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Shifting cultivation effects on creek water quality around Barkal Upazila in Chittagong Hill Tracts,Bangladesh

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Journal of Forestry Research 2012年第4期23卷 623-630页

作者： Shyamal karmakar S.m.Sirajul Haque m.mozaffar Hossain Sohag miah Institute of Forestry and Environmental Sciences University of ChittagongChittagong 4331Bangladesh

Abstract： We report the effects of shifting cultivation on water quality in 16 creeks investigated once in 2007 and twice in 2008 in 16 apparently similar small neighboring watersheds, each of 3 to 5 ha, at four locations around Barkal sub-district under Rangamati District of Chittagong Hill Tracts in Bangladesh. Concentrations of 5042- and k＋, and pH in creek water were lower, and NO3-N and Na＋ concentrations were higher in shifting-cultivation land compared to land with either plantation or natu- ral forest or a combination of these cover types. Shifting cultivation effects on some water quality parameters were not significant due to change in land cover of the watershed between two sampling periods either through introduction of planted tree species or naturally regenerated vegetation. Conductivity and concentrations of HCO3- PO43-, Ca2-- and mg2＋ in creek water showed no definite trend between shifting cultivation and the other land cover types. At one area near the Forest Range Office of Barkal, creek water pH was 5.8 under land cover with a com- bination of shifting cultivation and plantation. At this area Na~ concentra- tion in shitting-cultivation land ranged from 32.33 to 33.00 mg-L＂ and in vegetated area from 25.00 to 30.50 mg.L-1 in 2007. At another area, Chaliatali Chara, SO42 concentration in a shifting-cultivation watershed ranged from 4.46 to 10.51 mg-L-1, lower than in a vegetated watershed that ranged from 11.69 to 19.98 mg.L-1 in 2007. S042-concentration in this shifting-cultivation area ranged from 1.28 to 1.37 mg.L^-1 and in the vegetated area from 1.37 to 3.50 mg-L^-1 in 2008.

关键词： Shifting cultivation Creek water quality Chittagong Hill Tracts Riparian vegetation Land cover Bangladesh

Water quality of kaptai reservoir in Chittagong Hill Tracts of Bangladesh

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Journal of Forestry Research 2011年第1期22卷 87-92页

作者： Shyamal karmakar S. m. Sirajul Haque m. mozaffar Hossain m. Shafiq Institute of Forestry and Environmental Sciences University of Chittagong Chittagong Bangladesh 4331 Department of Soil Science University of Chittagong Chittagong Bangladesh 4331

A study was conducted in kaptai reservoir, one of the largest man-made freshwater lakes of South-east Asia, to determine present status of water quality and its suitability for fishing and other uses. Water samplings were from middle part of the reservoir at 0.2 and 0.8 fractional depths at five different locations from upstream to downstream viz. Burburichara, maichchari, Subolong, Basanthakum, and Rangamati. Water analyses show that concentrations of NO3-N, k＋ and total P, and suspended solid at all the sampling stations were beyond the recommended values for fish culture. Concentrations of Na^＋, Ca^2＋, mg^2＋, SO4^2-, Cl^-, total dissolved solid （TDS）, dissolved oxygen （DO） and chemical oxygen demand （COD） were within the standards for aquaculture. Concentrations of NO3-N, SO4^2-, k＋ and total P showed no definite trend with depths, locations as well as rainy and dry seasons. Water pH, conductivity, Na^＋ and HCO3- contents were lower in rainy season, and DO and COD higher at almost all the locations in both the depths, compared with dry season. Total solids and concentrations of TDS, DO, COD, Ca^2＋, mg^2＋ and Na^＋ were higher in upstream and decreased gradually towards downstream in the reservoir. Concentrations of DO and Ca2＋ and pH were higher and mg2＋ less at 0.2-fractional depth than those at 0.8-fractional depth at almost all the locations. The reservoir is in mesotrophic condition containing high concentration of NO3-N and total P, in alarming status with the presence of excessive suspended solids from urban pollution around the town. It is necessary to adopt measures for protecting water quality in the reservoir due to such deteriorations.

