Bangladesh Journal of Scientific and Industrial Research 2019-03-30T19:02:59+00:00 Dr Mamtaz Dawlatana Open Journal Systems Full text articles available Surface-capped copper nanoadditive for improvement of base oil properties 2019-03-30T19:02:40+00:00 F Shaon AA Rana SM Masum MA Ullah MM Karim <p>Copper nanoparticles surface-capped by alkanethiol with long carbon chain length was prepared successfully by chemical reduction method. 1-dodecanethiol was used as the coating material for the desired smooth and protected surface. Various reaction parameters, like effect of pH, molar ratio of the reactants etc. had been tested experimentally to explore the most suitable and economical way of using the chemical reduction method. Uniform, smooth surface and spherical shaped copper nanoparticles, with particle size of about 40-60 nm had been produced successfully. Copper nanoparticles surface-capped by alkanethiol (C<sub>12</sub>S-Cu) was characterized by means of x-ray diffraction, scanning electron microscopy, Fourier transform infrared spectrometry and ultraviolet-visible spectroscopy. Uniform dispersion of copper nanoadditive in base oil using ultrasonic method was investigated. The tribological behavior of C<sub>12</sub>S-Cu as an additive for base oil was evaluated. Viscosity, pour point, and flash point of nano lubricants at different concentrations of nanoadditive (0.2, and 0.5 wt %) were evaluated.</p> <p><em>Bangladesh J. Sci. Ind. Res.</em><strong>54(1)</strong>, 1-10, 2019</p> 2019-03-25T00:00:00+00:00 ##submission.copyrightStatement## Quality and vitamin A status assessment of different commercial edible oil 2019-03-30T19:02:41+00:00 SA Lisa S Khan MA Kabir F Islam S Mohajan K Chowdhury <p>The present study was done to evaluate the quality and the vitamin A fortification status of 5 types of commercial edible oils sold in Dhaka city markets. The percentages of free fatty acid (FFA), peroxide value (POV), iodine value (IV) and fatty acid composition were estimated to evaluate the quality and vitamin A content were determined to evaluate the vitamin A fortification status of 25 commercial edible oils- soybean oil, sunflower oil, rice bran oil, mustard oil and palm olein (5 brands of each) . The results revealed that FFA, POV and IV of the commercial oils analyzed were within the BSTI standard limits. The highest saturated fatty acids (SFA) values ranging from 39.85 ± 0.005 to 46.97 ± 0.002 % was found in palm olein samples and the lowest SFA values ranging from 4.56 ± 0.031 to 6.97 ± 0.096 % was found in mustard oils. On the other hand, mustard oils contained highest monounsaturated fatty acids (MUFA) ranging from 69.30 ± 0.189 to 75.87 ± 0.069 % compared to other oils analyzed. Highest polyunsaturated fatty acids (PUFA) were recorded in sunflower oils 64.78 ± 0.035% followed by soybean oils 63.25 ± 0.245%. In addition, except sunflower and mustard oils, vitamin A was found in all the soybean and rice bran oils analyzed. On the contrary, vitamin A was found only in 60% of the palm olein samples analyzed and the content was much lower than the standard value (15-30 ppm).</p> <p><em>Bangladesh J. Sci. Ind. Res.</em><strong>54(1)</strong>, 11-20, 2019</p> 2019-03-25T00:00:00+00:00 ##submission.copyrightStatement## Synergic effect of recycled cotton fabric and wood saw dust reinforced biodegradable polypropylene composites 2019-03-30T19:02:43+00:00 MK Islam A Sharif M Hussain I Hassan <p>Hybrid polymer matrix composites of waste cotton fabric and wood saw dust reinforcements were studied with a view to recycling the wastes from garments and carpentry industries. Polymer composites with cotton fabric and wood-saw-dust reinforcements were fabricated using hot press machine. Their physical, thermal and mechanical behaviors were discussed in terms of moisture absorption, thermal stability, tensile strength, elastic modulus, flexural strength and flexural modulus. Compositional analyses of fibers, matrix and composites were carried out with FTIR spectroscopy. Experimental results revealed that tensile and flexural strength of the composites increased with cotton fabric reinforcement. On the other hand, with increasing wood saw dust strength decreased up to a certain limit and then increased again. Water absorption of the hybrid composites increased substantially with increasing natural filler contents. Maximum water absorption was observed in 20% fabric/wood-saw-dust reinforced polymer composite. Furthermore, TGA graphs suggest better thermal stability of the hybrid composites than that of pure polypropylene.