1,289 research outputs found
Atmospheric Chemistry Modelling of Amine Emissions from Post Combustion CO2 Capture Technology
Emissions from post combustion CO2 capture plants using amine solvents are of concern due to their adverse impacts on the human health and environment. Potent carcinogens such as nitrosamines and nitramines resulting from the degradation of the amine emissions in the atmosphere have not been fully investigated. It is, therefore, imperative to determine the atmospheric fate of these amine emissions, such as their chemical transformation, deposition and transport pathways away from the emitting facility so as to perform essential risk assessments. More importantly, there is a lack of integration of amine atmospheric chemistry with dispersion studies. In this work, the atmospheric chemistry of the reference solvent for CO2 capture, monoethanolamine, and the most common degradation amines, methylamine and dimethylamine, formed as part of the post combustion capture process are considered along with dispersion calculations. Rate constants describing the atmospheric chemistry reactions of the amines of interest are obtained using theoretical quantum chemistry methods and kinetic modeling. The dispersion of these amines in the atmosphere is modeled using an air-dispersion model, ADMS 5. A worst case study on the UK's largest CO2 capture pilot plant, Ferrybridge, is carried out to estimate the maximum tolerable emissions of these amines into the atmosphere so that the calculated concentrations do not exceed guideline values and that the risk is acceptable
Joint Planck and WMAP Assessment of Low CMB Multipoles
The remarkable progress in cosmic microwave background (CMB) studies over
past decade has led to the era of precision cosmology in striking agreement
with the CDM model. However, the lack of power in the CMB temperature
anisotropies at large angular scales (low-), as has been confirmed by the
recent Planck data also (up to ), although statistically not very
strong (less than ), is still an open problem. One can avoid to seek
an explanation for this problem by attributing the lack of power to cosmic
variance orcan look for explanations i.e., different inflationary potentials or
initial conditions for infl ation to begin with, non-trivial topology, ISW
effect etc. Features in the primordial power spectrum (PPS) motivated by the
early universe physics has been the most common solution to address this
problem. In the present work we also follow this approach and consider a set of
PPS which have features and constrain the parameters of those using WMAP 9 year
and Planck data employing Markov-Chain Monte Carlo (MCMC) analysis. The
prominent feature of all the models of PPS that we consider is an infra-red cut
off which leads to suppression of power at large angular scales. We consider
models of PPS with maximum three extra parameters and use Akaike information
criterion () and Bayesian information criterion () of model and
Bayesian information criterion () of model selection to compare the
models. For most models, we find good constraints for the cut off scale ,
however, for other parameters our constraints are not that good. We find that
sharp cut off model gives best likelihood value for the WMAP 9 year data, but
is as good as power law model according to . For the joint WMAP 9+Planck
data set, Starobinsky model is slightly preferred by which is also able
to produce CMB power suppression up to to some extent.Comment: 27 pages, 10 figures, 3 tables, matches with the published version,
abstract is shortened to keep it within arXiv's limit (1920 characters
Energy Consumption Rate based Stable Election Protocol (ECRSEP) for WSNs
In recent few yearsWireless Sensor Networks (WSNs) have seen an increased
interest in various applications like border field security, disaster
management and medical applications. So large number of sensor nodes are
deployed for such applications, which can work autonomously. Due to small power
batteries in WSNs, efficient utilization of battery power is an important
factor. Clustering is an efficient technique to extend life time of sensor
networks by reducing the energy consumption. In this paper, we propose a new
protocol; Energy Consumption Rate based Stable Election Protocol (ECRSEP). Our
CH selection scheme is based on the weighted election probabilities of each
node according to the Energy Consumption Rate (ECR) of each node. We compare
results of our proposed protocol with Low Energy Adaptive Clustering Hierarchy
(LEACH), Distributed Energy Efficient Clustering (DEEC), Stable Election
Protocol (SEP), and Enhanced SEP(ESEP). Our simulation results show that our
proposed protocol, ECRSEP outperforms all these protocols in terms of network
stability and network lifetime
socialAWARE:mobile wireless sensing network
Abstract. This thesis presents a software tool for Android smartphones called socialAWARE, a mobile wireless sensing network. socialAWARE uses zeroconf networking to discover other mobile devices and their connection information on a local area network. It uses built-in mobile sensors to collect data and transmit it in real time using CoAPβs machine-to-machine protocol. SocialAWARE aims at helping users to quickly deploy a wireless sensor network without an emphasis in configuration or technical background.
