http://103.99.128.19:8080/xmlui/handle/123456789/44 Journals published in M.E. 2026-04-09T04:53:01Z http://103.99.128.19:8080/xmlui/handle/123456789/359 NUMERICAL AND EXPERIMENTAL INVESTIGATIONS ON THE INFLUENCE OF SURFACE MODIFICATIONS INTEGRATED WITH VORTEX GENERATORS ON NACA0010 AIRFOIL Srijan Dasgupta; Kazi Afzalur Rahman; Md. Kawsar Sajib; Md. Ibrahim Khalil Tanim Vortex generators and surface modifications are done to reduce the wake region and increase the aerodynamics efficiencies of an airfoil. The performance test of NACA0010 airfoil with various types of surface modifications integrated with vortex generators and comparison to a conventional rigid body airfoil is presented in this paper. The characteristics of airfoils were tested using numerical analysis and was validated using AF100 subsonic wind tunnel testing. Both the computations and experimentations were conducted at constant chord Reynolds number of 143,500. The test data shows the comparison between conventional NACA0010 airfoil with three types of surface modifications integrated with vortex generators at an angle of attack of zero degree. This study suggests that the airfoil with strips and vortex generators tend to increase lift to drag ratio most effectively. However, addition of vortex generators and surface modification was less effective in low angle of attack. 2022-10-01T00:00:00Z http://103.99.128.19:8080/xmlui/handle/123456789/358 PERFORMANCE ANALYSIS OF R32/R600a BLEND WITH TiO2/MO NANOFLUID FOR EXISTING RESIDENTIAL AIR CONDITIONING SYSTEM Ahmed, M. I.; Ahamed, J. U.; Razzaq, M. E. A. This experimental study investigated the energy and exergy performance of R32/R600a (50:50 by mass) with TiO2 nanofluid for a residential air conditioning system which was originally designed for R22. R32/R600a has been used along with 0.01%-0.02% volume concentration TiO2 nanolubricant. Cetyl trimethylammonium bromide (CTAB) has been used as surfactant. Pressures and temperatures of different components have been recorded for measuring energy and exergy parameters. RERPROP 7 software has been used to determine the thermal properties of the refrigerants and the blend at different conditions. The results show that the R32/R600a has lower value of COP compared to R22. Numerically R32/R600a blend has 32%, blend with 0.01% nanofluid has 26% and blend with 0.02% nanofluid has 61% less COP than R22. However, refrigerating effect of the blend has increased by 10 percent compared to R22 while the blend with 0.01% and 0.02% has 20% and 9% more refrigerating effect respectively. Again, the blend without nanofluid and along with nanofluid (0.01%, 0.02%) have 25%, 7% and 3% more power consumption than that of R22 respectively. Exergy analysis shows R32/R600a blend and the 0.01%, 0.02% nanofluid have higher irreversibility compared to R22. Overall, R32/R600a blend is not suitable for retrofitting in R22 system. 2022-10-01T00:00:00Z http://103.99.128.19:8080/xmlui/handle/123456789/357 PRIORITIZING THE FACTORS INFLUENCED PARTICULATE MATTER EMISSION APPLYING FUZZY TOPSIS Zerin, N.H.; Sayem, A.S.M. Particulate matter (PM) is a key component of ambient air that has a significant influence on climate change and is harmful to human health. Particulate matter in the high atmosphere affects the earth's radiation, cloud formation, visibility of aviation traffic, and other natural processes. In contrast, particulate matter is a substantial obstacle in the lower atmosphere. The most concerning problem is that it harms human health and has a negative influence on natural systems such as forests, animals, and coastal regions. With the presence of PM, air quality continues to degrade. To address this issue, it is critical to understand the underlying causes of pollution. PM is made up of a variety of small particles that can stay in the air for a long time and enter respiratory tracts and lungs. The properties and concentration variations of PM are determined by the origin of these substances. Crystal matter, vehicle traffic and fuel burning, urbanization, industrialization, climatic change, natural resources, and other factors all contribute to significant variations in particulate matter concentrations. This research evaluated, identified, and classified the sources of PM emissions in order to address the issue in the context of Bangladesh. Furthermore, FUZZY TOPSIS logic was used to prioritize the PM variables, which would aid in understanding the dangerous causes of PM emission from all general sources. Meanwhile, the real-time air quality was examined the recent time air quality. Monthly, weekly and daily variation of PM10 was analyzed for a selected time period to clarify the aspect 2022-10-01T00:00:00Z http://103.99.128.19:8080/xmlui/handle/123456789/356 SYNTHESIS AND CHARACTERIZATION OF TiO2 AND ZnO NANOPARTICLES Das, U. D.; Ahamed, J. U.; Hossain*, M. A. Mowazzem; Razzaq, M. E. A.; Dewanjee, S.; Jisu, R. N. In this experimental study, TiO2 nanoparticles were synthesized using an ultrasound-assisted method, while the ZnO nanoparticles were fabricated using a chemical precipitation method. Results of X-ray diffraction indicate that the fabricated TiO2 nanoparticles have a tetragonal anatase phase and ZnO nanoparticles have a hexagonal wurtzite phase. The calculated crystallite size of the fabricated nanoparticles using the Debye-Scherrer formula was consistent with the values estimated using the W-H plot and SSP methods. Crystallographic parameters of the XRD patterns were used to examine the dislocation density, morphology index, and specific surface area of the synthesized nanoparticles. The SEM images demonstrated uniform TiO2 and ZnO nanostructures and suggest that both TiO2 and ZnO nanoparticles were predominantly spherical in shape. The average grain size of 50.03 nm was observed for synthesized TiO2 nanoparticles and 40.96 nm for ZnO nanoparticles. 2022-10-01T00:00:00Z