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  • Assessing Renewable Resources at the Saronikos Gulf for the Development of Multi-Generation Renewable Systems

    George Lavidas; John K. Kaldellis (MDPI AG, 2020-11-01)
    Decarbonisation of any energy system implies that more renewables will have to be incorporated into the grid. This requires a thorough assessment of available resources to properly estimate potential contributions and identify opportunities. This work focuses on the Saronikos Gulf, which is part of the most crowded urban coastline in Greece. Solar, wind and wave resources are analysed, and the long-term characteristics affecting power production are discussed. Solar resources provide ≥250 Wh·<inline-formula><math display="inline"><semantics><msup><mi mathvariant="normal">m</mi><mrow><mo>−</mo><mn>2</mn></mrow></msup></semantics></math></inline-formula> with small long-term changes. Wind resources at coastal and onshore regions are ≥50 W·<inline-formula><math display="inline"><semantics><msup><mi mathvariant="normal">m</mi><mrow><mo>−</mo><mn>2</mn></mrow></msup></semantics></math></inline-formula>; however, it has higher annual volatility. Finally, the wave resources of the region are from 130 to 170 W/m with a positive resource rate of change ≈2.5 W·<inline-formula><math display="inline"><semantics><msup><mi mathvariant="normal">m</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></semantics></math></inline-formula>/year. It is expected that multi-generation by different resources, especially with temporal overlaps of wind and waves, will reduce intermittent production, hence accelerating the energy transition.
  • Harvester Productivity in Inclined Terrain with Extended Machine Operating Trail Intervals: A German Case Study Comparison of Standing and Bunched Trees

    Ferréol Berendt; Eduardo Tolosana; Stephan Hoffmann; Paula Alonso; Janine Schweier (MDPI AG, 2020-11-01)
    The complexity of highly structured forests with multiple tree species, especially when coniferous and broadleaved tree species are mixed, as well as stands with extended machine operating trail spacing and inclined terrain, create challenging operational conditions for mechanized timber harvesting and extraction. Motor-manually felling trees within the midfield and bunching them at the machine operating trails, prior to the arrival of a harvester-forwarder system, is a complex operation. The aim of this study was to assess and compare tethered harvester productivities of a thinning operation, for felling and processing standing trees and for processing bunched trees, through a time study in forest stands with 40-m distances between machine operating trails. Total operational costs of the analyzed thinning operation were 69 €/m<sup>3</sup><sub>o.b.</sub>, including extraction using a multiple forwarder approach. Tree species, merchantable timber volume, and whether the trees were standing or presented as bunched logs all had a significant effect on the harvester time consumption. Moreover, harvester positioning time was significantly shorter when trees were already bunched at the machine operating trail. While the productivity of standing or bunched spruce trees did not differ significantly between the cases (approximately 18 m<sup>3</sup><sub>o.b.</sub>/productive machine hours excluding all delays (PMH<sub>0</sub>)), the productivity of standing broadleaved tree species (8.3 m<sup>3</sup><sub>o.b.</sub>/PMH<sub>0</sub>) was much lower than that of bunched trees (15.5 m<sup>3</sup><sub>o.b.</sub>/PMH<sub>0</sub>). Thus, the described timber harvesting and extraction system may be a valuable option for forest stands with high proportion of broadleaved trees.
  • Design Thinking for Urban Water Sustainability in Huelva’s Households: Needfinding and Synthesis through Statistic Clustering

    Gustavo Bermejo-Martín; Carlos Rodríguez-Monroy; Yilsy M. Núñez-Guerrero (MDPI AG, 2020-11-01)
    This article shows the numerical results and the analysis of households’ degree of knowledge about the urban water cycle, needs, and values regarding water in an intermediary city with low water stress, such as Huelva (Andalusia, Spain). Results are also presented regarding how households maintain the acceptance of reclaimed water and new technologies to achieve more efficient and sustainable consumption. Surveys were sent to households, and different statistical analysis techniques were applied. The use of clustering as a mathematical tool has served to obtain three clusters of households with similar characteristics with respect to the previous factors. The first cluster corresponded to households with high knowledge of the integral water cycle and positive attitude to smart devices at home. The second cluster showed low knowledge of the integral water cycle and high sensitivity to price. The third one had average knowledge and predisposition to have a closer relationship with the water company. This classification allows implementing different water demand management strategies tailored to each cluster. Applying a Design Thinking methodology, a web-based prototype has been designed as an ICT tool concerning households. The goal is to achieve greater engagement of households concerning water and align citizens with their city’s sustainability.
  • Towards a Sustainable Society through Emerging Mobility Services: A Case of Autonomous Buses