关键词： karnaphuli river lake water quality Chittagong Hill Tract

Composites for electric vehicles and automotive sector: A review

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Green Energy and Intelligent Transportation 2023年第1期2卷 86-108页

作者： Adil Wazeer Apurba Das Chamil Abeykoon Arijit Sinha Amit karmakar School of Laser Science and Technology Jadavpur UniversityKolkata 700032West BengalIndia Design Head-Freight Titagarh Wagons Limited756 AnandapurKolkata 700107India North West Composites Centre and Aerospace Research Institute Department of MaterialsFaculty of Science and EngineeringUniversity of ManchesterManchesterM139PLUK Department of metallurgical Engineering Kazi Nazrul UniversityAsansol 713340West BengalIndia Department of mechanical Engineering Jadavpur UniversityKolkata 700032West BengalIndia

The automotive sector is undergoing a significant transformation to address critical challenges affecting consumers and the *** of the most difficult tasks is reducing the weight of vehicles in order to minimize energy consumption.A ten percent decrease in curb weight is predicted to result in a six to eight percent reduction in energy *** materials having better strength to weight ratio are one of the finest options for planning,designing and manufacturing of the lightweight *** automobile sector,employment of composite materials would reduce the weight of electric vehicles as well as influence their aerodynamic prop***,it would decrease the consumption of fuel as well by cutting down harmful emissions and particulate *** developments in such technologies are studied over the last decade by automobile establishments and academic ***-reinforced polymers,particularly those established on glass and carbon fibers,have attracted attention of the automobile sector due to their high performance and lesser *** paper reviews the applications of various types of composite materials and the fabrication techniques of such composites in electric vehicles and ***,a comprehensive data breakdown of the lightweight materials statistics and figures on market analysis of high performance composite is ***,a discussion is made on the different applications of these ***,the details presented in this study should be useful for automobile companies to align with NET ZERO global mission while sustaining their businesses.

关键词： Composites Electric vehicles Fabrication techniques Hybrid vehicles

Influence of Support Conditions on the Hydroelastic Behaviour of Floating Thick Elastic Plate

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Journal of marine Science and Application 2019年第3期18卷 295-313页

作者： k.m.Praveen D.karmakar C.Guedes Soares Department of Applied mechanics and Hydraulics National Institute of Technology KarnatakaSurathkalMangalore 575025India Centre for marine Technology and Ocean Engineering (CENTEC) Instituto Superior TécnicoUniversidade de LisboaAv. Rovisco Pais1049 001 LisbonPortugal

The hydroelastic response of very large floating structures (VLFS) under the action of ocean waves is analysed considering the small amplitude wave theory. The very large floating structure is modelled as a floating thick elastic plate based on Timoshenko- mindlin plate theory, and the analysis for the hydroelastic response is performed considering different edge boundary conditions. The numerical study is performed to analyse the wave reflection and transmission characteristics of the floating plate under the influence of different support conditions using eigenfunction expansion method along with the orthogonal mode-coupling relation in the case of finite water depth. Further, the analysis is extended for shallow water depth, and the continuity of energy and mass flux is applied along the edges of the plate to obtain the solution for the problem. The hydroelastic behaviour in terms of reflection and transmission coefficients, plate deflection, strain, bending moment and shear force of the floating thick elastic plate with support conditions is analysed and compared for finite and shallow water depth. The study reveals an interesting aspect in the analysis of thick floating elastic plate with support condition due to the presence of the rotary inertia and transverse shear deformation. The present study will be helpful for the design and analysis of the VLFS in the case of finite and shallow water depth.

