The main goal of this study is to examine future changes in meteorological, hydrological drought under the impact of climate change in Dong Nai River Basin, using Standardized Precipitation Index ...(SPI) and Stream flow Drought Index (SDI). The Soil and Water Assessment Tool (SWAT) is used as a simulated tool to estimate the streamflow in baseline (1980–2005) and climate change (RCP 4.5, 2016–2035) scenarios for meteorological, hydrological calculation. The results show that both types of drought tend to occur in the dry season. The area affected by meteorological and hydrological drought expand in both baseline and RCP 4.5 scenarios. In addition, meteorological drought duration is also significantly increased, especially severely drought months. Although it was detected slightly decreasing in the duration of hydrological drought, the number of months which is occurred moderately drought in sub-basins still goes up in the climate change scenario. These findings could be useful for water shortage assessment and allocation planning in this area in the climate change context in the Dong Nai River Basin.
Deep learning and more specifically Convolutional Neural Network (CNN) is a cutting edge technique which has been applied to many fields including biomedical image classification. To further improve ...the classification performance for biomedical images, in this paper, a feature concatenation method and a feature concatenation and ensemble method are proposed to combine several CNNs with different depths and structures. Three datasets, namely 2D Hela dataset, PAP smear dataset, and Hep-2 cell image dataset, are used as benchmarks for testing the proposed methods. It is shown from experiments that the feature concatenation and ensemble method outperforms each individual CNN, and the feature concatenation method, as well as several state-of-the-art methods in terms of classification accuracy.
The recent outbreak of the coronavirus disease 2019 (COVID-19) has rapidly become a pandemic, which calls for prompt action in identifying suspected cases at an early stage through risk prediction. ...To suppress its further spread, we exploit the social relationships between mobile devices in the Social Internet of Things (SIoT) to help control its propagation by allocating the limited protective resources to the influential so-called high-degree individuals to stem the tide of precipitated spreading. By exploiting the so-called differential contact intensity and the infectious rate in susceptible-exposed-infected-removed (SEIR) epidemic model, the resultant optimization problem can be transformed into the minimum weight vertex cover (MWVC) problem of graph theory. To solve this problem in a high-dynamic random network topology, we propose an adaptive scheme by relying on the graph embedding technique during the state representation and reinforcement learning in the training phase. By relying on a pair of real-life datasets, the results demonstrate that our scheme can beneficially reduce the epidemiological reproduction rate of the infection. This technique has the potential of assisting in the early identification of COVID-19 cases.
Although the impact of tourism and COVID-19 has been paid much attention, limited research considers the perspectives from local people working in tourism, especially those affected by the pandemic ...the most. This article examines the perspectives of tourism labors in Nha Trang, Vietnam on the dual impacts of tourism and the COVID-19 pandemic on their lives and the local economy. Semi-structured interviews were conducted with 26 participants working in different fields in a tourism sector. Results revealed that that before the COVID-19 hit Nha Trang, tourism had both positive and negative impacts on local people and economy. These impacts are differently among local people and economy. While tourism had improved the quality of local people lives who ran business relating to tourism activities such as hotels, restaurants, the tourism had damaged the local economy such as overloaded infrastructure and tourist facilities, lack of quality control of tourism, unfair competition between tourism companies, traffic congestion and floods in the city, and "zero-dollar tour". When the COVID-19 hit, the local tourism firms had broken down, particularly firms target their services at foreign visitors. To deal with these challenges of tourism under the impact of COVID-19, this study also found out sustainable approaches such as diversifying sources of tourists, multiplying local people's sources of income, and improving the local government's tourism management. Theoretical and practical implications are discussed.
•TrOC removal by the EMR was mainly due to laccase-catalyzed degradation.•Kinetic limitations caused reduced removal of resistant TrOCs for a dose over 50μg/L.•SA addition at a dose beyond 10μM did ...not improve TrOC removal by EMR.•Significant individual and interactive toxicity of laccase and SA was noted.•SA dose beyond 10μM increased the toxicity of EMR-treated effluent.
Redox-mediators such as syringaldehyde (SA) can improve laccase-catalyzed degradation of trace organic contaminants (TrOCs) but may increase effluent toxicity. The degradation performance of 14 phenolic and 17 non-phenolic TrOCs by a continuous flow enzymatic membrane reactor (EMR) at different TrOC and SA loadings was assessed. A specific emphasis was placed on the investigation of the toxicity of the enzyme (laccase), SA, TrOCs and the treated effluent. Batch tests demonstrated significant individual and interactive toxicity of the laccase and SA preparations. Reduced removal of resistant TrOCs by the EMR was observed for dosages over 50μg/L. SA addition at a concentration of 10μM significantly improved TrOC removal, but no removal improvement was observed at the elevated SA concentrations of 50 and 100μM. The treated effluent showed significant toxicity at SA concentrations beyond 10μM, providing further evidence that higher dosage of SA must be avoided.
