The column collapse experiment is a simplified version of natural and industrial granular flows. In this set-up, a column built with grains collapses and spreads over a horizontal plane. Granular flows are often studied with a monodisperse distribution; however, this is not the case in natural granular flows where a variety of grain sizes, known as polydispersity, is a common feature. In this work, we study the effect of polydispersity, and of the inherent changes that polydispersity causes in the initial packing fraction, in dry and immersed columns. We show that dry columns are not significantly affected by polydispersity, reaching similar distances at similar times. In contrast, immersed columns are strongly affected by the polydispersity and packing fraction, and the collapse sequence is linked to changes of the basal pore fluid pressure $P$. At the collapse initiation, negative changes of $P$ beneath the column produce a temporary increase of the column strength. The negative change of $P$ lasts longer in polydisperse columns than in monodisperse columns, delaying the collapse sequence. Conversely, during the column spreading, positive changes of $P$ lead to a decrease of the shear strength. For polydisperse collapses, the excess of $P$ lasts longer, allowing the material to reach farther distances, compared with the collapses of monodisperse materials. Finally, we show that a mobility model that scales the final runout with the collapse kinetic energy remains true for different polydispersity levels in a three-dimensional configuration, capturing the scaling between the micro to macro controlling features.

Calcined clays are used as a supplementary cementitious material (SCM) because, as hydrated aluminosilicates of the phyllosilicate group, they can be activated thermally, promoting dehydroxylation and structural disorder, i.e. making them reactive. The main effect of using calcined clay as an SCM is that CO2 emissions into the atmosphere are reduced by the reduction in the clinker/cement factor due to substitution of a proportion of clinker by calcined clay. Clays rich in kaolinite (1:1) group minerals offer most promise in terms of thermal activation. However, increased costs caused by demand for kaolinite from other industries means that type 2:1 calcined clays and mixtures of them have begun to be investigated as possible pozzolanic materials. The physical, chemical, and mineralogical characteristics that control the performance of these calcined clays as SCMs are still under discussion. Few in-depth studies of the behavior of these characteristics have been reported. The origin and geological history of raw materials, as well as their impact on the thermal activation and performance as SCM, are not well understood or, in some cases, have not been considered. The objective of the current work, therefore, was to study multicomponent clays from metamorphic rocks with low-grade kaolinite (<50%) from a tropical region of Colombia for possible use as SCMs. The clay deposit was identified by geological exploration techniques and classified in depth according to horizons of the weathering profile. The samples were extracted from the first 50 m of the deposit and characterized physically, chemically, and mineralogically; they were calcined at 650, 750, and 850°C; their degree of alteration was estimated by the Chemical Index of Alteration (CIA); and their performance as an SCM was evaluated by the Strength Activity Index (SAI) and Frattini test. As a main result, a relationship was found between the weathering profile of the deposit and the CIA of raw clays, which confirmed the high weathering and degree of alteration of the parent rock in the deposit (weathered rock and residual soil with a CIA > 80%). Furthermore, pozzolanic (physical and chemical) tests demonstrated the potential use of calcined clays from this deposit as SCMs, as well as their thermal activation at low temperature (≤750°C). In addition, the pozzolanic activity increased with the kaolinite/(muscovite+illite+vermiculite) ratio mainly, and, in turn, the thermal activation temperature increased with the mica and type 2:1 clay content.

The main objective of this study was to analyze the differences between older adults’ symptom profiles (subclinical, anxiety, depressive, and comorbid) in negative aging self-stereotypes, loneliness, and feelings of guilt associated with self-perception as a burden. Participants were 310 community-dwelling people aged 60 years and over. The sample was grouped into four symptom profiles of older adults: anxiety, depressive, comorbid anxiety-depression, and subclinical symptoms. We carried out multinomial logistic regression analyses to analyze the role of assessed variables in the explanation of the four symptom profiles. Older adults who reported a comorbid symptomatology presented higher negative aging self-stereotypes and feelings of loneliness than the other three profiles. Compared with the subclinical profile, older adults who reported clinical symptomatology (anxiety, depressive, and comorbid profile) presented higher feelings of guilt associated with self-perception as a burden. The findings of this study suggest potential associations that may contribute to understanding and treating comorbid anxiety and depressive symptoms in older adults.

This article introduces a symposium that aims to identify and critically assess the legal strategies of the tobacco, alcohol, and food and beverage industries which rest on freedom of expression arguments.

This article argues that the decision by the Columbian high court to totally ban the advertising and promotion of tobacco products is sound and could indeed be applied to other types of harmful products.

This article provides a critical and philosophical assessment of arguments invoked for and against the constitutional protection of commercial expression and the regulation of commercial speech with a focus on the commercialization of unhealthy food products.

The aim of this work was to study the deformation behavior of an Armco iron after severe plastic deformation by equal channel angular pressing (ECAP). Particular attention was paid to predict the dislocation density by different approaches like the model proposed by Bergström. Experimental measures of dislocation density by different techniques are used in the discussion. Cylindrical samples of ARMCO iron (8mm of diameter, 60mm of length) were subjected to ECAP deformation using a die with an intersecting channel of Φ=90° and outer arc of curvature of ψ= 37° die. Samples were deformed for up to 16 ECAP passes following route Bc. The mechanical properties of the material were measured after each pass by tensile tests. The original grain size of the annealed iron (70 μm) was drastically reduced after ECAP reaching grain sizes close to 300nm after 16 passes.

Equal channel angular pressing (ECAP) was carried out on extruded ZK60 magnesium alloy until an equivalent strain of ∼4 (corresponding to 4 passes) at 523K following route Bc. The effect of the deformation on both microstructure and texture was investigated by analysis of inverse pole figures and pole figures respectively, determined by EBSD. Additionaly, the mechanical properties were evaluated through tensile tests. The ECAPed processed ZK60 alloy showed the presence of dynamic recrystallization (DRX) process, correlated with a strong basal fiber texture. The presence of pyramidal slip was also observed, which can be correlated with the presence on twin-oriented boundaries in the material. Both the grain size reduction and the existence of texture influenced the ductility of the magnesium alloy processed by ECAP, as the ductility of the ZK60 alloy after four ECAP passes increased two times in comparation with the initial (un-processed) material.

There is perhaps no area of law that so effectively protects human health and thereby advances the right to the highest attainable standard of health, as tobacco control. Globally, tobacco is responsible for 1 in 10 adult deaths, and is on track to kill 10 million people per year, mostly in developing countries, representing a US$200 billion drain on the global economy. Yet experience in recent decades has shown that a range of tobacco control measures, such as comprehensive bans on smoking in public places, tobacco taxes, and limits on tobacco advertising, can greatly reduce smoking prevalence. These measures have slowly curtailed the epidemic, despite strong opposition from various sectors led by the tobacco industry. It is fitting that tobacco control is the focus of a recent, widely ratified global treaty (the Framework Convention on Tobacco Control) and of increasing national litigation, often directly linked to countries’ human rights commitments.

This article explores the connection between human rights and tobacco control, and in particular, the Framework Convention on Tobacco Control (FCTC). We address rights-based arguments used by the tobacco industry to argue against tobacco regulation. We demonstrate the weakness of these arguments, and that tobacco control and human rights are, in fact, not in conflict, but are mutually reinforcing. We also offer counter-arguments in favour of tobacco regulation based on international human rights obligations. Moreover, we argue that international human rights law and human rights bodies can provide tobacco control advocates with avenues for international monitoring and enforceability, which are lacking in the FCTC.