    Kenichiro Chinen; Yang Sun; Mitsutaka Matsumoto; Yoon-Young Chun (MDPI AG, 2020-11-01)
    The topic of emerging mobility services has quickly received attention from scholars and media in recent years. Mobility services employing autonomous buses in transport systems is one such example. Mobility services using emerging technologies are expected to create social, economic, and environmental benefits. However, the potential benefits of emerging mobility services using autonomous technology will not be realized unless self-driving vehicles are accepted and used by many passengers. The recent worldwide pandemic caused us to recognize the benefits of autonomous technologies. This pretest-and-posttest designed research examines the predictors of willingness to ride autonomous buses in a closed environment. The results of this study indicate that a combination of factors, such as societal benefits, attitude and technology adoption, directly and indirectly influence an individual’s acceptance of autonomous buses. This study finds that passengers’ willingness to use emerging mobility services after a sample riding experience is higher than before having a sample riding experience.
  • Default Behaviors of Contractors under Surety Bond in Construction Industry Based on Evolutionary Game Model

    Jiabao Jing; Xiaomei Deng; Rashid Maqbool; Yahya Rashid; Saleha Ashfaq (MDPI AG, 2020-11-01)
    In construction projects, some contractors will take default actions against the contracts to obtain maximum profits and damage the owners’ benefits as a result. In the construction markets where effective supervision is not performed well, contractors have more opportunities to default. Surety bonds were designed to solve the default problems and promote the sustainable development of the construction markets. This paper was proposed to explore the interactions between owners and contractors and investigate the influence of surety bonds (high penalty and low penalty) on the default behavior of contractors based on a static and dynamic evolutionary game analysis model. The results showed that applying the surety bond strategy is effective at decreasing the probability of the contractors’ default behavior when the credit system based on a surety bond system is well developed in the construction industry and the cost of the surety bond is low enough. Therefore, government strategies such as a better development of the credit system driven by surety bonds and the subsidies on surety bonds to reduce the cost can mitigate the contractors’ default behavior and keep the sustainability of the construction markets.
  • Development of a Two-Stage Pyrolysis Process for the End-Of-Life Nickel Cobalt Manganese Lithium Battery Recycling from Electric Vehicles

    Lingyun Zhu; Ming Chen (MDPI AG, 2020-11-01)
    With the continuous promotion of electric vehicles, the pressure to scrap vehicle batteries is increasing, especially in China, where nickel cobalt manganese lithium (NCM) batteries have gradually come to occupy a dominant position in the battery market. In this study, we propose a two-stage pyrolysis process for vehicle batteries, which aims to effectively deal with the volatilization of organic solvents, the decomposition of lithium salts in the electrolyte and the removal of the separator material and polyvinylidene fluoride (PVDF) during battery recycling. By solving these issues, recycling is more effective, safe. Through thermogravimetric analysis (TGA), the pyrolysis characteristics of the battery’s internal materials are discussed, and 150 °C and 450 °C were determined as the pyrolysis temperatures of the two-stage pyrolysis process. The results show that in the first stage of pyrolysis, organic solvents EC (C<sub>4</sub>H<sub>3</sub>O<sub>3)</sub>, DEC (C<sub>5</sub>H<sub>10</sub>O<sub>3</sub>) and EMC (C<sub>4</sub>H<sub>8</sub>O<sub>3</sub>) can be separated from the electrolyte. In the second stage, the pyrolysis can lead to the separator’s thermal decomposition. The gas products are alkane C<sub>2</sub>-C<sub>6</sub>, and the tar products are organic hydrocarbons C<sub>15</sub>-C<sub>36</sub>. Meanwhile, the solid residue of the battery’s internal material seems to be very homogeneous. Finally, the potential recovery value and pollution control countermeasures of the products and residues from the pyrolysis process are analyzed. Consequently, this method can effectively handle NCM vehicle battery recycling, which provides the basis for the subsequent hydrometallurgical or pyrometallurgical process for element recovery of the battery material.
  • (In)Sustainability of the Territory of Chapada Do Apodi-Rn (Brazil): The Expansion of Agribusiness versus the Impacts of Traditional Farmers and Local Rural Communities

