Time filter

Source Type

Mowri S.T.,Chittagong University of Engineering and Technology | Hossain Q.D.,Chittagong University of Engineering and Technology | Gafur M.A.,Bangladesh Council of Scientific and Industrial Research | Ahmed A.N.,Bangladesh Council of Scientific and Industrial Research | Bashar M.S.,Institute of Fuel Research & Development
Materials Science Forum | Year: 2017

(Bi2O3Fe2O3)0.8(Nb2O5)0.2 was synthesized by solid state reaction method. (Bi2O3Fe2O3)0.8(Nb2O5)0.2 was made for the investigation of X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Dielectric property. XRD pattern reveals that three phases were obtained with Bismuth Iron Niobium Oxide. SEM elicits that grain size increases with the enhancement of sintering temperature. Dielectric property decreases with the augmentation of frequency. © 2017 Trans Tech Publications, Switzerland.

Sultana S.,University of Dhaka | Sultana S.,Bangladesh Atomic Energy Commission | Khan R.A.,Bangladesh Atomic Energy Commission | Shahruzzaman M.,University of Dhaka | And 3 more authors.
Polymer - Plastics Technology and Engineering | Year: 2010

Gelatin films were prepared from gelatin granules in aqueous medium by casting. Tensile strength, tensile modulus, elongation at break and the glass point of the gelatin films were found to be 27 MPa, 100 MPa, 4% and 51.7°C, respectively. After irradiated with gamma radiation tensile properties were increased due to denser network structure. Gelatin films were soaked in five different formulations containing 2-hydroxyethyl methacrylate (HEMA) (10-50%, by wt), methanol and photoinitiator and then irradiated under gamma radiation. Again, a series of gelatin solutions was prepared by blending varying percentages (10-50% by wt) of HEMA and then films were prepared and irradiated under gamma radiation. It was found that tensile and thermal properties of gelatin films improved significantly. © Taylor & Francis Group, LLC.

Gafur M.A.,Bangladesh Council of Scientific and Industrial Research | Nasrin R.,Bangladesh University of Engineering and Technology | Mina M.F.,Bangladesh University of Engineering and Technology | Bhuiyan M.A.H.,Bangladesh University of Engineering and Technology | And 2 more authors.
Polymer Degradation and Stability | Year: 2010

Talc-loaded isotactic polypropylene (iPP) composites with various contents of talc were fabricated by compression molding, following slow- and fast-cooling processes, to obtain slow-cooled samples (SCS) and fast-cooled samples (FCS), respectively. Lamellar thickness of the α-crystal of iPP in the SCS is observed to be larger than that in the FCS by X-ray diffraction study. Rolled fast-cooled samples (RFCS) were also prepared at 25 °C in order to examine the crystal growth of iPP. An epitaxial growth mechanism of the α-crystal of iPP from the talc crystal is proposed. Surface of talc-loaded FCS appears with a smaller particle size than that of talc-loaded SCS and RFCS as observed by a scanning electron microscope. Young's modulus and tangent modulus of FCS are found lower than those of SCS with the addition of talc up to 20 wt% and higher above this concentration, except microhardness which is higher in SCS at all contents of talc. From thermal studies, talc-loaded SCS and FCS are found to show higher melting temperature than the neat samples. Effect of cooling and rolling on the structures and properties of the fabricated composites are elaborately discussed. © 2010 Elsevier Ltd. All rights reserved.

Mina M.F.,Bangladesh University of Engineering and Technology | Haque M.A.,Bangladesh University of Engineering and Technology | Bhuiyan M.K.H.,Bangladesh Agricultural University | Gafur M.A.,Bangladesh Council of Scientific and Industrial Research | And 2 more authors.
Journal of Applied Polymer Science | Year: 2010

Nanocomposites of isotactic polypropylene (iPP) and multiwalled carbon nanotubes (MWCNTs) with various contents of MWCNTs were fabricated by double molding techniques. X-ray diffraction measurements reveal a development of α-crystal with lamellar stacks having a long period of 150 Å in the neat iPP that increases to 165 Å in 2 wt % MWCNTs-loaded composites, indicating that MWCNTs enhance crystallization of iPP as a nucleating factor. Mechanical properties, such as tensile strength, flexural strength, Young's modulus, tangent modulus, and microhardness are found to increase with increasing MWCNTs content. Thermal analyses represent an increase of crystallization and melting temperatures and a decrease of thermal stability of the composites with increasing MWCNTs. Changes in structural, mechanical, and thermal properties of the composites due to the addition of MWCNTs are elaborately discussed. © 2010 Wiley Periodicals, Inc.

