Articles
Dovom-niasar, S.J.,
Seifi, A.,
Bahramian, A.R.,
Abzal, A. Journal of Vinyl and Additive Technology (15480585)29(5)pp. 849-863
An epoxy-based intumescent coating containing the silica and zinc borate nanoparticles was fabricated. The fire performance of the coating with the optimum formulation was investigated in terms of the changes in the physical and chemical structure of the formed char layer during the exposure to a temperature of 1000°C. The state of the chemical structure was analyzed by performing the Fourier-transform infrared spectroscopy, x-ray diffraction, and x-ray photoelectron spectroscopy analysis from the char layer at the three-time intervals of 10, 30, and 60 min of the heating process. The innovative Condorcet method was also employed to examine the changes in the physical structure of the formed char layer. Some instabilities were detected in the physical structure of the char layer in the middle period of heating. Moreover, a gradual formation of silicon carbide crystalline structure was observed on top of the surface, followed by its oxidation to silica over time. In contrast, in the bulk structure, silicon crystalline structures (Coesite) intensified with time. Boron nitride was also increasingly created on the top surface and in the bulk of the coating over the heating time. These findings proved the effective role of the silica and zinc-borate nanoparticles in the fire performance of epoxy-based intumescent coatings. © 2023 Society of Plastics Engineers.
Abzal, A.,
Saadatseresht, M.,
Varshosaz m., M.,
Remondino, F. Journal of Cultural Heritage (12962074)45pp. 204-214
In this paper, a new system for automatic drawing of bas-reliefs is presented. The system consists of a fringe projection scanner accompanied by a photometric stereo component. At first, the photometric stereo is used to accurately extract normals of the relief surface. Using a line tracing algorithm the normals are converted into 2D lines. Then, using the fringe projection scanner, the 2D lines are transformed to the 3D space to form a metric map required for cultural heritage applications. To evaluate the system, several tests were carried out using artificial and real bas-reliefs. The results showed that the system is able to draw 98.8% of the object lines correctly. © 2020 Elsevier Masson SAS
Hossein pouraghdam m., ,
Saadatseresht, M.,
Rastiveis h., ,
Abzal, A.,
Hasanlou m., CTIT workshop proceedings series (16821750)42(4/W18)pp. 483-488
In recent years, the applications of interior and exterior model of buildings have been increased in the field of surveying and mapping. This paper presents a new method for extracting a two-dimensional (2D) floor plan of a building from Simultaneous localization and mapping (SLAM)-based point clouds. In the proposed algorithm, after preprocessing, the voxel space is generated for the point cloud. Then, the optimal section of the voxel cube to generate building floor plan is identified. Finally, the linear structures and walls are extracted using the random sample consensus (RANSAC) algorithm. The proposed algorithm was examined on a collected point clouds of a building, and the walls of this building were automatically extracted. To evaluate the proposed method, the obtained walls by the algorithm were compared with the manually extracted walls. The algorithm successfully extracted almost 90% of the walls in the test area. Moreover, the average error of 3 cm for the extracted walls proved the high accuracy of the proposed method for building floor plan modeling. © 2019 M. Hossein Pouraghdam et al.
