Browsing by Author "Saifullah, Khaled"

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Effectiveness of water filters used in the households of Dhaka city
(BRAC University, 2023-07) Proma, Musharrat Shobnom; Oieshee, Monisha Hossain; Saifullah, Khaled; Tasnim, Jarin; Hossain, M. Mahboob; Nusrat, Fariha
This research aims to determine the microbiological quality of tap and filtered water and figure out the efficiency of filters used in the households of Dhaka city. To start, 51 individual samples of tap and filtered water from different areas were collected. The total Viable Count was done by spreading the samples on Nutrient Agar media. According to the study, the minimum TVC count for the tap water sample was 8.6×102 CFU/ml and the maximum was 3.4×105 CFU/ml, whereas the minimum TVC count for the filtered water sample was 5.7×102 CFU/ml and the maximum was 2.26×105 CFU/ml. The criterion for TVC is 1×103 CFU/ml, as stated by WHO and BDS (2009). WHO and BDS (2018) set 1×103 CFU/ml as the benchmark for TVC. Only 8 tap water samples and 15 filtered water samples were found to be within the range of WHO and BD standards based on the TVC values of all 51 samples. The Coliform count was performed after membrane filtration on MFC agar. In total, 51 tap water samples and 51 respective filtered water samples were spread over XLD and MacConkey agar plates. Among the samples, only 2 samples of tap water were not contaminated by E. coli, and only 4 samples of filtered water were not contaminated by E. coli. Next, different biochemical tests were performed to identify the organisms. After that, the research moved on to the Antibiotic Susceptibility Test with 12 different antibiotics. Afterward, a blood agar test and coagulase test were done to find out the pathogenicity of the organisms. These very tests were done to identify the pathogen more closely and precisely and to understand its species. All the suspected organisms showed Alpha hemolysis in the blood agar test, and 74% of organisms showed coagulase-positive results, which is alarming. Finally, to figure out the pathogenic organisms, PCR was performed. After the study of different types of filters, and testing the boiled water, it could be said that the boiled water showed less pathogenicity than some filters with high pathogenic rates.
Effectiveness of water filters used in the households of Dhaka city
(BRAC University, 2023-07) Proma, Musharrat Shobnom; Oieshee, Monisha Hossain; Saifullah, Khaled; Tasnim, Jarin; Hossain, M. Mahboob; Nusrat, Fariha
This research aims to determine the microbiological quality of tap and filtered water and figure out the efficiency of filters used in the households of Dhaka city. To start, 51 individual samples of tap and filtered water from different areas were collected. The total Viable Count was done by spreading the samples on Nutrient Agar media. According to the study, the minimum TVC count for the tap water sample was 8.6×102 CFU/ml and the maximum was 3.4×105 CFU/ml, whereas the minimum TVC count for the filtered water sample was 5.7×102 CFU/ml and the maximum was 2.26×105 CFU/ml. The criterion for TVC is 1×103 CFU/ml, as stated by WHO and BDS (2009). WHO and BDS (2018) set 1×103 CFU/ml as the benchmark for TVC. Only 8 tap water samples and 15 filtered water samples were found to be within the range of WHO and BD standards based on the TVC values of all 51 samples. The Coliform count was performed after membrane filtration on MFC agar. In total, 51 tap water samples and 51 respective filtered water samples were spread over XLD and MacConkey agar plates. Among the samples, only 2 samples of tap water were not contaminated by E. coli, and only 4 samples of filtered water were not contaminated by E. coli. Next, different biochemical tests were performed to identify the organisms. After that, the research moved on to the Antibiotic Susceptibility Test with 12 different antibiotics. Afterward, a blood agar test and coagulase test were done to find out the pathogenicity of the organisms. These very tests were done to identify the pathogen more closely and precisely and to understand its species. All the suspected organisms showed Alpha hemolysis in the blood agar test, and 74% of organisms showed coagulase-positive results, which is alarming. Finally, to figure out the pathogenic organisms, PCR was performed. After the study of different types of filters, and testing the boiled water, it could be said that the boiled water showed less pathogenicity than some filters with high pathogenic rates.
HYDROPHOBIC PROPERTY OF HANDMADE JUTE PAPER TREATED BY SIZING MATERIAL ‘ROSIN’
(Daffodil International University, 2010-01) Hossain, H. M. Zakir; Uddin, Md. Kama; Saifullah, Khaled; Rashid, M. M; Mollah, M.M
To produce hydrophobic handmade paper internal material rosin along with external additive (MCC suspension), internal additive(wax emulsion) and reinforcement were used. Optimum result was obtained when rosin along with alum was used as internal additive during pulp preparation and MCC in the form of suspension was applied as external additive. The hydrophobicity was increased by 92.46% due to rosin-alum treatment and application of MCC suspension as external additive. It was also observed that application of wax along with rosin hampered/hindered the hydrophobicity.
Study of Photovoltaic/Thermal Solar Energy Systems
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2012-10-15) Saifullah, Khaled; Nael, Mohammed; Shehada, Wael
Aiming the improvement of usage of solar thermal energy PV modules is widely used throughout the world. Due to the lack of desired level efficiency the numerous researches are carried out to escalate the output of PV modules one of the form of developed PV modules is PV/T solar system. The temperature of PV module increases while absorbing solar radiation causing the decrease of electrical output after certain level. The hybrid Photovoltaic/Thermal (PV/T) solar system enhances the output of PV module facility the harvest of both thermal and electrical energy using the same solar radiation absorbed by the same surface area. In this experiment the design of PV/T dual system is developed, using both air and water circulation as heat extraction medium modifying the air channel. The shape of painted black ribbed surfaces at the bottom of air channel has been used as trapezoidal, Saw tooth backward ,Saw tooth forward and Flat plate as reference. The capacity of all set up is similar and having same dimensions. The process of natural convection is applied to circulate the air and water to increase the system efficiency. The variation in the net output is studied due the difference of air channel.