Disaster risk reduction measures n Bangladesh

Disasters damage the entire economy of the country when they predominantly take place in developing countries. While no country in the world is entirely safe, lack of capacity to limit the impact of hazards has made developing countries being the most vulnerable nations to natural disasters. Bangladesh is being identified as a country that is vulnerable to climate change and subsequent natural disasters every year. Dense population and poverty has reduced the adaptability of Bangladesh in disastrous situations thus further increasing severity of impact from disasters. Owing to geographical settings, Bangladesh is currently ranked as one of the world’s most disaster-prone countries in the world. The frequent natural hazards such as cyclones, storm surges, floods, droughts, tornados,riverbank erosions, earthquakes, arsenic contamination of groundwater and landslides account for significant losses in human lives and physical assets while effects are further reflected in social settings, ecosystems and the economic well-being of the country. This paper evaluates the types of natural disasters Bangladesh is subjecting to, how they have affected the Bangladesh community and existing disaster risk reduction strategies. Paper also evaluates four main domains of disaster vulnerability reduction measures namely physical, engineering, structural and organisational. Existing disaster risk reduction strategies adopted in Bangladesh are linked with the aforementioned four domains of disaster vulnerability reduction measures. A comprehensive literature review is used as the research method. Literature synthesis suggests that Bangladesh is being using a combination of disaster risk reduction measures ranging from technical to social measures

Design and development of a slot-less permanent magnet linear motor using permeance analysis method for spray application

Mostly in industrial spray applications pneumatic systems are utilized for operating the automatic spray gun. Linear motor can be one of the alternatives for triggering the spray gun instead of pneumatic systems due to its accuracy in valve positioning according to the required flow rate. From this point of view a tubular linear permanent magnet motor has been designed using Permeance Analysis Method (PAM) and developed. Three permeance models have been developed for PAM analysis. Among these three models, only one model is selected as a PAM model which can be produced the required amount of thrust for triggering the spray gun. After selecting the PAM thrust model, the size of the motor has been optimized by analyzing the effect of thrust constant, electrical and mechanical time constant. Finally based on the optimized data, the motor has been fabricated and tested that shows the good argument with the analysis result

Intermittency in Two-Dimensional Turbulence with Drag

We consider the enstrophy cascade in forced two-dimensional turbulence with a linear drag force. In the presence of linear drag, the energy wavenumber spectrum drops with a power law faster than in the case without drag, and the vorticity field becomes intermittent, as shown by the anomalous scaling of the vorticity structure functions. Using a previous theory, we compare numerical simulation results with predictions for the power law exponent of the energy wavenumber spectrum and the scaling exponents of the vorticity structure functions $\zeta_{2q}$ obtained in terms of the distribution of finite time Lyapunov exponents. We also study, both by numerical experiment and theoretical analysis, the multifractal structure of the viscous enstrophy dissipation in terms of its R\'{e}nyi dimension spectrum $D_q$ and singularity spectrum $f(\alpha)$. We derive a relation between $D_q$ and $\zeta_{2q}$, and discuss its relevance to a version of the refined similarity hypothesis. In addition, we obtain and compare theoretically and numerically derived results for the dependence on separation $r$ of the probability distribution of \delta_{\V{r}}\omega, the difference between the vorticity at two points separated by a distance $r$. Our numerical simulations are done on a $4096 \times 4096$ grid.Comment: 18 pages, 17 figure

Modelling and simulation of electric drive vehicle based on space vector modulation technique and field oriented control strategy

Recently, the electric vehicle has emerged as a powerful platform for mitigating energy crisis and reducing environmental pollution in the transportation sector. The major drawbacks of electrically powered automobile that limits its competitiveness with the internal combustion engine counterpart are the vehicle driving range and battery energy capacity. Hence, limited energy storage warrants the need for an effective and efficient energy utilisation in the overall system. This paper uses Field Oriented Control algorithm and Space Vector Modulation technique to enhance and to optimise energy saving at the same time improve the vehicle induction motor efficiency. A simple electric vehicle drive with vehicle dynamic and tractive loads for motor driving load were modelled and simulated using Matlab/Simulink. Simulation results show that modelled vehicle speed satisfied the acceleration index for the electric vehicle

