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In this paper, a comprehensive life-cycle assessment (LCA) is carried out in order to evaluate the multiple environmental-health impacts of the biological wastewater treatment of the fish-processing industry throughout its life cycle. To this aim, the life-cycle impact assessment method based on endpoint modeling (LIME) was considered as the main LCA model. The proposed methodology is based on an endpoint modeling framework that uses the conjoint analysis to calculate damage factors for human health, social assets, biodiversity, and primary production, based on Indonesia’s local data inventory. A quantitative microbial risk assessment (QMRA) is integrated with the LIME modeling framework to evaluate the damage on human health caused by five major biological treatment technologies, including chemical-enhanced primary clarification (CEPC), aerobic-activated sludge (AS), up-flow anaerobic sludge blanket (UASB), ultrafiltration (UF) and reverse osmosis (RO) in this industry. Finally, a life-cycle costing (LCC) is carried out, considering all the costs incurred during the lifetime. The LCA results revealed that air pollution and gaseous emissions from electricity consumption have the most significant environmental impacts in all scenarios and all categories. The combined utilization of the UF and RO technologies in the secondary and tertiary treatment processes reduces the health damage caused by microbial diseases, which contributes significantly to reducing overall environmental damage.

This paper investigates the acceleration performance of a disk-shaped magnetohydrodynamics (MHD) accelerator. Quasi-1-dimensional (Q1D) numerical simulation employing the MacCormack scheme was developed. For the longer channel length of 0.9 m, thermal loss was estimated at over 60% and effective acceleration could not be achieved owing to large heat loss and large friction loss. For shorter channel lengths, thermal loss can be reduced below 20% owing to the smaller heat and the friction losses. However, with too short a channel length, accelerator performance was decreased by the MHD compression due to excessive Faraday current density. The effect of ratio of cross sectional area on performance was also studied. For a larger area ratio, the gas can be accelerated smoothly throughout the MHD channel. However, for the excessive expansion case of a sevenfold channel, gas velocity near the exit decreased due to transition to a ''generator mode''. For the best acceleration performance, the design channel length should be as short as possible preventing compression at the channel inlet. The area ratio should be large enough to prevent the compression but not too large, to prevent transition to a ''generator mode''.

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To improve the thrust efficiency of a pulsed magnetohydrodynamic (MHD) accelerator, we perform numerical calculations that simulate the experimental conditions, which were used earlier, in an apparatus that include a model rocket engine. The one-fluid one-dimensional-MHD simulation results show agreement between the experimental and numerical results. We discuss simulation results for temporal and spatial distributions of the electrical conductivity and current density.

The purpose of this study is to verify how the swirl vane influences the acceleration performance, namely, the radial gas velocity and the static gas pressure, for the Disk MHD accelerator. A quasi-1-dimensional (Q1D) numerical program is used for the calculations. Results of the current calculations show that the static gas pressure decreases approximately 40% when using the inlet swirl vane. It is found that the MHD compression phenomena, which generates at the closest to the MHD channel inlet due to the Joule heating, could suppress effectively. The maximum radial gas velocity of 3,380 m/s is successfully achieved at the channel exit when swirl ratio was −1.0, and swirl ratio was set to be 0.0 and mass flow rate was kept the same as that for the case of swirl ratio of 1.0 and −1.0. The acceleration efficiency of 40.5% and 36.7% are calculated when the swirl ratio is −1.0, and the case of swirl ratio was set to be 0.0 and mass flow rate was kept the same as that for the case of swirl ratio of 1.0 and −1.0 respectively. The difference of efficiency is due to increase the Hall parameter in the upstream and midstream of MHD channel. This current study can show and confirm the function of inlet swirl for Disk MHD accelerator.