Enhanced mechanical, thermal and flame retardant properties by combining graphene nanosheets and metal hydroxide nanorods for Acrylonitrile–Butadiene–Styrene copolymer composite

Three metal hydroxide nanorods (MHR) with uniform diameters were synthesized, and then combined with graphene nanosheets (GNS) to prepare acrylonitrile–butadiene–styrene (ABS) copolymer composites. An excellent dispersion of exfoliated two-dimensional (2-D) GNS and 1-D MHR in the ABS matrix was achieved. The effects of combined GNS and MHR on the mechanical, thermal and flame retardant properties of the ABS composites were investigated. With the addition of 2 wt% GNS and 4 wt% Co(OH)2, the tensile strength, bending strength and storage modulus of the ABS composites were increased by 45.1%, 40.5% and 42.3% respectively. The ABS/GNS/Co(OH)2 ternary composite shows the lowest maximum weight loss rate and highest residue yield. Noticeable reduction in the flammability was achieved with the addition of GNS and Co(OH)2, due to the formation of more continuous and compact charred layers that retarded the mass and heat transfer between the flame and the polymer matrix

Semiparametric Two-Part Models with Proportionality Constraints: Analysis of the Multi-Ethnic Study of Atherosclerosis (MESA)

SUMMARY. In this article, we analyze the coronary artery calcium (CAC) score in the Multi-Ethnic Study of Atherosclerosis (MESA), where about half of the CAC scores are zero and the rest are continuously distributed. When the observed data has a mixture distribution, two-part models can be the natural choice. With a two-part model, there are two covariate effects, with one in each part of the model. Determination of whether the two covariate effects are proportional can provide more insights into the process underlying development and progression of CAC. In this study, we model the CAC score using a semiparametric two-part model, and investigate the determination of proportionality of the covariate effects. We propose penalized maximum likelihood estimation and using thin plate splines in practical data analysis, and establish asymptotic estimation properties. We propose a step-wise hypothesis testing based approach to determine proportionality. Simulation studies suggest satisfactory finite-sample performance of the proposed approach. Analysis of the MESA data suggests that proportionality holds for all covariates except the LDL and HDL

A novel pattern recognition algorithm: Combining ART network with SVM to reconstruct a multi-class classifier

AbstractBased on the principle of one-against-one support vector machines (SVMs) multi-class classification algorithm, this paper proposes an extended SVMs method which couples adaptive resonance theory (ART) network to reconstruct a multi-class classifier. Different coupling strategies to reconstruct a multi-class classifier from binary SVM classifiers are compared with application to fault diagnosis of transmission line. Majority voting, a mixture matrix and self-organizing map (SOM) network are compared in reconstructing the global classification decision. In order to evaluate the method’s efficiency, one-against-all, decision directed acyclic graph (DDAG) and decision-tree (DT) algorithm based SVM are compared too. The comparison is done with simulations and the best method is validated with experimental data

Analyzing the Effects of Policy Options to Mitigate the Effect of Sea Level Rise on the Public Health and Medically Fragile Population: A System Dynamics Approach

A critical question related to climate change concerns to how rising sea level will affect underserved populations and medically fragile population in coastal zones and floodplains. As sea levels rise, coastal waters will regain near-tidal areas and co-mingle with human-made pollutants, resulting from decades of industrial and commercial activity. This poses potential threat and risks to public health and the environment. It is critical that decision makers will initiate a process of parsing resources to the mitigation and management of these issues. The purpose of this research is to model the inherent dynamics of this process and understand how near-term policy decisions will condition the dynamics of population health within traditionally underserved and medically fragile populations. We use a System Dynamics (SD) approach to model and simulate the sensitivity of affected populations to a range of remediation policy options intended to address these contaminated environments. Our research will assist policy makers to explore and prioritize policies with a specific focus on vulnerability, guarantee that remediation funds will be utilized effectively and equitably, and increase effectiveness of mitigation and management effort

Conversational ontology operator: Patient-centric vaccine dialogue management engine for spoken conversational agents

BACKGROUND: Previously, we introduced our Patient Health Information Dialogue Ontology (PHIDO) that manages the dialogue and contextual information of the session between an agent and a health consumer. In this study, we take the next step and introduce the Conversational Ontology Operator (COO), the software engine harnessing PHIDO. We also developed a question-answering subsystem called Frankenstein Ontology Question-Answering for User-centric Systems (FOQUS) to support the dialogue interaction. METHODS: We tested both the dialogue engine and the question-answering system using application-based competency questions and questions furnished from our previous Wizard of OZ simulation trials. RESULTS: Our results revealed that the dialogue engine is able to perform the core tasks of communicating health information and conversational flow. Inter-rater agreement and accuracy scores among four reviewers indicated perceived, acceptable responses to the questions asked by participants from the simulation studies, yet the composition of the responses was deemed mediocre by our evaluators. CONCLUSIONS: Overall, we present some preliminary evidence of a functioning ontology-based system to manage dialogue and consumer questions. Future plans for this work will involve deploying this system in a speech-enabled agent to assess its usage with potential health consumer users

Fast and slow shifts of the zonal-mean intertropical convergence zone in response to an idealized anthropogenic aerosol

