Dual Fire Retardant Action: The Combined Gas and Condensed Phase Effects of Azo-Modified NiZnAl Layered Double Hydroxide on Intumescent Polypropylene

Ternary nickel-substituted layered double hydroxide (C-LDH) was synthesized. It was intercalated with azobenzene-4,4'-dicarboxylic acid, using an ion exchange method to obtain organically modified NiZnAl-LDH (O-LDH). Both LDHs were melt-blended into polypropylene (PP) with intumescent fire retardant (IFR). The structure, morphology, thermal stability and combustible properties of intercalated LDH and its hybrid composite have been comprehensively characterized. SEM and EDX mapping show O-LDH exhibits better dispersion than ZnNiAl-CO3 LDH (C-LDH). Cone calorimetry shows the addition of IFR and LDH significantly reduced smoke and heat release rate. The composite with 1 wt% O-LDH, which showed dual gas phase and condensed phase fire retardant action, exhibited the lowest flammability with an LOI value of 29.3 % and achieved a UL-94 V-0 rating. In addition, incorporation of LDH improved the mechanical properties compared to PP/IFR composites. UV absorption showed that O-LDH could significantly improve the ultraviolet stability of PP composites

Integrating agriculture and health research for development: LCIRAH as an interdisciplinary programme to address a global challenge

The multiple burdens of persistent undernutrition and micronutrient deficiencies, along with the rapidly growing rates of overweight, obesity, and associated chronic diseases, are major challenges globally. The role of agriculture and the food system in meeting these challenges is very poorly understood. Achieving food security and addressing malnutrition in all its forms, a Sustainable Development Goal, requires an understanding of how changing food systems affect health outcomes and the development of new tools to design and evaluate interventions. An interinstitutional programme to address this interdisciplinary research challenge is described. Over the past seven years, the Leverhulme Centre for Integrative Research on Agriculture and Health has built a portfolio of successful and innovative research, trained a new cadre of interdisciplinary researchers in “Agri‐Health,” and built an international research community with a particular focus on strengthening research capacity in low‐ and middle‐income countries. The evolution of this programme is described, and key factors contributing to its success are discussed that may be of general value in designing interdisciplinary research programmes directed at supporting global development goals

Membrane Sigma-Models and Quantization of Non-Geometric Flux Backgrounds

We develop quantization techniques for describing the nonassociative geometry probed by closed strings in flat non-geometric R-flux backgrounds M. Starting from a suitable Courant sigma-model on an open membrane with target space M, regarded as a topological sector of closed string dynamics in R-space, we derive a twisted Poisson sigma-model on the boundary of the membrane whose target space is the cotangent bundle T^*M and whose quasi-Poisson structure coincides with those previously proposed. We argue that from the membrane perspective the path integral over multivalued closed string fields in Q-space is equivalent to integrating over open strings in R-space. The corresponding boundary correlation functions reproduce Kontsevich's deformation quantization formula for the twisted Poisson manifolds. For constant R-flux, we derive closed formulas for the corresponding nonassociative star product and its associator, and compare them with previous proposals for a 3-product of fields on R-space. We develop various versions of the Seiberg-Witten map which relate our nonassociative star products to associative ones and add fluctuations to the R-flux background. We show that the Kontsevich formula coincides with the star product obtained by quantizing the dual of a Lie 2-algebra via convolution in an integrating Lie 2-group associated to the T-dual doubled geometry, and hence clarify the relation to the twisted convolution products for topological nonassociative torus bundles. We further demonstrate how our approach leads to a consistent quantization of Nambu-Poisson 3-brackets.Comment: 52 pages; v2: references adde

{\AA}ngstr\"om-resolved Interfacial Structure in Organic-Inorganic Junctions

Charge transport processes at interfaces which are governed by complex interfacial electronic structure play a crucial role in catalytic reactions, energy storage, photovoltaics, and many biological processes. Here, the first soft X-ray second harmonic generation (SXR-SHG) interfacial spectrum of a buried interface (boron/Parylene-N) is reported. SXR-SHG shows distinct spectral features that are not observed in X-ray absorption spectra, demonstrating its extraordinary interfacial sensitivity. Comparison to electronic structure calculations indicates a boron-organic separation distance of 1.9 {\AA}, wherein changes as small as 0.1 {\AA} result in easily detectable SXR-SHG spectral shifts (ca. 100s of meV). As SXR-SHG is inherently ultrafast and sensitive to individual atomic layers, it creates the possibility to study a variety of interfacial processes, e.g. catalysis, with ultrafast time resolution and bond specificity.Comment: 19 page

The literacy practices for assessment in the vocational curriculum - the case of Hospitality

This article explores two case studies of the literacy practices of assessment in the vocational curriculum. Previous studies have identified learning in the vocational curriculum as being assessment-driven and that subjects often associated with limited levels of literacy actually require multiple literacy practices from students. Drawing upon studies of the literacy practices of assessment in the teaching of Hospitality, the study explores the academic and occupational forms of reading and writing required of students. These literacy practices are often invisible to both students and staff and yet are central to the success of students in relation to attainment. The article suggests that vocational subjects may actually be more demanding in the range of literacies required for assessment than is often considered to be the case

