Ma Rahman

Optimized model of a solar PV-biogas-diesel hybrid energy system for Adorsho Char Island, Bangladesh

Adorsho Char is an island situated in the bank of Feni River, Bangladesh with a current population of 860. This island is underdeveloped and lacks the electricity supply from the main grid. Majority of the population make use of conventional means i.e candles, lanterns, kerosene wick lamps for lighting the households whereas some market area use solar PV at a very small scale. The aim of this paper is to present an optimized model of a solar PV-biogas-diesel hybrid energy system to provide electricity for the people living in the island. A field survey has been conducted to collect the information about the population, load demand, number of cattle and the current condition present in the island. Hybrid Optimization Model for Electric Renewable (HOMER) has been used to optimize the energy system modelled for daily peak demand of 35 kW (181 kWh/day). Batteries have been considered to facilitate electricity storage. The optimization result from HOMER consisting all energy resources reveals an optimized system architecture of 7.2 kW solar PV, 16 kW biogas generator, 9 kW Diesel generator and 12 batteries (1,900 Ah each) in terms of cost of electricity (COE). This system configuration provides electricity at 17.37 Taka/kWh (

ASSESSMENT OF PHYTOCHEMICAL AND PHARMACOLOGICAL PROPERTIES OF ETHANOLI C EXTRACT OF CERBERA MANGHAS L. LEAVES

0.217/kWh) with a net present cost of 8,573,095 Taka (

Postharvest Loss Assessment of Rice at Selected Areas of Gazipur District

107,163.69).

Earthquake time history for Dhaka, Bangladesh as competent seismic record

The objective of the present study was to investigate the phytochemical nature (group determination of plant constituents) as well as the antioxidant and analgesic activity of ethanolic extract of the Cerbera manghas L. leaves (Family: Apocynaceae) . Phy tochemical an alysis of ethanolic extract of Cerbera manghas leaves indicated the presence of carbohydrate (reducing sugars), alkaloids, tannins, steroids, flavonoids & glycosides. The extract exhibited significant (P<0.01) analgesic effect in acetic acid i nduced writhing of white albino mice at the dose of 500 mg/kg body weight. The extract inhibited 30.65% writhing in mice and it is comparable to the activity of the standard analgesic drug Diclofenac sodium (79.03% P<0.001 ) at the dose of 25 mg/kg body wei ght. The extract showed the antioxidant property by the presence of strong yellow spot on a purple background on the TLC plate and i n the free radical scavenging activity study (DPPH assay) the extract showed significant antioxidant activity ( IC 50 ~ 269.1 5 µg/ml ) which is comparable to standard ( Ascorbic Acid , IC 50 ~14.45 μg/ml) . The findings suggest that the ethanolic extract of Cerbera manghas leaves possess antioxidant and analgesic activities.

Energy Audit for Rice Production under Power Tiller and Bullock Farming Systems in Bangladesh

Mechanical intervention in rice ( Oryza sativa L . ) postharvest operation especially harvesting, threshing and carrying is increasing due to shifting labour from agriculture to non-agricultural sector. It was hypothesized that mechanical intervention in rice postharvest operation will increase the postharvest losses. A two-year study (2008-2010) was conducted during Aus, Aman and Boro seasons in six locations of sadar upazila at Gazipur district to test the hypothesis. The widely used varieties of BR11, BR23, BR26, BR27, BRRI dhan28, BRRI dhan29 were used to assess the losses during harvesting to drying. In the study areas, farmer’s common practices (harvesting paddy by sickle; transportation by head, shoulder and power tiller operated trolley; threshing by open drum and close drum thresher; cleaning by traditional cleaning device kula and winnower and sun drying) were used to assess the postharvest losses. The average postharvest losses from harvesting to drying recorded 10% in three rice growing seasons. Losses due to mechanical threshing and traditional sun drying were 3.16% and 3.14% respectively. Power tiller operated trolley showed the lowest carrying loss compared to shoulder and head carrying methods. Both kula and winnower were observed as the most appropriate method of grain cleaning. Mechanical intervention in threshing increased the losses, whereas decreased in transportation and winnowing. These data might be used for policy makers to assess the national food grain loss and for researchers to design and development new technology to reduce the postharvest loss. The study should be continued to other regions for consistent results. Bangladesh Rice j. 2016, 20(1): 23-32