Activation of molecular oxygen for the oxidation of 2-mercaptoethanol: A kinetic and mechanistic approach

M.Z.A. Rafiquee,Masoom R. Siddiqui,H.N. Haque,M. Shamsul Ola,Hamad A. Al-Lohedan,Z.A. ALOthman,Saikh M. Wabaidur 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.34 No.-

Reduction of molecular oxygen by 2-mercaptoethanol in the presence of cobalt(II)histidine is described. Cobalt(II)histidine complex forms dinuclear 2:1 (Co:O2) complex with molecular oxygen (m-dioxyte-trakis(histidinato)dicobalt(II)). The molecular oxygen did not directly react with 2-mercaptoethanol, but,reacted in the form of an adduct with cobalt(II)histidine complex. During the course of the reaction themolecular oxygen is reduced to hydroxide ion while the cobalt(II)histidine complex was oxidized tocobalt(III)histidine while 2-mercaptoethanol is reduced into 2,20-dithiodiethanol. The decrease inabsorbance for the dioxygen complex was monitored spectrophotometrically and was observed that thevalues of rate constant increased with the increase in [2-mercaptoethanol]. The values of kobs also increasedwith increasing [NaOH]. Thus, from the results of these studies, mechanism of the reaction has beenproposed. In addition, the values of various equilibrium constants and rate constants were also determinedusing nonlinear least square techniques.

Nutrient Uptake and Productivity as Affected by Nitrogen and Potassium Application Levels in Maize/Sweet Potato Intercropping System

Haque, M.Moynul,Hamid, A.,Bhuiyan, N.I. The Korean Society of Crop Science 2001 Korean journal of crop science Vol.46 No.1

Field experiment was conducted during 1993-94 season to determine the pattern of nutrient uptake and productivity of maize/sweet potato intercropping system. Four levels of nitrogen (0, 50, 100 and 150kg N ${ha}_{-1}$) and four levels of potassium (0, 40, 80 and 120kg $K_2$O ${ha}_{-1}$) formed treatment variables. Plants were sampled periodically to determine dry matter and tissue concentrations of N and K in the individual plant components of intercropped maize and sweet potato. Nitrogen and potassium fertilizer did not interact significantly to nutrient uptake by any plant parts of intercropped maize and sweet potato. But application of N fertilizer independently enhanced N uptake in all the plant parts of maize and sweet potato. The uptake of N in leaf, leaf sheath, stem, husk, and cob of maize increased upto 90 days after planting (DAP) but grain continued to accumulate N till its maturity. Sweet potato exhibited a wide variation in N uptake pattern. Sweet potato leaf shared the maximum uptake of N at 50 DAP which rapidly increased at 70 DAP and then declined. Declination of N uptake by petiole and stem were observed after 120 DAP whereas N uptake by tuber increased slowly upto 90 DAP and then rapidly till harvest. Rate of applied K had very little effect on the uptake patterns in different components of intercropped maize. Pattern of K uptake by leaf, petiole and stem of sweet potato showed almost similar trend to N uptake. But uptake of K by tuber increased almost linearly with the K application. Pattern of N and K uptake by grain and tuber paralleled the grain yield of maize and sweet potato respectively. Intercropped productivity of maize and sweet potato found to be better by the application of 100kg N and 120 kg $K_2$O ${ha}_{-1}$

Nutrient Uptake and Productivity as Affected by Nitrogen and Potassium Application Levels in Maize/Sweet Potato Intercropping System

