less or no effect on the bioflocculant. The bioflocculant had up to 77.7% and 64.5 % on Kitchen wastewater and aquaculture wastewater. This study reveals the potential for utilization of spoilt orange juice as fermentable substrate for bioflocculant production especially if the fermentation conditions and flocculation parameters are well optimized.
Measurement of the diaphragm electromyogram (EMGdi) elicited by phrenic nerve stimulation could be useful to assess neonates suffering from respiratory distress due to diaphragm dysfunction, as ...observed in infants with abdominal wall defects (AWD) or congenital diaphragmatic hernia (CDH). The study aims were to assess the feasibility of recording EMGdi using a multipair oesophageal electrode catheter and examine whether diaphragm muscle and/or phrenic nerve function was compromised in AWD or CDH infants. Diaphragm compound muscle action potentials elicited by magnetic phrenic nerve stimulation were recorded from 18 infants with surgically repaired AWD (n = 13) or CDH (n = 5), median (range) gestational age 36.5 (34-40) weeks. Diaphragm strength was assessed as twitch transdiaphragmatic pressure (TwP(di)). One AWD patient had prolonged phrenic nerve latency (PNL) bilaterally (left 9.31 ms, right 9.49 ms) and two CDH patients had prolonged PNL on the affected side (10.1 ms and 10.08 ms). There was no difference in left and right TwP(di) in either group. PNL correlated significantly with TwP(di) in CDH (r = 0.8; p = 0.009). Oesophageal EMG and magnetic stimulation of the phrenic nerves can be useful to assess phrenic nerve function in infants. Reduced phrenic nerve conduction accompanies the reduced diaphragm force production observed in infants with CDH.
Testing plays an important role in controlling and ensuring required quality and reliability of manufactured integrated circuits (ICs) before supplying them to final users. Several types of testing ...are performed at different stages of the IC manufacturing process. One of them is the so-called burn-in testing (i.e., accelerated testing performed under elevated temperature and other stress conditions). Burn-in aims to accelerate detection and screening out of so-called "infant mortalities" (early-life latent failures). Burn-in is normally associated with lengthy test time and high cost, making it a bottleneck of the entire IC manufacturing process. It is no surprise, therefore, that much attention and effort has dedicated toward possible ways of reducing or even eliminating burn-in testing in IC manufacturing (for at least some types of products). This paper presents a methodology for burn-in test time reduction based on the use of the high-voltage stress test technique. Weibull statistical analysis is employed to model the infant-mortality-failure distribution. Weibull distribution parameters were estimated using the linear rectification method. The implemented industrial experimental study showed that burn-in duration can be significantly reduced with the application of the proposed approach
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