A numerical model for the fractional condensation of pyrolysis vapours

Experimentation on the fast pyrolysis process has been primarily focused on the pyrolysis reactor itself, with less emphasis given to the liquid collection system (LCS). More importantly, the physics behind the vapour condensation process in LCSs has not been thoroughly researched mainly due to the complexity of the phenomena involved. The present work focusses on providing detailed information of the condensation process within the LCS, which consists of a water cooled indirect contact condenser. In an effort to understand the mass transfer phenomena within the LCS, a numerical simulation was performed using the Eulerian approach. A multiphase multi-component model, with the condensable vapours and non-condensable gases as the gaseous phase and the condensed bio-oil as the liquid phase, has been created. Species transport modelling has been used to capture the detailed physical phenomena of 11 major compounds present in the pyrolysis vapours. The development of the condensation model relies on the saturation pressures of the individual compounds based on the corresponding states correlations and assuming that the pyrolysis vapours form an ideal mixture. After the numerical analysis, results showed that different species condense at different times and at different rates. In this simulation, acidic components like acetic acid and formic acids were not condensed as it was also evident in experimental works, were the pH value of the condensed oil is higher than subsequent stages. In the future, the current computational model can provide significant aid in the design and optimization of different types of LCSs

Response to “Comment on ‘Elasticity of flexible and semiflexible polymers with extensible bonds in the Gibbs and Helmholtz ensembles”’ [J. Chem. Phys. 138, 157101 (2013)]

No abstract: this is a "response" to a Comment

Monte Carlo simulations of single polymer force-extension relations

We present Monte Carlo simulations for studying the statistical mechanics of arbitrarily long single molecules under stretching. In many cases in which the thermodynamic limit is not satisfied, different statistical ensembles yield different macroscopic force-displacement curves. In this work we provide a description of the Monte Carlo simulations and discuss in details the assumptions adopted

An assessment of Li abundances in weak-lined and classical T Tauri stars of the Taurus-Auriga association

Accurate measurements of lithium abundances in young low-mass stars provide an independent and reliable age diagnostics. Previous studies of nearby star forming regions have identified significant numbers of Li-depleted stars,often at levels inconsistent with the ages indicated by their luminosity. We aim at a new and accurate analysis of Li abundances in a sample of ~100 pre-main sequence stars in Taurus-Auriga using a homogeneous and updated set of stellar parameters and model atmospheres appropriate for the spectral types of the sample stars.We compute Li abundances using published values of the equivalent widths of the Li 6708 A doublet obtained from medium/high resolution spectra. We find that the number of significantly Li-depleted stars in Taurus-Auriga is greatly reduced with respect to earlier results. Only 13 stars have abundances lower than the interstellar value by a factor of 5 or greater. All of them are weak-lined T Tauri stars drawn from X-ray surveys; with the exception of four stars located near the L1551 and L1489 dark clouds, all the Li-depleted stars belong to the class of dispersed low-mass stars, distributed around the main sites of current star formation. If located at the distance of Taurus-Auriga, the stellar ages implied by the derived Li abundances are in the range 3-30 Myr, greater than the bulk of the Li-rich population with implication on the star formation history of the region. In order to derive firm conclusions about the fraction of Li-depleted stars of Taurus-Auriga, Li measurements of the remaining members of the association should be obtained, in particular of the group of stars that fall in the Li-burning region of the HR diagram.Comment: Accepted for publication in Astronomy & Astrophysics. 20 pages, 5 figure

Diurnal patterns of energy intake derived via principal component analysis and their relationship with adiposity measures in adolescents. Results from the National Diet and Nutrition Survey RP (2008–2012)

