2,219 research outputs found
Modelling and Multi-stage Design of Membrane Processes Applied to Carbon Capture in Coal-fired Power Plants
AbstractAccording to recent predictions, energy generation from coal will continue to play a key role in the next decades. The UK 2008 Climate Change Act requires a reduction of 80% of greenhouse gases emissions by 2050, and carbon capture and storage will have a key role in order to meet this target.This work focuses on post-combustion capture from coal-fired power plants based on membrane separation. Adetailed multi-stage design is presented: the developed flowsheet includes cross-flow and countercurrent-sweep stages. The cross-flow stages are based on a 2D model implemented by our research group able to predict the separation through spiral-wound permeators. Different process configurations are analysed, with the aim of reducing both energy consumption and membrane area.An economic analysis is also included: both capture and avoidance costs are evaluated. The estimated values are compared with data available in the literature for processes based on amine capture technology
The Factors Involved in the Exit from Sex Trafficking: A Review
Sexual trafficking and exploitation are a worldwide phenomenon affecting a huge number of women. Many studies have examined the process of sex trafficking entering, but less have analyzed the exit process. The aim of this review is to provide an overview of factors that intervene on the sex trafficking exit, starting from the most common theoretical models in literature. We used the Sociological Abstract and Scopus database to identify articles; further relevant studies have been identified with the snowballing method. We focused on empirical studies, the exit factors, and studies based on victims’ point of view. There was no limitation for sample’s nationality, gender of trafficked people or age of victims, or timing. We included 13 empirical studies (9 qualitative, 3 quantitative, and 1 mixed method). The review revealed several factors that intervene in the exit process at the individual, relational, and structural level. For each level, facilitating, hindering, and controversial factors have been identified. Results show the complexity of the process of exiting sex trafficking; 4 ambivalent factors were identified, 7 hindering, and 21 facilitators. The review operationally suggests which factors are to be strengthened (like the social capital) to facilitate the emancipation of women from trafficking, which ones should be limited (as the stigma of women who have come out of prostitution) for the social inclusion of people, and which ones should be studied in more detail (for example, the role of families) because they are sometimes facilitators and barriers to the exit of sexual exploitation. The limitations of this study include that it only includes English studies, there is little coherence in defining sex trafficking among the scientific community, and secondary information (type of exploitation, destination of trafficking) is not present in the selected articles that complicate the exhaustive interpretation of the results
Abell 2384: the galaxy population of a cluster post-merger
We combine multi-object spectroscopy from the 2dF and EFOSC2 spectrographs
with optical imaging of the inner 30'x30' of A2384 taken with the ESO Wide
Field Imager. We carry out a kinematical analysis using the EMMIX algorithm and
biweight statistics. We address the possible presence of cluster substructures
with the Dressler-Shectman test. Cluster galaxies are investigated with respect
to [OII] and H{\alpha} equivalent width. Galaxies covered by our optical
imaging observations are additionally analysed in terms of colour, star
formation rate and morphological descriptors such as Gini coefficient and M20
index. We study cluster galaxy properties as a function of clustercentric
distance and investigate the distribution of various galaxy types in
colour-magnitude and physical space. The Dressler-Shectman test reveals a
substructure in the east of the 2dF field-of-view. We determine the mass ratio
between the northern and southern subcluster to be 1.6:1. In accordance with
other cluster studies, we find that a large fraction of the disk galaxies close
to the cluster core show no detectable star formation. Probably these are
systems which are quenched due to ram-pressure stripping. The sample of
quenched disks populates the transition area between the blue cloud and the red
sequence in colour-magnitude space. We also find a population of
morphologically distorted galaxies in the central cluster region. The
substructure in the east of A2384 might be a group of galaxies falling onto the
main cluster. We speculate that our sample of quenched spirals represents an
intermediate phase in the ram-pressure driven transformation of infalling field
spirals into cluster S0s. This is motivated by their position in
colour-magnitude space. The occurrence of morphologically distorted galaxies in
the cluster core complies with the hypothesis of A2384 representing a post
merger system.Comment: 14 pages, 18 figures, A&A accepte
