Volume 01, Issue-1, December 2023

Permanent URI for this collectionhttp://dspace.iiuc.ac.bd/handle/123456789/8469

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Now showing 1 - 13 of 13

Dynamic modeling and analysis of re-switching of an induction motor running at full load Condition
(CRP, International Islamic University Chittagong, 2023-12) Ullah, Aasim
The paper is about the study of the re-switching characteristic of an induction motor. The aim of this research is to analyze the re-switching characteristics of an induction motor and investigate the transient phenomena that occur during the switching process. The motivation behind this research is to understand the factors that influence re-switching and how it can be optimized to avoid disconnection of the machine from the power supply. To achieve this goal, the researchers performed simulations of the machine start-up and calculated various parameters such as initial torque values, steady-state values, speed vs time graph, stator and rotor flux details, and stator and rotor current details. The researchers then compared these parameters with re-switching simulated parameters of induction motor and observed transients in the re-switching case. The methods used in this study involved simulating re-switching in a re-connection situation and analyzing the resulting data using graphs and tables. The study found that different parameters influence the re-switching process and that quick re-switching is critical to prevent the machine disconnection.
Comparative valorisation on biological activities of Leea indica, Oroxylum indicum, Mikania micranth and Smilax macrophylla as a sustainable source of bioactive ingredients
(CRP, International Islamic University Chittagong, 2023-12) Islam, Mohammad Nazmul
In Bangladesh, Leea indica, Oroxylum indicum, Mikania micrantha and Smilax macrophylla have been reported to have medicinal properties to treat numerous types of diseases, such as inflammation, pain, diarrhoea, skin problems and asthma. The present study designed in a comparative manner, assesses the qualitative phytochemical analysis, cytotoxic and antinociceptive activities of methanol leaves extract of L. indica (MELI), O. indicum (MEOI), M. micrantha (MEMM), and methanol extract of S. macrophylla leaves (MESMl) and stems (MESMs). The methanol extract of each plant comprises a significant quantity of secondary metabolites in the phytochemical study. At the same time, a non-significant weak to high toxicity in the brine shrimp lethality bioassay was assessed. Acetic acid and formalin-induced antinociceptive activity demonstrated highly significant (p < 0.001) dose-dependent pain reduction at a higher dose (400 mg/kg). Hence, current findings suggest that all five methanol extracts have potential antinociception effects along with weak to high cytotoxicity. Remarkably, these plants can be a successful substitute besides agri-food substances in the treatment of nociception.
Optimization of chloride removal from tannery soaking wastewater by lime alum process
(CRP, International Islamic University Chittagong, 2023-12) Islam1, Md. Monirul; Zahid1, Rummon Bin; Raha1, Rajan Kumar; Sakib2, Md. Nazmus
Chloride removal from tannery-soaking wastewater has been a significant issue due to the presence of high levels of chloride in the wastewater produced by the tanning industry. High levels of chloride ions are harmful to human health as well as the environment if the water is not properly treated. Traditional methods like ion exchange, reverse osmosis, demineralization, coagulation, electrodialysis, precipitation, and adsorption are costly and often ineffective. The lime-alum process offers a promising alternative. This method involves adding lime and alum to the wastewater, forming hydroxide and aluminum hydroxide flocs that precipitate and remove chloride ions. Our research identified the optimal conditions for this process: a pH of 10, reaction time of 25 minutes, temperature of 25°C, and alum dosage of 0.5 grams. Under these conditions, chloride removal reached 635 mg/L. The lime-alum process is cost-effective, using inexpensive chemicals and low energy, and it can be easily integrated into existing wastewater treatment systems. These findings highlight its potential as an efficient solution for chloride removal in the tanning industry.
Evaluation of antioxidant, anti-arthritic and anthelmintic activities of methanolic leaves extract of Chaetocarpus castanocarpus (Roxb.)
(CRP, International Islamic University Chittagong, 2023-12) Khatun, Mst. Riniara
(Roxb.) leaves (MECCL). Phytochemical screenings were performed by using standard protocols. MECCL demonstrated solid free radical scavenging activity in DPPH (1, 1-diphenyl- 2-picrylhydrazyl) test, as well as total phenol and total flavonoid content were found in a quantitative assay. The topmost value of antioxidant potency (87.38%) of MECCL has exposed at 500 μg/ml concentration, whereas standard ascorbic acid reveals a 97.49% outcome at an identical concentration. However, the flavonoid and phenolic potentials of MECCL were found at 149.14± 0.084 mg QE/gm and 184.66 ± 0.064 mg GAE/gm, correspondingly. The in vitro anti-arthritic activity was appraised by protein denaturation method, whereas plant extracts proclaimed dose-dependent response working on protein denaturation method and the peak inhibition was found (60.32 ± 1.72) at 500 μg/mL concentration. MECCL also proclaimed the dose-related anthelmintic activity on aquarium worm (Tubifex tubifex) as revealed by the decreased paralyzing time and death time. So, the current research propose that Chaetocarpus castanocarpus (Roxb.) could be a better choice for managing cardiovascular disease, arthritis and helminthiasis .
