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Chittagong, Bangladesh

Noakhali Science and Technology University is a newly established public university in the coastal terrain Noakhali of Bangladesh. It is the 27th public university and fifth science and technology university in Bangladesh when it established, while in 2013, it places as 10th public university and 2nd science and technology university in national ranking. Its foundation stone was laid on 11 October 2003 and academic activities started on 22 June 2006. Founding a science and technology university in a coastal terrain like Noakhali is significant. A newly accrued coastal system may render this university a versatile field station to study the pattern of changes in the seashore and to harness its opportunities. Wikipedia.

Bahadur N.M.,Utsunomiya University | Bahadur N.M.,Noakhali Science and Technology University | Furusawa T.,Utsunomiya University | Sato M.,Utsunomiya University | And 3 more authors.
Journal of Colloid and Interface Science | Year: 2011

A novel, fast and facile microwave technique has been developed for preparing monodispersed silica coated silver (Ag@SiO2) nanoparticles. Without using any other surface coupling agents such as 3-aminopropyltrimethoxysilane (APS) or polymer such as polyvinyl pyrrolidone (PVP), Ag@SiO2 nanoparticles could be easily prepared by microwave irradiation of a mixture of colloidal silver nanoparticles, tetraethoxysilane (TEOS) and catalyst for only 2min. The thickness of silica shell could be conveniently controlled in the range of few nanometers (nm) to 80nm by changing the concentration of TEOS. Transmission electron microscopy (TEM) and UV-visible spectroscopy were employed to characterize the morphology and optical properties of the prepared Ag@SiO2 nanoparticles, respectively. The prepared Ag@SiO2 nanoparticles exhibited a change in surface plasmon absorption depending on the silica thickness. Compared to the conventional techniques based on Stöber method, which need 4-24h for silica coating of Ag nanoparticles, this new technique is capable of synthesizing monodispersed, uniform and single core containing Ag@SiO2 nanoparticles within very short reaction time. In addition, straightforward surface functionalization of the prepared Ag@SiO2 nanoparticles with desired functional groups was performed to make the particles useful for many applications. The components of surface functionalized nanoparticles were examined by Fourier transform infrared (FT-IR) spectroscopy, zeta potential measurements and X-ray photoelectron spectroscopy (XPS). © 2010 Elsevier Inc.

Islam M.S.,Noakhali Science and Technology University | Mostofa A.G.M.,University of Dhaka | Ahmed M.U.,University of Dhaka | Sayeed M.S.B.,The University of Asia Pacific | And 2 more authors.
Tumor Biology | Year: 2014

The rate of direct smoking, second hand smoking, and smokeless tobacco users as well as the amount of environmental pollutant like polycyclic aromatic hydrocarons is increasing in Bangladesh. Therefore, the prevalence of lung cancer is increasing day by day. To the best of our knowledge, no pharmacogentic study of CYP3A4, CYP3A5 genes has been reported on Bangladeshi population relating those with lung cancer. The present study was conducted to determine the association of CYP3A4, CYP3A5 gene polymorphisms and tobacco smoking in the development of lung cancer in Bangladeshi population. A case-control study was carried out on 106 lung cancer patients and 116 controls to investigate three allelic variants - CYP3A4*1B, CYP3A5*3, and CYP3A5*6 using Polymerase Chain Reaction Restriction Fragment Length Polymorphism. Risk of lung cancer was estimated as odds ratio (OR) and 95% confidence interval (CI) using unconditional logistic regression models. The variant allele frequencies for CYP3A4*1B (*1A/*1B+*1B/*1B) were 2.83%and 0.86%and that of CYP3A5*3 (*1A/*3+*3/*3) were 88.68% and 85.34% in cases and controls, respectively. Individual carrying at least one variant allele of CYP3A4*1B (CYP3A4*1A/1B+*1B/1B) has a 3.35 times more risk (OR=3.35, 95% Cl=0.34-32.71, p =0.271) for developing lung cancer whereas individual carrying at least one variant allele of CYP3A5 (CYP3A5*1A/3+*3/3) has a 1.26 times more risk (OR=1.35, 95% Cl=0.61-2.97) and both are statistically non-significant (p >0.05). CYP3A5*6 was absent in the study population. No association of lung cancer with the mentioned polymorphisms was found both in heavy and light smokers. In the cases of all three major types of lung cancer-squamous cell carcinoma, adenocarcinoma, and small cell carcinoma-significantly strong relationships (p 0.05) have been found. To confirm the association of lung cancer with the mentioned polymorphisms, large number volunteers (patients and controls) will be required. © International Society of Oncology and BioMarkers (ISOBM) 2013.

