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Climate change in polar marine ecosystems
No full textClimate change will have a significant effect on polar marine ecosystems. While primary production is likely to fall in tropical and temperate seas, it is likely to rise in polar seas. This, however, will only support shorter food chains, which will lead to a decline in major vertebrate species. In polar seas climate change will lead to increased sea-water temperatures, decreased ice cover and a lower pH. Because ice cover is largely impervious to satellite observation, our understanding of polar sea ice and under ice phytoplankton biomass and productivity is still poor. It is generally thought that sea algal communities contribute up to 25% of total annual production in ice covered seas of both Polar Regions but that annual production in the Arctic Ocean is approximately 270 Tg y-1 while in the Antarctic Ocean it is between 980 and 3620 Tg y-1. A simple model of ice reduction, due to global warming, in the Antarctic (the Arrigo and Thomas model) suggests a net increase of 21% in primary production will result in a 50% ice reduction and a further 7% with a 95% ice reduction. However, the location, concentration and position of this production are likely to be quite different to what it is now. A similar, simple model applied to the Arctic suggests that this region will also experience a significant net increase in marine primary production as more of the ocean becomes ice free in summer. A 50% reduction in summer sea ice in the Arctic Ocean would lead to at least an 80% increase in production. Once again, however, the nature, position and concentration of this production is likely to be very different from the current configuration. These changes are likely to induce major trophic realignments in both hemisphere
Pelaksanaan pengajaran dan pembelajaran kemahiran menulis di sekolah rendah
No full textThis study focused on the implementation of Malay Language writing skills in
the teaching and learning process. The respondents were selected through random
sampling among various schools in the Kuala Terengganu district. Writing skills rely on a
set of cognitive skills which can be considered very complex. Thus, teachers find it is very
hard to apply these skills, where as, the pupils struggle or not even try to develop the skills
through out the teaching and learning process in classrooms. For that reasons, a study has
been done to determine the profiency level of Malay Language writing skills among the
pupils. The finding and tools can be used as guidance for the pupils in improving their
writing schools. As for teachers, they could utilize them as alternative in teaching process.
The aim of this study is to study the teaching strategies applied by teachers and analyzing
the obstacles faced by them as well as the pupils during the Malay Language teaching and
learning process. This study has conducted in descriptive way where sets of questionnaires were used with the scale of likert 5. All data collected are processed using the SPSS version
17.0 software and the findings are further explained in quantitative way. Finding showed
that the teachers accepted that it was the teachers’ responsibility to teach writing skills,
with a highest mean score of 4.61. The report also shows that the teachers accepted the
suggestion that content used during the lesson from the range of easy to difficult, with a
highest mean score of 4.20. Findings also showed that obstacle occurred in Malay
Language teaching and learning process. Among them are lacked of knowledge and
teaching skills among teachers and the pupils’ inability in writing skills. This study found
that teachers should act positively towards the importance of writing skills and better
teaching strategies. Apart from that, teachers should overcome any obstacles occurred
during the teaching and learning process creatively. Thus, teacher conducted the lesson in
quality way and the pupils have better understanding and improving their writing skills.
Teachers should also carry out the lesson based on the latest curriculu
Effect of molecular weight on the properties of liquid epoxidised natural rubber acrylate (Lenra )/silica hybrid composites
No full textThis paper reports on the effect of molecular weight on the morphological and mechanical properties of liquid epoxidised natural rubber acrylate (LENRA)/silica hybrid composites prepared by sol-gel technique. The sol-gel reaction was conducted at different concentration of tetraethylorthosilicate (TEOS), used as a precursor of silica. TEOS were introduced in 10, 20, 30, 40 and 50 parts per hundred rubber (phr) in the composites. Two different molecular weights of ENR were used to study the effect of molecular weight on the mechanical and morphological properties of the compounds. These compounds were cured by ultraviolet (UV) irradiation. The mechanical properties were studied through pendulum hardness and scratch tests. Higher molecular weight of ENR showed better mechanical properties than lower molecular weight. Transmission electron microscope was used to determine the silica size and to study the distribution and dispersion of the silica particles. High molecular weight showed greater distribution and dispersion of silica particles with diameter of 13 nm–256 nm. Morphological and mechanical properties of LENRA/silica hybrid composites were improved by using high molecular weight of EN
A study on the potential of the periostracum of perna viridis as a biomonitoring material for Pb in tropical coastal waters based on correlation analysis
No full textThe periostracum is the outermost layer overlying the inner prismatic and nacreous layers of the shells of bivalves. In the present study, the distributions of Cd and Pb in the soft tissues (ST) and periostracum of the green-lipped mussel Perna viridis sampled from 15 sampling sites in the coastal waters of Peninsular Malaysia were determined. The concentrations of Cd (0.21-10.87 mg/g dry weight) and Pb (1.16-40.20 mg/g dry weight) in the periostracum were generally higher than those in the ST (Cd: 0.10-5.55 mg/g dry weight; Pb: 2.53-18.62 mg/g dry weight). Based on correlation analysis from nine geographical populations, the higher correlation coefficients (R values) between the periostracum-geochemical fractions of the sediments than between the ST-geochemical fractions of the sediments indicated that the periostracum could be a potential biomonitoring material for Pb. Hence, the present results supported the use of the periostracum of P. viridis as a potential biomonitoring material for Pb but not for Cd. However, more studies are warranted to verify its usefulness for the biomonitoring of heavy metal pollution in tropical coastal water
