Authors: Farjana Hossain, Md. Habeeb Faruk Khan
Published: 2023-June-15

EXPERIMENTAL AND NUMERICAL COMPARATIVE STUDY ON RC BEAM FLEXURALLY STRENGTHENED WITH CFRP LAMINATE

Authors: Md. Abdul Basit, Md Tanvir Ehsan Amin
Published: 2023-June-15

In this article finite element model is prepared for reinforced concrete beam which is flexurally held together by means of carbon fiber reinforced polymer laminate. The 3D analysis is conducted using ABAQUS software and the results are investigated, where maximum load, deflection at mid span and strain characteristics of both reinforcement and concrete are analyzed numerically. Later these parameters are investigated experimentally in a similar way by keeping all the important conditions such as loading, reinforcement detailing, boundary condition etc. identical. This comparative assessment illustrates that, the using of CFRP has a significant advantage to improve flexure behavior of RC beams. Various types of failure mode such as deflection and stress for whole cross section and for only reinforcement are achieved from finite element analysis. In addition, typical deflection, stress and strain contours of a specified node are found for unstrengthen and CFRP strengthened beam. This article also represents both the reinforcement strain values and concrete strain values for strengthened and unstrengthen RC beams and found a precise similarity while comparing with finite element modelling results. Furthermore, in terms of ultimate load, the deviation in result is as narrow as 4% for flexurally strengthened reinforced concrete beam by CFRP laminate.

HYBRID SWITCHING CONTROL-BASED DC TO AC INVERTER FOR MICROGRID USING RENEWABLE ENERGY SOURCES

Authors: Md. Hasan Bayazid, Tawfikur Rahman, Masuma Akter, Md. Moniruzzaman, Emtiaz Ahmed Mainul, Ratan Kumar Nondy, S. M. Rezaul Karim, Sadik Shahriar Haque Sifat
Published: 2023-June-15

IMPACTS OF DROUGHT ON THE MARKET IN THE NORTHWEST REGION OF BANGLADESH: AVAILABILITY, DIVERSITY AND PRICE

Authors: Md. Shafiqul Islam, Ummul Fatiha Binte-Shafiq
Published: 2023-June-15

THE NON-LINEAR IMPACTS OF CRUDE OIL PRICES AND TRADE OPENNESS ON THE FOREIGN INCOME OF BANGLADESH

Authors: Rehana Parvin, Md. Lutfar Rahman
Published: 2023-June-15

The asymmetric effects of crude oil prices, inflation, and trade openness on Bangladesh's foreign income are investigated in this study from 1995 to 2020.To evaluate the non-linear impacts of our research variables on foreign income; we used the non-linear autoregressive distributed lag model. Long-run co-integration is evident among the study variables, according to the NARDL method's bound test results. The empirical findings of this study demonstrate that higher oil prices have a considerable negative impact on foreign income in the long run, but a positive and significant impact in the short run. In contrast, lower oil prices have a negative and considerable impact on foreign income in both the short and long term. The adjustment asymmetry in the dynamic multiplier graphs shows that the response of foreign income to a negative change in oil prices is stronger than the response to a positive change. Accession or reductions in inflation and trade openness, on the other hand, have a major impact on foreign income both in the long run and in the short run. The Wald test indicates that there are asymmetries among variables. The ramifications of this study are critical for Bangladeshi politicians and investors.

DETERMINING CORROSION EFFICIENCY OF A GREEN SOLUTION PREPARED FROM EXTRACT OF DALBERGIA SISSOO LEAVES IN H2SO4 AND ITS CHARACTERIZATION

Authors: A. K. M. Foysal Ahmed, Nayem Hossain, A.K.M Parvez Iqbal
Published: 2023-June-15

Corrosion is one of the major reasons why many industrial machines and machine parts deteriorate throughout their lifetime due to corrosion. In this regard, enormous engineers and industry owners are after the remedy for such corrosion to sustain the lifetime of machines and machine parts. There are two obvious ways to think about the solution, one solution is to replace the material for constructing the machines with superior materials and other solution is to find a corrosion resistance technique. Firstly, using the Stainless Steel (SS) for machines is a viable solution to get ride of the corrosion but it will also boost the price of the machines. Thus machine manufacturers are still relying on Mild Steel (MS) to build the machines for different industries. Secondly, a popular solutions to resist corrosion is the synthetic corrosion inhibitors but the concern is the environmental impact of such inhibitors. Finding alternative of synthetic inhibitors is a hot topic of research now-a-days and a trending alternative is green inhibitor. In the search of such inhibitors, a solution of Dalbergia Sissoo extract and H2SO4 is used to examine the change of corrosive behavior of Mild Steel Block in the presence of the solution prepared. The result of corrosion efficiency is the prime question in choosing any inhibitors. The method of determining corrosion efficiency of the proposed green inhibitor is discussed in this article. A promising result of maximum 72.44% of corrosion efficiency has been observed in 1M H2SO4 solution. The characterization of the corroded mild steel sample blocks are then examined through Fourier-transform Infrared (FT-IR) Spectroscopy Test and Scanning Electron Microscopy (SEM). Result of FT-IR finds the reason of the inhibition whereas SEM reveals the evidence of corrosion inhibition due to the effect of Dalbergia Sissoo.

DESIGN AND FABRICATION OF AN AGRICULTURAL SPRAYING MACHINE USING A KNAPSACK SPRAYER

Authors: Md Rakibuzzaman, Aminul Islam, Md Al-Amin, Md Mahfujur Rahman Khan, Mohammad Saidur Rahman
Published: 2023-June-15

Plant protection equipment is essential in the agricultural field for increasing crop productivity and minimizing the losses caused. Specialized machinery for mechanically applying chemicals is crucial for maximizing crop yields in farming. Farmers use a wide range of pesticides to counteract the effects of insects, diseases, and fungi on their crops. The backpack sprayers do the spraying with staffing, which requires more human effort, covers a small area, is time-consuming, and has a low storage capacity. The market introduced many products to address these limitations, but they cannot work simultaneously. Solar, electrical, and chemical energy is now being used to spray pesticides, but these methods are expensive and require a trained operator. To address the issues above, a product designed with adaptable spraying equipment is proposed to benefit medium-and small-scale farmers. This study aims to look at the problem of manual backpack sprayers and reduce backpack and foot spraying, eliminate human efforts, and decrease labor costs by advancing the spraying method and a constant flow of droplets. Finally, we have investigated the effects of urging gardeners and farmers to spray their plants with liquids such as pesticides, herbicides, and water. The proposed design can help gardeners in terms of comfort during spraying, reducing energy used to pump tanks, and effectively utilizing spraying time.