</p> <p><em>Bangladesh J. Sci. Ind. Res.</em><strong>54(1)</strong>, 21-30, 2019</p> 2019-03-25T00:00:00+00:00 ##submission.copyrightStatement## Synthesis of solketal over zirconia based acid catalysts 2019-03-30T19:02:45+00:00 SS Reena SMZ Shamshuddin VT Vasantha JQ D’Souza <p>Microwave assisted synthesis of ‘solketal’ over zirconia (ZrO<sub>2</sub>) and its modified forms (Mo(VI)/ZrO<sub>2</sub>, W(VI)/ZrO<sub>2</sub> and V(V)/ZrO<sub>2</sub>) coated on honeycomb monoliths is reported. The solid acids were coated on honeycomb monoliths by ‘dip and dry’ method and characterized for their surface acidity, crystalinity, functionality, morphology and elemental analysis by using techniques such as NH3-Temperature programmed desorption (NH<sub>3</sub>-TPD), powder X-ray diffraction (PXRD), Fourier transform-infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Inductively coupled plasma-optical emission spectroscopy (ICP-OES). The honeycomb monoliths coated with solid acids were employed as catalysts in the condensation of glycerol with acetone to synthesize solketal under microwave irradiation conditions. The reaction conditions such as molar ratio of the reactants (glycerol: acetone), reaction temperature, reaction time were studied to obtain highest possible yield of solketal with greater selectivity. The catalytic activity of honeycomb catalytic material was compared with the powder forms of the catalysts. 98% yield of solketal with 98% selectivity was achieved over Mo(VI)/ZrO<sub>2</sub> coated on a honeycomb monolith in a very shorter reaction time of 8 min at 60 oC under microwave heating. These honeycomb catalytic material were found to be easily reactivable and reusable atleast for 6 reaction cycles. Hence, honeycomb catalysts were found to be efficient, economical and effective in the synthesis of value added chemical such as solketal. A possible mechanism for the formation of solketal is proposed.</p> <p><em>Bangladesh J. Sci. Ind. Res.</em><strong>54(1)</strong>, 31-38, 2019</p> 2019-03-25T00:00:00+00:00 ##submission.copyrightStatement## Bio-ethanol production from Jatropha curcus 2019-03-30T19:02:47+00:00 SMA Sujan MS Jamal MA Asad ANM Fakhruddin <p>Separate hydrolysis and fermentation (SHF) were employed to produce bio-ethanol from the jatropha stem and husk. This study investigates the favorable condition required to improve yield of monomeric sugars. Substrate was pretreated physically at first through cutter mill and subsequently by ball milling. Acremonium cellulase and optimash BG hydrolyzed the pretreated sample into fermentable sugars. In condition of 10% substrate concentration, ball milling for 60 min and 4 FPU/g enzyme loading and optimum sugar yield were observed. By comparison, jatropha stem is more favorable feedstock compared to jatropha husk in terms of both inherent sugar composition and sugar yield in enzymatic saccharification (hydrolysis). Yeast <em>Saccharomyces cerevisiae</em>, capable of converting hexose sugars into ethanol,was utilized in fermentation step. It was possible to extract 0.14 L and 0.20 L of ethanol per kg of dry substrate-based jatropha husk and jatropha stem, respectively.</p> <p><em>Bangladesh J. Sci. Ind. Res.</em><strong>54(1)</strong>, 39-46, 2019</p> 2019-03-25T00:00:00+00:00 ##submission.copyrightStatement## Synthesis of 1-phenyl-3, 4-dihydropyrimidine-2(1H)-ones derivatives under solvent free condition and their antimicrobial activity 2019-03-30T19:02:49+00:00 K Akhter K Jahan ME Halim S Shefa S Rifat KR Khan SM Ahmed UKR Romman <p>We report herein the use of nickel nitrate hexahydrate [Ni(NO3)2.6H2O] as a new catalyst for the one-pot Biginelli like reaction coupling of 1-phenyl thiourea, ethyl acetoacetate and aromatic aldehydes to afford the corresponding 1-phenyl-3,4-dihydropyrimidin-2(<em>1H</em>)-thiones under solvent free condition to avoid the usage of hazardous organic solvents. The synthesized compounds were evaluated for their antimicrobial activity by KIRBY-BAUER disk diffusion method. Most of the compounds showed good to moderate antimicrobial activity.</p> <p><em>Bangladesh J. Sci. Ind. Res.