Dissolved carbon dioxide in Dutch coastal waters

The role of shelf seas in global carbon cycling is poorly understood. The dissolved inorganic carbon system and air-sea exchange of carbon dioxide (CO2) are described for the Dutch coastal zone in September 1993. The inorganic carbon chemistry was affected by tidal mixing, wind speed, wind direction, freshwater input, stratification and coastal upwelling. Surface water had a variable fugacity of carbon dioxide (fCO2) between 300 and 800 μatm with short-term changes partly related to the tidal cycle. High contents of dissolved inorganic carbon (DIC) and CO2 in relatively saline water probably originated from mineralisation of accumulated organic matter in water and sediments farther out at sea and transport of water enriched in DIC into the coastal zone by upwelling. Air-sea exchange of CO2 ranged from —20 to 60 mmol m−2 day−1. These fluxes are critically discussed in the light of potential stratification. It is not possible to assess from this study whether the Dutch coastal zone is a net sink or source for atmospheric CO2

Analysing Personal Characteristics of Lone-Actor Terrorists: Research Findings and Recommendations

This Research Note presents the outcome of a project that looked at the personal characteristics of lone-actor terrorists. It is part of the larger Countering Lone-Actor Terrorism (CLAT) project. The project described here aimed to improve understanding of, and responses to, the phenomenon of (potentially) violent lone-actors based on an analysis of 120 cases from across Europe. The Research Note focuses on the personal characteristics of lone-actor terrorists. First of all, it presents the main findings of the general analysis of the study into personal variables of lone-actor terrorists. Subsequently, the authors outline a set of recommendations based on the key findings. In the beginning, we present the main research questions of the CLAT project and the working definition of lone-actor terroris

Fully abstract denotational models for nonuniform concurrent languages

AbstractThis paper investigates full abstraction of denotational model w.r.t. operational ones for two concurrent languages. The languages are nonuniform in the sense that the meaning of atomic statements generally depends on the current state. The first language, L1, has parallel composition but no communication, whereas the second one, L2, has CSP-like communications in addition. For each of Li (i = 1, 2), an operational model Oi is introduced in terms of a Plotkin-style transition system, while a denotational model Di for Li is defined compositionally using interpreted operations of the language, with meanings of recursive programs as fixed points in appropriate complete metric spaces. The full abstraction is shown by means of a context with parallel composition: Given two statements s1 and s2 with different denotational meanings, a suitable statement T is constructed such that the operational meanings of s1 ∥ T and s2 ∥ T are distinct. A combinatorial method for constructing such T is proposed. Thereby the full abstraction of D1 and D2 w.r.t. O1 and O2, respectively, is established. That is, Di is most abstract of those models C which are compositional and satisfy Oi = α ∘ C for some abstraction function α (i = 1, 2)

Tactility Trialing: Exploring Materials to Inform Tactile Experience Design

Although materials of tangible interaction designs largely determine their user experience, material choices are often steered by practical motives. This paper presents ‘tactility trialing’, an approach to explore tactile experiences of materials to inform the design of tangible artifacts. Through experience formulation, material selection, artifact creation and short user studies, designers and design-researchers are enabled to make informed decisions on the materials to be used in order to evoke the intended experience. The approach is illustrated through two case studies of student work. Tactility trialing helped them in getting acquainted with tactile material qualities in practice, and with the applicability of material characteristics such as resilience and hardness in design

Electromagnetic form factor of the pion in the space- and time-like regions within the front-form dynamics

The pion electromagnetic form factor is calculated in the space- and time-like regions from -10 $(GeV/c)^2$ up to 10 $(GeV/c)^2$, within a front-form model. The dressed photon vertex where a photon decays in a quark-antiquark pair is depicted generalizing the vector meson dominance ansatz, by means of the vector meson vertex functions. An important feature of our model is the description of the on-mass-shell vertex functions in the valence sector, for the pion and the vector mesons, through the front-form wave functions obtained within a realistic quark model. The theoretical results show an excellent agreement with the data in the space-like region, while in the time-like region the description is quite encouraging.Comment: 9 pages + 4 figures. To appear in Phys. Lett.

Measurements of total alkalinity and inorganic dissolved carbon in the Atlantic Ocean and adjacent Southern Ocean between 2008 and 2010

Water column dissolved inorganic carbon and total alkalinity were measured during five hydrographic sections in the Atlantic Ocean and Drake Passage. The work was funded through the Strategic Funding Initiative of the UK's Oceans2025 programme, which ran from 2007 to 2012. The aims of this programme were to establish the regional budgets of natural and anthropogenic carbon in the North Atlantic, the South Atlantic, and the Atlantic sector of the Southern Ocean, as well as the rates of change of these budgets. This paper describes in detail the dissolved inorganic carbon and total alkalinity data collected along east–west sections at 47° N to 60° N, 24.5° N, and 24° S in the Atlantic and across two Drake Passage sections. Other hydrographic and biogeochemical parameters were measured during these sections, and relevant standard operating procedures are mentioned here. Over 95% of dissolved inorganic carbon and total alkalinity samples taken during the 24.5° N, 24° S, and the Drake Passage sections were analysed onboard and subjected to a first-level quality control addressing technical and analytical issues. Samples taken along 47° N to 60° N were analysed and subjected to quality control back in the laboratory. Complete post-cruise second-level quality control was performed using cross-over analysis with historical data in the vicinity of measurements, and data were submitted to the CLIVAR and Carbon Hydrographic Data Office (CCHDO), the Carbon Dioxide Information Analysis Center (CDIAC) and and will be included in the Global Ocean Data Analyses Project, version 2 (GLODAP 2), the upcoming update of Key et al. (2004)