Repairing and commissioning of an AC motor speed controller for a centrifugal pump

A centrifugal pump was installed in 1984 in the Fluid Mechanics Laboratory of Mechanical Engineering Department of Rajshahi University of Engineering & Technology. The motor of the centrifugal pump was dc motor and was not working. It could not be commissioned for a long time because of the damaged speed controller. The main shaft (rotor) was also jammed. In this project work, the dc motor was tried to repair. But it could not be run because the specification of the motor and the operating manual was not available. To complete the project successfully, the dc motor was replaced by an ac induction motor. After replacing the motor, the speed of the new motor was controlled by a variable frequency drive (VFD). Using this device, the speed was controlled from 600 rpm to 3000 rpm smoothly. After the replacement, the testing of the centrifugal pump was successfully performed and the motor was controlled in various speeds. Experiment on the performance test of the centrifugal pump was carried out satisfactorily running the pump in various speeds operated by the VFD

Mechanical and Thermal Properties of Graphene over Composite Materials: A Technical Review

The recent years have seen numerous developments in the research and headway of graphene, the thinnest two-dimensional nuclear material. Graphene-based materials and their composites have promising applications in an extensive variety of fields; for example, gadgets, biomedical guides, films, adaptable wearable sensors, and actuators. The most recent investigations and movement in this branch of knowledge regularly deliver conflicting or uncertain outcomes. This article evaluates and outlines the distributed information in order to give a basic and complete diagram of the cutting edge. Initially, the particular basic nature of accessible graphene materials is illustrated as well as the distinctive generation methods accessible thus far. The appraisal at that point talks about the different composites that center diverse sub-practical routines; for example, mechanical and aggregate utilitarian applications (e.g., vitality, hardware biomedical, layers, and sensors). The use of graphene and its subsidiaries in the fabricate of nanocomposites with various polymer frameworks has been inspected. And finally, an ending and point of view are given to talking about the rest of the difficulties for graphene nanocomposites in useful science and building

Evaluation of 130 Eggplant (Solanum melongena L.) Genotypes for Future Breeding Program Based on Qualitative and Quantitative Traits, and Various Genetic Parameters

Eggplant is an essential widespread year-round fruit vegetable. This study was conducted using 130 local germplasm of brinjal to select diverse parents based on the multiple traits selection index for the future breeding program. This selection was performed focusing on 14 qualitative and 10 quantitative traits variation and genetic parameters namely, phenotypic and genotypic variance (PV and GV) and genotypic and phenotypic coefficients of variation (GCV and PCV), broad-sense heritability (hBS), genetic advance, traits association, genotype by trait biplot (G × T), heatmap analysis and multi-trait index based on factor analysis and genotype-ideotype distance (MGIDI). Descriptive statistics and analysis of variance revealed a wide range of variability for morpho-physiological traits. Estimated hBS for all the measured traits ranged from 10.6% to 93%, indicating that all the traits were highly inheritable. Genetic variances were low to high for most morpho-physiological traits, indicating complex genetic architecture. Yield per plant was significantly correlated with fruit diameter, fruits per plant, percent fruits infestation by brinjal shoot and fruit borer, and fruit weight traits indicating that direct selection based on fruit number and fruit weight might be sufficient for improvement of other traits. The first two principal components (PCs) explained about 81.27% of the total variation among lines for 38 brinjal morpho-physiological traits. Genotype by trait (G × T) biplot revealed superior genotypes with combinations of favorable traits. The average genetic distance was 3.53, ranging from 0.25 to 20.01, indicating high levels of variability among the germplasm. The heat map was also used to know the relationship matrix among all the brinjal genotypes. MGIDI is an appropriate method of selection based on multiple trait information. Based on the fourteen qualitative and ten quantitative traits and evaluation of various genetic parameters, the germplasm G80, G54, G66, and G120 might be considered as best parents for the future breeding program for eggplant improvement