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Topic review
Updated time: 22 Apr 2021
Submitted by: Giovanni Scardino
Definition: Over the last few years, several authors have presented contrasting models to describe the response of boulders to extreme waves, but the absence of direct observation of movements has hindered the evaluation of these models. The recent development of online video-sharing platforms in coastal settings has provided the opportunity to monitor the evolution of rocky coastlines during storm events. In September 2018, a surveillance camera of the Marine Protected Area of Plemmirio recorded the movement of several boulders along the coast of Maddalena Peninsula (Siracusa, Southeastern Sicily) during the landfall of the Mediterranean tropical-like cyclone (Medicane) Zorbas. Unmanned autonomous vehicle (UAV) photogrammetric and terrestrial laser scanner (TLS) surveys were performed to reconstruct immersive virtual scenarios to geometrically analyze the boulder displacements recorded in the video. Analyses highlighted that the displacements occurred when the boulders were submerged as a result of the impact of multiple small waves rather than due to a single large wave. Comparison between flow velocities obtained by videos and calculated through relationships showed a strong overestimation of the models, suggesting that values of flow density and lift coefficient used in literature are underestimated.
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Topic review
Updated time: 16 Apr 2021
Submitted by: Ille Gebeshuber
Definition: Acid rain has an acidity that is higher than that of normal rainwater. Normal rainwater is not neutral (which would be pH 7) but slightly acidic (it has a pH < 5.5), because some of the carbon dioxide CO2 dissolved in the water is present as carbonic acid H2CO3. In acid rain, chemicals from pollution and natural causes such as volcanic eruptions and emissions from vegetation increase the acidity of the water to as low as pH 4.4 to 4 (as measured in the 1990s in various places). Such acidic rainwater is dangerous for people, vegetation, water bodies including the oceans and its inhabitants, buildings and soil. Since the pH scale is logarithmic, a change from 5.5 to 4.5 means a tenfold increase in acidity. The three main pollutants that cause acid rain are the nitric oxides NO and NO2 (summarized as NOx) and sulfur dioxide SO2. These substances react with water to nitric acid HNO3 and sulfuric acid H2SO4. In the 1980s, in nearly all of Northern Europe and in the Northern United States, suddenly and unexpectedly, whole forests began to die (this effect got to be known as forest dieback). German forests especially experienced severe damage: from 8% in 1982 it increased to 50% in 1984, and stayed as such till 1987. The damage occurred amongst various tree species. Researchers established connections of this damage to acid rain. The mandatory installment of sulfur filters in coal power plants and of catalytic converters in cars in various industrialized countries reduced air pollution with the chemicals related to the formation of acid rain, and, although the forests are still not in perfect shape (about 20% are heavily impaired) a complete death was prevented.
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Topic review
Updated time: 16 Apr 2021
Submitted by: Fazila Younas
Definition: Wastewater generation and treatment is an ever-increasing concern in the current century due to increased urbanization and industrialization. To tackle the situation of increasing environmental hazards, numerous wastewater treatment approaches are used—i.e., physical, chemical, and biological (primary to tertiary treatment) methods. Various treatment techniques being used have the risks of producing secondary pollutants. The most promising technique is the use of different materials as adsorbents that have a higher efficacy in treating wastewater, with a minimal production of secondary pollutants. Biosorption is a key process that is highly efficient and cost-effective. This method majorly uses the adsorption process/mechanism for toxicant removal from wastewater.
Entry Collection : Wastewater Treatment
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Topic review
Updated time: 25 May 2021
Submitted by: Ram Ray
Definition: The agricultural industry is getting more data-centric and requires precise, more advanced data and technologies than before, despite being familiar with agricultural processes. The agriculture industry is being advanced in generating database by various information and advanced communication technologies, such as the Internet of Things (IoT).
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Topic review
Updated time: 08 Jun 2021
Submitted by: Regina Duarte
Definition: Atmospheric aerosol deposition (wet and dry) is an important source of macro and micronutrients (N, P, C, Si, and Fe) to the oceans. Most of the mass flux of air particles is made of fine mineral particles emitted from arid or semi-arid areas (e.g., deserts) and transported over long distances until deposition to the oceans. However, this atmospheric deposition is affected by anthropogenic activities, which heavily impacts the content and composition of aerosol constituents, contributing to the presence of potentially toxic elements (e.g., Cu). Under this scenario, the deposition of natural and anthropogenic aerosols will impact the biogeochemical cycles of nutrients and toxic elements in the ocean, also affecting (positively or negatively) primary productivity and, ultimately, the marine biota.
Entry Collection : Environmental Sciences
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Topic review
Updated time: 16 Apr 2021
Submitted by: Jens Götze
Definition: Agate ‒ a spectacular form of SiO2 and a famous gemstone ‒ is commonly characterized as banded chalcedony. In detail, chalcedony layers in agates can be intergrown or intercalated with macro-crystalline quartz, quartzine, opal-C, opal-CT, cristobalite and/or moganite. In addition, agates often contain considerable amounts of mineral inclusions and water as both interstitial molecular H2O and silanol groups.
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Topic review
Updated time: 16 Apr 2021
Submitted by: Camila Rodrigues
Definition: Monitoring the microbial quality of water used in agriculture is important to reduce the likelihood of produce contamination and possible future foodborne outbreaks. The U.S. Food and Drug Administration has established the Produce Safety Rule as part of the Food Safety Modernization Act to improve the safety of produce that is normally consumed raw during growing, harvesting, packing and holding activities. In order to comply with the rule, growers need to follow some standards for the microbial quality of water that is used on the produce field, however, more information on the water microbial profile is necessary in order to improve the accuracy of the testing.
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Topic review
Updated time: 26 May 2021
Submitted by: Oyetola Ogunkunle
Definition: Air pollution is a precursor to many health issues such as difficulty breathing, asthma, lung and heart diseases, and cancer.
Entry Collection : Environmental Sciences
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Topic review
Updated time: 28 Oct 2020
Submitted by: Maya Negev
Definition: Since its establishment in 1948, the State of Israel has been oriented towards economic development and industrialization, with a transportation sector increasingly focused on private cars. In 1961, initial awareness of environmental risks led to the adoption of the Abatement of Nuisances Law, which served as the platform for air pollution policy for several decades, even as population growth and growth of the industrial sector, including fossil fuel power plants, led to a continuous increase in air pollution. In the early 2000s, the environmental movement in Israel criticized local air pollution policy as being out of date and started to promote a new Clean Air Law. The law, which was adopted in 2008 and came into force in 2011, was a watershed in air pollution policy in Israel. It includes ambient air quality values for 28 contaminants, emission permits for the industrial sector based on best available techniques (BAT), an enforcement system, and a unified and transparent monitoring system. This entry introduces the history of air pollution policy in Israel from 1948, through the 1961 and 2008 landmark legislations and their strengths and weaknesses, to the present. Also, it gives recommendations for future air pollution policy in Israel.
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Topic review
Updated time: 18 Feb 2021
Submitted by: Eva Merico
Definition: Maritime transport has been recognized as an essential driver for economic and social development, especially for coastal regions. However, shipping and in-port activities pose public health issues and environmental pressures, exposing coastal population to associated emissions (i.e., particulate matter and gaseous pollutants). In the last decades, several policies have been implemented at local/regional and international level, reducing the content of sulphur in marine fuels. This work provides a brief comment of some recent results regarding the impacts of maritime emissions on air quality, health effects and future projections, taking into account the current implementation of the IMO-2020 legislation. Finally, future perspectives and potential mitigation strategies are discussed.
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