关键词： Timoshenko-mindlin plate theory Very large floating structure Support condition Rotary inertia Transverse shear deformation

Coastal afforestation effects on soil properties at Hatiya in Bangladesh

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Journal of Forestry Research 2009年第A3期20卷 243-248,287页

作者： k.m.Shaifullah S.m.Sirajul Haque m.Sujauddin Shyamal karmakar Institute of Forestry and Environmental Sciences University of Chittagong

An exploratory study was conducted in the coastal plantation (12-and 17-year-old Sonneratia apetala) of Char Alim and Char Piya and on their adjacent barren lands at Char Rehania and Char Nurul Islam in Hatiya of Noakhali district, in Bangladesh to determine afforestation effects on soil properties. At soil depths of 0-10, 10-30 and 30-40 cm across three different land strips viz. inland, middle and sea side in 12-and 17-year-old keora (Sonneratia apetala) plantations, soil moisture, particle density, organic matter and C, total N, pH, available P, k, Na, Ca and mg were significantly (p≤0.05, p≤0.01, p≤0.001) higher, and soil salinity significantly (p≤0.001) lower than that in their adjacent barren lands. Soil moisture, particle density, organic matter and C, total N, pH, soil salinity, available P, k, Na, Ca and mg of surface soil in Char Alim plantation at inland were 31.09%, 2.24 g·cm-3, 2.41%, 4.14%, 0.58%, 7.07, 0.09 dS·cm-1, 28.06 mg·L-1, 0.50 mg·L-1 11.5 mg·L-1, 3.30 mg·L-1 and 2.7 mmol·kg-1, respectively. Their corresponding values for the same depth and land position at adjacent Char Rehania barren land were 16.69%, 1.25g·cm-3, 0.43%, 0.74%, 0.25%, 6.57, 0.13 dS·cm-1, 13.07mg·L-1, 0.30 mg·L-1, 1.4 mg·L-1, 0.30 mmol·kg-1 and 0.50 mg·L-1, respectively. Soil moisture, particle density, organic matter and C, total N, pH, available P, k and Ca decreased, and soil salinity, available Na and mg increased from inland towards sea side in the plantations. Although soil texture did not differ in most soil depths between plantation and adjacent barren land, proportion of sand particle was significantly (p≤0.01) lower and silt particle significantly (p≤0.001) in the plantations higher than that in their adjacent barren lands. In the study, evaluation of all the parameters was also done for the other pair of lands.

关键词： coastal afforestation keora plantation soil physicochemical properties afforestation effect soil texture soil base cations Sonneratia apetala Bangladesh

Organic matter accumulation in hill forests of Chittagong region,Bangladesh

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Journal of Forestry Research 2009年第3期20卷 249-253,287页

作者： S.m.Sirajul Haque Nirmal Chandra karmakar Institute of Forestry and Environmental Sciences University of Chittagong

Litter fall and its effect on forest soil properties at each decomposition stages were investigated in tropical monsoon climatic conditions of three plantations (7-year acacia plantation, 15-year acacia plantation and 18-year mixed plantation) and one natural forest (Sitapahar forest) from Chittagong hilly region of Bangladesh. Results showed that total accumulation of organic matter increased with plantation age, accompanying with a decrease of annual accumulation rate. Within the same vegetation type, the organic accumulation of both fresh and partially decomposed litter with humus varied significantly (p≤0.05) on hill positions, being highest on bottom slope and decreased gradually towards hilltop in the forest. Reverse trend in accumulation of soil organic matters was shown in 15-year Acacia auriculiformis plantation, from where fuel wood collected. In 7-and 15-year acacia and 18-year mixed broadleaved plantations, rates of total organic matter production consisting of fresh, partially and completely decomposed litter as well as incorporated organic matter in soil were 2554.31, 705.79 and 1028.01 kg·ha-1·a-1, respectively, and the corresponding contribution from fresh litter were 38.23, 19.40 and 30.48 kg·ha-1·a-1, respectively. In the three plantations and the natural forest, on an average fresh litter constituted 32.45%, partially decomposed litter with humus 13.50% and incorporated organic matter in soil 54.56% of the total organic matter production with mean litter thickness of 0.90 cm. Soil acidity increased with the increase of decomposition stage of organic matter.