Process involved in designing of an intelligent additional track mechanism tracked vehicle for swamp peat terrain

Different types of off road vehicles are widely used in agriculture, oil industry, mining and military operations but none of them can effectively operate over the swamp peat terrain because of its low bearing capacity of 7kN/m 2. Segmented rubber tracked vehicle and intelligent air-cushion system tracked vehicle were developed in Malaysia for swamp peat terrain.16kN/m2 of ground pressure was exerted by using the segmented rubber tracked vehicle during field operation therefore could not be operated efficiently. The air-cushion tracked vehicle increased the floatation capacity but at the same time increased the frictional effects therefore the tracks of the vehicle easily slipped out from the traction wheels during operation. Addressing these issues an intelligent additional track mechanism for tracked vehicle has been designed to improve the mobility over swamp peat terrain where the additional track would be increased the ground surface area and reduced the vehicle ground pressure. This paper presents the process involved in designing the intelligent additional track mechanism tracked vehicle for transportation of agricultural and industrial goods on the swamp peat terrain with bearing capacity of 7kN/m2. The mechanical design comprises of track vehicle frame with track mechanism. Additional track mechanism with Fuzzy expert system. The design parameters are optimized using developed mathematical model based on the dynamics and kinematics behavior of the vehicle. In order to increase the vehicle contact surface area and reduce the surface contact pressure the additional track mechanism is designed in such way that it can be folded and unfolded from its position by using the ball-screw scissor lift mechanism. While, Fuzzy expert system is used to control the movement of the lift mechanism based on 70mm critical sinkage of vehicle detected from a set of sensors. The completed to vehicle system would be used for off-road applications as required

Lower bounds on the dilation of plane spanners

(I) We exhibit a set of 23 points in the plane that has dilation at least $1.4308$, improving the previously best lower bound of $1.4161$ for the worst-case dilation of plane spanners. (II) For every integer $n\geq13$, there exists an $n$-element point set $S$ such that the degree 3 dilation of $S$ denoted by $\delta_0(S,3) \text{ equals } 1+\sqrt{3}=2.7321\ldots$ in the domain of plane geometric spanners. In the same domain, we show that for every integer $n\geq6$, there exists a an $n$-element point set $S$ such that the degree 4 dilation of $S$ denoted by $\delta_0(S,4) \text{ equals } 1 + \sqrt{(5-\sqrt{5})/2}=2.1755\ldots$ The previous best lower bound of $1.4161$ holds for any degree. (III) For every integer $n\geq6$, there exists an $n$-element point set $S$ such that the stretch factor of the greedy triangulation of $S$ is at least $2.0268$.Comment: Revised definitions in the introduction; 23 pages, 15 figures; 2 table

Participatory rural appraisal and farmers’ perception about common bean varieties in temperate Kashmir

Present investigation was undertaken during 2012 to 2014 in which 54 genotypes, both pole and bush type of Common beans (Phaseolus vulgaris) were selected among a number of germplasm lines, land races and research material in order to generate information on the farmer’s’ perception about the Common bean varieties. Participatory rural appraisal was conducted in 32 villages of Kashmir through a broad questionnaires comprising of questions pertaining to the socio-economic conditions, farming systems, production constraints and varietal preferences of the common bean. The Participatory Rural Appraisal results revealed that common bean is generally grown as a rainfed crop (70 %) and is intercropped with maize/ potato/vegetable and merely as sole crop (20.66 %). Low yielding varieties and diseases (68.27 %) are considered as major challenges in the success of common bean crop, while as red colour with kidney shaped types (50 %) are highly being preferred as a pulse crop. The exercise of Participatory Rural Appraisal was carried out to generate basic information by assessing the need based constraints and devise the target breeding approach, by taking into consideration all constraints and also devise future breeding programme. A successful PRA provides the information needed to specify the characteristic in a new variety regarding its physical environment and the existing varietal diversity. For a breeding program, well applied Participatory Rural Appraisal techniques or customer profiling results in better client orientation and makes possible efficient goal setting or product design. Successful PRA provides everything that could be included in the full design specification of a new crop variety