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Search Results: 1 - 10 of 673380 matches for " S. A. Uddin "
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Organic Carbon Storage in the Tropical Peat Soils and Its Impact on Climate Change  [PDF]
Md. Jashim Uddin, A. S. M. Mohiuddin, Masud Hassan
American Journal of Climate Change (AJCC) , 2019, DOI: 10.4236/ajcc.2019.81006
Abstract: Soil carbon is one of the essential elements for soil quality, holding soil nutrients for plant uptake, soil conservation, and overall the natural soil systems that are the fundamental requirements for the soil security, and food production. Moreover, Peat soils are the vital storehouses of organic carbon where there is a scope to use this carbon for mitigating climate change. In this study, we consider three major soil series of peat soils in Bangladesh: sapric peat, hemic peat, and fabric peat. Single study on the estimation of organic carbon stocks in the peat soils of Bangladesh was conducted in the 1970s. For understanding the carbon emission, we conducted the same peat soils up to 100 cm depths. The research shows that the organic carbon in peat soils in Bangladesh was about 0.12 Pg in 2018 whereas it was about 0.25 Pg during the 1970s. So, it has observed that soil organic carbon loss is alarming in the tropical country like Bangladesh and the half of the total organic carbon has already reduced by the last 50 years. These reduced carbons have huge impact on climate change and global warming. It has also found that the carbon storage percentage is higher with the increasing soil profile depth from the soil surface. So, the management should be considered not only the surface soils but also the sub-surface soils. Another relationship found between the bulk density and carbon storage is inversely proportional (r = 0.65) in the peats soils. These peat soils are losing their carbon due to the decrease of inundation level by climate change, intensive agricultural and even used as fuel for cooking purposes by the local stakeholders. There were no regulations, maintenances, laws, even the evaluation and assessment of carbon storage was not appropriately estimated in Bangladesh. By representing the carbon percentage data and their changes over times will help to develop and implement the proper mitigation action which may improve soil health, soil quality, food security, and mitigation of climate changes.
Image Noise Analysis of a Large Ring PET Scanner  [PDF]
M. M. Ahasan, S. Akter, R. Khatun, M. F. Uddin, A. N. Monika, M. A. Rahman, M. N. Khanam
International Journal of Medical Physics,Clinical Engineering and Radiation Oncology (IJMPCERO) , 2017, DOI: 10.4236/ijmpcero.2017.62019
Abstract: Image noise analysis of a large ring PET scanner “macro PET” performed using two different phantoms, namely a Jaszczak SPECT phantom and a uniform cylindrical phantom. In the present work, simple 2D filtered back projection was used to reconstruct all the images, and in almost all the cases a Hamming filter of cutoff frequency 0.4 and a 256 by 256 matrix with zoom factors from 1 to 4 were used in order to investigate the imaging capabilities of the new scanner and the influence of filter and cut-off frequency on the filtered back projected images. Results indicate that 11.1 mm cold rod in the Jaszczak phantom images can consistently be seen. The Coefficient of variation (CV) results for Hann and Hamming filters are very similar and increase approximately in linear fashion with higher cutoff frequency. The value of CV for the Parsen filter is lower than the value for Hann and Hamming filters. It concludes that all filters with low cut off-frequency (<0.6) would suppress image noise but decrease contrast.
Warped Product Submanifolds of LP-Sasakian Manifolds
S. K. Hui,S. Uddin,C. zel,A. A. Mustafa
Discrete Dynamics in Nature and Society , 2012, DOI: 10.1155/2012/868549
Abstract: We study of warped product submanifolds, especially warped product hemi-slant submanifolds of LP-Sasakian manifolds. We obtain the results on the nonexistance or existence of warped product hemi-slant submanifolds and give some examples of LP-Sasakian manifolds. The existence of warped product hemi-slant submanifolds of an LP-Sasakian manifold is also ensured by an interesting example.
Warped Product Semi-Invariant Submanifolds of Nearly Cosymplectic Manifolds
Siraj Uddin,S. H. Kon,M. A. Khan,Khushwant Singh
Mathematical Problems in Engineering , 2011, DOI: 10.1155/2011/230374
Abstract: We study warped product semi-invariant submanifolds of nearly cosymplectic manifolds. We prove that the warped product of the type ?× is a usual Riemannian product of ? and , where ? and are anti-invariant and invariant submanifolds of a nearly cosymplectic manifold , respectively. Thus we consider the warped product of the type ×? and obtain a characterization for such type of warped product.
Free M-Modules
M.S. Uddin,A.C. Paul
Asian Journal of Information Technology , 2012,
Abstract: The characterizations of free M-modules are developed. The cardinality of the basis of the free M-modules is studied. At last we have studied the invariant rank property of free M-modules.
Experimental study of DI diesel engine performance using biodiesel blends with kerosene
A. K. Azad, S. M. Ameer Uddin, M. M. Alam
International Journal of Energy and Environment , 2013,
Abstract: The experimental investigation offers a comprehensive study of DI diesel engine performance using bio-diesel from mustard oil blends with kerosene. The vegetable oil without trans-esterification reaction have been blended with kerosene oil by volume in some percentage like 20%, 30%, 40% and 50% which have been named as M20 (20% mustard, 80% kerosene), M30 (30% mustard, 70% kerosene), M40 (40% mustard, 60% kerosene) and M50 (50% mustard, 50% kerosene). The properties of the bio-fuel blended with kerosene have been tested in the laboratories with maintaining different ASTM standards. Then a four stroke, single cylinder, direct injection diesel engine has been mounted on the dynamometer bed for testing the performance of the engine using the bio-diesel blends. Several engine parameters like bsfc, bhp, break mean effective pressure, exhaust gas temperature, lube oil temperature, sound level etc. have been determined. A comparison has been made for engine performance of different bio-diesel blends with kerosene with the engine performance of diesel fuel.