M. Moynul Haque,A. Hamid,N.I. Bhuiyan 韓國作物學會 2001 Korean journal of crop science Vol.46 No.1

Field experiment was conducted during 1993-94 season to determine the pattern of nutrient uptake and productivity of maize/sweet potato intercropping system. Four levels of nitrogen (0, 50, 100 and 150kg N ha-1 ) and four levels of potassium (0, 40, 80 and 120kg K2 O ha-1 ) formed treatment variables. Plants were sampled periodically to determine dry matter and tissue concentrations of N and K in the individual plant components of intercropped maize and sweet potato. Nitrogen and potassium fertilizer did not interact significantly to nutrient uptake by any plant parts of intercropped maize and sweet potato. But application of N fertilizer independently enhanced N uptake in all the plant parts of maize and sweet potato. The uptake of N in leaf, leaf sheath, stem, husk, and cob of maize increased upto 90 days after planting (DAP) but grain continued to accumulate N till its maturity. Sweet potato exhibited a wide variation in N uptake pattern. Sweet potato leaf shared the maximum uptake of N at 50 DAP which rapidly increased at 70 DAP and then declined. Declination of N uptake by petiole and stem were observed after 120 DAP whereas N uptake by tuber increased slowly upto 90 DAP and then rapidly till harvest. Rate of applied K had very little effect on the uptake patterns in different components of intercropped maize. Pattern of K uptake by leaf, petiole and stem of sweet potato showed almost similar trend to N uptake. But uptake of K by tuber increased almost linearly with the K application. Pattern of N and K uptake by grain and tuber paralleled the grain yield of maize and sweet potato respectively. Intercropped productivity of maize and sweet potato found to be better by the application of 100kg N and 120 kg K2 O ha-1

Comparative Study on Toxic Metal Contamination in Balu River Water in Bangladesh

M. E. Haque,M. A. B. Faruquei,M. A. Sattar,M. E. Hossain,A. N. A. Haque 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Effect of dilute alkali pretreatment on structural features and enhanced enzymatic hydrolysis of Miscanthus sinensis at boiling temperature with low residence time

Haque, Md.A.,Barman, D.N.,Kang, T.H.,Kim, M.K.,Kim, J.,Kim, H.,Yun, H.D. Academic Press 2013 Biosystems engineering Vol.114 No.3

The aim of this work was to evaluate the effect of dilute sodium hydroxide for conversion of Miscanthus sinensis to fermentable sugars at boiling temperature with low residence time. Various concentrations of NaOH (0.75%-2.5%) were applied for treatment of Miscanthus in an autoclave at 105 <SUP>o</SUP>C for 10 min. The non-cellulosic surface granules composed of lignin, waxes, and partly of hemicelluloses were exhibited in pretreated Miscanthus. The scanning electron microscopy, atomic force microscopy, and Fourier transform infrared spectroscopy studies showed that the 2.5% NaOH-treated Miscanthus exposed cellulose fibres and surface granules were removed, probably due to comprehensive disruption of the linkages between lignin and carbohydrates. The cellulose crystalline index was increased from the water-treatment to 2.0% NaOH-treatments and remarkably lowered by the 2.5% NaOH-treatment. Chemical component analysis showed that the level of cellulose increased to 70% and lignin was reduced to 4.2% by 2.5% NaOH-treated sample. The greatest removal of lignin and hemicellulose from pre-hydrolysate liquors was 74% and 55%, respectively. The reducing sugar yield with cellulase 15 FPU, β-glucosidase 30 IU, and xylanase 6 FXU g<SUP>-1</SUP> substrate was estimated as 73% and 87% for 2.0% and 2.5% NaOH-treated samples respectively. The 2.5% NaOH-treatment is judged to be effective for disrupting Miscanthus recalcitrance in this pretreatment regime.

Eu³⁺-activated potential red-emitting phosphor for solid-state lighting

Haque, Md.M.,Kudrat-E-Zahan, Md.,Jahan, N.A.,Lee, H.I. Wissenschaftliche Verlagsgesellschaft m. b. H 2017 OPTIK -STUTTGART- Vol.133 No.-

<P>The intense red-emitting NaCaY0.2Eu0.8(MoO4)(3) phosphor was prepared by using a sol-gel method for the first time. Thermogravimetric-diferential thermal analysis, X-ray diffraction, field-emission scanning electron microscopy, FT-IR and luminescent measurements were used to characterize the NaCaY0.2Eu0.8(MoO4)(3) particles. The resulting products obtained by using the sol-gel method have a narrower size distribution and a more regular particle shape than those obtained by using the solid- state reaction. The spectra analysis indicated that the obtained phosphor could be excited by UV light of 395 nm and visible light of 466 nm, also emits intense red light with a maximum at about 614 nm. The luminescent intensity of sol-gel derived is comparable with the solid state product and it is about 84% of solid-state product under 395 nm light excitation. Comparative study with YAG:Ce and CaS:Eu2+ phosphors, suggested that our synthesized phosphor can be used as an efficient red-emitting phosphor to compensate the red deficiency of YAG:Ce phosphor and also can serve as an alternative phosphor to replace sulfide based phosphors in the solid-state lighting applications. (C) 2016 Elsevier GmbH. All rights reserved.</P>

