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Topic Review
Reactions to Space Mining
There is currently a surge in interest from both private and government sectors in developing technology for mining asteroids and the moon (“space mining”). One of the key benefits highlighted by advocates of space mining is that it minimizes the usual problems associated with mining on earth in terms of pollution, environmental degradation, and encroachment on human habitats. Two studies—one conducted on a 27-nation sample (N = 4819), the other conducted in the U.S. (N = 607)—provide the first test of the assumed (but never studied) notion that space mining is more palatable to the public than terrestrial mining. Both studies indicate broad support for asteroid mining: levels of support were reliably above the mid-point, and much greater than for other forms of frontier mining such as mining the ocean floor, mining Antarctica, mining the Alaskan tundra, and lunar mining. Unlike terrestrial mining, community attitudes toward mining asteroids were largely non-ideological; support was not correlated with perceptions of ecological fragility, political ideology, or individualistic/hierarchical worldviews.
  • 425
  • 24 Apr 2022
Topic Review
Rare Earth Elements (REE)
The rare earth elements (REE) comprise a group of 16 chemically very similar elements that occur widespread in rocks, soils, and water bodies, share similar ionic radii to the essential element Ca2+, and consequently also occur in biota. Given that REE form mainly trivalent cations, they also share similarities to Al3+. Compared to their chemical cognate Ca, they have a higher reactivity. Thus, their accumulation in soils may constitute a severe environmental threat. Over the last decades, the increasing use of REE in modern technology and fertilizers raised concerns about the pollution of soils and water bodies, which led to a rapidly increasing number of publications dealing with REE toxicity to plants, animals and humans, the fate of REE in soil–plant systems, REE cycling in ecosystems and impacts of REE pollution on food security.
  • 278
  • 05 Feb 2024
Topic Review
Rare Earth Elements
The use of analytical techniques is important and critical in all areas related to REE (Rare Earth Elements), such as basic fundamental research, exploration, mining, extraction, and metallurgical activities at different stages by different industries. At every stage of these activities, rock, ore, minerals, and other related materials have to be analyzed for their REE contents in terms of elemental, isotopic, and mineralogical concentrations using different analytical techniques.
  • 267
  • 16 Aug 2023
Topic Review
Rank-Size Distribution
Rank-size distribution is the distribution of size by rank, in decreasing order of size. For example, if a data set consists of items of sizes 5, 100, 5, and 8, the rank-size distribution is 100, 8, 5, 5 (ranks 1 through 4). This is also known as the rank-frequency distribution, when the source data are from a frequency distribution. These are particularly of interest when the data vary significantly in scale, such as city size or word frequency. These distributions frequently follow a power law distribution, or less well-known ones such as a stretched exponential function or parabolic fractal distribution, at least approximately for certain ranges of ranks; see below. A rank-size distribution is not a probability distribution or cumulative distribution function. Rather, it is a discrete form of a quantile function (inverse cumulative distribution) in reverse order, giving the size of the element at a given rank.
  • 2.7K
  • 31 Oct 2022
Topic Review
Rangelands Livestock Production Systems
Rangelands as referred to herein can be defined as uncultivated lands that provide multiple ecosystem services for society, sustain habitat for grazing and browsing animals, and support the livelihoods of pastoralists and ranchers [1][2]. Under this definition rangelands comprise up to 70% of the world’s land area and include natural grasslands, deserts, temperate forests, and tropical forests [1]. Greenhouse gases (GHGs) released into the lower atmosphere mainly by the burning of fossil fuels and other anthropogenic activities have caused the earth’s temperature to rise by 1 °C since the 1860s [3][4]. If GHG emissions continue to rise, an increase in global temperature up to 3 to 5 °C is projected by the end of this century [4]. Extreme weather events are already increasing in frequency and severity in the US and globally [3][4][5]. Global concern is growing over the possibility that eventual irreversible, catastrophic climate change will result in massive loss of human livelihoods and mortality through adverse impacts on food production systems over both croplands and rangelands [3][4][6][7][8][9][10][11][12].
  • 1.5K
  • 05 Nov 2020
Topic Review
Rangeland Biodiversity and Climate Variability
Rangeland biodiversity related closely with climate variability. Rainfall plays an important role in arid rangeland restoration. Under favorable conditions, one-year grazing exclusion considerably enhanced species richness and evenness diversity compared to longer resting durations under dry to average rainfall conditions. The decision to how long livestock grazing exclusion would last should not be decided upfront as it depends on the climatic and the site-specific conditions.
  • 637
  • 27 Jun 2021
Topic Review
Range (Aeronautics)
The maximal total range is the maximum distance an aircraft can fly between takeoff and landing. Powered aircraft range is limited by the aviation fuel energy storage capacity (chemical or electrical) considering both weight and volume limits. Unpowered aircraft range depends on factors such as cross-country speed and environmental conditions. The range can be seen as the cross-country ground speed multiplied by the maximum time in the air. The fuel time limit for powered aircraft is fixed by the available fuel (considering reserve fuel requirements) and rate of consumption. Some aircraft can gain energy while airborne through the environment (e.g. collecting solar energy or through rising air currents from mechanical or thermal lifting) or from in-flight refueling. These aircraft could theoretically have infinite range. Ferry range means the maximum range that a aircraft engaged in ferry flying can achieve. This usually means maximum fuel load, optionally with extra fuel tanks and minimum equipment. It refers to transport of aircraft without any passengers or cargo. Combat radius is a related measure based on the maximum distance a warplane can travel from its base of operations, accomplish some objective, and return to its original airfield with minimal reserves.
  • 981
  • 18 Oct 2022
Topic Review
Ramsar Site Labudovo Okno for Sustainable Tourism
The Ramsar Site Labudovo Okno (LO) is located in Serbia, AP Vojvodina, on the left bank of the Danube. It covers an area of 3733 ha. This wet habitat is valuable for different ecosystems, among which the most important are those inhabited by rare bird species.
  • 224
  • 28 Feb 2024
Topic Review
Rainwater Treatment
Rainwater harvesting is an ancient practice currently used for flood and drought risk mitigation. It is a well-known solution with different levels of advanced technology associated with it. 
  • 273
  • 28 Apr 2023
Topic Review
Rainwater Harvesting Systems
Rainwater harvesting (RWH) can be used to mitigate global water crises; however, they have been poorly received by communities because of the unsuitable quality of stored rainwater. Heterotrophic bacteria present in the water can degrade the water’s microbiological quality and create health issues. Moreover, exposure to visible light can affect both suspended and surface-attached heterotrophic bacteria, a phenomenon that is poorly investigated.
  • 585
  • 29 Jul 2021
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