Rahman M.A.,Chittagong University | Yusuf M.,Chittagong University | Yusuf M.,Bangladesh Council of Scientific and Industrial Research
Bangladesh Journal of Plant Taxonomy | Year: 2013

Zingiber salarkhanii Rahman et Yusuf, belonging to the family Zingiberaceae, is described and illustrated from Bangladesh as a new species. It was collected from six different localities of hilly forests in Chittagong, Khagrachari and Moulvi Bazar districts. Morphological diagnostic characters of closely related species of the genus are discussed. © 2013 Bangladesh Association of Plant Taxonomists.

Uddin M.N.,Bangladesh Council of Scientific and Industrial Research | Ahmed N.U.,Bangladesh Council of Scientific and Industrial Research | Rahman M.A.,Chittagong University | Akter R.,Bangladesh Council of Scientific and Industrial Research
International Journal of Food Properties | Year: 2016

This study investigated the quantitative phytochemical contents, total phenolics, total flavonoids, total carotenoids, antioxidative capacity, tannin, proanthocyanidins, lycopene, chlorophyll a, and chlorophyll b of the Stephania japonica extract. Comprehensive antioxidative effects of the extract were also investigated. Quantitative assays were conducted through both spectrophotometric and high-performance liquid chromatographic methods. Antioxidative effects were measured through FeCl3 reducing power, metal chelating power, reducing power, 2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) scavenging activity, N, N-dimethyl-1,4-diaminobenzene free radical scavenging activity, superoxide radical scavenging activity, and nitric oxide scavenging effect. The contents of total phenolics, total flavonoids, total carotenoids, total antioxidative capacity, tannin, proanthocyanidins, lycopene, chlorophyll a, and chlorophyll b were found to be 47.32 ± 0.75 mg tannic acid equivalent, 61.41 ± 1.58 mg catechin equivalent, 63.29 ± 2.21 mg, 22.85 ± 0.70 mg ascorbic acid equivalent, 76.17 ± 0.97 mg tannic acid equivalent, 94.96 ± 4.49 mg catechin equivalent, 22.19 ± 0.79 μg, 22.19 ± 0.79 μg, 7.52 ± 1.24 mg, and 10.43 ± 2.11 mg, respectively, in 1 g of ethanol extract. A high concentration of epicatechin, p-coumaric acid, and rutin hydrate and moderate concentration of caffeic acid and quercetin was detected in the extract. The IC50 value for ferric reducing power assay, metal chelating assay, reducing power assay, ABTS scavenging assay, N, N-dimethyl-1,4-diaminobenzene scavenging assay, superoxide scavenging assay and nitric oxide (NO) assay were 465.06 ± 7.32 μmol ascorbic acid/g, 1656.52, 270.55, 457.27, 632.74, 217.5, and 464.00 μg/mL, respectively. No beta carotene was detected in the extract. The extract was demonstrated to be a very potential source of antioxidative metabolites. Copyright © Taylor & Francis Group, LLC.

Safarzadeh-Amiri A.,Ontario Center for Environmental Technology Advancement | Fowlie P.,Ontario Center for Environmental Technology Advancement | Kazi A.I.,Bangladesh Council of Scientific and Industrial Research | Siraj S.,Bangladesh Council of Scientific and Industrial Research | And 2 more authors.
Science of the Total Environment | Year: 2011

Groundwater, the only source of potable water for millions of people in Bangladesh during dry season, is often contaminated with arsenic (As) above the allowable drinking water limit of 50 μg/L. Testing well water - with arsenic field test kits (FTKs) - and switching to safe-wells can effectively reduce exposure to As. FTKs are low cost, provide fast results, and are commercially available. There are between 10 and 11 million shallow tubewells in Bangladesh. Approximately, 5 million have been tested using FTKs. FTKs with color comparator rely on visual identification for generating qualitative results, which may not be highly reliable at the lower range because human eyes have low sensitivity in this range and sensitivity varies from person to person. The Wagtech Digital Arsenator does not suffer from this limitation and should, in theory, be able to generate quantitative, accurate, and reliable results. The instrument has a linear range of 0-100 μg/L, an accuracy of ±20% for the 50 μg/L quality control standards, and a detection limit of about 4.4 μg/L. All Arsenators employed in this investigation also displayed high bias for 50 μg/L arsenic standard and were calibrated in order to improve measurement accuracy and reliability. Analyses of 179 raw and 92 treated well waters in the field and in two analytical laboratories were found to be highly correlated with the Spearman rank correlation coefficient of ≥0.800, indicating that Arsenator results are perhaps nearly as accurate and reliable as those from analytical laboratories. © 2011 Elsevier B.V. All rights reserved.