    Jorge Luís de Oliveira Pinto Filho; Alana Ticiane Alves do Rêgo; Anderson Rodrigues da Silva Lunes; Lucio Cunha (MDPI AG, 2020-11-01)
    The objective of this study is to investigate the conditions of family agriculture and the respective environmental impacts of agribusiness. The research methodology is grounded on a theoretical survey of study descriptions of the area, a characterization of rural communities and local population through interviews, an identification of medium and large agricultural enterprises through documentary research on environmental licensing processes, and determination of the environmental impacts of agribusiness via an interaction matrix. Based on the data generated, it was found that the majority of the population has an incomplete elementary education; is involved in agricultural activity, livestock farming, and honey production, which provide a family income of up to one minimum wage; and is located in rural communities with environmental sanitation restrictions. Moreover, it was found that irrigated agriculture has positive impacts, such as the generation of employment and income. It was also evidenced that this activity causes adverse socioeconomic impacts and adverse impacts on the traditional activities of local rural communities through plant removal, water scarcity, and pesticide use. Thus, to mitigate the problems, it is necessary to apply the principles of Brazilian Environmental Law as correlated with the instruments of the National Environment Policy through environmental management guidelines.
  • The Role of Human Operators in Safety Perception of AV Deployment—Insights from a Large European Survey

    Miltos Kyriakidis; Jaka Sodnik; Kristina Stojmenova; Arnór B. Elvarsson; Cristina Pronello; Nikolas Thomopoulos (MDPI AG, 2020-11-01)
    Autonomous vehicles are anticipated to play an important role on future mobility offering encouraging solutions to today’s transport problems. However, concerns of the public, which can affect the AVs’ uptake, are yet to be addressed. This study presents relevant findings of an online survey in eight European countries. First, 1639 responses were collected in Spring 2020 on people’s commute, preferred transport mode, willingness to use AVs and demographic details. Data was analyzed for the entire dataset and for vulnerable road users in particular. Results re-confirm the long-lasting discourse on the importance of safety on the acceptance of AVs. Spearman correlations show that age, gender, education level and number of household members have an impact on how people may be using or allowing their children to use the technology, e.g., with or without the presence of a human supervisor in the vehicle. Results on vulnerable road users show the same trend. The elderly would travel in AVs with the presence of a human supervisor. People with disabilities have the same proclivity, however their reactions were more conservative. Next to safety, reliability, affordability, cost, driving pleasure and household size may also impact the uptake of AVs and shall be considered when designing relevant policies.
  • GIS-Enabled Digital Twin System for Sustainable Evaluation of Carbon Emissions: A Case Study of Jeonju City, South Korea

