331 research outputs found
United Nations Framework Classification for Resources including case studies on anthropogenic resources and its provisions on the Critical Raw Materials Act proposal
On 16 March 2023, the European Commission published a proposal for a Regulation of the European Critical Raw Materials Act. This presentation introduces the benchmarks for capacities along the raw material supply chain, highlights the role of the United Nations Framework Classification (UNFC) in the Act and presents pilot case studies to assess the maturity level of raw material projects in view of secondary raw material production
Accelerating circular economy solutions to achieve the 2030 agenda for sustainable development goals
Circular economy seems a vital enabler for sustainable use of natural resources which is also important for achieving the 2030 agenda for sustainable development goals. Therefore, a special session addressing issues of "sustainable solutions and remarkable practices in circular economy focusing materials downstream" was held at the 16th International Conference on Waste Management and Technology, where researchers and attendees worldwide were convened to share their experiences and visions. Presentations focusing on many key points such as new strategies, innovative technologies, management methods, and practical cases were discussed during the session. Accordingly, this article compiled all these distinctive presentations and gave insights into the pathway of circular economy towards the sustainable development goals. We summarized that the transition to circular economy can keep the value of resources and products at a high level and minimize waste production; the focus of governmental policies and plans with the involvement of public-private-partnership on 3Rs (reduce, reuse, and recycle) helps to improve the use of natural resources and take a step ahead to approach or achieve the sustainability
Site-specific dataset of mining and metallurgical residues for resource management
This geospatial dataset provides a compilation of findings from an evidence-based review of site-specific resource assessments of mining and metallurgical residues. Information pertaining to location, target material, geological knowledge, extractability, resource classification and stakeholder perspectives was collected from publicly available reports, articles, academic theses, and databases. The dataset includes 44 relevant data attributes from 64 mining and metallurgical sites in 27 countries. Resource classification is available for 38 sites. The dataset can be used by evaluators of recovery projects, authorities that provide permits, as well as by decision makers in support of developing regulatory policies. The dataset facilitates future addition of sites by the research community and can be further used as a starting point to bridge the estimates on recoverable quantities to the United Nations Framework Classification (UNFC). The UNFC is a universally applicable scheme for the sustainable management of all energy, primary and secondary mineral resources. Its use is stimulated by the European Commission and is intended to be adopted by geological surveys to harmonize the data on the availability of primary and secondary raw materials in Europe in future
The faint young Sun problem
For more than four decades, scientists have been trying to find an answer to
one of the most fundamental questions in paleoclimatology, the `faint young Sun
problem'. For the early Earth, models of stellar evolution predict a solar
energy input to the climate system which is about 25% lower than today. This
would result in a completely frozen world over the first two billion years in
the history of our planet, if all other parameters controlling Earth's climate
had been the same. Yet there is ample evidence for the presence of liquid
surface water and even life in the Archean (3.8 to 2.5 billion years before
present), so some effect (or effects) must have been compensating for the faint
young Sun. A wide range of possible solutions have been suggested and explored
during the last four decades, with most studies focusing on higher
concentrations of atmospheric greenhouse gases like carbon dioxide, methane or
ammonia. All of these solutions present considerable difficulties, however, so
the faint young Sun problem cannot be regarded as solved. Here I review
research on the subject, including the latest suggestions for solutions of the
faint young Sun problem and recent geochemical constraints on the composition
of Earth's early atmosphere. Furthermore, I will outline the most promising
directions for future research. In particular I would argue that both improved
geochemical constraints on the state of the Archean climate system and
numerical experiments with state-of-the-art climate models are required to
finally assess what kept the oceans on the Archean Earth from freezing over
completely.Comment: 32 pages, 8 figures. Invited review paper accepted for publication in
Reviews of Geophysic
Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at TeV
The elliptic, , triangular, , and quadrangular, , azimuthal
anisotropic flow coefficients are measured for unidentified charged particles,
pions and (anti-)protons in Pb-Pb collisions at TeV
with the ALICE detector at the Large Hadron Collider. Results obtained with the
event plane and four-particle cumulant methods are reported for the
pseudo-rapidity range at different collision centralities and as a
function of transverse momentum, , out to GeV/.
The observed non-zero elliptic and triangular flow depends only weakly on
transverse momentum for GeV/. The small dependence
of the difference between elliptic flow results obtained from the event plane
and four-particle cumulant methods suggests a common origin of flow
fluctuations up to GeV/. The magnitude of the (anti-)proton
elliptic and triangular flow is larger than that of pions out to at least
GeV/ indicating that the particle type dependence persists out
to high .Comment: 16 pages, 5 captioned figures, authors from page 11, published
version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/186
Centrality dependence of charged particle production at large transverse momentum in Pb-Pb collisions at TeV
The inclusive transverse momentum () distributions of primary
charged particles are measured in the pseudo-rapidity range as a
function of event centrality in Pb-Pb collisions at
TeV with ALICE at the LHC. The data are presented in the range
GeV/ for nine centrality intervals from 70-80% to 0-5%.
The Pb-Pb spectra are presented in terms of the nuclear modification factor
using a pp reference spectrum measured at the same collision
energy. We observe that the suppression of high- particles strongly
depends on event centrality. In central collisions (0-5%) the yield is most
suppressed with at -7 GeV/. Above
GeV/, there is a significant rise in the nuclear modification
factor, which reaches for GeV/. In
peripheral collisions (70-80%), the suppression is weaker with almost independently of . The measured nuclear
modification factors are compared to other measurements and model calculations.Comment: 17 pages, 4 captioned figures, 2 tables, authors from page 12,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/284
Effective Rheology of Bubbles Moving in a Capillary Tube
We calculate the average volumetric flux versus pressure drop of bubbles
moving in a single capillary tube with varying diameter, finding a square-root
relation from mapping the flow equations onto that of a driven overdamped
pendulum. The calculation is based on a derivation of the equation of motion of
a bubble train from considering the capillary forces and the entropy production
associated with the viscous flow. We also calculate the configurational
probability of the positions of the bubbles.Comment: 4 pages, 1 figur
Charge separation relative to the reaction plane in Pb-Pb collisions at TeV
Measurements of charge dependent azimuthal correlations with the ALICE
detector at the LHC are reported for Pb-Pb collisions at TeV. Two- and three-particle charge-dependent azimuthal correlations in
the pseudo-rapidity range are presented as a function of the
collision centrality, particle separation in pseudo-rapidity, and transverse
momentum. A clear signal compatible with a charge-dependent separation relative
to the reaction plane is observed, which shows little or no collision energy
dependence when compared to measurements at RHIC energies. This provides a new
insight for understanding the nature of the charge dependent azimuthal
correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published
version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286
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