关键词： accumulation rate decomposition stages hill forest organic matter plantation forest

Effect of land cover on water quality of creek and seepage in mountainous watershed in Bangladesh

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Journal of Forestry Research 2010年第2期21卷 251-254,I0008页

作者： S.m.Sirajul Haque Shyamal karmakar m.mozaffar Hossain Institute of Forestry and Enviromental Science University of Chittagong

The flowing water was collected from very small creeks and seepage water from small dug holes at three different areas,***,Ghagra and muralipara in Rangamati district of Chittagong Hill Tracts,Bangladesh to investigate the impact of the existing varied land covers on water *** analyses shows that flowing creek water from either mature mixed plantation or young gamar（Gmelina arborea） plantation had significantly（p〈0.05） higher pH value,SO4^2-and Ca^2＋ concentrations,and significantly lower Na＋ concentration at manikchari,compared to natural vegetation and plantation in *** flowing creek water of Ghagra,the concentrations of SO4^2-and k＋,conductivity and total dissolved solids from watershed of 8-year-old teak（Tectona grandis） plantation were significantly higher and the concentrations of HCO3^-,NO3^-and PO4^3-were significantly lower,compared to those of watershed of degraded natural *** muralipara,flowing creek water from natural vegetation and shifting cultivated land in combination showed significantly higher concentrations of HCO3^-,NO3^-,Na＋,k＋,Ca^2＋ and mg^2＋,and conductivity and total dissolved solids than seepage water as well as tube well water installed in shifting cultivated area alone.

关键词： plantation flowing water shifting cultivation Chittagong Hill Tracts

medication beliefs predict medication adherence in ambulatory patients with decompensated cirrhosis

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World Journal of Gastroenterology 2017年第40期23卷 7321-7331页

作者： kelly L Hayward Patricia C Valery Jennifer H martin Antara karmakar Preya J Patel Leigh U Horsfall Caroline J Tallis katherine A Stuart Penny L Wright David D Smith katharine m Irvine Elizabeth E Powell W Neil Cottrell Pharmacy Department Princess Al-exandra Hospital The Centre for Liver Disease Research Translational Research Institute The University of Queensland Cancer and Chronic Disease Research Group QIMR Berghofer Medical Research Institute School of medicine and Public Health The University of Newcastle The Centre for Liver Disease Research Translational Research Institute The University of Queensland Department of Gastroenterology and Hepatology Princess Alexandra Hospital The Centre for Liver Disease Research Translational Research Institute The University of Queensland Department of Gastroenterology and Hepatology Princess Alexandra Hospital Statistics Unit QIMR Berghofer Medical Research Institute School of Pharmacy The University of Queensland

AIm To investigate the impact of medication beliefs, illness perceptions and quality of life on medication adherence in people with decompensated *** One hundred adults with decompensated cirrhosis completed a structured questionnaire when they attended for routine outpatient hepatology review. measures of self-reported medication adherence(morisky medication Adherence Scale), beliefs surrounding medications(Beliefs about medicines Questionnaire), perceptions of illness and medicines(Brief Illness Perception Questionnaire), and quality of life(Chronic Liver Disease Questionnaire) were examined. Clinical data were obtained via patient history and review of medical records. Least absolute shrinkage and selection operator and stepwise backwards regression techniques were used to construct the multivariable logistic regression model. Statistical significance was set at alpha = *** medication adherence was " High " in 42 % o f participants, "medium" in 37%, and "Low" in 21%. Compared to patients with "High" adherence, those with "medium" or "Low" adherence were more likely to report difficulty affording their medications(P ment helpfulness(P = 0.003) and stronger medication concerns relative to medication necessity beliefs(P = 0.003). People with "Low" adherence also experienced greater symptom burden and poorer quality of life, including more frequent abdominal pain(P = 0.023), shortness of breath(P = 0.030), and emotional disturbances(P = 0.050). multivariable analysis identified having stronger medication concerns relative to necessity beliefs(Necessity-Concerns Differential ≤ 5, OR = 3.66, 95%CI: 1.18-11.40) and more frequent shortness of breath(shortness of breath score ≤ 3, OR = 3.87,95%CI: 1.22-12.25) as independent predictors of "Low"*** The association between "Low" adherence and patients having strong concerns or doubting the necessity or helpfulness of their medications should be explor

关键词： medication adherence medication beliefs Illness perceptions Quality of life Liver cirrhosis

Structural behaviour of carbon single wall nanotubes under high pressure

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Structural behaviour of carbon single wall nanotubes under h...