1,553 research outputs found
The comprehensive environmental management model in post-Covid19 era
To restrict the adverse impact of Green House Gas there is a need of rapid action for transformation of the current situation to achieve the targets mentioned by the United Nations Programme. The coronavirus crisis generated additional challenges but also generated a provision for companies to develop a sustainable model in the recovery period by incorporating the non-financial aspect of green environment in their business model. In this paper, we identify some of the main problems of the existing projects related to Green House Gas control and propose the Dragon Value System with a potentiality of overcoming the drawbacks of the existing models. We find a comprehensive environmental management model that will be opportunity driven, based on certain financial assets associated with wide spectrum of stakeholders and applicable by company of any size. The findings of the paper will contribute to the academic literature related to environmental management and SDG 7. The proposed model will assist the investors to identify a comprehensive model to invest and could generate new public-private partnership to apply highly beneficial and comprehensive environmental management model
Robustness of a bisimulation-type faster-than preorder
TACS is an extension of CCS where upper time bounds for delays can be
specified. Luettgen and Vogler defined three variants of bismulation-type
faster-than relations and showed that they all three lead to the same preorder,
demonstrating the robustness of their approach. In the present paper, the
operational semantics of TACS is extended; it is shown that two of the variants
still give the same preorder as before, underlining robustness. An explanation
is given why this result fails for the third variant. It is also shown that
another variant, which mixes old and new operational semantics, can lead to
smaller relations that prove the same preorder.Comment: Express Worksho
Blown-up p-Branes and the Cosmological Constant
We consider a blown-up 3-brane, with the resulting geometry R^(3,1) \times
S^(N-1), in an infinite-volume bulk with N > 2 extra dimensions. The action on
the brane includes both an Einstein term and a cosmological constant. Similar
setups have been proposed both to reproduce 4-d gravity on the brane, and to
solve the cosmological constant problem. Here we obtain a singularity-free
solution to Einstein's equations everywhere in the bulk and on the brane, which
allows us to address these question explicitely. One finds, however, that the
proper volume of S^(N-1) and the cosmological constant on the brane have to be
fine-tuned relatively to each other, thus the cosmological constant problem is
not solved. Moreover the scalar propagator on the brane behaves 4-dimensionally
over a phenomenologically acceptable range only if the warp factor on the brane
is huge, which aggravates the Weak Scale - Planck Scale hierarchy problem.Comment: 21 pages, no figure
Insights into rapid explosive volcanic processes from ground- and space-based intraday SO2 flux measurements
Observations of volcanic degassing yield insights into the sub-surface magmatic processes which control volcanic activity during both quiescent and eruptive phases. By combining information on volcanic gas flux with constraints on original dissolved volatile contents the volume of degassing magma can be determined. Comparisons between the volume of degassing magma, erupted volume, and ground deformation allow mass balance calculations to be performed, providing insight into the shallow volcanic plumbing system dynamics. For these reasons there is great interest in improving the quality and frequency of volcanic gas flux measurements.
Ultraviolet and infrared remote sensing techniques allow determination of SO2 column amounts within volcanic plumes. By calculating SO2 column amounts in a profile orthogonal to the plume-wind direction and multiplying the integrated SO2 cross section by the wind speed the SO2 emission rate can be retrieved. There are currently three main approaches for determining volcanic SO2 fluxes; (i) ground-based mini-DOAS systems, (ii) ground-based SO2 imaging cameras, and (iii) satellite-based infrared and ultraviolet imaging.
Here we examine SO2 fluxes obtained by the Flux Automatic Measurement (FLAME) network of scanning mini-DOAS instruments installed at Mt. Etna and by the MODIS instrument aboard the NASA EOS satellite AQUA during the 2006 eruption of Mt. Etna, Sicily, Italy. Mt. Etna produced a highly variable eruptive activity from the South-East crater, characterised by explosive sequences, which could be either ash-rich or ash-poor, lava effusion, partial flank collapse and periods of quiescence. We examined intraday variations in SO2 flux measured with FLAME and MODIS during both ash-rich and ash-poor explosive phases. In general, good agreement was found between the datasets. Of particular interest was the successful recalculation and validation of temporal variations in SO2 flux recorded in a single image from MODIS. By examining the temporal evolution of gas emissions our results provide insight in the eruption mechanism driving the explosive activity
Eruption column height estimation of the 2011-2013 Etna lava fountains
In this paper, we use calibrated images collected by the video-surveillance
system of the Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio
Etneo, to retrieve the height of the eruption column during the recent
Etna explosive activity. The analysis is carried out on nineteen lava fountains
from the New South East Crater dataset. The novel procedure described
in this work is achieved in three main steps: at first we calibrated
the camera, then we selected the images which recorded the maximum
phase of the eruptive activity, and finally we applied an appropriate correction
to account for the plume projection on the camera line of sight due
to the wind. The results show that the column altitudes range between 6
and 9 km (upper limit of the camera system). The comparison with the
plume height values estimated from the analysis of several SEVIRI and
MODIS satellite images, show a good agreement. Finally, for nine events
we also evaluated the thickness of the volcanic plumes in the umbrella region
which ranges between 2 and 3 km
Aspects of Quantum Gravity in Cosmology
We review some aspects of quantum gravity in the context of cosmology. In
particular, we focus on models with a phenomenology accessible to current and
near-future observations, as the early Universe might be our only chance to
peep through the quantum gravity realm.Comment: 15 pages, 1 figure. Invited review for Modern Physics Letter A.
Version 2: minor typos corrected, few references adde
Multi annual comparisons of summer and under ice phytoplankton communities of a mountain lake
Little is known on the dynamics of under-ice phytoplankton communities. We investigated phytoplankton communities in the upper (0-20 m) and lower (30-35 m) layer of oligotrophic Lake Tovel, Brenta Dolomites (Italy) over six years during summer and under ice. Winter conditions were different from one year to another with respect to ice thickness and snow cover. Proxies for light transmission (Secchi disk transparency, light attenuation) were similar between seasons, even though the incident solar radiation was lower in winter. Algal richness and chlorophyll-a were not different between seasons while biomass was higher during summer. In four of the six years, Bacillariophyta dominated during summer and Miozoa (class Dinophyceae) under ice while in two years Bacillariophyta also dominated under ice. Generally, a shift to larger size classes from summer to under ice was observed for Bacillariophyta, Chlorophyta, and Ochrophyta (class Chrysophyceae) while Dinophyceae showed the opposite pattern. No strong links between phytoplankton community composition and abiotic factors (under-ice convective mixing, snow on ice, under-ice light) were found. We suggest that inter-species relationships and more precise indicators of under-ice light should be considered to better understand under-ice processes
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