Effect of Level of Leucaena leucocephala in the Diets of Jamunapari Goats on carbon Nitrogen and Energy Balances

Haque, N.,Khan, M.Y.,Murarilal, Murarilal Asian Australasian Association of Animal Productio 1997 Animal Bioscience Vol.10 No.5

Fifteen intact male Jamunapari goats, average body weight $22.0{\pm}1.18kg$ were divided into three groups of 5 animals in each to investigate the effects of feeding leucaena on energy retention and distribution of retained energy. Leucaena leaves and twigs provided 0%, 25% and 50% of CP in the rations of animals in $L_1$ (control), $L_2$ and $L_3$ groups, respectively. Energy balances were determined in an open circuit respiration chamber from gaseous exchange and nitrogen carbon balances. Energy retentions calculated from gaseous exchange data were 181.6, 190.0 and 172.8 kJ/kg $W^{0.75}/d$ and from carbon-nitrogen balances were 178.2, 199.5 and 171.1 kJ/kg $W^{0.75}/d$ in $L_1$, $L_2$ and $L_3$ groups, respectively. No significant difference was observed among the groups in both the methods. The retention of nitrogen and energy in the form of protein was similar in different treatment groups. Similarly, no significant effect was observed on energy retention in the form of fat and total energy retention due to incorporation of leucaena in the diets.

Strategy to Develop Efficient Grid System for Flow Analysis Around Two-dimensional Bluff Bodies

M. N. Haque,H. Katsuchi,H. Yamada,M. Nishio 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.5

Computational Fluid Dynamics (CFD) is becoming more and more popular in various fields of engineering due to improvement of turbulence model and availability of high performance computing system. In bluff body and bridge aerodynamics fields CFD is applied to predict the aerodynamic response for reconfirming experimental results and revealing the flow mechanism. Accurate prediction of response largely depends on the accurate generation of grid system having converged solution. However, conventional grid convergence test takes much time to obtain the desired grid system. It becomes even worse for a beginner or user having lack of experience. In this paper, a strategy was proposed and demonstrated for faster generation of accurate and converged grid system for two-dimensional bluff bodies. First, the strategy was proposed and demonstrated by conducting simulation for a square rectangular cylinder at Reynolds number (ReB) of 1.22 × 104. An equation was derived to initialize the first grid height (y) and a Growth Factor (GF) was recommended to expand the grid away from the target body to obtain a grid system having converged solution. The strategy was checked and examined by conducting standard grid convergence test and by comparing solution of various aerodynamic parameters with past experimental works. Finally, the strategy was applied for an elongated rectangular cylinder and for a streamlined bridge deck for further checking the performance of the strategy and found to be efficient enough for faster and quick generation of accurate and converged grid system.

Audio Segmentation and Classification Using a Temporally Weighted Fuzzy C-Means Algorithm

Nguyen, N.T.T.,Haque, M.A.,Kim, C.-H.,Kim, J.-M. SPRINGER-VERLAG 2011 ICHIT 2012 Vol.6676 No.-

Physicochemical characterization and deodorant activity of essential oil recovered from Asiasarum heterotropoides using supercritical carbon dioxide and organic solvents

J.N. Moon,Adane Tilahun Getachew,A.S.M. Tanbirul Haque,Periaswamy Sivagnanam Saravana,Y.J. Cho,David Nkurunziza,B.S. Chun 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.69 No.-

This study was aimed to extract oil from Asiasarum heterotropoides using supercritical carbon dioxide (Sc-CO2) with and without ethanol as co-solvent and to compare the results with conventional extraction solvents. A total of 27 major volatile organic compounds (VOCs) were identified among them eucarvone, 3-carene, safrole, methyleugenol, and camphene were found to be the highest. The solvent Sc-CO2 + ethanol at 250 bar and 50 °C was found to be the best condition to get high yield of oil with 3.54 ± 0.21%. The extracted oil showed 100% of deodorant efficiency within 30 min of reaction with an artificially manufactured odorant.