A. K. Azad,S. M. Ameer Uddin,M. M. Alam
International Journal of Automotive and Mechanical Engineering , 2012,
Abstract: This study offers comprehensive details on the use of bio-fuel as a viable and alternative source of energy. The bio-fuel was prepared from vegetable oil, i.e., mustard oil and tested in a diesel engine in both pure form and as a diesel blend. The mustard oil blend proportions were 20%, 30%, 40% and 50% and named as bio-diesel blends B20, B30, B40 and B50. A fuel-testing laboratory determined the properties of the pure mustard oil fuel and its blends, i.e., density, viscosity, dynamic viscosity, carbon residue, flash point, fire point and calorific value. An assessment of engine performance, i.e., brake horsepower (bhp), brake specific fuel consumption (bsfc), brake thermal efficiency (bte) and brake mean effective pressure (bmep) etc., was carried out for pure diesel, pure mustard and the blends, both in laboratory conditions and under British Standard (BS) conditions. Finally, an analysis and comparison was made of the effects of the various fuels on the different engine properties.
Comparative Study of Nitrogen, Phosphorus and Potassium Fertilizers on Yield and Nutrient Uptake by Rice
M. Uddin,M. M. Rahman,M. A. Hoque,S. Begum
Journal of Biological Sciences , 2001,
Abstract: The field experiment was conducted in a silt loam soil to compare the effect of N, P and K fertilizers on the yield and nutrient uptake by rice and post-harvest soil properties. Seven treatments were T0 (control), T1 (Urea + Triple superphosphate + Muriate of potash), T2 (Urea + Diammonium phosphate + Muriate of potash), T3 (Urea + Triple superphosphate + Ash), T4 (Urea + Single superphosphate + Muriate of potash), T5 (Urea + Single superphosphate + Ash) and T6 (Urea + Diammonium phosphate + Ash). Application of fertilizers significantly increased the grain and straw yields of rice. Panicle length, effective tillers hill-1 and filled grains panicle-1 were also increased significantly due to application of fertilizers but the increase of 1000-grain weight was insignificant. Grain yield was highest with T3 (Urea + Triple superphosphate + Ash) treatment (5.46 t ha-1) which was followed by T1 (Urea + Triple superphosphate + Muriate of potash) treatment (5.30 t ha-1), while the lowest was in control. The grain yields were increased by 47.0 to 68.0% over control due to application of fertilizers. The results on straw yield reflected similar trend as in grain yield. Application of fertilizers caused a significant increase during NPKS uptake by rice. The application of fertilizers had a negligible influence on pH, CEC, organic matter, total N, available P, exchangeable K, and available S content of the post-harvest soils compared to their initial status.
Yield and Chemical Composition of Common Roadside Grasses Available in Bangladesh
F. Kabir,M. Shahjalal,S. A. Chowdhury,M. J. Uddin
Journal of Biological Sciences , 2002,
Abstract: This experiment was conducted to estimate the yield and nutritive value of common roadside grasses available in Bangladesh. A land was developed as an experimental plot and made for growing roadside grasses and was partitioned into four quarters each of 200 sq.m. Pasture was established as a grazing land. The average herbage yield (DM and OM) recorded in the month of November was significantly (P<0.05) higher than that of August, September or February. The fresh yield (P<0.05) and CP yield of Phaseolus mungo were significantly higher than that of other grass species. The OM content of Imperata cylindrica was significantly (P<0.05) than other grasses. The DM content of Cynodon dactylon and Imperata cylindrica, NDF content of Cynodon dactylon and CP content of Phaseolus mungo were significantly (P<0.01) higher than other grass species.
g-Jitter Mixed Convective Slip Flow of Nanofluid past a Permeable Stretching Sheet Embedded in a Darcian Porous Media with Variable Viscosity
Mohammed J. Uddin, Waqar A. Khan, Norsarahaida S. Amin
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0099384
Abstract: The unsteady two-dimensional laminar g-Jitter mixed convective boundary layer flow of Cu-water and Al2O3-water nanofluids past a permeable stretching sheet in a Darcian porous is studied by using an implicit finite difference numerical method with quasi-linearization technique. It is assumed that the plate is subjected to velocity and thermal slip boundary conditions. We have considered temperature dependent viscosity. The governing boundary layer equations are converted into non-similar equations using suitable transformations, before being solved numerically. The transport equations have been shown to be controlled by a number of parameters including viscosity parameter, Darcy number, nanoparticle volume fraction, Prandtl number, velocity slip, thermal slip, suction/injection and mixed convection parameters. The dimensionless velocity and temperature profiles as well as friction factor and heat transfer rates are presented graphically and discussed. It is found that the velocity reduces with velocity slip parameter for both nanofluids for fluid with both constant and variable properties. It is further found that the skin friction decreases with both Darcy number and momentum slip parameter while it increases with viscosity variation parameter. The surface temperature increases as the dimensionless time increases for both nanofluids. Nusselt numbers increase with mixed convection parameter and Darcy numbers and decreases with the momentum slip. Excellent agreement is found between the numerical results of the present paper with published results.
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