    Jiman Park; Byungyun Yang (MDPI AG, 2020-11-01)
    <b> </b>Despite the growing interest in digital twins (DTs) in geospatial technology, the scientific literature is still at the early stage, and concepts of DTs vary. In common perspectives, the primary goals of DTs are to reduce the uncertainty of the physical systems in real-world projects to reduce cost. Thus, this study is aimed at developing a structural schematic of a geographic information system (GIS)-enabled DT system and exploring geospatial technologies that can aid in deploying a DT system for a real-world project—in particular, for the sustainable evaluation of carbon emissions. The schematic includes three major phases: (1) data collection and visualization, (2) analytics, and (3) deployment. Three steps are designed to propose an optimal strategy to reduce carbon emissions in an urban area. In the analytics phase, mapping, machine learning algorithms, and spatial statistics are applied, mapping an ideal counterpart to physical assets. Furthermore, not only are GIS maps able to analyze geographic data that represent the counterparts of physical assets but can also display and analyze spatial relationships between physical assets. In the first step of the analytics phase, a GIS map spatially represented the most vulnerable area based on the values of carbon emissions computed according to the Intergovernmental Panel on Climate Change (IPCC) guidelines. Next, the radial basis function (RBF) kernel algorithm, a machine learning technique, was used to forecast spatial trends of carbon emissions. A backpropagation neural network (BPNN) was used to quantitatively determine which factor was the most influential among the four data sources: electricity, city gas, household waste, and vehicle. Then, a hot spot analysis was used to assess where high values of carbon emissions clustered in the study area. This study on the development of DTs contributes the following. First, with DTs, sustainable urban management systems will be improved and new insights developed more publicly. Ultimately, such improvements can reduce the failures of projects associated with urban planning and management. Second, the structural schematic proposed here is a data-driven approach; consequently, its outputs are more reliable and feasible. Ultimately, innovative approaches become available and services are transformed. Consequently, urban planners or policy makers can apply the system to scenario-based approaches.
  • Mobile Augmented Reality in Electronic Commerce: Investigating User Perception and Purchase Intent Amongst Educated Young Adults

    Tegegne Tesfaye Haile; Mincheol Kang (MDPI AG, 2020-11-01)
    Even though the presence and use of mobile augmented reality (MAR) technology has become increasingly popular in the field of marketing and advertising in recent years, it has largely been neglected in the study of consumer behavior research. This paper utilizes a single-group posttest-only quasi-experimental design to investigate how the feature of mobile augmented reality application influences consumers’ attitude and purchasing intention as explained by the dimensions of persuasion (i.e., consumers’ cognitive, affective, and conative dimensions). Structural Equation Modeling (SEM) with SPSS and AMOS is used to analyze the psychometric survey data collected from 179 participants. The results supported the prediction that MAR application’s real-time interactivity and entertainment increase cognition and affection, respectively; while irritation with MAR application decreases affection. The unsupported hypothesis, which predicted a positive relationship between informativeness and cognition, came as a surprise. The overall result of the study demonstrates the positive influence of MAR application in enhancing consumers’ purchasing intention. Finally, implications and future research directions are discussed.
  • An Overview of Environmental Policies for Mitigation and Adaptation to Climate Change and Application of Multilevel Regression Analysis to Investigate the CO<sub>2</sub> Emissions over the Years of 1970 to 2018 in All Brazilian States

    Anny Key de Souza Mendonça; Silvio Aparecido da Silva; Luísa Zeredo Pereira; Antonio Cezar Bornia; Dalton Francisco de Andrade (MDPI AG, 2020-11-01)
    Background: Brazil, one of the largest greenhouse gas emitting countries in the world, emitted approximately 2 billion gigatonnes of carbon dioxide (CO<sub>2</sub>) in 2018. This data is practically the same recorded in the previous year, suggesting that the country’s trajectory of CO<sub>2</sub> emissions is stabilized. Methods: This study presents an overview of environmental protection and climate change mitigation policies adopted in Brazil, as well as makes use the multilevel regression modeling technique to investigate the relationship between economic activities variables in relation to CO<sub>2</sub> emissions over the years of 1970 to 2018 in all Brazilian states. Results: The results show that the CO<sub>2</sub> emissions in the states have the same behavior as the timeline of the change in land use. Conclusions: The public policies and actions by society and the private sector were fundamental to the reduction verified from the year of 2004 that followed until 2010, both in CO<sub>2</sub> emissions and in the change in land use and forests. As of this year, there has been a trend towards stability in CO<sub>2</sub> emissions. Another important characteristic is that even with a drop in the number of deforestation, the production variables continued to grow, which shows that there may be an increase in production activities, while there is a reduction in deforestation and in CO<sub>2</sub> emissions.
  • Effects of Different Ages of <i>Robinia pseudoacacia</i> Plantations on Soil Physiochemical Properties and Microbial Communities

