The diffusive gradients in thin films (DGT) passive sampler has emerged as a 21 powerful tool for measuring in situ concentrations of organic contaminants in waters with 22 appropriate spatial and temporal resolution at low cost. This study addresses the property range of compounds which can be routinely sampled with the present design of DGT device.24 Sorption experiments and DGT deployment with 9 model chemicals [organophosphate esters 25 with a wide range of log K OW (0.8-9.5), molecular weight (182-435 Da)] and different 26 functional groups showed compounds with high hydrophobicity and aromatic rings are prone 27 to retention on membrane filters, which slows the supply of chemical to the binding resin of 28 the sampler. The current DGT sampler (PTFE membrane filter, agarose gel diffusion layer 29 and HLB binding layer) is potentially reliable for measuring hydrophilic [log K OW (0.8-2.6)]30 and non-aromatic-ring chemicals. For compounds of higher values of K OW or with aromatic 31 rings, knowledge of the lag phase is necessary to optimize sampling times to avoid biasing 32 subsequent laboratory analyses. A standard procedure is used to measure lag times (from 33 minutes to days), by exposing a series of DGT samplers in waters until linear mass 34 accumulation in samplers is achieved. We discuss how monitoring of a wide array of organic 35 contaminants across classes should be possible in future, with a range of validated new DGT 36 devices, optimized for the choice of membrane filter, diffusive material and binding resin.

COVID-19 is a respiratory infectious disease that spreads readily between people, and an urgent issue of passengers’ exposure risk assessment in commercial aircraft has been raised because an aircraft cabin as a confined space may carry and transmit the disease worldwide. In this study, the droplets transmission process under different ventilation systems in a twin-aisle wide-body aircraft was studied using CFD simulations and the infection risk of passengers was assessed by the improved Wells–Riley model. Numerical results found that the transmission mechanism of droplets in the aircraft cabin was different depending on the type of ventilation systems and the location of the infectious source. Annular airflow could effectively enhance the ability of droplets transmission, while direct airflow, represented by displacement ventilation, could significantly inhibit droplets transmission. Accordingly, a new type of ventilation system was proposed based on the concept that the overall space is organized by annular airflow and the local area is direct airflow. Compared with sidewall mixing ventilation system, the infection risk of the new ventilation system presented in this study is reduced by 27%.

The high-temperature exhaust gases and the hot surfaces of the ejector device in marine gas turbines generate significant levels of infrared radiation. An appropriate nozzle structure can effectively lower the exhaust gas temperature and reduce the high-temperature radiation surface area, thereby minimizing external infrared radiation. In this study, a numerical simulation of the nozzle structure in the ejector device was conducted using computational fluid dynamics (CFD) methods. By investigating the orthogonal combinations of nozzle inclination angles and the number of nozzles, the temperature distribution and flow characteristics under different operating conditions were analysed. The results showed that as the nozzle inclination angle increased, the entrainment coefficient (Ce) and the temperature ratio at the inlet and outlet (Rt) initially improved but then worsened. Simultaneously, the pressure loss coefficient (Cpl) increased with the inclination angle. The CRITIC weight method was employed to objectively allocate weights to Rt, Ce, and Cpl, determining the optimal solution. The results indicated that Rt and Cpl had significant and similar weights. The optimal solution was found in Case 10 (α = 5°, x = 4), with corresponding evaluation indices of Ce=2.38, Cpl=11.45, and =0.68. This study's findings are of great importance for enhancing the performance of marine gas turbines and reducing external infrared radiation.

Energy storage system (ESS) provides a new way to solve the imbalance between supply and demand of power system caused by the difference between peak and valley of power consumption. [1][2][3] Compared with various energy storage technologies, the container storage system has the superiority of long cycle life, high reliability, and strong environmental adaptability, which attracts more and more attention. 4,5 The ESS has some vertical racks, equipped with a battery management system, a heating ventilation air conditioning system, and a fire detection and suppression system. 6,7 Unfortunately, there were many energy storage battery fires in previous years. 8-10 A Korean government report indicated that a significant factor in the cause of the fires was the thermal runaway of batteries. 11 Therefore, a well-designed battery thermal management system (BTMS) is highly needed. [12][13][14] It has been found that air cooling is currently the most widely used cooling method due to its low manufacturing cost, low energy consumption, and low layout requirements. [15][16][17][18]