Contributions from DMS and ship emissions to CCN observed over the summertime North Pacific

Measurements of cloud condensation nuclei (CCN) made over the North Pacific Ocean in July 2002 are analysed with concurrent measurements of aerosol number, mass and composition. Overall the CCN are controlled by the sulphate, including one case that suggests particle nucleation and growth resulting from dimethyl sulphide oxidation that enhanced CCN concentrations. Hourly CCN concentrations are correlated with concentrations of sulphate plus methanesulphonic acid (MSA) over the entire study period (<i>r</i><sup>2</sup>=0.43 and 0.52 for supersaturations of 0.34% and 0.19%, respectively), and are not well correlated with other organics (<i>r</i><sup>2</sup><0.2). One case study reveals elevated mass and number concentrations of ultrafine and fine organic particles due to regional ship emissions, identified through quadrupole aerosol mass spectrometer (Q-AMS) measurements, during which organic mass concentrations are correlated with CCN values (<i>r</i><sup>2</sup>=0.39 and 0.46 for supersaturations of 0.19% and 0.34%, respectively). The evolution of the time series and mass distributions of organics, sulphate and MSA over this timeframe indicate that the regional distribution of small, diffuse ship-sourced organic particles act as condensation sites for sulphur species, resulting in a subsequent increase in number concentrations of CCN. We conclude that, where present, direct emissions of anthropogenic organic particles may exert a strong control on marine CCN concentrations once diffused into the marine atmosphere, by acting as condensation sites for biogenic and anthropogenic sulphur species

The effect of organic compounds on the growth rate of cloud droplets in marine and forest settings

International audienceOrganic matter represents an important fraction of the fine particle aerosol, yet our knowledge of the roles of organics in the activation of aerosol particles into cloud droplets is poor. A cloud condensation nucleus (CCN) counter is used to examine the relative growth rates of cloud droplets for case studies from field measurements on the North Pacific Ocean and in a coniferous forest. A model of the condensational growth of water droplets, on particles dissolving according to their solubility in water, is used to simulate the initial scattering of the droplets as they grow in the CCN counter. Simulations of the growth rates of fine particles sampled in the marine boundary layer of the North Pacific Ocean indicate that the main influence of the marine organic material on the water uptake rate is from its effect on the size distribution of the sulphate. Simulations of the observations of water uptake on biogenic organic aerosol particles sampled in a coniferous forest indicate an impact of the organic on the water uptake rates, but one that is still smaller than that of pure sulphate. The solubility of the organic becomes an important factor in determining the water uptake as the organic mass increases relative to sulphate. The values of the organic component of the hygroscopicity parameter ? that describes the CCN activity were found to be negligible for the marine particles and 0.02?0.05 for the forest particles

Mechanical tuning of the evaporation rate of liquid on crossed fibers

We investigate experimentally the drying of a small volume of perfectly wetting liquid on two crossed fibers. We characterize the drying dynamics for the three liquid morphologies that are encountered in this geometry: drop, column and a mixed morphology, in which a drop and a column coexist. For each morphology, we rationalize our findings with theoretical models that capture the drying kinetics. We find that the evaporation rate depends significantly on the liquid morphology and that the drying of liquid column is faster than the evaporation of the drop and the mixed morphology for a given liquid volume. Finally, we illustrate that shearing a network of fibers reduces the angle between them, changes the morphology towards the column state, and so enhances the drying rate of a volatile liquid deposited on it

Beyond capitalism and liberal democracy: on the relevance of GDH Cole’s sociological critique and alternative

This article argues for a return to the social thought of the often ignored early 20th-century English thinker GDH Cole. The authors contend that Cole combined a sociological critique of capitalism and liberal democracy with a well-developed alternative in his work on guild socialism bearing particular relevance to advanced capitalist societies. Both of these, with their focus on the limitations on ‘free communal service’ in associations and the inability of capitalism to yield emancipation in either production or consumption, are relevant to social theorists looking to understand, critique and contribute to the subversion of neoliberalism. Therefore, the authors suggest that Cole’s associational sociology, and the invitation it provides to think of formations beyond capitalism and liberal democracy, is a timely and valuable resource which should be returned to

The effects of conflict role and intensity on preschoolers’ expectations about peer conflict

Using a puppet procedure depicting hypothetical conflict involving the participant and a peer, 96 preschoolers’ (48 boys and 48 girls; M 1/4 5.14 years, SD 1/4 0.78 years) expectations about peer conflict were assessed as a function of their role in the conflict (i.e., initiator of or responder to initial provocation) and the intensity level of the conflict. Initiators of conflict expected less conflict escalation and subsequent problems with the same peer from the conflict than did responders, particularly following low-intensity conflict. Findings also indicated that, for low-intensity but not high-intensity conflict, girls expected the same peer to provoke them during a subsequent interaction more often than did boys. Results provide further support for assessing preschoolers’ understanding of conflict and are consistent with previous work demonstrating a self-serving bias in young children’s perceptions and reports of their conflicts with other children. Moreover, findings are discussed in terms of their implications for the development of peer relations.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Educational archaeology and the practice of utopian pedagogy

This paper explores the idea, and some elements of the (potential) practice, of utopian pedagogy. It begins by outlining the general aims of ‘utopian pedagogy’ and notes the shift within contemporary writings away from the metaphor of the architect (armed with a utopian ‘blueprint’) towards that of the archaeologist. The ontological underpinnings of educational archaeology are discussed before attention turns to a critical examination of the pedagogical process of excavation. The key questions here are (to labour the metaphor) where to dig and how to identify a utopian find. The paper argues that, without a substantive normative vision to serve as a guide, utopian archaeology is conceptually flawed and practically ineffectual, romanticising an endlessly open process of exploration. The final section suggests that the fears associated with utopian architecture (authoritarian imposition, totalising closure) are misplaced and that drawing up a ‘blueprint’ should be the aim and responsibility of utopian pedagogy

Introduction

Why do parent\u2013child argumentative interactions matter? What is the reason for such an interest? This chapter provides the reasons that motivated the study of parent\u2013child argumentation with the aim to understand the function of this type of interactions. Focusing on the activity of family mealtime, in the first part, the chapter draws attention to the distinctive features of parent\u2013child conversations. A second section of the chapter is devoted to discussing whether and, eventually, when children have the competence to construct arguments and engage in argumentative discussions with the aim to convince their parents to change opinion. In the last part of the chapter, research questions and structure of the volume are presented

Search for invisible modes of nucleon decay in water with the SNO+ detector

This paper reports results from a search for nucleon decay through invisible modes, where no visible energy is directly deposited during the decay itself, during the initial water phase of SNO+. However, such decays within the oxygen nucleus would produce an excited daughter that would subsequently deexcite, often emitting detectable gamma rays. A search for such gamma rays yields limits of 2.5×1029  y at 90% Bayesian credibility level (with a prior uniform in rate) for the partial lifetime of the neutron, and 3.6×1029  y for the partial lifetime of the proton, the latter a 70% improvement on the previous limit from SNO. We also present partial lifetime limits for invisible dinucleon modes of 1.3×1028  y for nn, 2.6×1028  y for pn and 4.7×1028  y for pp, an improvement over existing limits by close to 3 orders of magnitude for the latter two