Journal of Engineering Science 2021-04-24T12:27:35+00:00 Professor Dr. Md. Shahjahan Ali Open Journal Systems <p>Published by the Faculty of Civil Engineering, <a href="">Khulna University of Engineering &amp; Technology (KUET), Khulna</a>. Full-text articles available.</p> <p><a href="" rel="license"><img style="border-width: 0;" src="" alt="Creative Commons Licence"></a><br>Articles in the <em>Journal of Engineering Science </em> are Open Access articles published under a <a href="" rel="license">Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License</a> (CC BY-NC-ND)</p> <div> <p>Previous volumes [<em>fromVol.1 (1) to Vol.10 (2)</em>] of <em>Journal of Engineering Science </em>can be found <a href=""></a></p> <span style="font-size: large;"><a href="" target="_blank" rel="noopener" data-saferedirecturl=";source=gmail&amp;ust=1619584299555000&amp;usg=AFQjCNHEasR4By1GuusqdsRbnk8HRAsnVw"></a></span></div> Meteorological Influences on Urban Air Quality Parameters in Dhaka City 2021-04-24T12:27:21+00:00 Nafisa Islam Md Golam Saroar Tanvir Ahmed <p>This study aims at investigating the effect of meteorological parameters on seasonal variation of particulate matter(PM) (both PM<sub>2.5</sub> and PM<sub>10</sub>) using a 4-year (2013-2016) monitoring data of air quality parameters from CASE project implemented by the Department of Environment (DoE). Using monthly data of the Continuous Air Monitoring Station(CAMS) of Darus-Salam, Dhaka, cross correlation analysisis performed between PM and meteorological parameters where inverse relationships of PM with temperature, rainfall and relative humidity are found. Increased biomass burning during low temperature period, washout effect of rainfall, wet deposition mechanism of higher humidity may be held responsible for these negative correlations. Significant seasonal variation is observed from daily data analysis of Darus Salam station and it is found that winter PM concentrations are 4.5-5.5 times higher than monsoon PM concentrations. Seasonal cross-correlation between PM<sub>10</sub> and PM<sub>2.5</sub> shows lower correlation during winter (December-February) and monsoon (June-September) seasons. Two possible effects can attribute to this seasonal difference: i) presence of biomass burning during winter which increases PM<sub>2.5</sub> and ii) presence of rainfall during monsoon which decreases PM<sub>10</sub>.PM<sub>2.5</sub>/PM<sub>10</sub> ratios for different months indicate the contrasting influences of different mechanisms on different sized PM particles. PM<sub>2.5</sub>/PM<sub>10</sub> ratio is found to be higher during December-February and lower during March- September with a rise in August, which indicates the effect of 3 mechanisms: i) dilution effect of wind speed on PM<sub>2.5</sub> during December-February, ii) re-suspension effect of wind speed on PM<sub>10</sub> during March-September and iii) more pronounced scavenging effect of rainfall on PM<sub>10</sub> during August. The study indicates the need for properly accounting the influence of meteorology for better understanding of PM variation in urban areas in Bangladesh.</p> <p>Journal of Engineering Science 12(1), 2021, 1-8</p> 2021-04-21T00:00:00+00:00 ##submission.copyrightStatement## Assessment of Contamination Potential of Groundwater Adjacent to the Waste Disposal Site at Khulna: Contamination Indices, Multivariate Statistics and Geostatistical Approach 2021-04-24T12:27:22+00:00 Islam M Rafizul Debatosh Banik Partha <p>This study aimed to evaluate the contamination potential of groundwater using various contamination indices available in the literature. To these attempts, fifteen groundwater samples were collected during rainy and dry seasons from the selected tubewells located nearby waste disposal site at Rajbandh, Khulna, Bangladesh. In the laboratory, the concentration of metal elements such as Fe, Mn, Cr, Cu, Pb, Zn, Ni, Cd, Na, K, Ca, As and Mg in groundwater were measured through stanadard methods. The contamination indices such as groundwater quality index (GWQI), degree of contamination (C<sub>d</sub>), heavy metal evaluation index (HEI) and heavy metal contamination index (HPI) were used to quantify the level of contamination of groundwater. The values of GWQI, C<sub>d</sub>, HEI and HPI of groundwater were found less in rainy season than that of dry season due to dilution of groundwater. GWQI reveals that 26.67% of tubewells yield very poor, while, 73.33% of poor water condition. The result of principal component analysis (PCA) indicates that As contamination in groundwater caused from anthropogenic activities, while, Na, Ca and Mg from natural sources. Pearson’s correlations indicates that most of the metal elements were in highly positive correlations with each other. The spatial distribution of various indices reveals that contamination of groundwater was found comparatively higher in the nearest tubewells and decreases in relation to the increasing of water sampling distances. The outcome of this study will further be helpful for other researchers to quantify the level of contamination of groundwater from tubewells.</p> <p>Journal of Engineering Science 12(1), 2021, 9-20</p> 2021-04-21T00:00:00+00:00 ##submission.copyrightStatement## Application of Landsat Imagery and Vegetation Index Property to Assess the Shoreline Changes Along Cox’s Bazar–Teknaf Coast 2021-04-24T12:27:24+00:00 Umme Kulsum Navera Md Safin Ahmed <p>Bangladesh is located at the head of the Bay of Bengal. The coast of Bangladesh is known as a zone of vulnerabilities as well as opportunities which involves coast and island boundaries. The eastern coastal zone consists of sandy beaches and hilly areas and is morphologically very dynamic. This shoreline is an important zone which facilitates tourism opportunity, fishing industry, natural resources and regional highway. Cox’s Bazar-Teknaf shoreline has been experiencing severe erosion at a number of places due to wave action. Wave and wind induced motion results in sediment distribution and shaping of nearshore morphology. The study has been performed by using Remote Sensing and GIS techniques. The shoreline shifting analysis has been performed by the process of open source Landsat images from 1980 to 2017. Satellite derived band algebra; Normalized Difference Vegetation Index has been utilized to identify the vegetation cover. The satellite images of an object carry a unique index property. In this study the index property of vegetation cover has been used to delineate more stable shorelines. At different locations, the average change in shoreline goes up to 120 m in erosion and 100 m in deposition. Based on the coastline shifting the erosion behaviour and the vulnerable areas are identified.</p> <p>Journal of Engineering Science 12(1), 2021, 21-28</p> 2021-04-21T00:00:00+00:00 ##submission.copyrightStatement## Batch Electrocoagulation Process for Removal of Chromium from Tannery Wastewater 2021-04-24T12:27:26+00:00 Md Anik Hasan Md Abul Hashem Md Navid Arman Md Abdul Momen <p>This study was aimed to investigate the chromium removal from the tannery wastewater through electrocoagulation. The zinc and copper plates were used as electrodes for the electrocoagulation process. The effectiveness of the electrocoagulation for chromium removal efficiency was examined investigating various parameters: applied voltage, time, and current density. In batch experiment, 500 mL chromium-containing wastewater was used for electrocoagulation. Chromium content in the raw wastewater and after treatment at optimized conditions was 340.1 and 6.9 mg/L, respectively. The efficiency of chromium removal and reduction of biochemical oxygen demand (BOD) was at 98.0 and 64.6%, accordingly. Although total dissolved solids (TDS) was slightly increased. The increment of current density enhances forming zinc hydroxide which causes the damage of electrodes. Electrocoagulation is an effective technique to remove chromium from the wastewater especially from the tannery wastewater.