Enhancement of thermoset polymer properties incorporating modified graphene
(CRP, International Islamic University Chittagong, 2023-12) Sakib, Md. Nazmus
Thermoset polymers are extensively used across various industries due to their superior mechanical and thermal properties. However, their inherent limited flexibility and low tensile strength have constrained their application in high-performance fields. This study explores the reinforcement of thermoset polymers with modified graphene, specifically graphene oxide (GO), to overcome these limitations. GO is chemically or physically treated to enhance its dispersion and compatibility with thermoset polymers. Epoxy resin is used as the thermoset polymer, and GO is incorporated in varying weight percentages (0, 0.1, 0.3, 0.5) using a solution mixing technique. The resultant GO/epoxy nanocomposites are characterized by Scanning Electron Microscope (SEM) and Energy-Dispersive X-ray Spectroscopy (EDX). Mechanical testing reveals that incorporating 0.3 wt.% GO into the epoxy matrix increases hardness and flexural strength by 11% and 28.48%, respectively, compared to pure epoxy. These findings indicate that GO-epoxy nanocomposites exhibit superior properties, highlighting their potential applications in the automotive, aerospace, and electronic industries
Gesture recognition through binary video transformation with IoT
(CRP, International Islamic University Chittagong, 2023-12) Arefin, Muhammed Nazmul
Sign language is used by those who are deaf to communicate. The use of American Sign Language (ASL) is widespread all over the world. For those who are deaf, it is problematic because many others do not understand sign language. Both deaf individuals and any service staff would greatly benefit if there was an innovative solution that could identify signs and convert them into simple English. Convolutional neural networks (CNN), one of the subtypes of neural networks, are utilized for picture applications and have a wide range of uses. For video applications with time components, we use Recurrent Neural Networks (RNN) or Long Short-Term Memory (LSTM) networks. However, these networks require a substantial amount of conditioning before producing accurate results, leading to longer processing times. In this work, we achieved improved results with 99.40% accuracy for alphabets and 99.70% accuracy for words when using CNN to recognize gestures from video.
Image based color correction for dichromatic colorblind patients
(CRP, International Islamic University Chittagong, 2023-12) Khaliluzzaman, Md.
Color correction for color blindness to understand the vision defect images is an active research area in the field of computer vision and image processing. The problem occurs due to the lack of human cone cells. For that, defective people cannot recognize specific wavelengths and colors. To mitigate this problem, we focus on fixing the color of images for dichromatic patients in this work. In this regard, the Ishihara test distinguishes the dichromatic patient. After that, the second Ishihara test is used to specifically categorize the patient, i.e., protanopia, deuteranopia, or tritanopia. These processes are used to reduce the processing time. Afterwards, the evaluation method is applied to create the image that the colourblind people originally saw. Finally, the daltonization algorithm is utilized to correct the color. The proposed method shows better results with respect to the other method and real-time images.
Investigation of some heterocyclic derivatives as sars-cov-2 main protease inhibitors: An in-silico approach
(CRP, International Islamic University Chittagong, 2023-12) Kabir, Emranul
A respiratory disease termed COVID-19 is brought on by one of the most potent ribonucleic acids (RNA) viruses. It has captivated the interest of scientists, virologists, and medical experts to create mechanisms to fight the disease. Computational research is needed on COVID-19 proteins and drugs due to their health risks. Till now, the only appropriate therapy was a vaccination. As a consequence, in the current study, a few heterocyclic derivatives with isoxazole, as well as pyrazole functionalities, are selected for docking studies with the primary proteases of SARS-CoV-2 (PDB ID: 7BQY and 6LU7). Compared to well-known antibiotics like azithromycin, remdesivir, and hydroxychloroquine, heterocyclic analogs 2-7 have significant docking scores (-8.0 to -6.2 kcal/mol). This study clearly showed that the pyrazole analogue 7 exhibited the most binding affinity with both 7BQY and 6LU7 (-8.0 and -7.1 respectively) proteins as well as the interactions between the residues of amino acid in proteins and drugs in the docked conformers to explain such high scores incorporating B3LYP and 6-31G+ DFT method.
Unleashing class imbalance problem in loan dataset through a novel oversampling approach based on FCM
(CRP, International Islamic University Chittagong, 2023-12) Akter, Subrina
Commercial companies highly depend on loan approval models trained by machine learning and statistical methods to predict loan status. However, imbalanced datasets present a key challenge in this sector. Addressing this issue, this paper proposes a new oversampling method based on Fuzzy C means clustering. This clustering algorithm assigns the instances to several groups by assigning a flexible degree of membership. K-Nearest Neighbor and the Decision Tree served as the basic classifiers in an extensive test on the Kaggle loan dataset. Three distinct imbalanced ratios—2.2, 4.2, and 8.45—were used in the experiment. The effectiveness of the recommended strategy was compared with SMOTE and WBOT using 5-fold CV. The outcomes showed that the proposed method outperformed both SMOTE and WBOT, obtaining higher average F-measure and G-mean values across the machine learning algorithms. These findings show how the suggested method may correct class imbalance while also enhancing prediction accuracy in the context of loan acceptance.
