An experiment was carried out at the Agroforestry and Environment Research Farm, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh, during April, 2014 to January 2015. The experiment was la...An experiment was carried out at the Agroforestry and Environment Research Farm, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh, during April, 2014 to January 2015. The experiment was laid out in two factors Randomized Complete Block Design (RCBD) with three replications. Among the two factors, one factor like A was two production systems: S1 = Mango + Turmeric and S2 = Turmeric (sole crop);another factor like B was three turmeric variety: V1 = BARI Holud-1, V2 = BARI Holud-2 and V3 = BARI Holud-3. So, the treatment combinations were: S1V1 = Mango + BARI Holud-1, S1V2 = Mango + BARI Holud-2, S1V3 = Mango + BARI Holud-3, S2V1 = sole cropping of BARI Holud-1, S2V2 = sole cropping of BARI Holud-2 and S2V3 = sole cropping of BARI Holud-3. The result of the experiment revealed that interaction effect of production systems and variety was found significant on plant height, number of leaf per plant, length of leaf blade, breadth of leaf blade, number of finger per rhizome, fresh and dry yield per hectare. The higher fresh yield of turmeric (34.75 t/ha) and dry yield (6.10 t/ha) was found from S1V1 treatment (Mango + BARI Holud-1). Whereas the lowest fresh yield (33.41 t/ha) and dry yield (4.93 t/ha) was found from S2V2 treatment (sole cropping of BARI Holud-2). However, the suitability of the cultivation of different turmeric variety under mango based agroforestry systems may be ranked as S1V1 > S2V1 > S1V3 > S2V3 > S1V2 > S2V2. Finally it may be concluded that, BARI Holud-1 would be the best variety to be grown under mango based agroforestry.展开更多
Gravity dams are solid concrete structures that maintain their stability against design loads from the geometric shape, mass and strength of the concrete. The purposes of dam construction may include navigation, flood...Gravity dams are solid concrete structures that maintain their stability against design loads from the geometric shape, mass and strength of the concrete. The purposes of dam construction may include navigation, flood damage reduction, hydroelectric power generation, fish and wildlife enhancement, water quality, water supply, and recreation. The design and evaluation of concrete gravity dam for earthquake loading must be based on appropriate criteria that reflect both the desired level of safety and the choice of the design and evaluation procedures. In Bangladesh, the entire country is divided into 3 seismic zones, depending upon the severity of the earthquake intensity. Thus, the main aim of this study is to design high concrete gravity dams based on the U.S.B.R. recommendations in seismic zone II of Bangladesh, for varying horizontal earthquake intensities from 0.10 g - 0.30 g with 0.05 g increment to take into account the uncertainty and severity of earthquake intensities and constant other design loads, and to analyze its stability and stress conditions using analytical 2D gravity method and finite element method. The results of the horizontal earthquake intensity perturbation suggest that the stabilizing moments are found to decrease significantly with the increment of horizontal earthquake intensity while dealing with the U.S.B.R. recommended initial dam section, indicating endanger to the dam stability, thus larger dam section is provided to increase the stabilizing moments and to make it safe against failure. The vertical, principal and shear stresses obtained using ANSYS 5.4 analyses are compared with those obtained using 2D gravity method and found less compares to 2D gravity method, except the principal stresses at the toe of the gravity dam for 0.10 g - 0.15 g. Although, it seems apparently that smaller dam section may be sufficient for stress analyses using ANSYS 5.4, it would not be possible to achieve the required factors of safety with smaller dam section. It is observed during stability analyses that the factor of safety against sliding is satisfied at last than other factors of safety, resulting huge dam section to make it safe against sliding. Thus, it can be concluded that it would not be feasible to construct a concrete gravity dam for horizontal earthquake intensity greater than 0.30 g without changing other loads and or dimension of the dam and keeping provision for drainage gallery to reduce the uplift pressure significantly.展开更多
文摘An experiment was carried out at the Agroforestry and Environment Research Farm, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh, during April, 2014 to January 2015. The experiment was laid out in two factors Randomized Complete Block Design (RCBD) with three replications. Among the two factors, one factor like A was two production systems: S1 = Mango + Turmeric and S2 = Turmeric (sole crop);another factor like B was three turmeric variety: V1 = BARI Holud-1, V2 = BARI Holud-2 and V3 = BARI Holud-3. So, the treatment combinations were: S1V1 = Mango + BARI Holud-1, S1V2 = Mango + BARI Holud-2, S1V3 = Mango + BARI Holud-3, S2V1 = sole cropping of BARI Holud-1, S2V2 = sole cropping of BARI Holud-2 and S2V3 = sole cropping of BARI Holud-3. The result of the experiment revealed that interaction effect of production systems and variety was found significant on plant height, number of leaf per plant, length of leaf blade, breadth of leaf blade, number of finger per rhizome, fresh and dry yield per hectare. The higher fresh yield of turmeric (34.75 t/ha) and dry yield (6.10 t/ha) was found from S1V1 treatment (Mango + BARI Holud-1). Whereas the lowest fresh yield (33.41 t/ha) and dry yield (4.93 t/ha) was found from S2V2 treatment (sole cropping of BARI Holud-2). However, the suitability of the cultivation of different turmeric variety under mango based agroforestry systems may be ranked as S1V1 > S2V1 > S1V3 > S2V3 > S1V2 > S2V2. Finally it may be concluded that, BARI Holud-1 would be the best variety to be grown under mango based agroforestry.
文摘Gravity dams are solid concrete structures that maintain their stability against design loads from the geometric shape, mass and strength of the concrete. The purposes of dam construction may include navigation, flood damage reduction, hydroelectric power generation, fish and wildlife enhancement, water quality, water supply, and recreation. The design and evaluation of concrete gravity dam for earthquake loading must be based on appropriate criteria that reflect both the desired level of safety and the choice of the design and evaluation procedures. In Bangladesh, the entire country is divided into 3 seismic zones, depending upon the severity of the earthquake intensity. Thus, the main aim of this study is to design high concrete gravity dams based on the U.S.B.R. recommendations in seismic zone II of Bangladesh, for varying horizontal earthquake intensities from 0.10 g - 0.30 g with 0.05 g increment to take into account the uncertainty and severity of earthquake intensities and constant other design loads, and to analyze its stability and stress conditions using analytical 2D gravity method and finite element method. The results of the horizontal earthquake intensity perturbation suggest that the stabilizing moments are found to decrease significantly with the increment of horizontal earthquake intensity while dealing with the U.S.B.R. recommended initial dam section, indicating endanger to the dam stability, thus larger dam section is provided to increase the stabilizing moments and to make it safe against failure. The vertical, principal and shear stresses obtained using ANSYS 5.4 analyses are compared with those obtained using 2D gravity method and found less compares to 2D gravity method, except the principal stresses at the toe of the gravity dam for 0.10 g - 0.15 g. Although, it seems apparently that smaller dam section may be sufficient for stress analyses using ANSYS 5.4, it would not be possible to achieve the required factors of safety with smaller dam section. It is observed during stability analyses that the factor of safety against sliding is satisfied at last than other factors of safety, resulting huge dam section to make it safe against sliding. Thus, it can be concluded that it would not be feasible to construct a concrete gravity dam for horizontal earthquake intensity greater than 0.30 g without changing other loads and or dimension of the dam and keeping provision for drainage gallery to reduce the uplift pressure significantly.