</p> <p>Journal of Engineering Science 12(1), 2021, 29-34</p> 2021-04-21T00:00:00+00:00 ##submission.copyrightStatement## Heavy Metals Phytoremidiation Potential of Napier Grass Cultivated on Tannery Sludge in Bangladesh 2021-04-24T12:27:27+00:00 Md Ariful Islam Juel Thuhin Kumar Dey Md Ibrahim Sardar Akash Kushol Kumar Das <p>Phytoremediation is a cost effective and eco-friendly method for cleanup of contaminated soil. This study focused on the assessment of phytoremediation potential of Napier grass (Pennisetum purpureum) and Indian mastered (Brassica juncea) yielding in tannery sludge. Initial characterization of tannery sludge showed a high concentration of chromium, lead, copper and zinc which were 6845.5±50.2, 73±2.5, 93±1.5 and 29±2.5 mg/kg, respectively. Both seeds of these plants were sown on tannery sludge kept in baskets and harvested after 8 and 12 weeks of plantation. Analysis indicated that both Napier grass and Indian mustard accumulated heavy metals in the order of Cr&gt;Zn&gt;Cu&gt;Pb at different parts of these plants. Transfer factor (TF) for both plants were greater than 1 for Cu, Zn, Pb though it was less than 1 for Cr. Indian mustard accumulated highest concentration of Cr, Cu, and Pb whereas Napier grass showed highest Zn uptake and good Cr and Cu accumulation capacity. The uptake rate of Cr increased in Napier grass with the increase of plant age. Moreover, Napier grass is one of the rapid yielding tropical grasses and can retain for a longer period than Indian mustard for that attribute, it may accumulate more heavy metals than Indian mustard within its life span. Both of these plants can be used for remediating heavy metals from contaminated tannery sludge.</p> <p>Journal of Engineering Science 12(1), 2021, 35-41</p> 2021-04-21T00:00:00+00:00 ##submission.copyrightStatement## Modeling of Cover Concrete Cracking Due to Uniform Corrosion of Reinforcement 2021-04-24T12:27:29+00:00 Sheikh Shakib Abu Zakir Morshed <p>Cracking of cover concrete due to the corrosion of reinforcing steel is one of the main causes of deterioration in Reinforced Concrete (RC) structures. An outbound stress is developed in concrete surrounding the reinforcing steels due to the expansive corrosion products of reinforcement leading to cracking of the concrete cover. In this paper, the cracking pressure was simulated through a finite element modeling. The effect of geometrical and material parameters, i.e. concrete cover thickness, bar diameter, and concrete tensile strength, on the cracking pressure was also investigated. Abaqus 6.14 was used as modeling platform. The cracking pressure was found to dependent on the cover thickness and tensile strength of concrete. A higher pressure was required to initiate crack for a higher cover thicknesses and tensile strength. The cracking pressure was decreased with the increase in bar diameter. Finally the crack initiation and propagation has been simulated successfully for different arrangements of reinforcements.</p> <p>Journal of Engineering Science 12(1), 2021, 43-49</p> 2021-04-21T00:00:00+00:00 ##submission.copyrightStatement## Verification of APHRODITE Precipitation Data Set in Bangladesh 2021-04-24T12:27:31+00:00 Md Atiqul Islam Asif Ahmed Md Munirujjaman Munir Zarif Zaman Khandakar <p>We investigated the preformance of Asian Precipitation-Highly-Resolved Observational Data Integration Towards Evaluation (APHRODITE) of water resources precipitation products in Bangladesh taking rain gauge data as reference for a 3-year period (2003-2005). Various statistical and categorical indices such as coefficient of correlation (CC), bias, relative bias (RB), mean absolute error (MAE), root mean square error (RMSE), probability of detection (POD), and false alarm ratio (FAR), were applied to measure the performance of the product. With CC value of 0.85, bias of 0.91, RB of -9.5%, MAE of 7.7 mm, and RMSE of 15.2 mm the product tended to underestimate rainfall values during the study period. Although, the POD score of 1.00 demonstrated very good skill in detecting the occurrence of rainfall events, FAR value of 0.25 indicated a considerable amount of false alarms. Moreover, as the precipitation threshold increased, the underestimation became more prominent over the study region. Analysis on the basis of location of the rain gauges also showed that APHRODITE consistently underestimated rainfall values with the increase of extreme rainfall thresholds.