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Search Results: 1 - 10 of 5965 matches for " Md. Samsul Alam "
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Economic Growth and Environmental Sustainability: Empirical Evidence from East and South-East Asia
Md. Samsul ALAM,Md. Nurul KABIR
International Journal of Economics and Finance , 2013, DOI: 10.5539/ijef.v5n2p86
Abstract: This study investigates the relationship between economic growth and environmental sustainability in the East and South-East Asian countries focused on the environmental Kuznets curve hypothesis, using data from environmental performance index (EPI) in 2010. Both pollution and eco-efficiency measures, two components of environmental sustainability, are considered as dependent variables while GDP per capita is used as an independent variable. Besides independent variable, the study also considers population density and civil and political liberty index (CIVLIB) as control variables and East and South-East Asia as a dummy variable. By using ordinary least square (OLS) method, this study reveals that while the increase of the GDP per capita appears to have positive impact on the pollution measures, it is found mix (both positive and negative) results on eco-efficiency measures. These findings prove the hypothesis of environmental Kuznets curve partially but not entirely. We conclude the paper by suggesting that the policy makers should give priority to the eco-efficiency measures along with pollution measures in order to ensure environmental sustainability in the process of economic development.
Intraspecific Genetic Variation in the Japanese Loach (Misgurnus anguillicaudatus) Revealed by Random Amplified Polymorphic DNA (RAPD) Analysis
Md. Samsul Alam,Md. Mukhlesur Rahman Khan
Pakistan Journal of Biological Sciences , 2001,
Abstract: To assess the extent of genetic diversity within and between four populations of the Japanese loach, Misgurnus anguillicaudatus, an analysis for random amplified polymorphic DNA (RAPD) variations was carried out. Three out of 10 random primers produced consistent and reproducible pattern of RAPD products. Populations showed a nonsignificant difference in their degree of similarity and polymorphism. Difference however, was observed in the primers in producing similarities in the populations. Among the four populations, Futtsu appeared to be an outgroup while the Ueda, Nasu and Nikko populations were genetically closer, as revealed by Nei`s unbiased genetic distance values. The RAPD technique was found to be useful in discriminating the populations of Japanese loach.
High levels of genetic variability and differentiation in hilsa shad, Tenualosa ilisha (Clupeidae, Clupeiformes) populations revealed by PCR-RFLP analysis of the mitochondrial DNA D-loop region
Mazumder, Sabuj Kanti;Alam, Md. Samsul;
Genetics and Molecular Biology , 2009, DOI: 10.1590/S1415-47572009005000023
Abstract: the hilsa shad, tenualosa ilisha (clupeidae, clupeiformes) is an important anadromous clupeid species from the western division of the indo-pacific region. it constitutes the largest single fishable species in bangladesh. information on genetic variability and population structure is very important for both management and conservation purposes. past reports on the population structure of t. ilisha involving morphometric, allozyme and rapd analyses are contradictory. we examined genetic variability and divergence in two riverine (the jamuna and the meghna), two estuarine (kuakata and sundarbans) and one marine (cox's bazar) populations of t. ilisha by applying pcr-rflp analysis of the mtdna d-loop region. the amplified pcr products were restricted with four restriction enzymes namely, xbai, ecori, ecorv, and haeiii. high levels of haplotype and gene diversity within and significant differentiations among, populations of t. ilisha were observed in this study. significant fst values indicated differentiation among the river, estuary and marine populations. the upgma dendrogram based on genetic distance resulted in two major clusters, although, these were subsequently divided into three, corresponding to the riverine, estuarine and marine populations. the study underlines the usefulness of rflp of mtdna d-loop region as molecular markers, and detected at least two differentiated populations of t. ilisha in bangladesh waters.