Mounting evidence points towards the existence of an association between energy intake in the evening and an increased prevalence and risk of being overweight and of obesity. The present study aimed to describe diurnal eating patterns (DEP) in a nationally representative sample of UK adolescents and to relate the derived DEP to anthropometrical measures. Data from four-day food records of adolescents aged 11–18 years participating in the 2008–2012 UK National Diet and Nutrition Survey Rolling Programme (NDNS RP) was utilised. The DEP were derived using a principal component analysis on the correlation matrix. Three orthogonal diurnal patterns were interpretable as (i) a linear contrast (8% of total system variation) between breakfast and an earlier lunch vs. a later lunch, late dinner, and evening/night snack, renamed “phase shift” DEP; (ii) a linear contrast (6.0% of system variation) between midmorning snacks, late lunch, and early dinner vs. breakfast, early and late morning snacks, early lunch, midafternoon snacks, and late dinner, renamed “early eating and grazing” DEP; (iii) a linear contrast (6.0% of system variation) between late main meals vs. early main meals and night snacks which was renamed “early main meals and night snacks vs. late main meals” DEP. After the adjustment for confounders, every 1 unit increase in the “early main meals and night snacks vs. late main meals”’ DEP score was significantly associated with a 0.29 kg/m2 and 11.6 mm increase in Body Mass Index (BMI) and waist circumference, respectively. There were no significant associations with the other two main DEPs. In conclusion, adolescents who tended to eat large early main meals and night snacks rather than slightly later main meals without night snacks had higher BMI and waist circumference. Further research is required to explore the determinants of DEP and to explore the impact of the context of eating and socioecological factors in the development of specific DEP

Association between vitamin intake and respiratory complaints in adults from the UK National Diet and Nutrition Survey years 1–8

Objective: To examine the cross-sectional association between vitamins A, E, C and D from diet and supplements and the prevalence of respiratory complaints in a nationally representative sample of UK adults. Methods: Data from adult participants of the National Diet and Nutrition Survey Rolling Programme years 2008-2016 were used for the analysis. Logistic regression adapted for complex survey design was used to investigate the relationship between each vitamin intake in turn (exposure) and self-reported respiratory complaints (outcome), adjusting for relevant confounders. Results: Overall, respiratory complaints were found in 33 of the 6115 adult patients aged 19 years and above. After adjustment for potential confounders, a negative association was observed between the intake of vitamin A and E intake from diet and supplements and respiratory complaints. For vitamin D, intake from supplements, but not diet, was inversely significantly associated with respiratory complaints. No association between vitamin C and respiratory complaints was observed. Conclusion: In conclusion, intake of vitamin A and E from diet and supplements, and vitamin D from supplements, show strong evidence of association with lower self-reported prevalence of respiratory complaints in a nationally representative sample of UK adults

SiGMa: Simple Greedy Matching for Aligning Large Knowledge Bases

The Internet has enabled the creation of a growing number of large-scale knowledge bases in a variety of domains containing complementary information. Tools for automatically aligning these knowledge bases would make it possible to unify many sources of structured knowledge and answer complex queries. However, the efficient alignment of large-scale knowledge bases still poses a considerable challenge. Here, we present Simple Greedy Matching (SiGMa), a simple algorithm for aligning knowledge bases with millions of entities and facts. SiGMa is an iterative propagation algorithm which leverages both the structural information from the relationship graph as well as flexible similarity measures between entity properties in a greedy local search, thus making it scalable. Despite its greedy nature, our experiments indicate that SiGMa can efficiently match some of the world's largest knowledge bases with high precision. We provide additional experiments on benchmark datasets which demonstrate that SiGMa can outperform state-of-the-art approaches both in accuracy and efficiency.Comment: 10 pages + 2 pages appendix; 5 figures -- initial preprin

An Introduction to Community Detection in Multi-layered Social Network

Social communities extraction and their dynamics are one of the most important problems in today's social network analysis. During last few years, many researchers have proposed their own methods for group discovery in social networks. However, almost none of them have noticed that modern social networks are much more complex than few years ago. Due to vast amount of different data about various user activities available in IT systems, it is possible to distinguish the new class of social networks called multi-layered social network. For that reason, the new approach to community detection in the multi-layered social network, which utilizes multi-layered edge clustering coefficient is proposed in the paper.Comment: M.D. Lytras et al. (Eds.): WSKS 2011, CCIS 278, pp. 185-190, 201

Local modularity measure for network clusterizations

Many complex networks have an underlying modular structure, i.e., structural subunits (communities or clusters) characterized by highly interconnected nodes. The modularity $Q$ has been introduced as a measure to assess the quality of clusterizations. $Q$ has a global view, while in many real-world networks clusters are linked mainly \emph{locally} among each other (\emph{local cluster-connectivity}). Here, we introduce a new measure, localized modularity $LQ$, which reflects local cluster structure. Optimization of $Q$ and $LQ$ on the clusterization of two biological networks shows that the localized modularity identifies more cohesive clusters, yielding a complementary view of higher granularity.Comment: 5 pages, 4 figures, RevTex4; Changed conten