Filaments of the radio cosmic web: opportunities and challenges for SKA
The detection of the diffuse gas component of the cosmic web remains a
formidable challenge. In this work we study synchrotron emission from the
cosmic web with simulated SKA1 observations, which can represent an fundamental
probe of the warm-hot intergalactic medium. We investigate radio emission
originated by relativistic electrons accelerated by shocks surrounding cosmic
filaments, assuming diffusive shock acceleration and as a function of the
(unknown) large-scale magnetic fields. The detection of the brightest parts of
large () filaments of the cosmic web should be within reach of the
SKA1-LOW, if the magnetic field is at the level of a percent
equipartition with the thermal gas, corresponding to for the
most massive filaments in simulations. In the course of a 2-years survey with
SKA1-LOW, this will enable a first detection of the "tip of the iceberg" of the
radio cosmic web, and allow for the use of the SKA as a powerful tool to study
the origin of cosmic magnetism in large-scale structures. On the other hand,
the SKA1-MID and SKA1-SUR seem less suited for this science case at low
redshift (), owing to the missing short baselines and the
consequent lack of signal from the large-scale brightness fluctuations
associated with the filaments. In this case only very long exposures ( hr) may enable the detection of filament for field of view in
the SKA1-SUR PAF Band1.Comment: 10 pages, 4 figures, to appear in Proceedings of 'Advancing
Astrophysics with the SKA (AASKA14) - Cosmic Magnetism' Chapter
Development of a Solar-reflective Ceramic Tile Ready for Industrialization
Solar-reflective surfaces represent an effective countermeasure to UHI. The market of "cool" materials is dominated by polymeric solutions which, under UV exposure, are damaged. On the other hand, an increasing attention was paid recently to ceramic-based solar-reflective surfaces, characterized by very long lifespan. A ceramic tile is typically made by a three layers structure: substrate-engobe-glaze. This structure has been exploited to develop a cool ceramic tile that can be produced in the same production facilities of common products to create a whole tile by merging technological results and industrial production needs, to achieve a compromise between performance and costs
Efficient Simulation and Acceleration of Convergence for a Dual Piston Pressure Swing Adsorption System
A staged screening of registered drugs highlights remyelinating drug candidates for clinical trials
There is no treatment for the myelin loss in multiple sclerosis, ultimately resulting in the axonal degeneration that leads to the progressive phase of the disease. We established a multi-tiered platform for the sequential screening of drugs that could be repurposed as remyelinating agents. We screened a library of 2,000 compounds (mainly Food and Drug Administration (FDA)-approved compounds and natural products) for cellular metabolic activity on mouse oligodendrocyte precursors (OPC), identifying 42 molecules with significant stimulating effects. We then characterized the effects of these compounds on OPC proliferation and differentiation in mouse glial cultures, and on myelination and remyelination in organotypic cultures. Three molecules, edaravone, 5-methyl-7-methoxyisoflavone and lovastatin, gave positive results in all screening tiers. We validated the results by retesting independent stocks of the compounds, analyzing their purity, and performing dose-response curves. To identify the chemical features that may be modified to enhance the compounds' activity, we tested chemical analogs and identified, for edaravone, the functional groups that may be essential for its activity. Among the selected remyelinating candidates, edaravone appears to be of strong interest, also considering that this drug has been approved as a neuroprotective agent for acute ischemic stroke and amyotrophic lateral sclerosis in Japan
The EMMA Experience. Emerging Patterns and Factors for Success
Since 2008, when the first experiment with MOOCs took place, much has been said, written and explored.
However, almost ten years later we are unable to say whether MOOCs are really a desirable learning
experience and, moreover, what are the factors for success in the MOOC environment. Literature in the
field seems to clearly endorse learner engagement and participation as activities that ensure a higher
completion rate and a satisfying learning experience, yet a high degree of dropout can be attributed to a
request for participation which learners find unsustainable. On many MOOC projects, the data opens
opportunities for discussion but provides few answers, as so much depends on individual variables of the
specific course. Far from being a limit of the research, this uncertainty is the only way to preserve learning
from becoming a hostage of algorithms, thus leaving teachers and learners the freedom to plan, decide, and
experience, and to evaluate their teaching and learning
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