2,559 research outputs found
Estimation of Industrial Emissions during Pyrolysis and Combustion of Different Wastes Using Laboratory Data
In our lab, we have been studying the emissions of different pollutants during pyrolysis and combustion of wastes under different conditions for the last three decades. These studies have focused on the effect of temperature and presence of oxygen on the production of different pollutants. Waste decomposition has been studied in a horizontal laboratory scale reactor, but no estimate has been made of the actual emissions in a conventional thermal decomposition system. In the present study, emissions during these wastes’ thermal decomposition were estimated using Aspen HYSYS. In the simulation software, the waste composition (elemental analysis) was given as an input parameter, as well as the gas flow rate used as atmosphere during the decomposition. The emitted hydrocarbons measured in the laboratory were equated to the emission of a single compound (propylene). The simulation permitted calculating the percentage of oxygen in the emitted gas, and the pollutant emissions were then recalculated under standard conditions. The emission of dioxins and furans were estimated under different conditions of decomposition, and an adequate approximation of the waste decomposition in actual incineration systems could be obtained.Support for this work was provided by the CTQ2016-76608-R project from the Ministry of Economy, Industry and Competitiveness (Spain) and the UAUSTI18-06 grant from University of Alicante (Spain). Damià Palmer thanks IQS – Universitat Ramon Llull for its financial support
MPA network design based on graph network theory and emergent properties of larval dispersal
Despite the recognised effectiveness of networks of Marine Protected Areas
(MPAs) as a biodiversity conservation instrument, nowadays MPA network design
frequently disregards the importance of connectivity patterns. In the case of
sedentary marine populations, connectivity stems not only from the stochastic
nature of the physical environment that affects early-life stages dispersal,
but also from the spawning stock attributes that affect the reproductive output
(e.g., passive eggs and larvae) and its survivorship. Early-life stages are
virtually impossible to track in the ocean. Therefore, numerical ocean current
simulations coupled to egg and larval Lagrangian transport models remain the
most common approach for the assessment of marine larval connectivity. Inferred
larval connectivity may be different depending on the type of connectivity
considered; consequently, the prioritisation of sites for marine populations'
conservation might also differ. Here, we introduce a framework for evaluating
and designing MPA networks based on the identification of connectivity hotspots
using graph theoretic analysis. We use as a case of study a network of
open-access areas and MPAs, off Mallorca Island (Spain), and test its
effectiveness for the protection of the painted comber Serranus scriba. Outputs
from network analysis are used to: (1) identify critical areas for improving
overall larval connectivity; (2) assess the impact of species' biological
parameters in network connectivity; and (3) explore alternative MPA
configurations to improve average network connectivity. Results demonstrate the
potential of graph theory to identify non-trivial egg/larval dispersal patterns
and emerging collective properties of the MPA network which are relevant for
increasing protection efficiency.Comment: 8 figures, 3 tables, 1 Supplementary material (including 4 table; 3
figures and supplementary methods
New Models Used to Determine the Dioxins Total Amount and Toxicity (TEQ) in Atmospheric Emissions from Thermal Processes
In order to reduce the calculation effort during the simulation of the emission of polychlorinated dibenzo-p-dioxins and furans (PCDD/F) during municipal solid waste incineration, minimizing the number of simulated components is mandatory. For this purpose, two new multilinear regression models capable of determining the dioxins total amount and toxicity of an atmospheric emission have been adjusted based on previously published ones. The new source of data used (almost 200 PCDD/F analyses) provides a wider range of application to the models, increasing also the diversity of the emission sources, from industrial and laboratory scale thermal processes. Only three of the 17 toxic congeners (1,2,3,6,7,8-HxCDD, 2,3,7,8-TCDF and OCDF), whose formation was found to be linearly independent, were necessary as inputs for the models. All model parameters have been statistically validated and their confidence intervals have been calculated using the Bootstrap method. The resulting coefficients of determination (R2) for the models are 0.9711 ± 0.0056 and 0.9583 ± 0.0085; its root mean square errors (RMSE) are 0.2115 and 0.2424, and its mean absolute errors (MAE) are 0.1541 and 0.1733 respectively.Juan A. Conesa and Nuria Ortuño acknowledge the support for this work by the CTQ2016-76608-R project from the Ministry of Economy, Industry and Competitiveness (Spain). Damià Palmer thanks IQS—Universitat Ramon Llull for its financial support
Quenched complexity of the p-spin spherical spin-glass with external magnetic field
We consider the p-spin spherical spin-glass model in the presence of an
external magnetic field as a general example of a mean-field system where a one
step replica symmetry breaking (1-RSB) occurs. In this context we compute the
complexity of the Thouless-Anderson-Palmer states, performing a quenched
computation. We find what is the general connection between this method and the
standard static 1-RSB one, formulating a clear mapping between the parameters
used in the two different calculations. We also perform a dynamical analysis of
the model, by which we confirm the validity of our results.Comment: RevTeX, 11 pages, including 2 EPS figure
Measures of Similarity Between Objects Based on Qualitative Shape Descriptions
A computational approach for comparing qualitative shape descriptions
(QSDs) of objects within digital images is presented. First, the dissimilarity
of qualitative features of shape is measured: (i) intuitively using conceptual
neighbourhood diagrams; and (ii) mathematically using interval distances.
