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In this study, the learning of science outside the classroom is believe to be an added value to science learning as well as it offers students to interact with the environment. This study presents data obtained from two days' workshop on Lichen as Biological Indicator for Air Quality. The aim of the workshop is for the students to gain an understanding on various aspects on Lichens and its role as a biological indicator. Students are exposed to the following concepts and skills in the workshop: characteristics of algae, the concept of Lichen, causes of polluted air, the concept of quadrant, how to measure the frequency of Lichen, types of Lichen, determining the air quality index, factors determining the quality of air, the role of Lichen, the function of Lichen as a biological indicator and determining the level of air pollution. Four schools participated in the two day workshop whereby two schools were located in rural and urban areas respectively. A total of 125 students were given a pre-test on the concept of Lichen before the workshop followed by brief lecture sessions, hands-on and field work activities, presentation by students. At the end of the workshop, students were given a post-test. Overall, from the pre and post-test results, there is a significant difference in terms of students' performance from all the four schools, in knowledge and skills relating to Lichen and its role as a biological indicator in determining the quality of air.

A series of polypyrrole supported WO3 were fabricated and characterized by FT-IR, XRD, XPS, BET, TGA, and FESEMEDX. The activity of the catalysts was tested in glycerol esterification with acetic acid, and it found that WO3-Ppy-20 (nanocomposite with 20% WO3 loaded) showed the maximum catalyst activity with 98% and selectivity of 70% to triacetin at 110°C with a reaction duration of 10h and also recorded the highest selectivity (75%) for acetylation of glycerol to monoacetin with about 59% conversion only. The highest acidity of WO3-Ppy-20 is also confirmed using TPD-NH3 analysis. The activity and selectivity to triacetin of the catalyst were enhanced by increasing WO3 loading amount, resulting in 82% conversion for WO3-Ppy-5 with about 32 and 50% selectivity to monoacetin and diacetin and about 18% selectivity to triacetin; in case of WO3-Ppy-20, these amounts were changed to 5, 25, and 70% selectivity to monoacetin, diacetin, and triacetin, respectively with the conversion of 98%. TPD-NH3 analysis found that polypyrrole supported WO3 increases the catalyst acidity of WO3. BET and FES EM analyses revealed that WO3 particles were well dispersed with the smallest average size in nanocomposite compared to pure WO3, which could contribute to the high activity of WO3-Ppy catalyst for esterification of glycerol. [ABSTRACT FROM AUTHOR]

Development of a green chemistry process for the synthesis of silver nanoparticles has become a focus of interest. This would offer numerous benefits, including ecofriendliness and compatibility for biomedical applications. Here we report the synthesis of silver nanoparticles from the reduction of silver nitrate and an aqueous extract of the lichen Parmotrema praesorediosum as a reductant as well as a stabilizer. The physical appearance of these silver nanoparticles was characterized using ultraviolet-visible spectroscopy, electron microscopy, energy-dispersive spectroscopy, and X-ray diffraction techniques. The results show that silver nanoparticles synthesized using P. praesorediosum have an average particle size of 19 nm with a cubic structure. The antibacterial activity of the synthesized silver nanoparticles was tested against eight micro-organisms using the disk diffusion method. The results reveal that silver nanoparticles synthesized using P. praesorediosum have potential antibacterial activity against Gram-negative bacteria.

The dithio-carbamate anions in the title compound, [Sn(C(4)H(9))(2)(C(5)H(10)NS(2))(2)], chelate to the Sn(IV) atom, which is six-coordinated in a skew-trapezoidal-bipyramidal geometry. The mol-ecule lies across a twofold rotation axis. The crystal studied was a non-merohedral twin, the ratio of the twin components being 0.82 (1):0.18 (1).