Energy, emission, profitability, and sustainability analyses of a grid-connected solar power plant proposed in airport sites of Bangladesh: a case study.

Nowadays, the aviation industry is one of the significant contributors to greenhouse gas emissions. An optimum solution to this concern is the substitution of conventional electricity consumption with clean energy sources. Barren lands are available in airport sites as buffer zones. These lands can be utilized to generate electricity from clean energy sources like solar, wind, and others. This study proposed a 5 MW grid-connected solar power plant at airport sites by utilizing the substantial barren area of the airport. The targeted airports for this study are Hazrat Shahjalal International Airport, Dhaka, and Shah Amanat International Airport, Chittagong, Bangladesh. Mathematical and simulation analyses have been performed for this purpose. Besides, sustainability analysis has also been incorporated for the grid-connected solar power plant. The energy efficiency varies from 18.74 to 7.79% for the Shah Amanat International Airport, and for the Hazrat Shahjalal International Airport, it ranges from 17.71 to 7.45%. Based on the project outcome, the revenue earned was 25% higher if the total cost was invested in power plants rather than keeping it in the bank as a deposit. On the other hand, emission analysis presented that a gross reduction of 3827.5 tons of CO2/MWh can be achieved from the Shah Amanat International Airport, while 3926 tons of CO2/MWh can be removed from the Hazrat Shahjalal International Airport. Based on the sustainability analysis, the energy depletion ratio for Shahjalal Airport varies from 0.82 to 0.93, while for Shah Amanat Airport, it is in the range of 0.81 and 0.92. The findings of this study suggested that investment in grid-connected solar power plants is economically viable and environmentally benign.

Exergetic sustainability analysis of industrial furnace: a case study.

Industrial furnaces play a significant role in industrial energy consumption and production. Minimizing losses from these furnaces can contribute to industrial sustainability. Exergy being an optimization tool can reduce energy loss and emission from furnaces and contribute to environmental sustainability. Currently, no exergy-based sustainability analysis has been adopted in the literature. In this analysis, a reheater furnace that is fired by natural gas is analyzed in terms of energy and exergy utilization. To address the sustainability of the furnace, several exergy-based sustainability parameters have been used. The overall energy efficiency of the furnace is 93.40%, while exergy efficiency is only 27.37%. From sustainability analysis, it is found that 72.63% of the fuel is diminished from the furnace, and it contributes to a lower sustainability index of 1.38. Higher exergy losses from this furnace positively affect the environment, which is validated from the higher value of the environmental destruction coefficient, the environmental destruction index, and the lower value of the environmental benign index. The value of the environmental destruction coefficient is 3.65, and the value of the environmental benign index is 0.38. Recovering waste energy and optimizing auxiliary equipment will increase the value of sustainability parameters.

Is the Gothic Arch a reliable radiographic landmark for migration percentage in children with cerebral palsy?

INTRODUCTION: Reimers migration percentage (MP) is the gold standard for measuring hip displacement in children with cerebral palsy (CP). Hip surveillance registries proposed using the top of the Gothic arch (GA) as a modification in patients with acetabular dysplasia because the classical method (CM) described by Reimers may underestimate hip migration. The aim of this study is to assess the inter- and intra-observer reliability of the modified method (MM) versus the CM and identify their effect on the MP. METHODS: We performed a retrospective review of 50 children with CP, who had a hip radiograph at our institution between 1st April 2014 and 28th February 2018. All hip radiographs were carefully selected to show the presence of a GA. Four observers measured the MP using the CM and MM for each patient. Interclass coefficient was used to estimate inter- and intra-observer reliability. RESULTS: Inter-observer reliability was excellent for the CM with ICC 0.96 (95% CI 0.94 to 0.97) and good for the MM, ICC 0.78 (95% CI 0.51 to 0.89) p < 0.001. Intra-observer reliability was excellent for both methods raging from ICC 0.94 to 0.99 for the CM and ICC 0.89 to 0.95 for the MM. The mean MP was 19% for the CM and 28% for the MM (p < 0.001). CONCLUSION: The CM is more reliable than the MM to measure hip migration in children with CP. If the CM is used and acetabular dysplasia with a GA are present on the hip radiograph, then a 9% hip migration underestimation should be considered on decisions for both referral and surgical management. LEVEL OF EVIDENCE: II.