</em><strong>54(1)</strong>, 47-54, 2019</p> 2019-03-25T00:00:00+00:00 ##submission.copyrightStatement## Spatial variability and geostatistical analysis of selected soil 2019-03-30T19:02:51+00:00 MZ Khan MA Islam M Sadiqul Amin MMR Bhuiyan <p>A study was conducted to explore the spatial variability of major soil nutrients of Agricultural fields in South-western region of Bangladesh. From the study area, 40 surface soil samples were collected by a random sampling strategy using GPS. Then soil physico-chemical properties i.e., pH, electrical conductivity (EC), organic matter (OM), total nitrogen (TN) N, soil available nutrients (P, K and S) were measured in laboratory. After data normalization, classical and geo-statistical analyses were used to describe soil properties and spatial correlation of soil characteristics. Spatial variability of soil physico-chemical properties was quantified through semi-variogram analysis and the respective surface maps were prepared through ordinary Kriging. Spherical model fits well with experimental semi-variogram of pH, EC, OM, TN, available P, K and S. Soil pH, available phosphorus (Av P), potassium (Av K) and sulfur (Av S) have the moderate spatial dependence, with nugget/sill ratios of 41.13% to 72.21%. The others have the strong dependence with nugget/sill ratios of less than 25%. The spatial variability of estimating soil properties varies within range of 0.0142 for Av P to 0.0383 for Av S and this model can calculate the un-sampled within neighboring distance of about 12.65 m for Av S to 150.82 m for TN, respectively. Cross validation of kriged map shows that spatial prediction of soil nutrients using semi-variogram parameters is better than assuming mean of observed value for any un-sampled location. Therefore, it is a suitable alternative method for accurate estimation of chemical properties of soil in un-sampled positions as compared to direct measurement which has time and costs concerned.</p> <p><em>Bangladesh J. Sci. Ind. Res.</em><strong>54(1)</strong>, 55-66, 2019</p> 2019-03-25T00:00:00+00:00 ##submission.copyrightStatement## Macro nutrient status of Sundarbans forest soils in Southern region of Bangladesh 2019-03-30T19:02:52+00:00 MZ Khan MS Amin <p>An attempt has been made to evaluate the condition of soil of the Sundarban mangrove forest of Bangladesh by applying standard method. Soil pH was varied from 6.63 to 7.87. Organic carbon of soil was found 4.06, 4.79, 5.59, 9.38 and 9.80 (gKg<sup>-1</sup>) at Kotka, Kochikhali, Hironpoint, Harbaria, and Dublarchar, respectively. The electrical conductivity of soil was varied from 14.39, to 42.89 (dSm<sup>-1</sup>) in the study areas.The cation exchange capacity in the soils was varied from 22.32 to 27.2 Cmolckg<sup>-1</sup> in the study area. The average percentages of total nitrogen content in the soil were varied from 0.04 to 0.08%. The soils of Oligohaline zone of Sundarban mangrove forest are rich in water soluble and exchangeable magnesium followed by calcium and the potassium. The percentages of silt and clay were higher than sand in all study areas. Dissolved chloride in the soil was found 7010, 4186,11750 and 16389 (μg g<sup>-1</sup>) at Hironpoint, Harbaria, Dublarchar and Kotka respectively.</p> <p><em>Bangladesh J. Sci. Ind. Res.</em><strong>54(1)</strong>, 67-72, 2019</p> 2019-03-25T00:00:00+00:00 ##submission.copyrightStatement## Alkali pretreatment of cotton stalk for bioethanol 2019-03-30T19:02:53+00:00 A Bano M Irfan <p>Cotton stalk biomass was treated with NaOH and NaOH-steam pretreatements to get maximum cellulose content. Three factors with three levels such as biomass concentration (5, 10 and 15%), NaOH concentration (1, 3 and 5%) and residence time (4, 6 and 8 h) was performed through Box-Bhenken Design of response surface methodology. The treatment was performed with and without heating at 121<sup>o</sup>C for 15min and 15psi in an autoclave. Among these two types of treatment, maximum yield of cellulose content 87.80% was observed with 5% w/v NaOH concentration, 10g substrate loading and 4h residence time. The substrate having high cellulose content under optimized pretreatment conditions were analysed through FTIR revealing efficiency of pretreatment. The proposed model for this study was found significant in terms of lower p&lt;0.05 values and findings of this study could be utilized for further processes like saccharification and fermentation to bioethanol.</p> <p><em>Bangladesh J. Sci. Ind. Res.