Evidence of the validity and accuracy of the Brazilian social attitude of students scale towards politics

Objetivou-se apresentar as evidências de validade e confiabilidade de uma escala brasileira para medir atitudes políticas de estudantes brasileiros de nível superior ante seus comportamentos políticos. O estudo teve uma amostra de abrangência nacional (N = 445), com estudantes brasileiros oriundos de distintos estados. Os resultados indicaram uma estrutura empírica sustentável (teste de Kaiser-Meyer-Olkin - KMO = 0,81), com indicadores psicométricos considerados adequados à mensuração das atitudes políticas. Três fatores empíricos foram identificados: grau de conhecimento sobre política (15 itens, cargas fatoriais entre 0,31 e 0,82, alfa = 0,82, eigenvalue = 5,07 e variância explicada = 18,78 %), afetos relativos à política (7 itens, cargas fatoriais entre 0,41 e 0,58, alfa = 0,72, eigenvalue = 3,17 e variância explicada = 11,73 %) e intenções de comportamento político (2 itens, cargas fatoriais entre 0,70 e 0,72, alfa = 0,80, eigenvalue = 1,8 e variância explicada = 6,8 %). Conclui-se que os resultados fortalecem a estrutura fatorial original da escala e mostram sua utilidade para a identificação de atitudes sociais ante comportamentos políticos.El objetivo de la presente investigación fue presentar las pruebas de confiabilidad y validez de una escala brasileña para medir las actitudes políticas de los estudiantes universitarios brasileños ante su comportamiento político. El estudio contó con una muestra nacional (N = 445) de estudiantes brasileños de diferentes Estados. Los resultados indicaron una estructura empírica sustentable (KMO = .81), con indicadores psicométricos que se consideran adecuados para la medición de las actitudes políticas. Específicamente, se identificaron tres factores empíricos: nivel de conocimiento sobre la política (15 ítems, cargas factoriales entre .31 y .82, alfa = .82, eigenvalue = 5.07 y varianza explicada = 18.78 %), sentimientos acerca de la política (7 ítems, factoriales de .41 y .58, alfa = .72, eigenvalue = 3.17 y varianza explicada = 11.73 °/o) e intenciones del comportamiento político (2 ítems, factoriales de .70 y .72, alfa = .80, eigenvalue = 1.8 y varianza explicada = 6.8 %). Se llegó a la conclusión de que los resultados apoyan la estructura factorial original de la escala y muestran su utilidad en la identificación de las actitudes sociales ante la conducta política.The objective of this study was to present the validity and reliability evidences of a Brazilian scale to measure the political attitudes of Brazilian higher education students regarding their political behavior. The study had a nationwide sample (N = 445), with Brazilian students from different states. The results indicated a sustainable empirical structure (KMO = 0.81), with psychometric indicators considered adequate to the measurement of political attitudes. Three empirical factors were identified: degree of political knowledge (15 items, factorial loads between 0.31 and 0.82, alpha = 0.82, eigenvalue = 5.07 and explained variance = 18.78%), feelings about politics (7 items, factorial loads between 0.41 and 0.58, alpha = 0.72, eigenvalue = 3.17 and explained variance = 11.73%) and intentions of political behavior (2 items, factorial loads between 0, 70 and 0.72, alpha = 0.80, eigenvalue = 1.8 and explained variance = 6.8%). It is concluded that the results strengthen the original factorial structure of the scale and show its utility for the identification of social attitudes regarding political behaviors

Analysis Method and Experimental Conditions Affect Computed Circadian Phase from Melatonin Data

Accurate determination of circadian phase is necessary for research and clinical purposes because of the influence of the master circadian pacemaker on multiple physiologic functions. Melatonin is presently the most accurate marker of the activity of the human circadian pacemaker. Current methods of analyzing the plasma melatonin rhythm can be grouped into three categories: curve-fitting, threshold-based and physiologically-based linear differential equations. To determine which method provides the most accurate assessment of circadian phase, we compared the ability to fit the data and the variability of phase estimates for seventeen different markers of melatonin phase derived from these methodological categories. We used data from three experimental conditions under which circadian rhythms - and therefore calculated melatonin phase - were expected to remain constant or progress uniformly. Melatonin profiles from older subjects and subjects with lower melatonin amplitude were less likely to be fit by all analysis methods. When circadian drift over multiple study days was algebraically removed, there were no significant differences between analysis methods of melatonin onsets (P = 0.57), but there were significant differences between those of melatonin offsets (P<0.0001). For a subset of phase assessment methods, we also examined the effects of data loss on variability of phase estimates by systematically removing data in 2-hour segments. Data loss near onset of melatonin secretion differentially affected phase estimates from the methods, with some methods incorrectly assigning phases too early while other methods assigning phases too late; missing data at other times did not affect analyses of the melatonin profile. We conclude that melatonin data set characteristics, including amplitude and completeness of data collection, differentially affect the results depending on the melatonin analysis method used