    Chaoyi Luo; Bingxue Zhang; Jiang Liu; Xiaoxia Wang; Fengpeng Han; Jihai Zhou (MDPI AG, 2020-11-01)
    <i>Robinia pseudoacacia</i> is widely planted on the Loess Plateau as a strong drought-tolerant and salt-tolerant species for vegetation restoration. However, this mode of pure plantation has triggered great concern over the soil ecosystem. The aim of this study was to explore the effects of the plantation on soil physiochemical properties, soil microorganisms, and the relationship between them in <i>Robinia pseudoacacia</i> plantations of different ages. Four different ages of <i>Robinia pseudoacacia</i> stands, including 10-year-old, 15-year-old, 25-year-old, and 40-year-old (abbreviated as Y10, Y15, Y25, and Y40, respectively) were selected, and 20 soil physicochemical and biological indicators were determined. The variation in soil microbial biomass was influenced by sampling depth, and consistent with the variations in TN (soil total nitrogen) and SOC (soil organic carbon) during 25 years’ artificial forestation. Soil moisture increased significantly at Y15 and then decreased at Y40 but other soil properties remained relatively stable. The contents of phosphor lipid fatty acid (PLFA) of different microbial groups followed the order of B (Bacteria) > G<sup>−</sup> (Gram-negative) > G<sup>+</sup> (Gram-positive) > A (Actinomycetes) > F (Fungi). The ratios of F/B (Fungi to Bacteria) and Sat/Mono (Saturated PLFAs to Monosaturated PLFAs) of different ages of plantations showed a similar trend, i.e., declined first, then rose, and declined again. The ratios of Cy/Pre (Cyclopropyl PLFAs to Precursor PLFAs) and G<sup>+</sup>/G<sup>−</sup> (Gram-positive to Gram-negative) of the soil of all ages of plantations showed a trend of slow growth and a trend of rapid growth, respectively. Redundancy analysis showed that the contents of individual PLFAs and total PLFA were positively correlated with SOC and TN, but variations of soil PLFA ratios mostly depended on other soil properties. After artificial forestation, the ratios of F/B and Sat/Mono were lower than before forestation, while the ratio of Cy/Pre varied with different soil layers. The ratio of G<sup>+</sup>/G<sup>−</sup> increased with the increase in afforestation time, peaking at the 25th year. The contents of individual PLFAs and total PLFA may be sensitive indicators of SOC and TN within 25 years’ plantation. Lower ratio of F/B and higher G<sup>+</sup>/G<sup>−</sup> suggest that the sustainability of the ecosystem is weaker and the fertility of the soil is lower after plantation of <i>Robinia pseudoacacia</i>.
  • Safety and Nonoptimal Usage of a Protected Intersection for Bicycling and Walking: A Before-and-After Case Study in Salt Lake City, Utah

    Torrey Lyons; Dong-ah Choi; Keunhyun Park; S. Hassan Ameli (MDPI AG, 2020-11-01)
    This paper describes a before-and-after case study of a protected intersection in Salt Lake City, Utah. The intersection was completed in late 2015 and represented one of the first examples of a protected intersection design in North America. We analyzed bird’s-eye view video data that was recorded before the intersection was implemented and compared it against video data recorded from the exact same location after implementation. In order to examine changes in intersection usage and behavior, we operationalized safety in terms of the frequency of nonoptimal behaviors demonstrated by active transportation modes. We found that active transportation usage of the intersection has increased since the new configuration, with most of that growth attributable to e-scooter users. There was minimal change in the rates of nonoptimal behaviors by pedestrians. Bicyclists showed mostly decreased rates of nonoptimal behaviors, suggesting improved safety for this mode. E-scooter users, however, demonstrated nonoptimal behaviors at very high rates as compared with other active modes. This case study gives evidence that a protected intersection can have positive effects on active transportation volume and safety in a U.S. context.
  • Environmental Energy Sustainability at Universities

