Studies on neutron diffraction and X-ray radiography for material inspection

Among the different probes to study the structures of the bio and structural materials, X-ray and neutron are widely used because of their distinctive usefulness in investigating different structures. X-ray radiography and neutron diffraction are two widely known non-destructive techniques for material inspection. Here we demonstrate the design of neutron diffractometer with low power source and analyze the digital image produced by the X-ray radiography instead of neutron diffraction because of the availability of the data. Neutron diffraction is a powerful tool for understanding the behavior of crystal structures and phase behaviors of materials. While neutron diffraction capabilities continue to explore new frontiers of materials science, such capabilities currently exist in limited places, which require high neutron flux. The study seeks to design a low-resolution neutron diffraction system that can be installed on low power reactors (e.g. 250 kW thermal power). The performance of the diffractometer is estimated using Monte-Carlo ray-tracing simulations with McStas with an application in material science. Both monochromatic and polychromatic configurations are considered in order to maximize the net diffracted neutron flux at the detectors with reasonable resolution. On the other hand, considering X-ray radiography as a structure inspecting technique, analysis of dental X-ray panorama is performed for the detection of oral lesions. A novel automatic computer-aided method to identify dental lesions from dental X-ray is presented. Morphological operations, intensity profile analysis, automated seed point selection, region growing, feature extraction and neural network application are carried out to perform the job. Results show that the performance of the proposed method surpasses existing automated methods utilizing dental X-rays --Abstract, page iii

Integration of chemical and manual control methods for sustainable weed management in inbred and hybrid rice

Herbicidal weed control is gaining popularity in the developing countries but its efficacy still remains unclear. Therefore, an experiment was conducted to find out appropriate weed management practices for inbred and hybrid rice. The experiment comprised of inbred and hybrid varieties (two of each), and eight weed control treatments arranged in randomized complete block design with three replicates. Hybrid varieties performed better in terms of yield attributes and yield than inbred varieties. The highest grain yield (5.3 t ha−1) was obtained from the hybrid Agrodhan-12 and the lowest one (4.3 t ha−1) was from inbred Binadhan-7. Weed free treatment resulted in the highest grain yield (6.1 t ha−1) and the lowest one was with weedy treatment (1.96 t ha−1). The highest grain yield was obtained from Agrodhan-12 in weed free condition (6.9 t ha-1), while the lowest value was in inbred BRRI dhan49 under weedy condition (1.73 t ha−1). Weed-free treatment and the treatments of Pretilachlor fb Penoxsolum, Pretilachlor fb hand weeding, and Pendimethalin fb hand weeding showed similar performances in reducing weed density and eventually resulted in similar and the highest grain yield. Based on these results it may conclude that Pretilachlor applied at 2 days after transplanting (DAT) fb Penoxsolum at 21 DAT is the best weed management option. But from sustainability viewpoint, Pretilachlor or Pendimethalin applied at 2 DAT along with one hand weeding at 35 DAT may be recommended for effective weed management in inbred and hybrid rice during monsoon season

Micronutrients and Anaemia

Micronutrient deficiencies and anaemia remain as major health concerns for children in Bangladesh. Among the micronutrient interventions, supplementation with vitamin A to children aged less than five years has been the most successful, especially after distribution of vitamin A was combined with National Immunization Days. Although salt sold in Bangladesh is intended to contain iodine, much of the salt does not contain iodine, and iodine deficiency continues to be common. Anaemia similarly is common among all population groups and has shown no sign of improvement even when iron-supplementation programmes have been attempted. It appears that many other causes contribute to anaemia in addition to iron deficiency. Zinc deficiency is a key micronutrient deficiency and is covered in a separate paper because of its importance among new child-health interventions

Efficacy and Economics of Herbicidal Weed Management in Monsoon Rice of Bangladesh: Weed Management in Monsoon Rice of Bangladesh

