查看更多>>摘要：Owing to the inherent complications in membrane distillation (MD) operations, it has become a challenge to acknowledge swiftly and appropriately to safeguard the quality of effluent, particularly when the processing cost is a prominent concern. Membrane wetting in MD operations is a major concern during long-term performance. In this study, machine learning (ML) methodologies were utilized to overcome the limitations of conventional mechanistic modeling. ML applications have never been explored to investigate how operational factors, such as water flux and salt flux, are affected during long-term MD performance. Furthermore, time-dependent factors were neglected, making it difficult to analyze the relationship between effluent quality and operational factors. Therefore, this study demonstrates a novel ML-based framework designed to enhance the performance of MD. The ML-based framework consists of an autoregressive integrated moving average (ARIMA) and utilizes a unique pathway to explain the impact of time series among operational factors. The accuracy of forecasting has been explored by utilizing 180 h (180 datasets), that was further used and divided into training (165 datasets) and test datasets (15 datasets). Eventually, the ARIMA model demonstrated a highly precise relationship order between the model and experimental data, which can be further used to forecast membrane performance in terms of wetting and fouling. The selected ARIMA model (3,2,1) appears to be an adequate model for water and salt flux data which has been effectively used to capture the course of permeate water and salt flux by producing the smallest forecast RMSE. The RMSE values were observed to be 0.22 and 0.05 for water and salt flux respectively, which can better predict long time series with high frequency. These frameworks can be applied for the early prediction of membrane wetting if ample high-resolution data are available.
查看更多>>摘要：To ensure the safe operation of static and dynamic devices in a limited platform space and prevent security threats caused by accidents and external intruders, the unmanned aerial vehicle (UAV) is becoming an important tool to monitor and reduce the operational risk of unattended offshore oil platforms. However, UAVs may encounter location errors, adversely affecting patrol efficiency and accuracy. Therefore, the optimal UAV path planning is vital to ensure complete monitoring routes and reduce the risk presented by the marine environment, devices, and employees on unattended offshore platforms. This paper established a multi-objective mathematical model with the shortest flight path and minimum correction times for the intelligent UAV patrol of unattended offshore platforms. An intelligent algorithm with large-scale constraints for UAV path planning was proposed based on non-dominated sorting genetic algorithms. A flight path length of 8076.11 m and 25 correction times presented the optimal solution. The results indicated that the proposed algorithm could be used to plan an effective and accurate three-dimensional (3D) UAV flight path according to the size of the offshore oil platform. This is highly significant for the intelligent risk monitoring of unattended offshore platforms in practical engineering in the future.
查看更多>>摘要：Tetracycline (TC) is a group of antibiotics that includes chlorotetracycline (CTC), doxycycline (DC), and oxytetracycline (OTC). TC is the secondary most used antibiotic worldwide to treat diseases caused by bacteria. It is noteworthy that in the human and animal metabolic processes, about 60% and 17-80% of the TC dosage administered are not adsorbed and are excreted in urine and feces. Its widespread use in human and veterinary treatments is leading to the situation of environmental contamination, both in soil, surface, and underground waters. The first two sections of this review paper present an overview of the problem of water and soil contamination, and the situation on the worldwide use of TC. The third section focuses on analytical methods for detecting TC in the most diverse types of samples. Furthermore, in the following chapters it is discussed TC toxicity and the application of chemical, physical, and biological processes in removing TC in wastewater. At last, hybrid and emerging technologies for TC degradation as an environmental contaminant are presented, and some future challenges that must be faced by this research field are summarized. A critical analysis from the authors' perspective is presented at the end of each session.
查看更多>>摘要：The measurement of efficiency of water utilities has been traditionally carried out using econometric methods or linear programming techniques. Alternatively, in this study a data mining non-parametric method is used, such as an artificial neural network (ANN) approach, to predict the efficiency of several water companies in England and Wales. The further use of a regression tree model allowed us to visualize and quantify the impact of operating characteristics on efficiency. The average efficiency score for the water industry was 0.411. Average scores for water only companies and water and sewerage companies were 0.210 and 0.626, respectively. Only one water company was identified as being fully efficient. This indicates that most of the English and Welsh water companies need to make substantial improvements in their managerial practices to catch-up with the most efficient ones in the industry. Several operating characteristics such as water leakage, water taken from different sources and population density were found to influence efficiency. The percentage of water leakage was identified as the most relevant operational variable influencing the efficiency of water companies. The findings of our study aim to support benchmarking analysis in regulated industries and to get a better insight on what drives efficiency.
查看更多>>摘要：Vacuum pressure impregnation (VPI) is a primary process by which epoxy resin is impregnated into the stator windings of large generators and motors to enhance their physical properties. However, the vaporization of epoxy resin generates hazardous resin fumes during the VPI process, and the residual fumes leak into the atmosphere. This leakage is a safety and environmental hazard in the workplace as it can cause fire, explosion, and respiratory diseases. Therefore, it is crucial to reduce the hazard by designing an optimal ventilation system. This study proposed optimization of the explosive fumes ventilation Layout in the VPI process using computational fluid dynamics (CFD). A total of 12 Layouts of the ventilation system was designed according to the air inlet and outlet positions. This investigation used the pseudo transient method and the RNG k-e turbulence model. An optimal Layout with the highest ventilation efficiency and the shortest LEL arrival time was determined through CFD analysis. In the optimal Layout, the LEL arrival time was 372 s, down about 59% from the model presented in the previous study, and the ventilation efficiency was the highest at 0.962.