Volchek K.,Environment Canada | Miah M.Y.,Environment Canada | Miah M.Y.,Noakhali Science and Technology University | Kuang W.,Environment Canada | And 2 more authors.
Journal of Hazardous Materials | Year: 2011

The adsorption of cesium on cement mortar from aqueous solutions was studied in series of bench-scale tests. The effects of cesium concentration, temperature and contact time on process kinetics and equilibrium were evaluated. Experiments were carried out in a range of initial cesium concentrations from 0.0103 to 10.88mgL-1 and temperatures from 278 to 313K using coupons of cement mortar immersed in the solutions. Non-radioactive cesium chloride was used as a surrogate of the radioactive 137Cs. Solution samples were taken after set periods of time and analyzed by inductively coupled plasma mass spectroscopy.Depending on the initial cesium concentration, its equilibrium concentration in solution ranged from 0.0069 to 8.837mgL-1 while the respective surface concentration on coupons varied from 0.0395 to 22.34μgcm-2. Equilibrium test results correlated well with the Freundlich isotherm model for the entire test duration. Test results revealed that an increase in temperature resulted in an increase in adsorption rate and a decrease in equilibrium cesium surface concentration. Among several kinetic models considered, the pseudo-second order reaction model was found to be the best to describe the kinetic test results in the studied range of concentrations. The adsorption activation energy determined from Arrhenius equation was found to be approximately 55.9kJmol-1 suggesting that chemisorption was the prevalent mechanism of interaction between cesium ions and cement mortar. © 2011.

Khan M.A.R.,Noakhali Science and Technology University | Rahman M.M.,Universiti Malaysia Pahang | Kadirgama K.,Universiti Malaysia Pahang
International Journal of Automotive and Mechanical Engineering | Year: 2014

The proper selection of machining parameters can result in better machining performance in the electrical discharge machining process. However, this job is not always easy since the phenomena occurring between the electrodes in EDM are not yet fully understood. This study reports the development of a comprehensive mathematical model for the electrode wear rate (EWR) of a graphite tool in EDM on Ti-5Al-2.5Sn alloy, which has not yet been presented. Experiments for positive polarity of the graphite electrode, based on design of experiment (DOE), are first conducted. Modeling and analysis are carried out through the response surface methodology, utilizing the experimental results. A confirmation test is also executed to confirm the validity and the accuracy of the mathematical model developed. The confirmation test exhibits an average error of less than 6%. Negative electrode wear is evidenced for particular settings. The combination of 15A peak current, 350μs pulse-on time, 180μs pulse-off time and 95V servo-voltage and positive polarity causes negative tool wear. It is apparent that the developed model can evaluate electrode wear rate accurately and successfully. © Universiti Malaysia Pahang.

Miah M.Y.,Environment Canada | Miah M.Y.,Noakhali Science and Technology University | Volchek K.,Environment Canada | Kuang W.,SAIC | Tezel F.H.,University of Ottawa
Journal of Hazardous Materials | Year: 2010

A series of experiments were performed to quantify the adsorption of cesium on ceiling tiles as a representative of urban construction materials. Adsorption was carried out from solutions to mimic wet environmental conditions. Non-radioactive cesium chloride was used as a surrogate of the radioactive 137Cs. The experiments were performed in the range of initial cesium concentrations of 0.114-23.9mgL-1 at room temperature (21°C) around three weeks. Solution samples were taken after set periods of time and analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The quantity of adsorbed Cs was calculated by mass balance as a function of time.Two kinetic and three equilibrium models were employed to interpret the test results. Determination of kinetic parameters for adsorption was carried out using the first-order reaction model and the intra-particle diffusion model. Adsorption equilibrium was studied using Langmuir, Freundlich and three-parameter Langmuir-Freundlich adsorption isotherm models. A satisfactory correlation between the experimental and the predicted values was observed. © 2010.

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