Arabic character recognition in air-writing based on motion data from 3-axis accelerometer
(CRP, International Islamic University Chittagong, 2023-12) Kader, Mohammed Abdul
Air-writing is a cutting-edge, non-touch human-machine interaction technique that enables users to input text into digital devices by moving their hands in free space, instead of using conventional input devices like keyboards and touch screens. This approach appears to be one of the most effective ways to enter text into digital systems in the future. English air-writing has received significant scholarly attention, but no studies on Arabic air-writing were found. In this research, a system is developed to recognize Arabic characters in air-writing based on motion data from a 3-axis accelerometer. A data acquisition system is constructed to record hand movements during air-writing. Each Arabic letter is written 25 times in the air using this data acquisition system, and a motion-sensor-based Arabic air-writing dataset is prepared. Using this dataset, several supervised machine learning models have been trained, and their accuracy has been determined. It is observed that the Fine KNN and Quadratic SVM models have demonstrated the highest accuracy (98.5%) in identifying Arabic characters from air-writing among the various available supervised machine learning models.
A wideband ENG meta-atom for microwave applications
(CRP, International Islamic University Chittagong, 2023-12) Islam, Sikder Sunbeam
Effective medium ratio (EMR) is an important parameter for a meta-atom for ensuring its emerging performance those not naturally available. This paper depicts an effective medium obeying new meta-atom that shows epsilon negative (ENG) property in the wideband region of microwave electromagnetic regime. Initially, the simple basic unit cell (atom) structure was designed on Rogers RT6010 substrate material that displays nearly 3 GHz epsilon negative property with good effective medium ratio (EMR). The structure shows better performance with more than 3GHz ENG property with better EMR in the microwave region when it was designed on FR-4 substrate material. A material with good ENG property can be utilized in many important electromagnetic applications. Finite integration technique-based CST microwave studio software was used to investigate the characteristics of the unit cell. The simple construction, good EMR and wide band ENG property has made the design significant for the electromagnetic microwave operations.
In vitro antimicrobial and antiarthritic effects of methanolic extract of Zanthoxylum rhetsa leaves
(CRP, International Islamic University Chittagong, 2023-12) Sayeed, Mohammed Abu; Ali, Md. Sekendar; Chowdhuy, U Swe Sing; Islam, Ameerul; Ruzzama, Naiya; Muzammil Ahmad; Azad, Afrina
The antimicrobial study of Zanthoxylum rhetsa leaves methanol extract was evaluated by the disc diffusion method against some pathogenic organisms. It exhibits the activity against almost all the test bacterial and fungal species with the zone of inhibition from mild to moderate in different concentrations- 100, 300 and 500 μg/disc where microbial species exhibits from minimum 10 to maximum 27 mm zone of inhibition. The Antiarthritic test have also done by using six concentrations for UV absorbance of test solution, product control solution, test control solution and percentage of inhibition of methanolic extract of Z. rhetsa with comparison of standard Diclofenac sodium in different concentrations like 31.75 μg/mL, 62.5 μg/mL, 125 μg/mL, 250 μg/mL, 500 μg/mL and 1000 μg/mL where different concentrations showed an increase in all the parameters that was significant from test, control and standard groups. The present study indicates that, the extract has both antibacterial and antifungal activity from mild to moderately in different concentrations and has significantly antiarthritic activities.
Optimization of thickness and dye loading time for p25 based dye-sensitized solar cell
(CRP, International Islamic University Chittagong, 2023-12) Choudhury, Md. Shamimul Haque
In this study, TiO2-based DSSCs are prepared using the Blade coating technique to find the suitable photoelectrode thickness and optimum dye loading time. The dye loading time is varied from 14 to 26 hours for the photoelectrode thickness of 5 to 30 μm. Photovoltaic performance is measured for the cells under various thicknesses and different dye loading times using a solar simulator. The surface morphology has been observed using a scanning electron microscopy (SEM) image for the photoelectrodes having various thicknesses. The result shows that a smaller thickness of photoelectrode (5 μm) requires relatively less dye loading time of about 14 hours for optimum photoelectric performance. For higher thicknesses (greater than 12 μm), the optimum dye loading time is relatively higher. At 12 μm the maximum solar conversion efficiency has been obtained where the dye loading time was about 18 hours. SEM image confirms a smooth and clean surface morphology for the 12 μm photoelectrode cell compared to other photoelectrode cells.