</p> <p>Journal of Engineering Science 12(1), 2021, 51-56</p> 2021-04-21T00:00:00+00:00 ##submission.copyrightStatement## Key Safety Approaches in Bangladesh Railway 2021-04-24T12:27:32+00:00 Hasib Mohammed Ahsan <p>Bangladesh Railways (BR) is an integral part of the country's transportation system since the British era. At present it covers a length of 2,877 route kilometres. Train accident data collected from BR revealed that train accidents reduced from 590 per year for 2001-10, to 250 per year for 2010-2015 and to 166 for 2015-16. Data also shows that derailments are the major concern in railway safety. Mixed railway gauges, rail weight, battered and damaged rails, low sleeper density and damaged sleepers, lack of maintenance of fittings and fastenings, and inadequate amount of ballasts are the main reasons for such derailments. So as a safety approach against derailments BR has taken rail track rehabilitation projects as well as speed restriction programs. 2015-16 data showed benefit of such restriction program. A speed map is prepared according to the speed restriction program and speed capacity of different sections of the railway network.</p> <p>Journal of Engineering Science 12(1), 2021, 57-62</p> 2021-04-21T00:00:00+00:00 ##submission.copyrightStatement## The Effect of Fire on the Strength of Concrete Material 2021-04-24T12:27:34+00:00 HM Iqbal Mahmud Md Kawser Babu Raju Md Lokman Hosen <p>Structural members exposed to fire may damage considerably, lose their durability, and even collapse due to the failure of the members. This work presents the results of an experimental investigation of the effect of fire on the strength of concrete. Cylindrical and beam specimens were prepared and burnt in the fire for one hour. In both cases, two systems were followed for cooling the samples, (i) natural cooling in the air (ii) forced cooling in the water. Afterwards, the compressive and flexural strength of the specimens were determined. The result shows that the strength of concrete was considerably reduced due to burning in fire. The compressive strength of cylindrical specimens was decreased by 44% and 60%, respectively, for the natural and forced cooling of the specimens. In the case of beam samples, the flexural strength was decreased60% and 69%, respectively, for the natural and forced cooled specimens. This research also reveals that the specimen cooled in air showed better performance compared to that cooled in water.</p> <p>Journal of Engineering Science 12(1), 2021, 63-68</p> 2021-04-21T00:00:00+00:00 ##submission.copyrightStatement## Sulfate and Chloride Resistance Properties of Portland Cement Blends 2021-04-24T12:27:35+00:00 Abu Zakir Morshed Suraiya Hashi Nitai Biswas Miftaul Sadik <p>About 53% area of Bangladesh is alluvial deposited and affected by sulfate, salinity and chloride in water and soil. Existing sulfate and chloride can severely damage the building in coastal regions. In this paper durability of cement is evaluated on the basis of strength of mortar cube, concrete cylinder test. Besides the sulfate resistance is measured by change of length of the mortar bar specimens during exposure to sulfate solution and the attacking chloride properties by Rapid chloride ion penetration test using OPC, PCC, 20% FA, 30% FA and 40% FA. The strength was observed in cube sample about 40.65, 37.2MPa after 13 weeks in sulfate solution and linear expansion was obtained about 0.28% and 0.133% for OPC and PCC cement with reference to the water. The compressive strength of the cylindrical specimens was about 16.96, 18.34 MPa for OPC and PCC, respectively at the age of 28 days. The permeability of chloride ion of OPC sample was 22.8% higher than the PCC at this age.</p> <p>Journal of Engineering Science 12(1), 2021, 69-75</p> 2021-04-21T00:00:00+00:00 ##submission.copyrightStatement##