Interaction of a di-nitro aniline herbicide (Trifluralin) with soil vegetation system under sub-tropic condition: A dissipation kinetics study
Dwaipayan Sengupta,Md. Wasim Aktar,Samsul Alam,Ashim Chowdhury
Orbital : the Electronic Journal of Chemistry , 2010,
Abstract: A field study was carried out to investigate persistence and dissipation kinetics of Trifluralin (48 EC) applied pre emergently in Green gram (Variety T-44) @ 1 Kg ai ha-1 (T1) and 2 Kg ai ha-1 (T2) for the control of broad leaf weeds during kharif 2006. The dissipation on 90 days was around 71.56 - 64.55% in T1 and T2. Kinetics studies revealed that dissipation of Trifluralin residues followed first order kinetics. The half life values observed were 60.21 days in T1 and 75.56 days in T2. Irrespective of any dose no residues were detected in cropped soil as well as plant samples at harvest.
Interaction of a di-nitro aniline herbicide (Trifluralin) with soil vegetation system under sub-tropic condition: A dissipation kinetics study
Dwaipayan Sengupta,Md. Wasim Aktar,Samsul Alam,Ashim Chowdhury
Orbital : the Electronic Journal of Chemistry , 2009,
Abstract: A field study was carried out to investigate persistence and dissipation kinetics of Trifluralin (48 EC) applied pre emergently in Green gram (Variety T-44) @ 1 Kg ai ha-1 (T1) and 2 Kg ai ha-1 (T2) for the control of broad leaf weeds during kharif 2006. The dissipation on 90 days was around 71.56 - 64.55% in T1 and T2. Kinetics studies revealed that dissipation of Trifluralin residues followed first order kinetics. The half life values observed were 60.21 days in T1 and 75.56 days in T2. Irrespective of any dose no residues were detected in cropped soil as well as plant samples at harvest.
Degradation dynamics of an oxime carbamate insecticide (methomyl) in aqueous medium of varying pH under laboratory simulated condition
Md. Wasim Aktar,Samsul Alam,Dwaipayan Sengupta,Ashim Chowdhury
Orbital : the Electronic Journal of Chemistry , 2011,
Abstract: Laboratory degradation studies were performed in water at pH 4.0, 7.0 and 9.2 using methomyl (Lannate 12.5 L) formulation at the rates of 1.0 (T1) and 2.0 (T2) μgmL-1. Water samples collected on 0 (2 h), 3, 7, 15, 30, 45, 60 and 90 days after treatments were processed for residue analysis of methomyl by HPLC equipped with Photo Diode Array Detector. In 60 days, dissipation was 84-87% at pH 4.0, 71-77% at pH 7.0, and 91-93% at pH 9.2 in both treatments showing very little effect of pH on dissipation. The half-life periods observed were 20.76 and 22.13 days at pH 4.0, 27.87 and 28.67 days at pH 7.0 and 15.84 and 16.54 days at pH 9.2 at T1 and T2 doses respectively.
Comparison of Genetic Variability Between a Hatchery and a River Population of Rohu (Labeo rohita) by Allozyme Elctrophoresis
Mohammad Ashraful Alam,Mohammad Shariful Haque Akanda,Md. Muklesur Rahman Khan,Md. Samsul Alam
Pakistan Journal of Biological Sciences , 2002,
Abstract: In order to compare the genetic variability of a hatchery and a wild population of rohu (Labeo rohita), four enzyme systems, PGM, GPI, MDH and LDH were studied using horizontal starch gel electrophoresis. The enzymes were found to be encoded by 6 gene loci: Ldh-1*, Mdh-1*, Mdh-2*, Gpi-1*, Gpi-2* and Pgm*. Within the six loci, Gpi-2*, Mdh-1* and Pgm* were found to be polymorphic. The mean number of alleles per locus and heterozygosity values (observed and expected) in wild population were 1.660 and 0.217 respectively which were higher than those observed in hatchery population (1.500 and 0.142 respectively). The relatively lower level of genetic variability of hatchery population could be attributed to a limited number of founders of the hatchery stock and inbreeding.