socialAWARE is implemented as a plug-in for AWARE framework [1], which uses diverse protocols to enhance its capabilities. Together, socialAWARE plug-in and AWARE allows for data collection and real-time sharing of sensor data between different devices (LAMP server, smartwatch, Android, iOS). After the implementation of the plug-in, the performance of the protocols were evaluated by conducting several experiments. We also compare CoAP with MQTT with respect to their technical performance in terms of latency, throughput, and network usage. Based on the experimental results, we discuss the advantages and limitations of the system. Finally, we conclude this thesis by discussing a number of improvements for future iterations of socialAWARE, based on the literature survey and experiment results
An agent-based model for integrated emotion regulation and contagion in socially affected decision making
This paper addresses an agent-based computational social agent model for the integration of emotion regulation, emotion contagion and decision making in a social context. The model integrates emotion-related valuing, in order to analyse the role of emotions in socially affected decision making. The agent-based model is illustrated for the interaction between two persons. Simulation experiments for different kinds of scenarios help to understand how decisions can be affected by regulating the emotions involved, and how these emotions are affected by emotion regulation and contagion
Excess entropy and energy feedback from within cluster cores up to r
We estimate the "non-gravitational" entropy-injection profiles, ,
and the resultant energy feedback profiles, , of the intracluster
medium for 17 clusters using their Planck SZ and ROSAT X-Ray observations,
spanning a large radial range from up to . The feedback
profiles are estimated by comparing the observed entropy, at fixed gas mass
shells, with theoretical entropy profiles predicted from non-radiative
hydrodynamic simulations. We include non-thermal pressure and gas clumping in
our analysis. The inclusion of non-thermal pressure and clumping results in
changing the estimates for and by 10\%-20\%. When
clumpiness is not considered it leads to an under-estimation of keV cm at and keV cm at
. On the other hand, neglecting non-thermal pressure results in an
over-estimation of keV cm at and
under-estimation of keV cm at . For the
estimated feedback energy, we find that ignoring clumping leads to an
under-estimation of energy per particle keV at and
keV at . Similarly, neglect of the non-thermal
pressure results in an over-estimation of keV at
and under-estimation of keV at . We find entropy
floor of keV cm is ruled out at
throughout the entire radial range and keV at more than
3 beyond , strongly constraining ICM pre-heating scenarios. We
also demonstrate robustness of results w.r.t sample selection, X-Ray analysis
procedures, entropy modeling etc.Comment: 17 pages, 15 figures, 5 tables, Accepted in MNRA
Little evidence for entropy and energy excess beyond - An end to ICM preheating?
Non-gravitational feedback affects the nature of the intra-cluster medium
(ICM). X-ray cooling of the ICM and in situ energy feedback from AGN's and SNe
as well as {\it preheating} of the gas at epochs preceding the formation of
clusters are proposed mechanisms for such feedback. While cooling and AGN
feedbacks are dominant in cluster cores, the signatures of a preheated ICM are
expected to be present even at large radii. To estimate the degree of
preheating, with minimum confusion from AGN feedback/cooling, we study the
excess entropy and non-gravitational energy profiles upto for a
sample of 17 galaxy clusters using joint data sets of {\it Planck} SZ pressure
and {\it ROSAT/PSPC} gas density profiles. The canonical value of preheating
entropy floor of keV cm, needed in order to match cluster
scalings, is ruled out at . We also show that the feedback
energy of 1 keV/particle is ruled out at 5.2 beyond . Our
analysis takes both non-thermal pressure and clumping into account which can be
important in outer regions. Our results based on the direct probe of the ICM in
the outermost regions do not support any significant preheating.Comment: 6 pages, 4 figures, 1 table, Accepted in MNRAS Letter
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