    Francisco G. Montoya; Alberto-Jesus Perea-Moreno (MDPI AG, 2020-11-01)
    The use of renewable energies and energy saving and efficiency are needs of global society and universities. Universities have a large responsibility and social impact, as they are an example and engine of social change. Universities, in the European context, must be at the forefront of sustainability progress, seeking to be at the same level, and preferably higher than the rest of society, seeking the goal of 20% in renewable energy for 2020 and, in the longer term, greater energy efficiency based on a diverse use of renewable energy and studying the feasibility of other energy processes (cogeneration, trigeneration, etc.). The application of renewable energies and efficiency allow universities to make significant savings in their costs and contribute to sustainable development and the fight against climate change. Actions on these aspects in addition to the objective of saving should seek to promote research and form an example for the university community. This Special Issue aims to advance the contribution of energy saving and the use of renewable energies in order to achieve more sustainable universities.
  • Aquatic Macrophytes in Constructed Wetlands: A Fight against Water Pollution

    Leticia Y. Kochi; Patricia L. Freitas; Leila T. Maranho; Philippe Juneau; Marcelo P. Gomes (MDPI AG, 2020-11-01)
    There is growing concern among health institutions worldwide to supply clean water to their populations, especially to more vulnerable communities. Although sewage treatment systems can remove most contaminants, they are not efficient at removing certain substances that can be detected in significant quantities even after standard treatments. Considering the necessity of perfecting techniques that can remove waterborne contaminants, constructed wetland systems have emerged as an effective bioremediation solution for degrading and removing contaminants. In spite of their environmentally friendly appearance and efficiency in treating residual waters, one of the limiting factors to structure efficient artificial wetlands is the choice of plant species that can both tolerate and remove contaminants. For sometimes, the chosen plants composing a system were not shown to increase wetland performance and became a problem since the biomass produced must have appropriated destination. We provide here an overview of the use and role of aquatic macrophytes in constructed wetland systems. The ability of plants to remove metals, pharmaceutical products, pesticides, cyanotoxins and nanoparticles in constructed wetlands were compared with the removal efficiency of non-planted systems, aiming to evaluate the capacity of plants to increase the removal efficiency of the systems. Moreover, this review also focuses on the management and destination of the biomass produced through natural processes of water filtration. The use of macrophytes in constructed wetlands represents a promising technology, mainly due to their efficiency of removal and the cost advantages of their implantation. However, the choice of plant species composing constructed wetlands should not be only based on the plant removal capacity since the introduction of invasive species can become an ecological problem.
  • Effect of Occupant Activity on Indoor Particle Concentrations in Korean Residential Buildings

    Hyungkeun Kim; Kyungmo Kang; Taeyeon Kim (MDPI AG, 2020-11-01)
    Due to the recent industrial development and COVID-19 pandemic, people are spending more time indoors. Therefore, indoor air quality is becoming more important for the health of occupants. Indoor fine particles are increased by outdoor air pollution and indoor occupant activities. In particular, smoking, cooking, cleaning, and ventilation are occupant activities that have the largest impact on indoor particle concentrations. In this study, indoor and outdoor particle concentrations were measured in ten apartment houses in South Korea for 24 h. Indoor particle concentrations were measured in the kitchen and living room to evaluate the impact of cooking, one of the most important sources of indoor particles. An occupant survey was also conducted to analyze the influence of occupant activities. It was found that the impact of outdoor particles on indoor particle concentrations in winter was not significant. The largest particle source was cooking. In particular, a large amount of particles was generated by broiling and frying. In addition, cooking-generated particles are rapidly dispersed to the living room, and this was more obvious for small particles. It is expected that this result will be statistically generalized if the particle concentration of more houses is analyzed in the future.
  • Sustainable Development, Energy Transition, and Climate Challenges in the Context of Gender: The Framework of Gender Determinants of Environmental Orientation in Poland

    Piotr Żuk; Anna Pacześniak (MDPI AG, 2020-11-01)
    How does gender affect attitudes towards ecology? This question is of particular interest in a society where conservative and populist power elites perceive the concepts of “gender” and “ecology” as manifestations of “foreign” cultural influences. In turn, the dependence of the Polish energy system on coal forces us to look for various social factors that may support energy transition and the principles of sustainable development. The article outlines the results of computer-assisted telephone interviewing (CATI) research on a representative sample of Polish society composed of 1.001 people and analyses the gender differentiation of attitudes towards the policy of sustainable development in Poland. The results presented in this article clearly show that women in Poland constitute an important support for ecological activities and energy transition. This is also the case with the entire progressive vision of politics: Women have become its main driver and an opportunity for change.
  • Salinity Stress Mitigation Using Encapsulated Biofertilizers for Sustainable Agriculture