Molecular Characterization of Potato Germplasm by Random Amplified Polymorphic DNA Markers
Sabina Yasmin,Md. Shahidul Islam,Khondoker Md. Nasiruddin,Md. Samsul Alam
Biotechnology , 2006,
Abstract: Random Amplified Polymorphic DNA (RAPD) analysis was used to study the genetic diversity of six cultivars of potato. Amplification with three decamer random primers generated 35 RAPD markers of which 33 (94.29%) were polymorphic. The proportion of polymorphic loci and the gene diversity estimates were 14.29% and 0.068, 8.57% and 0.138, 17.14% and 0.075, 51.43% and 0.217 and 54.29% and 0.245 for Cardinal, Diamant, Heera, Raja and TPS, respectively. The results indicated that relatively high level of genetic variation was observed in the TPS and Raja cultivars compared to other cultivars studied. No intra-cultivar genetic variation was observed in the Ailsa cultivar. The high level of cultivar differentiation (GST = 0.634) and low level of gene flow (Nm = 0.289) across all loci reflected that the level of genetic divergence among six cultivars was high. The UPGMA dendrogram based on the Nei`s genetic distances segregated the cultivars into three clusters: Ailsa and Heera made one cluster, Cardinal and TPS made another cluster whereas Diamant and Raja grouped into another cluster. The RAPD markers were found to be useful in studying genetic diversity of potato cultivars.
Characterization of different strains of common carp (Cyprinus carpio L.) (Cyprinidae, Cypriniformes) in Bangladesh using microsatellite DNA markers
Mondol, Rashedul Kabir;Islam, Shahidul;Alam, Samsul;
Genetics and Molecular Biology , 2006, DOI: 10.1590/S1415-47572006000400009
Abstract: characterization of different strains of common carp (cyprinus carpio l.) using molecular markers is essential for the management of this fish in respect to the evaluation of the potential genetic effects induced by hatchery operations and the genetic improvement of carp varieties. five microsatellite loci (mfw1, mfw2, mfw11, mfw15 and mfw20) were analyzed for the molecular characterization of four common carp strains, i.e. scaled carp, mirror carp, red carp and koi carp. we observed differences in heterozygosities and the average numbers of alleles but not in polymorphic loci (p95) among the strains. koi carp displayed the highest level of variability in terms of heterozygosity. the nm values and the fst values indicated a low level of gene flow and high level of differentiation among the strains. the highest genetic distance was observed between the scaled carp and the koi carp whilst the lowest genetic distance was found between the red- and koi carp. the unweighted pair group method with averages (upgma) dendrogram resulted in two clusters, one containing only the scaled carp and the other the remaining three varieties. microsatellite markers have been found to be effective tools for characterization of different strains of common carp.
A Numerical Study of MHD Laminar Flow in a Rotating Curved Pipe with Circular Cross Section  [PDF]
Md. Mainul Hoque, Md. Mahmud Alam
Open Journal of Fluid Dynamics (OJFD) , 2015, DOI: 10.4236/ojfd.2015.52014
Abstract: The incompressible viscous steady flow through a rotating curved pipe of circular cross-section with magnetic field is investigated numerically to examine the combined effects of rotation (Coriolis force), magnetic field and curvature (centrifugal force) on the flow. The curvature of the pipe has been assumed to be small, that is, the radius of the circle in which the central line of the pipe is coiled is large in comparison with the radius of the cross section. Spectral method is applied as a main tool for the numerical technique, where Fourier series, Chebyshev polynomials, Collocation methods, and Iteration method are used as secondary tools. The flow depends on the Taylor number (Tr), Dean Number (Dn), Magnetic Parameter (M) and the dimensionless curvature of the pipe δ. When Tr > 0, the rotation is in the direction so that the Coriolis force enforces the curvature effect. When Tr < 0, the rotation is in the direction so that the Coriolis force exhibits an opposite effect to that of the curvature. The calculations are carried out for 1500 ≤ Tr ≤ 1500, Dn ≥ 1000 (large Dean number), M ≥ 0 and δ = 0.01. Due to high magnetic field four-vortex solution is observed in a rotating curved pipe system. Visualization is attained with MAPLE software.
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