5,734 research outputs found

    Polycyclic aromatic hydrocarbons (PAHs) in air and vegetation: case study at three selected toll stations along North South Expressway in Johor, Malaysia

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    Polycyclic aromatic hydrocarbons (PAHs) from vehicular emission are products of the incomplete combustion of organic fuel, and are usually attached to the particulate matter from the emission and can caused pollution and hazard to human health due to its carcinogenic, mutagenic and teratogenic characteristics. The objective of this study is i) to determine the concentration PAHs in the air of sampling area, ii) to determine the concentration PAHs in vegetation, iii) to determine the relationship of concentration of PAHs in plants and air of sampling area and iv) to study the different composition of PAHs in different species of plants to determine the potential biomonitoring agent. The study is carried out at three toll stations along PLUS’ North-South Expressway in Johor. Air sample and plant leaves sample collected were extracted with ultrasonic agitation in dichloromethane and fractionated according to polarity before submitted to gas chromatography – mass spectrometry analysis to determine the concentration of the PAHs compounds. Spearman’s rank correlation test was carried out using SPSS to determine the correlation between concentration of PAHs in air and plant leaves sample. Seven PAHs were identified and quantified in the atmospheric sample and plant leaves sample. Those PAHs were acenaphtylene (ACN), phenanthrene (PHE), fluorene (FL), pyrene (PY), chrysene (CHR), benzo[a]anthracene (BaA), and benzo[a]pyrene (BaP). Significant correlation at 0.05 level (2-tailed) was observed in samples of Ficus microcarpa, Cordyline fruticosa, Hibiscus spp., and Ixora coccinea with the value 0.622, 0.643, 0.680 and 0.608 respectively. The positive correlation shows that the plants have capabilities to absorb organic pollutants from the environment. Based from this research, the most suitable species to be introduced into the environment as a biomonitoring agent and to be further studied as a medium for low and medium level pollution bioremediation is Ficus microcarpa, Cordyline fruticosa, and Ixora coccine

    Positive linear functionals on BP*-algebras

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    Let A be a BP*-algebra with identity e, P_{1}(A) be the set of all positive linear functionals f on A such that f(e) = 1, and let M_{s}(A) be the set of all nonzero hermitian multiplicative linear functionals on A. We prove that M_{s}(A) is the set of extreme points of P_{1}(A). We also prove that, if M_{s}(A) is equicontinuous, then every positive linear functional on A is continuous. Finally, we give an example of a BP*-algebra whose topological dual is not included in the vector space generated by P_{1}(A), which gives a negative answer to a question posed by M. A. Hennings.Comment: This is an English translation of the original article written in Frenc

    On saturated uniformly A-convex algebras

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    Following ideas of A.C.Cochran, we give a suitable definition of a saturated uniformly A-convex algebra. In the m-convex case, such algebra is a uniform topological one.Comment: 6 page

    On a conjecture concerning some automatic continuity theorems

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    Let A and B be commutative locally convex algebras with unit. A is assumed to be a uniform topological algebra. Let h be an injective homomorphism from A to B. Under additional assumptions, we characterize the continuity of the homomorphism h^(-1) / Im(h) by the fact that the radical (or strong radical) of the closure of Im(h) has only zero as a common point with Im(h). This gives an answer to a conjecture concerning some automatic continuity theorems on uniform topological algebras.Comment: 5 page

    A real seminorm with square property is submultiplicative

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    A seminorm with square property on a real associative algebra is submultiplicativeComment: 3 page

    A remark on continuity of positive linear functionals on separable Banach *-algebras

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    Using a variation of the Murphy-Varopoulos Theorem, we give a new proof of the following R.J.Loy Theorem: Let A be a separable Banach*-algebra with center Z such that ZA has at most countable codimension, then every positive linear functional on A is continuous.Comment: 3 page

    A real p-homogeneous seminorm with square property is submultiplicative

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    We give a functional representation theorem for a class of real p-Banach algebras. This theorem is used to show that every p-homogeneous seminorm with square property on a real associative algebra is submultiplicative.Comment: 8 page
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