排序方式： 共有23条查询结果，搜索用时 15 毫秒
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Taehoon Oh Md. Mizanur Rahman Ji-Hey Lim Mi-Sun Park Dae-Yong Kim Jung-hee Yoon Wan Hee Kim Masanori Kikuchi Junzo Tanaka Yoshihisa Koyama Oh-Kyeong Kweon 《Journal of veterinary science (Suw?n-si, Korea)》2006,7(1):73-77
This study was performed to evaluate the effect of beta-tricalcium phosphate and poly L-lactide-co-glycolide-co-epsilon-caprolactone (TCP/PLGC) membrane in the repair of partial bone defects in canine proximal humerus. Three adult mixed-breed dogs were used during the experimental period. The length of the defect was quarter of the full length of humerus, and width of the defect was quarter of middle diameter of the lateral aspect of humerus. The humeri of each dog were divided into treatment (TCP/PLGC) and control groups. The defect was covered with TCP/PLGC membrane in treatment group. To evaluate regeneration of the bone, computerized tomography (CT) and histopathologic examination were performed. The radiopaque lines were appeared at the original defect sites in TCP/PLGC group but below the original site in control at 4th week. Radiopacity and thickness of the defect sites, and radiopaque lines were more increased at 8th week than those of 4th week. Histopathologic findings revealed fibrous connective tissue migration into the defect and the migration inhibited the structure of new cortex to be placed in the original level in control whereas new cortex growth was found in the level of original line in TCP/PLGC group. However, the new cortical bone in the TCP/PLGC group was thinner and less organized than the adjacent intact cortex, and the amount of new cancellous bones were also scanty. The result suggested that TCP/PLGC membrane is a good guided bone regeneration material to restore the original morphology of humerus in partial defect. 相似文献
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Adam C.D. Barlow Md. Ishtiaq U. Ahmed Md. Mizanur Rahman 《Biological conservation》2008,141(8):2032-2040
Baseline data on distribution and abundance of tigers in the Sundarbans is required to identify problem areas and evaluate management strategies. This paper outlines a khal (creek) bank survey of track set frequency throughout the Bangladesh Sundarbans to aid formulation of a management-driven monitoring program. Three teams of two observers surveyed a total of 1 201 km of waterways throughout the Sundarbans, recording 1 338 tiger track sets. These sets became unrecognizable as tiger sign after a mean 10 days (range 6-14). Proportion of detectable sign recorded was 0.91. Mean (±standard error) sample unit track frequency was 1.12 ± 0.86 track sets/km of khal. The mean coefficient of variance in sample unit track rate, estimated by multiple counts of six sample units, was 0.21 (range 0.06-0.34). Track frequency generally increased from northeast to southwest. Four sample units (6%) had signs of reproduction, with a mean litter size of 1.75 ± 0.5. Monte Carlo simulation suggests a monitoring program of one complete survey every two years will have power of 0.8 (α = 0.2), to detect track frequency declines of ?19% and increases of ?17%. We recommend this monitoring scheme be implemented on the Indian side of the Sundarbans to provide a standard assessment of the tiger population and to form the basis for setting management objectives and evaluating transboundary conservation initiatives. 相似文献
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Small-scale Forestry - Tropical agroforestry systems have immense potential to sequester carbon both in aboveground and belowground biomass and soil. Homegarden agroforestry is a popular land-use... 相似文献
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Mohammad Mizanur Rahman Han Do Kim Ho-Hwan Chun Inwon Lee Hyun Park 《Fibers and Polymers》2013,14(6):886-894
Waterborne polyurethane (WBPU) dispersions were prepared via a pre-polymer process using 4,4-dicyclohexylmethane diisocyanate (H12MDI), poly(tetramethyleneoxideglycol) (PTMG), 2,2-dimethylol propionic acid (DMPA), ethylene diamine (EDA), and tertiary amines (TAs) with varying amounts of DMPA and TAs. Three TAs with different alkyl chain lengths were used to neutralize the DMPA carboxylic group: N,N-dimethylbutylamine (DMBA, C4), N,N-dimethylhexylamine (DMHA, C6), and N,N-dimethyloctylamine (DMOA, C8). The structures of the synthesized WBPUs were determined via FT-IR and 1H NMR spectroscopic techniques. The effects of DMPA and TA content and the TA alkyl chain length on stability of dispersions and properties such as water swelling (%), glass transition temperature (T g ), tensile strength, binding energy and adhesive strength were investigated. The initial adhesive strength of the intact coatings increased with increasing DMPA and TA content and increasing alkyl chain length of TA. However, after immersion of the coatings in water, the adhesive strength decreased. The maximum adhesive strength under water was observed at a DMPA content of 20.20 mol% with 5.30 wt% DMOA, which has the longest alkyl chain. 相似文献
