Urban Regeneration for Sustainable Economic Growth: the study of Boro Bazaar in Khulna, Bangladesh

The major dynamic driving forces of cities in developing countries are economic and social forces to change the urban system with the growing demand of population and urbanization. Of course, the problems are different and unique to a particular city based on the city growth pattern, economic and social character. Khulna, the third largest metropolitan city in Bangladesh with 1.2 million populations within 45.6 square kilometer was developed as a medium scale industrial city since 1950s. Previously the city economy was completely established on river-based trade and the city developed around the river port locally named “Boror Bazaar†means big market place. The changing city form gave Boro Bazaar the shape of mixed-use zone rather solely commercial or business zone. Now, as a central economic hub in the city centre, Boro Bazaar needs to be more dynamic to response to the city economy and its growth pattern. For last one decade, Boro Bazaar has faced compact unplanned haphazard development even along the riverside just to meet the demand of rapid urbanization process. Therefore, it has become an urban challenge to revitalize the Boro Bazaar area to make more effective response to the rapid economic growth and to ensure better urban environment for the residents, businesspersons and the employers

Thermodynamic efficiency limits of classical and bifacial multi-junction tandem solar cells: An analytical approach

Bifacial tandem cells promise to reduce three fundamental losses (i.e., above-bandgap, below bandgap, and the uncollected light between panels) inherent in classical single junction photovoltaic (PV) systems. The successive filtering of light through the bandgapcascade and the requirement of current continuity make optimization of tandem cellsdifficult and accessible only to numerical solution through computer modeling. The challenge is even more complicated for bifacial design. In this paper, we use an elegantly simple analytical approach to show that the essential physics of optimization is intuitively obvious, and deeply insightful results can be obtained with a few lines of algebra. This powerful approach reproduces, as special cases, all of the known results of conventional and bifacial tandem cells and highlights the asymptotic efficiency gain of these technologies

Impact of Rohingya Refugees on Food Prices in Bangladesh: Evidence from a Natural Experiment

The Rohingya crisis is the fourth largest displacement of population in the world, with most refugees sheltering in neighbouring Bangladesh. We use this event as a natural experiment to examine the impact of the sudden influx of Rohingyas on food prices in the main host region of Bangladesh. We have pieced together a unique data set on food prices based on unpublished information at local government levels covering the pre- and post-influx period. We use a difference-in-difference approach to identify the impact of the refugee influx on the prices in the local area. Our baseline results indicate that overall food prices increased by 8 percent in the host sub-district of Ukhia, with prices of protein and vegetables increasing by 7 and 36 percent, respectively. For aid-supplied food products, such as cereals and lentils, we do find a statistically significant mitigating effect on prices. However, they were not substantial enough to reverse the increase in food prices

Effect of Homogeneous Condensation on the Interaction of Supersonic Moist Air Jets with Resonance Tube

The Hartmann tube, can use for flow-control, is a device which generates high intensity sound through the shock wave oscillations, are created by the interaction of the supersonic jet. In this study, two-phase flow simulations are carried out to characterize the effect of non-equilibrium condensation on the unsteady flowfield of the Hartmann resonance tube. This present numerical work provides a new insight on the flow dynamics and acoustics of the resonance tube – including the shock nature, the tube gas heating, and the effect of non-equilibrium condensation on the flow structure. A TVD numerical method is applied to the Reynolds and Favre-averaged Navier-Stokes equations, and droplet growth equation of liquid phase production. The simulations are performed over a range of nozzle pressure ratios. The numerically simulated flow structure of under-expanded supersonic jets is compared with experimental data. Moreover, the predicted frequency of end wall pressure fluctuations is compared with the experimental results

Creek`s Aquaculture Techniques in Rangamati Hill Tracts of Bangladesh

An experiment was conducted in nine suitable (average .10±2 ha) creeks of Rangamati hill tracts Bangladesh viz., of Langadu, Naniarchar and Sadar Upazila for evaluating growth, survival and production performance of Indian major carps (Labeo rohita, Catla catla, Cirrhinus mrigala) in a completely randomized design into three different treatments with three replications for a period of one year. Stocking density, growth, survival was checked periodically and total yield calculated from stocking and harvesting data. A significant spatial variation in specific growth rate (SGR) and yields was found despite uniform stocking densities, attributable to variation in environmental parameters. Among the results rohu was found to have comparatively higher SGR of 1.51±0.55 in Naniarchar where as langadu creek was reported with higher SGR of 1.46±0.94, 1.57±0.41 and 1.46 ±.64 for rohu catla, and mrigal. Rangamati sadar Upazilla creek was found to be conducive to Catla with a SGR of 1.55±.78. In general, higher gross and net productions were reported from Sadar Upazilla, Langadu and Naniarchar creeks, suggestive of its suitability for developing creeks aquaculture technology. However research findings will help the community of Chittagong hill tracts by giving appropriate technology for sustainable fish production in creeks

STUDY OF PROBIOTICS ON THE SEED PRODUCTION OF BLACK TIGER SHRIMP Penaeus monodon

Currently, antibiotics are widely used in shrimp hatcheries to control bacterial infections. Appearance of antibiotic resistant pathogens and restriction on the use of antibiotics have led to the development of alternatives to antibiotics in hatchery systems. In light of this, an attempt was undertaken to investigate the effects of probiotics on the larval rearing of Penaeus monodon, compared with control tanks (without probiotics). The results showed that several issues significantly improved with administering probiotics in the experimental tanks compared with the tanks without probiotics. For example, the concentration of ammonia was estimated to be 1.25 mg/L that was less than half of what was measured in the control tanks. The size variation was observed more in the control tanks than in the experimental tanks. Moreover, the muscle gut ratio of PL15 was about 85 to 92% in the probiotic treated tank and 70 to 80% in the control tank during the eight cycles of production. The fouling organisms were more in the control tank compared to the experimental tanks. The average length of PL15 was maximum when reared in the experimental tanks compared to the control tanks. The final survival rate of PL15 from the control and experimental tank was 35 and 52%, respectively. The present investigation indicated that probiotics played an important role in the growth, survival and health status of P. monodon larvae