Zobrazení zdroje stránky Humphreystrand2748

As an important factor affecting the mangrove wetland ecosystem, water quality has become the focus of attention in recent years. Therefore, many studies have focused on the prediction of water quality to help establish a regulatory framework for the assessment and management of water pollution and ecosystem health. To make a more accurate and comprehensive forecast analysis of water quality, we propose a method for water quality prediction based on the multi-time scale bidirectional LSTM network. In the method, we improve data integrity and data volume through data preprocessing. And the network processes input data forward and backward and considers the dependencies at multiple time scales. Besides, we use the Box-Behnken experimental design method to adjust hyper-parameters in the process of modeling. In this study, we apply this method to the water quality prediction research of Beilun Estuary, and the performance of our proposed model is evaluated and compared with other models. The experiment results show that this model has better performance in water quality prediction than that of using LSTM or bidirectional LSTM alone. Graphical Abstract Schematic of research work.Numerical simulations were conducted to study the effects of the pulverized-coal bias distribution in the primary air on the coal combustion and NOx generation characteristics of a 600-MW down-fired boiler with multiple-injection and multiple-staging combustion technology. The total pulverized-coal in the primary air was kept constant, and the ratio of the pulverized-coal mass flux in the fuel-rich coal/air flow to the total pulverized-coal mass flux (RPR) was set as 60%, 70%, 80%, and 90%. By changing the RPR, the excess air coefficient of the fuel-rich flow was adjusted from 0.700 to 0.467. It was found that numerical simulation results were almost in agreement with cold modeling and in situ experimental results respectively, including the flow fields in the lower furnace at the RPR of 80% and the heating processes for the fuel-rich coal/air flow at the RPR of 90%, which verified the rationality of the numerical model and the grid. The simulation results indicated that the change of RPR has little effect on the symmetry of the flow field in the furnace. With the increase of the RPR from 60 to 90% (1) the maximum airflow declination angle near the tertiary air slot decreased from 71 to 66°, which indicates that the downward airflow penetration depth gradually decreased; (2) the ignition distance of the fuel-rich coal/air flow decreased from 1.2 to 0.9&nbsp;m, and the high-temperature area in the furnace hopper decreased and the position gradually moved away from the hopper water walls; (3) the oxygen consumption rate at the initial combustion stage constantly accelerated, and the fuel NOx generation rate under the fuel-rich flow nozzle increased first and then decreased; (4) the NOx emissions at the furnace exit dropped from 778 to 662&nbsp;mg/m3 at 6% O2, and the carbon in the fly ash decreased from 5.87 to 5.52%. Increasing the RPR reasonably controlled the excess air coefficient of the fuel-rich flow, and realized the high-efficiency combustion in the furnace and the reduction of NOx emissions simultaneously.The pollution haven hypothesis (PHH) suggests that foreign direct investment (FDI) inflows contribute to rising carbon dioxide (CO2) emissions in developing countries. This study aims to investigate the validity of the PHH in Cote d'Ivoire. For this purpose, FDI, real gross domestic product (GDP) per capita, energy consumption, and agriculture value added are included in the carbon dioxide emissions' function. Based on time series data spanning from 1980 to 2014, the study utilized the autoregressive distributed lag (ARDL) approach. [https://www.selleckchem.com/products/diphenhydramine.html Diphenhydramine] In addition to the introduction of structural breaks in the estimations techniques, this study contributes to the literature by focusing on a typical developing country that is currently experiencing increases both in FDI inflows and in CO2 emissions. The findings indicated a cointegration relationship between the variables. Additionally, the ARDL results validate the PHH in Cote d'Ivoire as we find a positive relationship between FDI and CO2 emissions. Likewise, the results showed that GDP per capita, energy consumption, and agriculture value added have a positive impact on CO2 emissions. Based on the results, we advise Ivorian policymakers to strengthen the environmental regulations and focus on attracting clean FDI. Besides, the Ivorian government should implement energy-saving policies and promote the use of environment-friendly techniques in the agriculture sector.The performance of engine parameters is more influenced with fuel injection strategies namely start of main injection timing (SoMI). An experimental analysis was performed to find the optimum SoMI timing based on performance, emission, and combustion characteristics. Base fuel of diesel and neem biodiesel was used as test fuels. The neem biodiesel was prepared by esterification and transesterification process. It is found from literature that neem biodiesel blend NB20 with diesel gives optimum performance and emission characteristics; therefore, NB20 blend was used for experiments. A variable geometry turbocharger (VGT) compression ignition (CI) engine was used to conduct the experiments. Engine performance parameters were estimated and compared with a base fuel of diesel and with NB20 blends. In this experimentation, fuel injection pressure (FIP) of 800&nbsp;bar and engine speed of 1700&nbsp;rpm were considered. SoMI timing was varied from 2° to 10° bTDC with an increment of 2° bTDC timing. Cylinder pressure (CP) and heat release rate (HRR) were estimated and found that are higher for diesel fuel compared to NB20 blend at different SoMI timings. The addition of neem biodiesel NB20 blend to diesel fuel decreases the exhaust emissions except NOx emissions. The BSFC was considerably reduced and BTE was improved almost equivalent to the diesel fuel for NB20. From the results, it is concluded that 10° bTDC SoMI timing provides 13% improvement in BTE, 21% decrement in BSFC, and 7.5% reduction in CO2 emissions.