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A series of crosslinked waterborne polyurethane (WBPU) adhesives were prepared by prepolymer synthesis. Modified melamine,
hexamethoxymethyl melamine (HMMM) was used as the crosslinking agent. It was elucidated by FTIR and 1H-NMR spectroscopy that the crosslinking reaction occurred between the polyurethane carboxyl acid salt groups and the HMMM
methoxy groups. The hydrophobicity of the WBPU films increased after HMMM crosslinking. As the HMMM content was increased
(increasing mole ratio of HMMM/dimethylol propionic acid (DMPA)), the water uptake (%) of the film decreased, and the water
contact angle increased. The thermal stability, tensile strength, and initial modulus increased with increasing HMMM content
up to an optimum value (mole ratio of HMMM/DMPA=0.5) at which point the maximum thermal stability, tensile strength, and initial
modulus were recorded. The adhesive strength was found to be dependent on HMMM content, curing time, and temperature. The
adhesive strength of crosslinked WBPU in the case of optimum HMMM content (8.46 wt%) was only slightly affected after immersing
adhesive bonded nylon fabrics in water (for up to 2 days). 相似文献
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Alam Md. Ashraful Rahman Md. Mizanur Biswas Jatish Chandra Akhter Sohela Maniruzzaman M. Choudhury Apurba Kanti Jahan M. Abu Hena Sorwar Miah Md. Main Uddin Sen Ranjit Kamal M. Zia Uddin Mannan Md. Abdul Shiragi Humayun Kabir Kabir Wais Kalra Naveen 《Paddy and Water Environment》2019,17(4):677-688
Paddy and Water Environment - Rice-based cropping systems in Bangladesh have received little consideration of changing nitrogen (N) and carbon (C) in soil. Therefore, this study was conducted at... 相似文献
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Md. Mizanur Rahman Marina Basaglia Elena Vendramin Bruno Boz Federico Fontana Bruna Gumiero Sergio Casella 《Biology and Fertility of Soils》2014,50(1):25-35
This research is part of a project aimed at verifying the potential of a specifically assessed wooded riparian zone in removing the excess of combined nitrogen from the Zero River so as to reduce nutrient inputs into the Venice Lagoon. Among the specific objectives of the project, there was the determination of change in the composition of the microbial populations of soil of the wooded riparian strip. The composition of the bacterial communities collected at different depths inside and outside the riparian strip was determined by combined approaches involving cultivation (CFU), microscopic approaches (CTC test), and DNA-based techniques (ARDRA and DGGE). The size of the living population was the same inside and outside the experimental strip, with a minor percentage of culturable bacteria. Higher numbers of metabolically active bacteria and higher bacterial diversity were detected in the internal soil, with deeper soil layers showing reduced diversity, thus indicating that soil management within the riparian strip effectively supports the viability of bacterial communities. Total operational taxonomic units (OTUs) and percentage of single OTUs were also found to be always higher in the internal soil samples for all soil layers, with the percentage of Firmicutes increasing and Actinobacteria decreasing with depth. The increasing soil organic carbon inputs due to the contribution of the growing plants were found to support bacterial diversity in all soil layers. DNA-based analysis also indicated a clear effect of the applied treatments on soil bacterial diversity and a well-defined separation of the bacterial communities related to the different soil layers of the riparian strip. 相似文献
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In order to improve the water swelling, thermal/mechanical and adhesion properties of waterborne polyurethane (WBPU), a series
of the crosslinkable WBPUs containing hydrophilic ionic component, dimethylol propionic acid (20 mole%), were prepared by
in-situ polymerization using a cross-linker hexakis (methoxymethyl) melamine (HMMM). Effects of the HMMM content (2, 4, and
6 wt%) and curing temperature on these properties of the crosslinked WBPUs samples were investigated. All properties were
found to increase with increasing HMMM content. It was found that the optimum curing temperature of the WBPU films and adhesives
was near 120°C, which was not dependent on the HMMM content. 相似文献