Hira A.,Khulna University | Dey S.K.,Khulna University | Howlader M.S.I.,World University of Bangladesh | Ahmed A.,Khulna University | And 2 more authors.
Asian Pacific Journal of Tropical Biomedicine | Year: 2013

Objective: To investigate the inflammatory and antioxidant activities of ethanolic extract of aerial part of Vernonia patula (Dryand.) Merr (EAV). Methods: The anti-inflammatory activity of EAV was studied using carrageenan and histamine-induced rat paw edema test at different doses (100, 200 and 400 mg/kg body weight). DPPH free radical scavenging, nitric oxide scavenging, reducing power and Fe2+ ion chelating ability were used for determining antioxidant activities. Results: The EAV, at the dose of 400 mg/kg, showed a significant anti-inflammatory activity (P<0.01) both in the carrageenan and histamine-induced oedema test models in rats, showing 62.86% and 64.42% reduction in the paw volume comparable to that produced by the standard drug indomethacin (67.26% and 66.01%) at 5 h respectively. In DPPH free radical scavenging test, IC50 value for EAV was found fairly significant 36.59 μg/mL when compared to the IC50 value of the reference standards ascorbic acid 8.97 μg/mL. The IC50 values of the extract and ascorbic acid were 47.72 and 12.39 μg/mL, respectively in nitric oxide scavenging assay. The IC50 value of the EAV (33.59 μg/mL) as percentage of Fe2+ ion chelating ability was also found significant compared to that of EDTA (9.16 μg/mL). The maximum absorbance for reducing power assay was found to be 1.928 at 100 μg/mL when compared to 2.449 for standard ascorbic acid. The total phenolic content was 198.81 mg/g of gallic acid equivalent. Acute toxicity test showed that the plant might be safe for pharmacological uses up to a dose level of 3 200 mg/kg of body weight in rats. Conclusions: Therefore, the obtained results suggest the acute anti-inflammatory and antioxidant activities of the EAV and thus provide the scientific basis for the traditional uses of this plant part as a remedy for inflammations. © 2013 Asian Pacific Tropical Biomedical Magazine.

PubMed | University of Dhaka and Bangladesh Council of Scientific and Industrial Research
Type: Comparative Study | Journal: Malaysian journal of nutrition | Year: 2014

Tilapia (Oreochromis niloticus) is an important cultured fish that is widely distributed in Bangladesh. This study was conducted to improve the growth performance and nutrient contents of the fish using five different types of feeds.Tilapia fingerlings were fed two types of commercial fish feeds (Feed-1 and Feed-2), Spirulina flakes (Feed-3), Feed-2 mixed with Spirulina flakes (Feed-4) and manually mixed feed made from a mixture of mustard oil cake and rice bran (Feed-5). After 4 weeks of being fed with the diets, growth parameters and meat nutrient composition of the tilapia fingerlings were recorded.Significant growth in length and weight was observed in juvenile tilapia fish fed with commercial Feed-1 only, while growth performance varied significantly among fingerlings fed other types of feeds. Body tissue calcium (92.8 mg/100 g), iron (1.29 mg/100 g) was higher in fishes fed with dry Spirulina flakes (Feed 3), while the highest amount of zinc (2.09 mg/100 g) was recorded in fishes fed Feed-5. Protein (13.32%) content was highest in fish fed Feed-2 mixed with Spirulina flakes (Feed-4).Meat nutritional quality of tilapia can be improved by combining commercial feeds with Spirulina flakes, compared with feeding commercial feeds in isolation.

Alam M.K.,Bangladesh University of Engineering and Technology | Islam M.T.,Bangladesh University of Engineering and Technology | Mina M.F.,Bangladesh University of Engineering and Technology | Gafur M.A.,Bangladesh Council of Scientific and Industrial Research
Journal of Applied Polymer Science | Year: 2014

Carbon black (CB) reinforced polyester resin (PR) composites (CPC) have been fabricated from mechanical mixtures of liquid PR and CB powder having 0-50 wt% CB contents and cured with 1% of methyl ethyl ketone peroxide at room temperature under a pressure of 50 MPa. The samples have been examined by the Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) technique, scanning electron microscopy (SEM), mechanical test, micromechanical test, differential thermal analysis (DTA), and thermogravimetric analysis (TGA) and electrical test. FTIR spectra confirm the physical and chemical bond formations between CB and PR. XRD shows a very partial crystalline structure in cured PR and hexagonal structure in CB particles. SEM exhibits a clear dispersion of CB particles in PR matrix at lower loading and aggregates at higher loading. With the increase of fillers, while the tensile and flexural strengths of CPCs decrease, the Young's and tangent modulii increase by 80 and 100%, respectively. These increments are found consistent with the theoretical values. The degree of physical crosslinking between CB and PR as well as the aspect ratio of CB in CPCs are found to increase with the increase of filler. A remarkable increase in microhardness of about 61% at 50 wt% CB content is observed. The TGA represents that the thermal degradation temperature for pure PR is 373°C and that for CPC is 393°C. The dielectric constant of CPCs decreases with increasing frequency, whereas the ac- and dc- conductivities of CPC are found to increase with CB content. Copyright © 2014 Wiley Periodicals, Inc.

Loading Bangladesh Council of Scientific and Industrial Research collaborators
Loading Bangladesh Council of Scientific and Industrial Research collaborators