Then, a similarity measure between QSDs is defined and tested using
images of different categories of the MPEG-7-CE-Shape-1 library, images
of tiles used to build mosaics, and a collection of Clipart images. The
results obtained show the effectiveness of the similarity measure defined,
which is invariant to translations, rotations and scaling, and which implicitly
manages deformation of shape parts and incompleteness
Glassiness and constrained dynamics of a short-range non-disordered spin model
We study the low temperature dynamics of a two dimensional short-range spin
system with uniform ferromagnetic interactions, which displays glassiness at
low temperatures despite the absence of disorder or frustration. The model has
a dual description in terms of free defects subject to dynamical constraints,
and is an explicit realization of the ``hierarchically constrained dynamics''
scenario for glassy systems. We give a number of exact results for the statics
of the model, and study in detail the dynamical behaviour of one-time and
two-time quantities. We also consider the role played by the configurational
entropy, which can be computed exactly, in the relation between fluctuations
and response.Comment: 10 pages, 9 figures; minor changes, references adde
Status of Muon Collider Research and Development and Future Plans
The status of the research on muon colliders is discussed and plans are
outlined for future theoretical and experimental studies. Besides continued
work on the parameters of a 3-4 and 0.5 TeV center-of-mass (CoM) energy
collider, many studies are now concentrating on a machine near 0.1 TeV (CoM)
that could be a factory for the s-channel production of Higgs particles. We
discuss the research on the various components in such muon colliders, starting
from the proton accelerator needed to generate pions from a heavy-Z target and
proceeding through the phase rotation and decay ()
channel, muon cooling, acceleration, storage in a collider ring and the
collider detector. We also present theoretical and experimental R & D plans for
the next several years that should lead to a better understanding of the design
and feasibility issues for all of the components. This report is an update of
the progress on the R & D since the Feasibility Study of Muon Colliders
presented at the Snowmass'96 Workshop [R. B. Palmer, A. Sessler and A.
Tollestrup, Proceedings of the 1996 DPF/DPB Summer Study on High-Energy Physics
(Stanford Linear Accelerator Center, Menlo Park, CA, 1997)].Comment: 95 pages, 75 figures. Submitted to Physical Review Special Topics,
Accelerators and Beam
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Phenotypic heterogeneity and genetic modification of P102L inherited prion disease in an international series
The largest kindred with inherited prion disease P102L, historically Gerstmann-Sträussler-Scheinker syndrome, originates from central England, with émigrés now resident in various parts of the English-speaking world. We have collected data from 84 patients in the large UK kindred and numerous small unrelated pedigrees to investigate phenotypic heterogeneity and modifying factors. This collection represents by far the largest series of P102L patients so far reported. Microsatellite and genealogical analyses of eight separate European kindreds support multiple distinct mutational events at a cytosine-phosphate diester-guanidine dinucleotide mutation hot spot. All of the smaller P102L kindreds were linked to polymorphic human prion protein gene codon 129M and were not connected by genealogy or microsatellite haplotype background to the large kindred or each other. While many present with classical Gerstmann-Sträussler-Scheinker syndrome, a slowly progressive cerebellar ataxia with later onset cognitive impairment, there is remarkable heterogeneity. A subset of patients present with prominent cognitive and psychiatric features and some have met diagnostic criteria for sporadic Creutzfeldt-Jakob disease. We show that polymorphic human prion protein gene codon 129 modifies age at onset: the earliest eight clinical onsets were all MM homozygotes and overall age at onset was 7 years earlier for MM compared with MV heterozygotes (P = 0.02). Unexpectedly, apolipoprotein E4 carriers have a delayed age of onset by 10 years (P = 0.02). We found a preponderance of female patients compared with males (54 females versus 30 males, P = 0.01), which probably relates to ascertainment bias. However, these modifiers had no impact on a semi-quantitative pathological phenotype in 10 autopsied patients. These data allow an appreciation of the range of clinical phenotype, modern imaging and molecular investigation and should inform genetic counselling of at-risk individuals, with the identification of two genetic modifiers
Systematic review and metaanalysis of genetic association studies of urinary symptoms and prolapse in women
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