</em><strong>54(1)</strong>, 73-82, 2019</p> 2019-03-25T00:00:00+00:00 ##submission.copyrightStatement## Mixed convection heat transfer from a heated circular cylinder 2019-03-30T19:02:55+00:00 H Laidoudi M Bouzit <p>This paper performs the effects of thermal buoyancy and the triangular arrangement of circular cylinders on fluid flow and heat transfer within a horizontal channel, the governing equations involving continuity; momentum and energy are solved in two-dimensional, laminar and steady flow regime. The average Nusselt number and drag coefficient are computed for the range of these conditions: <em>Ri </em>= 0 to 2 at fixed value of <em>Pr </em>= 1, Reynolds number <em>Re </em>= 30 and geometrical configurations (blockage ratio of <em>β </em>= 0.1). In order to observe the flow structure and temperature field under the gradual effect of thermal buoyancy, the streamlines and isotherm contours are illustrated. It is found that, a gradual increase in the value of buoyancy strength creates an asymmetrical flow around the cylinders. Interesting variations of drag coefficient and average Nusselt number are plotted with respect to Richardson number for each cylinder.</p> <p><em>Bangladesh J. Sci. Ind. Res.</em><strong>54(1)</strong>, 83-88, 2019</p> 2019-03-25T00:00:00+00:00 ##submission.copyrightStatement## Modified coconut coir to remove hexavalent chromium from aqueous solution 2019-03-30T19:02:56+00:00 N Ahmed MN Islam MY Hossain AKML Rahman A Sultana <p>Hexavalent chromium (Cr(VI)) was removed from aqueous solution by adsorption using chemically modified lignin-rich low-cost coconut coir. The equilibrium time, adsorption isotherm and adsorption kinetics at certain conditions such as pH, particle size and the initial concentration of adsorbate were investigated. The coconut coir was modified by sodium chlorite for adsorption studies. The scanning electron microscopic image depicted the morphology of SCM-CC of different particle sizes whereas the elemental composition of this sort of bioadsorbent was determined by using energy dispersive spectroscopic data. Fourier transform infrared (FTIR) spectrometry analysis indicated that the carbonyl (C=O) groups and hydroxy (O–H) groups from the lignin structure in coconut coir may be involved in the mechanism of Cr(VI) adsorption. The maximum Cr(VI) adsorption capacity of sodium chlorite modified coconut coir (SCM-CC) was found to be 28.03 mg Cr(VI) g<sup>-</sup><sup>1</sup> SCM-CC at pH 2.00 for the particle size of 75-100 μm with the dose of 7.5 g/L. The equilibrium was established within three hours resulting in the maximum removal (99.92%) of chromium. Freundlich isotherm was better fitted than Langmuir isotherm at pH 2.00 on the basis of the regression coefficient (R<sup>2</sup>). The kinetic data well-fitted with Ho’s pseudo second order kinetics. The SCM-CC can be treated as an excellent adsorbent for the remediation of chromium toxicity.</p> <p><em>Bangladesh J. Sci. Ind. Res.</em><strong>54(1)</strong>, 89-98, 2019</p> 2019-03-25T00:00:00+00:00 ##submission.copyrightStatement## Sawdust-kaolinite composite as efficient sorbent for heavy metal ions 2019-03-30T19:02:58+00:00 IC Ogbu KG Akpomie AA Osunkunle SI Eze <p>The improvement of the adsorption capacity of clay minerals using chemicals though effective is expensive, results in secondary contamination and noxious to the environment. This study was therefore aimed at the development of a new sawdust clay modified adsorbent (SDKC) as an alternative means of improving the adsorption capacity of kaolinite. The adsorbents were characterized by the Fourier transform infrared spectroscopy and X-ray diffraction analysis. Batch sorption was employed to determine the effect of pH, metal concentration, sorbent dose, time and temperature on the removal of Pb (II) and Cd (II) ions from solution by the adsorbents. Optimum operating conditions of pH 6.0, metal concentration 200mg/L, sorbent dose 0.1g was obtained. Equilibrium isotherm analysis indicated the Langmuir, Temkin and Flory-Huggins models to be more suitable than the Freundlich, Dubinin–Radushkevich (D-R). The kinetic data were analyzed using the pseudo-first order, pseudo-second order, the Elovich and intraparticle diffusion models. The analysis revealed that the adsorption process followed pseudo second order model. The calculated thermodynamic parameters showed an endothermic, spontaneous and a physisorption process between both metal ions and the adsorbents. The obtained result of the experiment indicated a significant improvement in the uptake of Pb (II) and Cd (II) ions on the sawdust modified kaolinite adsorbent than the untreated kaolinite clay. This could be utilized as an alternative to chemical treatment methods</p> <p><em>Bangladesh J. Sci. Ind. Res.</em><strong>54(1)</strong>, 99-110, 2019</p> 2019-03-25T00:00:00+00:00 ##submission.copyrightStatement##