Previous modeling work showed that aerosol can affect the position of the tropical rain belt, i.e., the intertropical convergence zone (ITCZ). Yet it remains unclear which aspects of the aerosol impact are robust across models, and which are not. Here we present simulations with seven comprehensive atmosphere models that study the fast and slow impacts of an idealized anthropogenic aerosol on the zonal-mean ITCZ position. The fast impact, which results from aerosol atmospheric heating and land cooling before sea-surface temperature (SST) has time to respond, causes a northward ITCZ shift. Yet the fast impact is compensated locally by decreased evaporation over the ocean, and a clear northward shift is only found for an unrealistically large aerosol forcing. The local compensation implies that while models differ in atmospheric aerosol heating, this does not contribute to model differences in the ITCZ shift. The slow impact includes the aerosol impact on the ocean surface energy balance and is mediated by SST changes. The slow impact is an order of magnitude more effective than the fast impact and causes a clear southward ITCZ shift for realistic aerosol forcing. Models agree well on the slow ITCZ shift when perturbed with the same SST pattern. However, an energetic analysis suggests that the slow ITCZ shifts would be substantially more model-dependent in interactive-SST setups due to model differences in clear-sky radiative transfer and clouds. We also discuss implications for the representation of aerosol in climate models and attributions of recent observed ITCZ shifts to aerosol

Can the Youth Materialism Scale be used across different countries and cultures?

As global material wealth rises and young people are heavily exposed to advertising across a range of channels, including rapidly developing social media where material goods are flaunted as symbols of a happy and successful lifestyle, materialism levels across the world seem likely to rise. Given consistent research showing the correlation between materialism and low well-being, this gives cause for concern. However, no studies have so far tested whether current measures of youth materialism are generalizable across different countries and cultures. Our article fills this gap by exploring through a range of internal and external validity tests whether the popular Youth Materialism Scale (YMS) can be used with confidence across China, France, Belgium, Poland, the United Kingdom, and the United States. We show that a 5-item version of YMS is invariant across the countries (internal validity) and that it broadly correlates in expected ways with six different theoretically related constructs: Self-Esteem, Life Satisfaction, Attitude to Advertising, Parental Support, TV Use, and Internet Use (external validity). We believe that researchers and policy makers can confidently use this 5-item version of the scale in international contexts

Global Issues – Local Alternatives

After realising their theses’ topics were all related to environmental and human sustainability, a group of young researchers from the Erasmus Mundus International Masters in Global Markets, Local Creativities decided they could take action by sharing their research findings in an easily-understandable, non-academic language, impacting communities outside the academic bubble by making knowledge accessible.This book is the result of the ambition of this group of researchers to critically discuss the main issues of our times: environmental emergency and social inequality. Through a collection of thought-provoking case studies, the reader is invited to reflect upon global issues, from the perspective of local initiatives, considering three main aspects of globalisation: space, global dynamics and social scene, and the role of institutions

Alleged Lessepsian foraminifera prove native and suggest Pleistocene range expansions into the Mediterranean Sea

Biogeographical patterns are increasingly modified by the human-driven translocation of species, a process that accelerated several centuries ago. Observational datasets, however, rarely range back more than a few decades, implying that a large part of invasion histories went unobserved. Small-sized organisms, like benthic foraminifera, are more likely to have been reported only recently due to their lower detectability compared to larger-sized organisms. Recently detected native species of tropical affinity may have thus been mistaken for non-indigenous species due to the lack of evidence of their occurrence in pre-invasion records. To uncover the unobserved past of the Lessepsian invasion—the entrance of tropical species into the Mediterranean through the Suez Canal—we collected sediment cores on the southern Israeli shelf. We deployed state-of-the-art radiocarbon techniques to date 7 individual foraminiferal tests belonging to 5 alleged non-indigenous species and show that they are centuries to millennia old, thus native. Two additional species previously considered non-indigenous occurred in centennial to millennia-old sediments, suggesting their native status. The evidence of multiple tropical foraminiferal species supposed to be non-indigenous but proved native in the eastern Mediterranean suggests either survival in refugia during the Messinian Salinity Crisis (5.96−5.33 million years) or, more likely, dispersal from the tropical Atlantic and Indo-Pacific during the Pleistocene. In the interglacials of this epoch, higher sea levels may have allowed biological connectivity between the Mediterranean and the Red Sea for shallow-water species, showing that the Isthmus of Suez was possibly a more biologically porous barrier than previously considered

Incommensurate spin order in the metallic perovskite MnVO3

Incommensurate Mn spin order has been discovered in the perovskite MnVO3 containing localized 3d5 Mn2+ and itinerant 3d1 V4+ states. This phase has a distorted Pnma crystal structure (a = 5.2741(6) Å, b = 7.4100(11) Å, and c = 5.1184(8) Å at 300 K) and is metallic at temperatures of 2-300 K and at pressures of up to 67 kbar. Neutron scattering reveals a (0.29 0 0) magnetic vector below the 46 K spin ordering transition, and both helical and spin density wave orderings are consistent with the diffraction intensities. Electronic structure calculations show large exchange splittings of the Mn and V 3d bands, and (kx 0 0) crossings of the Fermi energy by spin up and down V 3d bands may give rise to Ruderman-Kittel-Kasuya-Yosida coupling of Mn moments, in addition to their superexchange interactions. © 2011 American Physical Society