Catalytic study on TiO2 photocatalyst synthesized via microemulsion method on atrazine
No full textTitanium dioxide photocatalyst was synthesised by microemulsions method under controlled hydrolysis of titanium butoxide, Ti(O(CH2)3)CH3. The synthesised TiO2 photocatalyst was compared with Sigma-commercial TiO2 by carrying out the investigation on its properties using scanning electron microscopy (SEM), x-ray diffraction (XRD) analysis and thermal gravimetric analysis (TGA). The photocatalytic activities for both photocatalysts were studied for atrazine photodegradation
Estimation of p-adic sizes of common zeros of partial derivatives associated with a cubic form
No full textIn this paper we determined the estimate of p-adic sizes of common zeros of partial derivative polynomials associated with a cubic form whose indicator diagrams have one overlapping segment by using Newton polyhedron technique. We showed that the p-adic sizes of such common zeros can be found explicitly on the overlapping segment of the indicator diagrams associated with the polynomials
Tail dependence estimate in financial market risk management:clayton-gumbel copula approach
No full textThis paper focuses on measuring risk due to extreme events going beyond the multivariate normal distribution of joint returns. The concept of tail dependence has been found useful as a tool to describe dependence between extreme data in finance. Specifically, we adopted a multivariate Copula-EGARCH approach in order to investigate the presence of conditional dependence between international financial markets. In addition, we proposed a mixed Clayton-Gumbel copula with estimators for measuring both, the upper and lower tail dependence. The results showed significant dependence for Singapore and Malaysia as well as for Singapore and US, while the dependence for Malaysia and US was relatively weak
Evaluation of the spatial risk factors for high incidence of dengue fever and dengue hemorrhagic fever using GIS application
No full textIn Malaysia, the incidence of Dengue Fever (DF) and Dengue Hemorrhagic Fever (DHF) have risen dramatically in the last twenty years. With the use of Geographical Information System an explanation for the spread and control of these diseases can be obtained. This study aims to develop a spatial modeling that can predict the risks for DF and DHF based on environmental factors such as physical surroundings, land use, rainfall, temperature and GIS application using logistic regression. A total of 16 variables were used in the process of spatial modeling development. At the significant level of 0.05, the results of logistic regression showed that only 10 out of 16 significant variables in the modeling process. The accuracy of the resulting model is 70.3%. A crucial feature of this study is a risk area map for incidence of DF and DHF in the study area. This study also highlights the application of spatial analysis in planning and implementing the process for the prevention and control activities of DF and DHF in Malaysia
Curcuminoid compounds isolated from curcuma domestica val. as corrosion inhibitor towards carbon steel in 1% NaCl solution
No full textThe corrosion inhibitor of carbon steel in 1% NaCl solution by curcuminoids has been studied at 27oC using weight loss and electrochemical method. The determination of corrosion inhibition efficiency (%eff) utilising weight loss method at the concentration of 80 ppm showed the best result of 78.70% for third isolated fraction. Further determination utilising Tafel method showed the following results: raw pure extract of curcuminoid gave 89.88% at 50 ppm; the first isolated fraction gave 46.50% at 80 ppm; the second isolated fraction gave 44.83% at 30 ppm; and the third isolated fraction gave 92.44% at 70 ppm. Based on the analysis of Tafel extrapolation curve, the raw pure extract and the third fraction of curcuminoid acted as anodic inhibitor, whereas the first and the second fraction performed as cathodic inhibitors. The evaluations of synergism parameter (Sθ) indicate that the enhancement in inhibition efficiency towards raw pure extract was caused by the presence of second and third fractions as cathodic and anodic inhibitors. The contribution of steric hindrance of methoxy groups in curcuminoid structure causes the decrease in curcuminoid activity to be adsorbed on the electrode (carbon steel) surface
The forum on China-Africa cooperation (focac): a framework for China’s re-engagement with Africa in the 21st Century.
No full textThis article offers an examination of FOCAC as a framework for Sino-African engagement in the 21st Century. China‟s growing and expanding engagement with Africa has assumed a prominent feature of International Relations and discourses. The engagement is multifaceted, encapsulating mainly trade and related economic ties. Given China‟s fast economic and industrial growth, thirst and huge demand
for new sources of energy and other resources has been generated, bringing China closer to Africa where the availability of these resources abound. This situates China‟s renewed interest in Africa since the 21st Century. The deepening of economic involvement in Africa is realized through a mix of aid,special concessions, debt relief, scholarships, the provision of educational and medical training personnel and infrastructural investment projects. This represents a stark departure from the past
under Mao Zedong, when the relationship was guided by the ideological conflict of the Cold War and especially Beijing‟s attempts to dislodge Moscow‟s influence in the Third World. Now economic pragmatism and symbolic diplomacy appear to navigate Sino-African relations. The lynchpin of
China‟s re-engagement of African in this century is the Forum on China-Africa Cooperation (FOCAC), initiated at the Ministerial Conference in Beijing in 2000. The article explores the FOCAC framework, assesses the reality of its promises, and addresses the question of its problems and
challenges. The findings are that China‟s increased presence in Africa under the FOCAC framework has been faced with criticisms and confrontations, but the forum has equally strengthened bilateral economic relationship between China and Africa, and has provided platform for Beijing to become a serious humanitarian benefactor to Africa