Judul: Perilaku difusi ketoprofen melalui membran kitosan-alginat
Abstrak: Gel kitosan-alginat berpotensi sebagai membran untuk digunakan dalam sistem pengantman obat. Dalam penelitian ini, membran kitosan-alginat yang dibuat dengan mencampurkan 30 ml larutan kitosan 2.25% (blv), 5 ml algiuat 0.83% (blv), dan 1 ml glutaraldehida 4% (vfv) digunakan untuk menguji perilaku difusi ketoprofen pada suhu 37 C dan 42 C.
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Judul: Perilaku Difusi Ketoprofen Melalui Membran Gel Kitosan-CMC
Abstrak: Chitosan-carboxymethyl cellulose (CMC) gel is potential as a coating agent for ketoprofen sustained-drug-release. In the previous research, this gel has been reported to have good rheological properties as a drug delivery system, and persistent to gastric pH condition. This membrane was made by mixing 3% (w/v) chitosan, 1% (w/v) CMC, and 6% (v/v) glutaraldehyde in 30:5:1 ratio, and then poured into a mold. The membrane thickness (h) was varied by varying the volume used. Afterwards, the membrane was used for diffusion test at 37 and 42 °C temperatures (T). Three concentrations of ketoprofen in donor cell (A) were used: 25, 50, and 75 μg/ml, whereas the recipient cell was filled with ethanol-water (1:1) solvent. Aliquot was taken from recipient cell every 30 minutes until the equilibrium concentration (Cs) was reached. The absorbance of each aliquot was measured at wavelength of 258 nm. The Cs range obtained, namely 3.1-17,3 mg/l, had approached the ketoprofen therapy concentration (15 mg/l), so this membrane has better properties as a coating agent as compared with chitosan-alginate membrane previously reported. Further analysis using response surface method showed positive effects of A, h, and T towards flux (J) of ketoprofen through the membrane. The models obtained were Cs = 19.9277 – 0.01h – 0.3542A – 0.4069T + 0.0001h2 + 0.0013A2 + 0.0002hA – 0.0002hT + 0.00088 AT with R2 = 90.8%, and J = 6.42999 + 0.04251h +0.02198A – 0.1839T – 1.012Cs – 0.00009h2 + 0.00113A2 + 0.06862Cs 2 + 0.00078hA – 0.00040hT – 0.00040hCs + 0.00079AT – 0.01882ACs + 0.02169TCs with R2 = 98.9%. However, further morphological analysis is needed for the membrane having higher flux value.
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Judul: 3D model reconstruction using aerial photo to measure object height
Abstrak: 3D reconstruction, especially for height extraction, using digital aerial photos taken from a non-metric camera and Unmanned Aerial Vehicle (UAV) is a challenging study. The purposes of the study are to determine the factors affect the accuracy of an object’s height reveal from a 3D model and establish procedures to deliver the optimal result. Two or more overlapping aerial photos can be constructed into the 3D model by applying the principles of collinearity and epipolar geometry using 3D reconstruction algorithm. Due to the instability of non-metric digital camera, the camera must be calibrated before 3D reconstruction is processed, in that way the quality of spatial extraction can be then measured. The study is conducted using 24 megapixels resolution Sony NEX7 digital camera and Hexacopter UAV. UAV was flown to a height of 50 m, 60 m and 70 m and placed at a certain position in order to get some height variations of camera. Camera Calibration Toolbox is utilized to calculate intrinsik parameters of the camera and a specific program is developed using MATLAB in order to build the 3D model and to obtain the object’s height. The result validation is done by comparing the height from 3D model with that one measured using Electronic Total Station. The accuracy of the object’s height up to 1 mm successfully achieved, with the largest height prediction error reaches 15.2 cm at 70 m flying height above ground level and average percentage error 4.07 for 20 objects.
Keyword: 3D reconstruction, collinearity, epipolar geometry, UAV