There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

The ERA5 global reanalysis

Soil Chemical Analysis

Abstract A two-dimensional version of the Pennsylvania State University mesoscale model has been applied to Winter Monsoon Experiment data in order to simulate the diurnally occurring convection observed over the South China Sea. The domain includes a representation of part of Borneo as well as the sea so that the model can simulate the initiation of convection. Also included in the model are parameterizations of mesoscale ice phase and moisture processes and longwave and shortwave radiation with a diurnal cycle. This allows use of the model to test the relative importance of various heating mechanisms to the stratiform cloud deck, which typically occupies several hundred kilometers of the domain. Frank and Cohen's cumulus parameterization scheme is employed to represent vital unresolved vertical transports in the convective area. The major conclusions are: Ice phase processes are important in determining the level of maximum large-scale heating and vertical motion because there is a strong anvil componen...

Numerical study of convection observed during the Winter Monsoon Experiment using a mesoscale two-dimensional model [presentation]

Climate change 2014 - Synthesis Report

Hossain, Faisal, 2010. Conclusion to the Featured Series on Satellites and Transboundary Water: Emerging Ideas. Journal of the American Water Resources Association (JAWRA) 46(4): 663-664. DOI: 10.1111/j.1752-1688.2010.00449.x

Conclusion to the Featured Series on Satellites and Transboundary Water: Emerging Ideas1

For clean hydropower generation while sustaining ecosystems, minimizing harmful impacts and balancing multiple water needs is an integral component. One particularly harmful effect not managed explicitly by hydropower operations is thermal destabilization of downstream waters. To demonstrate that the thermal destabilization by hydropower dams can be managed while maximizing energy production, we modelled thermal change in downstream waters as a function of decision variables for hydropower operation (reservoir level, powered/spillway release, storage), forecast reservoir inflow and air temperature for a dam site with in situ thermal measurements. For data-limited regions, remote sensing-based temperature estimation algorithm was established using thermal infrared band of Landsat ETM+ over multiple dams. The model for water temperature change was used to impose additional constraints of tolerable downstream cooling or warming (1–6 °C of change) on multi-objective optimization to maximize hydropower. A reservoir release policy adaptive to thermally optimum levels for aquatic species was derived. The novel concept was implemented for Detroit dam in Oregon (USA). Resulting benefits to hydropower generation strongly correlated with allowable flexibility in temperature constraints. Wet years were able to satisfy stringent temperature constraints and produce substantial hydropower benefits, while dry years, in contrast, were challenging to adhere to the upstream thermal regime.

/pdf/realizing-ecosystem-safe-hydropower-from-dams-38kp8du0le.pdf

Realizing ecosystem-safe hydropower from dams

In the Lower Mekong River Basin floodplains, rice cultivation is highly crucial for regional and global food security. However, prolonged flooding can pose damage to rice cultivation and other socio-economic aspects. Yet, there is no rapid operational inundation forecasting system that can help decision-makers proactively mitigate flood damages. Here, we integrated the so-called Forecasting Inundation Extents using Rotated empirical orthogonal function analysis (FIER) framework with an altimetry-based operational Mekong River level forecasting system and built an operational web application, FIER-Mekong, (https://fier-mekong.streamlit.app/) that generates daily skillful forecasted inundation extents (>70% of critical success index) and depths in about 3 and 30 seconds, respectively, with up to 18-day lead times. One of its applications, predicting flood-induced rice economic losses, is also presented. Had FIER-Mekong being adopted, we estimated that the rice damages, up to 87 and 53 million US dollars during the 2020 and 2021 harvest time, respectively, could have been avoided. 

Operational forecasting inundation extents using REOF analysis (FIER) over lower Mekong and its potential economic impact on agriculture

Background and objectives: Recurrent pterygium is an important ocular problem in our country. There are different modalities of treatment for recurrent pterygium. The present study was undertaken to determine the effect of intraoperative mitomycin C along with conjunctival auto graft to prevent recurrence of pterygium. Methods: Patients with recurrent pterygium attending a tertiary care hospital in Dhaka from January 2013 to June 2015 were included in the study. Cases were randomized into two groups. Group 1 had pterygium surgery with conjunctival auto graft and Group 2 had auto graft and intraoperative mitomycin C (0.02%). All cases were followed up for one year to assess recurrence of pterygium. Results: A total of 54 recurrent pterygia cases were included in the study. The age of study population was 25 to 65 years. The recurrence rate of pterygium after 12 months was 77.7% in group 1 and none in group 2. No major postoperative complication was observed. Conclusion: The study demonstrated that the use of intraoperative mitomycin C along with conjunctival auto graft had significant effect in preventing the recurrence of pterygium. IMC J Med Sci 2016; 10(2): 49-52

/pdf/outcome-of-intraoperative-use-of-mitomycin-c-combined-with-3g2zryjmm4.pdf

Outcome of intraoperative use of mitomycin C combined with conjunctival auto graft in recurrent pterygium

The paper contains an empirical research approach on the demand and supply analysis for sugarcane in Bangladesh. In be more specific, how sufficient yield of sugarcane could be achieved, as well as sustained in the country, is discussed in the paper based on the analysis, along with exploring its strengths, weaknesses, opportunities and threats. Bangladesh imports around 1.26 million metric ton of sugar each year to meet its national demand deficit. The research shows that local growing of sugarcane rather imports of sugar would save around BDT8,937.94 million per year. In addition, local production of sugarcane and its processing to sugar would result in the by-production of molasses, chobra and spirit/ alcohol at massive scale that might considerably contribute to the national economy. The paper, in this regard, proposes eight contiguous districts of Bangladesh with high sugarcane productivity to form a regional belt where deficit amount of sugarcane could be grown every year. In addition, several policy recommendations are made with a view to sustaining this yield of sugarcane in the country.

Faisal Hossain

Papers

Conclusion to the Featured Series on Satellites and Transboundary Water: Emerging Ideas1

Realizing ecosystem-safe hydropower from dams

Operational forecasting inundation extents using REOF analysis (FIER) over lower Mekong and its potential economic impact on agriculture

Outcome of intraoperative use of mitomycin C combined with conjunctival auto graft in recurrent pterygium

Attaining Sufficient Yield of Sugarcane in Bangladesh: An Empirical Approach