查看更多>>摘要：Humic acid (HA) is an organic macromolecular compound that widely exists in nature, but its effect on antibiotic resistance genes (ARGs) in Cd-contaminated soil is unknown. This study investigated the effects of Cadmium (Cd) and HA in soil on ARGs, mobile genetic elements (MGEs), and bacterial communities. The relative abundance of ARGs and MGEs increased 0.89-fold and 1.12-fold after the addition of 2 mg kg~(-1) Cd to the soil, and 1.06-fold and 1.68-fold after the addition of 8 mg kg~(-1) Cd. Redundancy analysis further revealed that among environmental factors, available Cd was the dominant factor influencing ARGs. In Cd-contaminated conditions, the addition of high concentrations of HA suppressed the expression of ARGs and MGEs. The abundance of ARGs and MGEs decreased by 0.12-fold and 0.44-fold after the addition of HA (50 mg kg~(-1)) to the soil at a Cd concentration of 2 mg kg~(-1), and by 0.18-fold and 0.41-fold at a Cd concentration of 8 mg kg~(-1). Intll was significantly associated with all ARGs {sull,sul2, tetG, tetW), and intI2 was significantly correlated with most ARGs {sul2, tetG, tetW). Network analysis illustrated that Proteobacteria were the main host bacteria causing changes in the abundance of ARGs and MGEs. HA has an important role in agricultural production. To reduce the enrichment of ARGs in Cd-contaminated soil, the addition of higher concentrations of humic acid can be considered to mitigate the environmental and biological hazards.
查看更多>>摘要：The highly selective recovery of Dy(III) from used rare earth products has high environmental and economic benefits. In this paper, biocompatible bacterial cellulose with a unique 3D network structure was used as the basic structure, graphene oxide and polyethylene glycol were introduced to increase the adsorption capacity, and the ion imprinting technology was used to prepare a green aerogel that could adsorb dysprosium ions with a high selectivity. The various properties of aerogels were characterized by SEM, FT-IR and BET. Experiments proved that the introduction of graphene oxide and polyethylene glycol brought a higher stability and repeatability to aerogel, and the introduction of a large number of carboxyl groups also promoted the effective coordination of aerogel with dysprosium. Adsorption experiments showed that I-GO-OBC-pDA-PEG aerogel could effectively adsorb dysprosium, and its maximum adsorption capacity for Dy(III) was 49.904 mg g~(-1), and its maximum adsorption capacity was 10 mg g~(-1) higher than that of the non-imprinted aerogel, which was a good proof of the effectiveness of the ion imprinting technology. The repeatability test showed that after five adsorption-desorption cycles, the adsorption capacity of the imprinted aerogel was maintained at about 80% of the maximum adsorption capacity. All results showed that I-GO-OBC-pDA-PEG aerogel could efficiently recover dysprosium ions.
查看更多>>摘要：The high nickel layered oxide cathode LiNi_(0.8)Co_(0.1)Mn_(0.1)O2 (NCM811) is widely used in new energy power and equipment due to its high density and low cost. However, the NCM811 cathode is prone to structural rupture, dissolution of transition metal ions, and damage to the electrode/electrolyte interface under high voltage, causing degradation of battery performance and safety issues. In this paper, 3-(Trifluoromethyl) benzoylacetonitrile (3-TBL) was selected as a film-forming flame-retardant additive for the NCM811 cathode of the high-voltage lithium-ion battery, and the synergistic effect with lithium difluoro(oxalato) borate enhanced the battery cycle and safety performance. The results show that: 3-TBL is oxidized preferentially more than carbonate solvent to form a stable and dense cathode-electrolyte interface film, which effectively prevents the continuous oxidative decomposition of the electrolyte and enhances the rate of cycling and overcharge resistance of the Li/NCM811 cells under high pressure. Furthermore, the 3-TBL modified electrolyte can also delay the thermal decomposition temperature of the commercial electrolyte and improve its flame retardant properties. Kinetic analysis showed that the additive increased the activation energy required for the thermal decomposition reaction of electrolyte and NCM811 cathode mixture. Therefore, the additives 3-TBL improve the intrinsic safety of the electrolyte and electrolyte interface, providing a feasible idea for the development of high energy density and high safety electrolytes.
查看更多>>摘要：Since the 1990 s, sporadic explosion accidents have occurred in the chemical industry. Accidents related to nitrification reactions or nitrification substances have had the most severe consequences. One reason for this phenomenon is the high risk of nitrification by-products, which are liable to combust and explode. Special attention must be paid to the production, collection, storage, and disposal of nitrification by-products. This study examined the thermal stabilities of the phenolic by-products created during nitrobenzene formation. The thermal stabilities of three representative aromatic nitrophenol by-products were determined using differential scanning calorimetry, accelerating rate calorimetry, and thermogravimetric analysis. Advanced thermodynamic models were established for calculation and fitting, which provided reliable data support for exploring the intrinsic stability of nitrification by-products.
Jean A. BarbosaChristian J.R. CoronadoJose C. de Andrade
14页
查看更多>>摘要：Synthesized iso-paraffins (SIP) are compounds that can be blended with traditional aviation fuels up to 10% vol. to reduce greenhouse gas emissions. The safety properties of these fuels need to be determined to guarantee their reliable utilization. These properties include the upper flammability limit (UFL). The objective was to determine experimentally the UFL in air of SIP, jet fuel, and mixtures containing 10% (F10) and 50% (F50) of SIP on a mass basis, respectively. The initial conditions involved different initial temperatures and pressures. The experimental configuration followed the ASTM E681 standard. The temperature range was from 420 to 470 K and the pressure range was from 101.3 kPa to 20 kPa. The results show that the UFLs of the tested compounds have a second-order tendency with respect to pressure and constant temperature. The F10 mixture has a significant reduction of the UFL at 20 kPa. The experimental results were fitted by using regression models and empirical correlations which allow the determination of UFLs at different initial temperatures and pressures.
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