Weed management is a challenging task in sustainable rice production. Physical and cultural methods of weed control are laborious and expensive, whereas chemical control is cheaper and less time consuming despite of some detrimental effect on environment with its inappropriate application. Considering these points, an experiment was conducted at the Agronomy Field Laboratory of Bangladesh Agricultural University, Mymensingh, Bangladesh during July–December 2015 to find out appropriate weed management practices for inbred and hybrid rice. The experiment comprised of four rice varieties (two inbred; BRRI dhan49 and Binadhan-7, and two hybrids; Dhani gold and Agrodhan-12); and eight herbicidal weed control treatments (season-long weedy or weed free, Pretilachlor fb Penoxsolum or 2,4-D dimethyl amine, Pendimethalin fb Penoxsolum or 2,4-D dimethyl amine, Pretilachlor or Pendimethalin fb one-time hand weeding). Eleven weed species belonging to five families were observed in the experimental plots. The highest weed density and dry weight were found in season-long weedy treatment and the lowest one was found in Pretilachlor fb one-time hand weeding. The highest above ground crop biomass (9.7 t ha-1) and harvest index (46.3%) were obtained from the hybrid variety Agrodhan-12 and the lowest biomass (8.3 t ha-1) was obtained from the inbred variety Binadhan-7. Season long weed free condition resulted the highest above ground crop  biomass (10.9 t ha-1), harvest index (48.7%), highest yield increase over control (213.8), weed control efficiency (100%) and gross return (BDT 141480 ha-1) and the lowest values for all those parameters were obtained from season-long weedy treatment. Season-long weed free treatment combined with Pretilachlor or Pendimethalin fb one-time hand weeding showed the best performance in reducing weed density and increasing above ground crop biomass, but gross return was higher because of high labour wages in these treatments. The highest BCR (2.5) was observed in Pretilachlor fb Penoxsolum. Therefore from economic view point Pretilachlor fb Penoxsolum is the best combination. But from sustainability view point Pretilachlor or Pendimethalin along with one-time hand weeding may be recommended for effective weed management in inbred and hybrid rice during monsoon season

Dirhenium carbonyl compounds bearing cis-1,2-bis(diphenylphosphino)ethylene and cis-1,2-bis(diphenylphosphino)ethylene oxide ligands

1289-1295Reaction of [Re2(CO)9(MeCN)] with cis-1,2-bis(diphenylphosphino)ethylene (cis-Ph2PCH=CHPPh2) in boiling benzene (80 °C) afforded two compounds, ax-[Re2(CO)9(κ1-cis-Ph2PCH=CHPPh2)] (1) and ax-[Re2(CO)9{κ1-cis- Ph2PCH=CHPh2P(O)}] (2) where the ligand is axially coordinated in a κ1 monodentate fashion through phosphorus. The close-bridged compound eq-[Re2(CO)8(μ-κ2-cis-Ph2PCH=CHPPh2)] (3) is obtained from a similar reaction of the same ligand with [Re2(CO)8(NCMe)2] in refluxing benzene. In this case the diphosphine is equatorially coordinated to two Re atoms in a symmetrical bridging fashion. Compounds 1−3 have been characterized by IR, 1H NMR, 31P{1H} NMR spectroscopy and single crystal X-ray diffraction analyses

Dirhenium carbonyl compounds bearing cis-1,2-bis(diphenylphosphino)ethylene and cis-1,2-bis(diphenylphosphino)ethylene oxide ligands

Reaction of [Re2(CO)9(MeCN)] with cis-1,2-bis(diphenylphosphino)ethylene (cis-Ph2PCH=CHPPh2) in boiling benzene (80 °C) afforded two compounds, ax-[Re2(CO)9(κ1-cis-Ph2PCH=CHPPh2)] (1) and ax-[Re2(CO)9{κ1-cis-Ph2PCH=CHPh2P(O)}] (2) where the ligand is axially coordinated in a κ1 monodentate fashion through phosphorus. The close-bridged compound [Re2(CO)8(μ-κ2-cis-Ph2PCH=CHPPh2)] (3) was obtained from a similar reaction of the same ligand with [Re2(CO)8(NCMe)2] in refluxing benzene. In this case the diphosphine is equatorially coordinated to two Re atoms in a symmetrical bridging fashion. Compounds 1−3 have been characterized by IR, 1H NMR, 31P{1H} NMR spectroscopy and single crystal X-ray diffraction analyses

The 2017 Rohingya Influx into Bangladesh and Its Implications for the Host Communities

We addressed the research question, how does the host community perceive the effects of Rohingya influx to Bangladesh, from their perspectives using a questionnaire survey, key informant interviews, and focus group discussions. Bangladesh sheltered over a million Rohingyas, fleeing genocide and serious crimes against humanity, on humanitarian grounds. The local people welcomed them and offered direct support and assistance. Our findings suggest that their immediate sympathy for Rohingyas faded over time due to various factors. An overwhelming majority perceived the Rohingyas as pressure on their land and resources and being deprived on numerous grounds outweighed the disproportionate economic incentives of the influx. The findings offer fresh insights into the challenges of hosting refugees in the local communities because of the diverse impacts of forced displacemen