    Nermin Adel Hussein El Semary; Mohamed Helmi Hadj Alouane; Olfa Nasr; Munirah F. Aldayel; Fatimah H. Alhaweti; Faheem Ahmed (MDPI AG, 2020-11-01)
    The harmful effect of salinity stress on crops needs to be mitigated. Therefore, the application of microbial inoculum in combination with nanomaterials and methyl salicylate was investigated. Initially, different seeds were exposed to salinity levels treated with variable microbial treatments using different modes of applications. The microbial treatments included application of cyanobacterial strain <i>Cyanothece</i> sp. and the rhizobacterium <i>Enterobacter cloacae</i>,<i> </i>alone or in combination with one another, and a final treatment using combined microbial inoculum supplied with methyl salicylate. Later, different nanomaterials were used, namely, graphene, graphene oxide, and carbon nanotubes in combination with biofertilizers on the highest salinity level. The nanomaterial with microbial treatment and methyl salicylate were applied partly as a mixture in soil and partly as capsules. Results showed that salinity stress had a drastic inhibitory effect on growth parameters, especially at −5 MPa level. Nonetheless, the microbial treatments significantly alleviated the deleterious effect of salinity stress, especially when combined with methyl salicylate. When the nanomaterials were added to biofertilizers at highest salinity level, the inhibitory effect of salinity was mostly alleviated. Smart use of synergistic biofertilizers alongside the right nanomaterial, both encapsulated and in soil, would allow for mitigation and alleviation of inhibitory effect of salinity.
  • LCA-Based Investigation of Environmental Impacts for Novel Double-Beam Floor System Subjected to High Gravity Loads

    Insub Choi; JunHee Kim; DongWon Kim (MDPI AG, 2020-11-01)
    In populated downtown areas, a floor system with secured environmental performance is needed to reduce greenhouse gases (GHGs) and global warming problems related to buildings. This study aims to assess environmental impacts on a novel double-beam floor system subjected to high gravity loads. Life cycle assessment (LCA) was conducted to investigate the environmental impacts on the reduction in construction materials by calculating global warming potential (GWP) in the structural design phase. For different structural systems, the environmental performance was compared based on the GWP, and the contributions of structural elements to the GWP in each structural system were analyzed. The rotational constraints induced by the beam-end concrete panel can significantly reduce the GWP of the double-beam floor system by up to 13.8% compared to the conventional beam-girder system. Thus, the double-beam floor system reinforced with the concrete panel can be a candidate for eco-friendly structural systems in underground structures requiring high gravity loads. This result provides valuable findings that the structural effect on the rotational constraint of the concrete panel was quantitatively evaluated by converting it into an environmental impact.
  • Noise Estimation Using Road and Urban Features

    Guillermo Rey Gozalo; Enrique Suárez; Alexandra L. Montenegro; Jorge P. Arenas; Juan Miguel Barrigón Morillas; David Montes González (MDPI AG, 2020-11-01)
    Noise pollution must be considered to achieve sustainable cities because current levels of exposure to environmental noise are a considerable risk to the health and quality of life of citizens. Urban features and sound levels were registered in 150 streets in the Chilean cities of Talca and Valdivia to analyze the relationship between both types of variables. Urban variables related to street location, urban land use, street geometry, road traffic control, and public and private transportation showed very significant correlations with the noise levels, and multiple regression models were developed from these variables for each city. Models using only urban variables in Valdivia and Talca explained 71% and 73%, respectively, of the variability of noise. The prediction error was similar in the different types of urban roads and did not exhibit significant differences between models developed in different cities. The urban models developed in one city could, therefore, be used in other similar cities. Considering the usefulness of these variables in urban planning, these models can be a useful tool for urban planners and decision-makers to implement action plans regarding noise pollution.

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