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•CM addition for direct interspecies electrons transfer can enhance AD performance.•Research to date is limited to carbon and iron based CMs using small scale reactors.•Future work at ...pilot scale is recommended to validate the benefits of CM addition.•Future work is also to access the impact of CM addition on downstream processing.
Addition of conductive materials (CMs) has been reported to facilitate direct interspecies electron transfer (DIET) and improved anaerobic digestion (AD) performance. This review summarises the benefits and outlines remaining research challenges of the addition of CMs with a focus on the downstream processing of AD. CM addition may alter biogas quality, digestate dewaterability, biosolids volume, and centrate quality. Better biogas quality has been observed due to the adsorption of H2S to metallic CMs. The addition of CMs results in an increase in solid content of the digestate and thus an additional requirement for sludge dewatering and handling and the final biosolids volume for disposal. This review highlights the need for more research at pilot scale to validate the benefits of CM addition and to evaluate CM selection, doses, material costs, and the impact on downstream processes. The lack of research on the impact of CMs on the downstream process of AD is highlighted.
The lack of communication between local authorities, first aid responders, and the population that are present in a natural disaster area, represents critical aspects which can compromise relief ...operations in saving human lives. During natural disasters (earthquakes/tsunamis), the typical telecommunications network infrastructure in the affected area could be damaged or unfunctional. This can seriously compromise the efficiency of first aid operations. In this paper, we propose a device-to-device (D2D)-based framework which, starting from some basic information such as positions and battery level of victim's devices, could provide communication from a disaster area towards a functional area. This framework, utilized by a base station located in a functional area, organizes users of disaster area into clusters of users and for each cluster select a gateway. This framework permits also, to evaluate the optimal transmission power for each gateway in order to maximize the energy efficiency in the area and to create a multi-hop path from the disaster area to relay node minimizing the end-to-end delay. The simulations results demonstrate that our proposed approach outperforms either random policy assignment and static policies assignment in both power allocation and routing path creations.
The occurrence of emerging contaminants, such as estrogens, in secondary and tertiary treated effluents and in sewage-impacted water bodies is one of the major obstacles to the implementation of ...water reuse. This review critically evaluates the performance of emerging process of enzymatic degradation of estrogens, and its efficiency. The data collected from peer-review literature show that enzymes have been extensively applied (in both free and immobilized form) in estrogen removal. Amongst others, the use of laccase as a catalyst provides over 90% removal of estrogens. Immobilized enzymes can overcome some limitations of the free biocatalysts, including reusability. Research evidence points to the formation of by-products, such as dimers and trimers. Nevertheless, estrogenic activity assessment indicates a reduction in toxicity after enzyme treatment. The cost and stability of enzymes, as well as their performance in a real wastewater matrix, are the major obstacles to the implementation of enzymatic processes in wastewater treatment. Continued endeavors are required to enhance the successful application of enzymes in the wastewater treatment industry.
This work examined the chiral inversion of 2-arylpropionic acids (2-APAs) under anaerobic conditions and the associated microbial community. The anaerobic condition was simulated by two identical ...anaerobic digesters. Each digester was fed with the substrate containing 11 either pure (R)- or pure (S)-2-APA enantiomers. Chiral inversion was evidenced by the concentration increase of the other enantiomer in the digestate and the changes in the enantiomeric fraction between the two enantiomers. Both digesters showed similar and poor removal of 2-APAs (≤30%, except for naproxen) and diverse chiral inversion behaviors under anaerobic conditions. Four compounds exhibited (S → R) unidirectional inversion flurbiprofen, ketoprofen, naproxen, and 2-(4-tert-butylphenyl)propionic acid, and the remaining seven compounds showed bidirectional inversion. Several aerobic and facultative anaerobic bacterial genera (Candidatus Microthrix, Rhodococcus, Mycobacterium, Gordonia, and Sphingobium) were identified in both digesters and predicted to harbor the 2-arylpropionyl-CoA epimerase (enzyme involved in chiral inversion) encoding gene. These genera presented at low abundances, <0.5% in the digester dosed with (R)-2-APAs and <0.2% in the digester dosed with (S)-2-APAs. The low abundances of these genera explain the limited extent of chiral inversion observed in this study.
Unmanned aerial vehicles (UAVs) have acquired remarkable popularity, thanks to their variety of applications in numerous domains spanning from surveillance, health to agriculture and smart cities. ...UAVs are also enabler in wireless communication that has potential features such as ubiquitous and reliable connectivity, fast and easy deployment, adaptive altitude, higher chance of line of sight (LOS) propagation path, higher mobility and flexibility. There are numerous surveys that summarized these advantages for different situations and scenarios. However, none of these surveys discussed the role of UAVs in public safety communications from the energy efficiency perspective. In this paper, we review the existing literature for UAV communication with taking into account the energy consumption criteria, and propose a multi-layered network architecture incorporating UAVs for public safety communication. Future research directions are also discussed.
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