Terrain Mapping From Unmanned Aerial Vehicles

In land surveying, digital terrain model (DTM) and digital surface model (DSM) have long been benefitted in many applications related to terrain mapping. Conventional methods of generating DTM and DSM have limitations in terms of practicality, time consumption and costing. The problems are much more serious for tropical regions where clouds are persistence and tend to affect the accuracy of most of these devices. This study aims to propose a novel way of generating DTM and DSM by utilizing unmanned aerial vehicle (UAV) for different land covers including forest, plantation and developed areas in the tropical region of Malaysia. The aerial images obtained from non-matrix digital compact camera payload on UAV were processed photogrammetrically to produce terrain mapping products including DTM, DSM and orthophoto. A detailed survey is also conducted at these areas to produce contour map as benchmark data in which is less being practiced by UAV mappers. To determine the accuracy, quantitative and qualitative analysis were carried out by means of root mean square error (RMSE) and visual inspection. The results show that the RMSE of DTM for forest, plantation and developed area are ± 1.806m, ± 0.938m and ± 0.549m, respectively while for DSM are ± 3.143m, ± 0.637m and ± 0.276m respectively. This study has determined that, the development area gives the highest accuracy compared to the plantation and forested area in which for developed and plantation area the DSM is better than DTM while vice-versa for forested area. It can be concluded that the complexity if terrain is found to be one of the key factors that influences the accuracy of the generated DSM and DTM

Partial purification and characterization of lipases from thermophilic rhizopus rhizopodiformis

Lipase daripada satu stren Rhizopus rhizopodifonnis yang baru dipencilkan telah diseparatulen dan diciri. Melalui fraksi asiton, enzim telah ditulen lebih kurang 2.8 ganda, dengan pengutipan 62.5% dan aktiviti spesifik 3.2 U/mg. Dengan penurasan gel melalui Sephadex G-l00, enzim ditulenkan lagi hingga 9.7 ganda dengan aktiviti spesifik mencapai 11.1 U/mg. Dengan elektroforesis gel poliakritamida, 5 jalur protein didapati selepas fraksi asetone, sementara 2 jalur protein dilihati selepas penurasan gel Sephadex G-10. Enzim ini mempunyai pH optimum pada pH 6.0 dan suhu optimumnya ialah 45°C Enzim ini paling stabit pada pH 7.0 dan suhu 50°C Enzim mempunyai kepilihan pada trigliserida rantai pendek dan dapat menghidrolisiskan beberapa ester metit. Lipase ini spesifik pada posisi 1,3