387 research outputs found
Microbial community in a biofilter traeting odours from an organic recovery plant for municipal solid waste treatment
Microbial community in a biofilter treatingodours from a valorization center for municipal solid waste treatment (MSW)
Isolation and identification of microbial populations from an odour treating biofilter
Complex odour emissions are normally associated to the operation of wastewater
treatment plants, composting facilities and agro-industry activities. The most common
contaminants are hydrogen sulfide (H2S), organic reduced sulfur compounds (e.g.,CH3SH), and volatile organic compounds (VOCs). These compounds can be treated using biological air treatment systems, such as biofilters. Five different types of material, including pieces of wood and polymeric material, were collected from different locations of a biofilter treating odours at an organic waste treatment plant and subjected to microbiological characterization. Colony forming units (CFU/g) ranged from 107 to 108 CFU/g from each different material analyzed. The different materials showed high heterogeneity of microbial colonization, being the diversity higher in a heather based material. After random amplification of polymorphic DNA (RAPD) analysis, a total of 22 different isolates were identified by 16S rRNA sequencing analysis. Ten isolates demonstrated capacity to grow on solid sulphur oxidizing medium. Their capacity to
oxidize sulphur compounds in liquid medium is being further studied
Phase conversion in a weakly first-order quark-hadron transition
We investigate the process of phase conversion in a thermally-driven {\it
weakly} first-order quark-hadron transition. This scenario is physically
appealing even if the nature of this transition in equilibrium proves to be a
smooth crossover for vanishing baryonic chemical potential. We construct an
effective potential by combining the equation of state obtained within Lattice
QCD for the partonic sector with that of a gas of resonances in the hadronic
phase, and present numerical results on bubble profiles, nucleation rates and
time evolution, including the effects from reheating on the dynamics for
different expansion scenarios. Our findings confirm the standard picture of a
cosmological first-order transition, in which the process of phase conversion
is entirely dominated by nucleation, also in the case of a weakly first-order
transition. On the other hand, we show that, even for expansion rates much
lower than those expected in high-energy heavy ion collisions, nucleation is
very unlikely, indicating that the main mechanism of phase conversion is
spinodal decomposition. Our results are compared to those obtained for a
strongly first-order transition, as the one provided by the MIT bag model.Comment: 12 pages, 10 figures; v2: 1 reference added, minor modifications,
matches published versio
Pressure of massless hot scalar theory in the boundary effective theory framework
We use the boundary effective theory (BET) approach to thermal field theory
in order to calculate the pressure of a system of massless scalar fields with
quartic interaction. The method naturally separates the infrared physics, and
is essentially non-perturbative. To lowest order, the main ingredient is the
solution of the free Euler-Lagrange equation with non-trivial (time) boundary
conditions. We derive a resummed pressure, which is in good agreement with
recent calculations found in the literature, following a very direct and
compact procedure.Comment: 10 pages, 4 figure
Effective potential in the BET formalism
We calculate the one-loop effective potential at finite temperature for a
system of massless scalar fields with quartic interaction in
the framework of the boundary effective theory (BET) formalism. The calculation
relies on the solution of the classical equation of motion for the field, and
Gaussian fluctuations around it. Our result is non-perturbative and differs
from the standard one-loop effective potential for field values larger than
.Comment: 10 pages, 3 figure
Zero-mode analysis of quantum statistical physics
We present a unified formulation for quantum statistical physics based on the
representation of the density matrix as a functional integral. We identify the
stochastic variable of the effective statistical theory that we derive as a
boundary configuration and a zero mode relevant to the discussion of infrared
physics. We illustrate our formulation by computing the partition function of
an interacting one-dimensional quantum mechanical system at finite temperature
from the path-integral representation for the density matrix. The method of
calculation provides an alternative to the usual sum over periodic
trajectories: it sums over paths with coincident endpoints, and includes
non-vanishing boundary terms. An appropriately modified expansion into
Matsubara modes provides a natural separation of the zero-mode physics. This
feature may be useful in the treatment of infrared divergences that plague the
perturbative approach in thermal field theory.Comment: 9 pages, 5 figure
Cut hours, not people : no work, furlough, short hours and mental health during COVID-19 pandemic in the UK
The unprecedented shock to the UK economy inflicted by government measures to contain the Coronavirus (COVID-19) risked plunging millions of workers into unemployment as businesses were forced to close or scale back activity. To avoid that cliff edge, and the predictable damage to both workers mental health and to the viability of the closed down businesses, the government also introduced the Coronavirus Job Retention Scheme (CJRS) that allowed for the furloughing of workers. Even so the number of people claiming benefits as unemployed has soared above 2 million for the first time since 1996 and others have been working significantly reduced working hours. The first wave of Understanding Society COVID-19 Study provides an early opportunity to examine how far these changes in employment status, work hours and involvement in furlough job retention scheme are related to the likelihood of having mental health problems, measured by 12-item General Health Questionnaire. Our findings confirm that leaving paid work is significantly related to poorer mental health, even after controlling for the household income and other factors. In contrast having some paid work and/or some continued connection to a job is better for mental health than not having any work at all. Those who remain part-time employed before and during the COVID-19, those who are involved in furlough job retention scheme or transition from full-time to part-time employment are all found to have similar levels of mental health as those who continued to work full-time. The patterns are similar for men and women. Both short working hours and furlough job retention schemes can thus be seen to be effective protective factors against worsening mental health. However, the key issue is now how to move beyond the furlough scheme. A v-shaped bounce back is not on the horizon and many sectors will at most move into partial activity. So, the need to avoid a huge further leap in unemployment is just as vital with all the risk to mental health that that would entail. These findings point to the need to move towards sharing work around more equitably, including introducing a shorter working week for all ( except in those sectors under extreme pressure) in order to minimize the risk to mental health and well-being if those on furlough are now pushed into unemployment
Labour protests during the pandemic: The case of hospital and retail workers in 90 countries
With a novel methodology searching news events from world’s largest news agencies via the online GDELT project, this report documents protest of key workers against their working conditions during the COVID-19 pandemic in 90 countries
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