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>

Investigation of luminescent properties of red-emitting Ba(Gd,Eu)B9O16 phosphors and the effect of Ca and Sr on its luminescent properties

Haque, Md. Masuqul,Lee, Hong-In,Hui, K. N. Springer-Verlag 2015 Journal of materials science. Materials in electro Vol.26 No.7

Current Status and Technologies for Treating Groundwater Arsenic Pollution in Bangladesh

Haque MD Tashdedul,N. J. D. G. Reyes,전민수,김이형 한국습지학회 2022 한국습지학회지 Vol.24 No.2

Arsenic (As) contamination in groundwater is one of the main problems in Bangladesh. As toxicity causes serious human health problems such as edema, skin cancer, bladder cancer, lung cancer, hyperkeratosis, premature birth, and black foot disease. As contamination in groundwater mainly originates from the geological characteristics of the area due to the influence of anthropogenic activities. Since most of the people in Bangladesh rely on tube well for drinking water, it is necessary to investigate the current status of As pollution and identify the treatment technologies that can be used to provide arsenic-free drinking water in water-scarce areas. A total of 92 papers were reviewed in this study to present a complete overview of the recent status of groundwater As contamination in Bangladesh and different low-cost remediation technologies. A method for evaluating the relative feasibility of different treatment technologies was also utilized to determine the most appropriate technologies for groundwater As treatment in Bangladesh. The districts with the highest groundwater As contamination include Brahamanbariya, Tangail, Barisal, Pabna, Patuakhali, Kurigram, Magura, and Faridpur, with concentrations exceeding 0.05 mg/L. Only six districts had relatively low groundwater arsenic concentrations (0.01 mg/L), including Kushtia, Khagrachari, Jessore, Dinajpur, Meherpur, and Munshiganj. There were a number of technologies used for treating As in water, but aerated electrocoagulation, Mg-Fe-based hydrotalcite-like compound, and electro-chemical As remediation (ECAR) reactor were found to be the most feasible treatment methods for As. Overall, the investment, operational, and maintenance costs, availability of materials, and expertise requirements should be considered when selecting the most appropriate treatment method for As in water.

Influence of geometric configuration on aerodynamics of streamlined bridge deck by unsteady RANS

Md. N. Haque,Hiroshi Katsuchi,Hitoshi Yamada,Haeyoung Kim 한국풍공학회 2019 Wind and Structures, An International Journal (WAS Vol.28 No.5

Long-span bridge decks are often shaped as streamlined to improve the aerodynamic performance of the deck. There are a number of important shaping parameters for a streamlined bridge deck. Their effects on aerodynamics should be well understood for shaping the bridge deck efficiently and for facilitating the bridge deck design procedure. This study examined the effect of various shaping parameters such as the bottom plate slope, width ratio and side ratio on aerodynamic responses of single box streamlined bridge decks by employing unsteady RANS simulation. Steady state responses and flow field were analyzed in detail for wide range of bottom plate slopes, width and side ratios. Then for a particular deck shape Reynolds number effect was investigated by varying its value from 1.65x104 to 25x104. The aerodynamic response showed very high sensitivity to the considered shaping parameters and exhibited high aerodynamic performance for a particular combination of shaping parameters.

Radix Puerariae modulates glutamatergic synaptic architecture and potentiates functional synaptic plasticity in primary hippocampal neurons

Bhuiyan, M.M.,Haque, Md.N.,Mohibbullah, Md.,Kim, Y.K.,Moon, I.S. Elsevier Ireland Ltd 2017 Journal of Ethnopharmacology Vol.209 No.-

Ethnopharmacological relevance: Neurologic disorders are frequently characterized by synaptic pathology, including abnormal density and morphology of dendritic spines, synapse loss, and aberrant synaptic signaling and plasticity. Therefore, to promote and/or protect synapses by the use of natural molecules capable of modulating neurodevelopmental events, such as, spinogenesis and synaptic plasticity, could offer a preventive and curative strategy for nervous disorders associated with synaptic pathology. Radix Puerariae, the root of Pueraria monatana var. lobata (Willd.) Sanjappa&Pradeep, is a Chinese ethnomedicine, traditionally used for the treatment of memory-related nervous disorders including Alzheimer's disease. In the previous study, we showed that the ethanolic extracts of Radix Puerariae (RPE) and its prime constituent, puerarin induced neuritogenesis and synapse formation in cultured hippocampal neurons, and thus could improve memory functions. Aims of the study: In the present study, we specifically investigated the abilities of RPE and puerarin to improve memory-related brain disorders through modulating synaptic maturation and functional potentiation. Materials and methods: Rat embryonic (E19) brain neurons were cultured in the absence or presence of RPE or puerarin. At predetermined times, cells were live-stained with DiO or fixed and immunostained to visualize neuronal morphologies, or lysed for protein harvesting. Morphometric analyses of dendritic spines and synaptogenesis were performed using Image J software. Functional pre- and postsynaptic plasticity was measured by FM1-43 staining and whole-cell patch clamping, respectively. RPE or puerarin-mediated changes in actin-related protein 2 were assessed by Western blotting. Neuronal survivals were measured using propidium iodide exclusion assay. Results: RPE and puerarin both: (1) promoted a significant increase in the numbers, and maturation, of dendritic spines; (2) modulated the formation of glutamatergic synapses; (3) potentiated synaptic transmission by increasing the sizes of reserve vesicle pools at presynaptic terminals; (4) enhanced NMDA receptor-mediated postsynaptic currents, and (5) increased cell viability against naturally occurring cell death. Moreover, upregulation of actin-related protein 2 (ARP2) in RPE and puerarin treated brain neurons suggest that RPE and puerarin induced synaptic plasticity might be associated, at least in part, with ARP2-mediated actin-dependent regulation of spinogenesis. Conclusions: Our findings indicate that RPE and puerarin might play a substantial role in the morphological and functional maturation of brain neurons and suggest that RPE and puerarin are potentially valuable preventative therapeutics for memory-related nervous disorders.