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Eruptive column models are crucial for managing volcanic crises, forecasting future events, and reconstructing past eruptions. Given their central role in volcanology and the large uncertainties weakening their predictions, the evaluation and improvement of these models is critical. Such evaluation is challenging as it requires independent estimates of the main model inputs (e.g. mass eruption rate) and outputs (e.g. column height). Despite recent efforts to extend datasets of independently estimated eruption source parameters (ESP) (e.g. Mastin 2014, Aubry et al. 2017), there is no standardized, maintained, and community-based ESP database devoted to the evaluation of eruptive column models.Here we present a new ESP database designed to respond to the needs of the plume modelling community, and which will also be valuable to observatories, field volcanologists, and volcanic ash advisory centers. We compiled data for over 130 eruptive events with independent estimates of: i) the mass eruption rate; ii) the height reached by the column; and iii) atmospheric conditions during the eruption. In contrast with previous ESP datasets, we distinguish estimates of column height that relate to different phases (ash and SO2) and parts of the column (plume top or umbrella). We additionally provide the total grain size distribution, uncertainties in eruption parameters, and multiple sources for atmospheric profiles for events where these parameters are available. The database also includes a wealth of additional information which will enable modelers to distinguish between different eruptions when evaluating or calibrating models. This includes the type of eruption, the morphology of the plume (weak/transitional/strong), and the occurrence and mass entrained within pyroclastic density currents.We will apply the new database to revisit empirical scaling relationships between the mass eruption rate and “plume height”. In particular, we will show how such relationships depend on the type of height (e.g. SO2 height vs. ash top height) and eruption (e.g. magmatic vs. phreatomagmatic) considered. We will also discuss the difficulties and limitations of compiling ESP estimates from the literature as well as characterizing fundamentally unsteady volcanic events by a single value for each ESP.

Hydrothermal synthesis of Sn(O3PC6H5)2 yields globular aggregates of nanoparticles that are layered. The particle size depends upon the time and temperature of hydrothermal treatment but may be as small as 20 nm in the lateral directions and three or four layers thick. Because of their small size, the particles form globules within which the particles form “house of cards” type pores. Surface areas as high as 300 m2/g are common with pores in the micropore range. Tin(IV) methylphosphonate is also layered, but the particles tend to aggregate into rosettes. Mixed derivatives of the type Sn(O3PC6H5)x(O3PCH3)2-x, where x > 0.5, also form globules, with higher surface areas than the tin phenylphosphonates. The formation of these spherical aggregates appears to be general for tin(IV) phosphonates as a result of a lack of particle growth.

The historical record of Mediterranean volcanism is arguably the richest available for any region of the world. Documentary records date back to the Classical period, and archaeological records date back further still (Stothers and Rampino 1983; Chester et al. 2000). The Mediterranean is also home to some of the most famous, or indeed infamous, volcanoes on Earth, several of which still present major threats to society today (Kilburn and McGuire 2001; Chester et al. 2002; Guest et al. 2003). A number, for example Santorini, Etna, and Vesuvius, have menaced human populations since Antiquity, and the human response and risk perception today are strongly shaped by a culture, which itself owes much to the volcanic landscapes and eruptions (Chester et al. 2008). The science of volcanology was born, and has since flourished, in the cradle of the Mediterranean. It began, arguably, with the careful descriptions by Pliny the Younger of the AD 79 eruption of Vesuvius that buried Pompeii, and developed through the scientific investigations of Sir William Hamilton in the eighteenth century. The region was the playground of the pioneers of modern volcanological studies in the nineteenth century (e.g. Fouqué 1879), and today it boasts a number of state of the art volcano observatories such as that which monitors Vesuvius. Several volcanoes, eruption styles, geothermal manifestations, and rock types have inspired nomenclature now widely used within the volcanological community: plinian, vulcanian, and strombolian eruptions; low temperature gas emanations known as solfataras; rocks known as pantellerites. The very word ‘volcano’ comes from the Aeolian island Vulcano, where Vulcan’s forge was situated. The sea-filled crater of Santorini was one of the first volcanic ‘calderas’ to be described, by Ferdinand Fouqué in the 1870s. The Mediterranean basin tracks the geological suture between the African plate to the south, and the Eurasian tectonic plate to the north (Chapters 1, 13, and 16). Many regions along this suture have experienced volcanic activity within the past 10–20 Myr (million years), most of it related to the continuing process of subduction that has consumed the northern margin of the African plate.

At first sight crime may appear to be a peculiar topic for economic analysis. What can an economist contribute to an understanding of such a self-evidently non-economic phenomenon? It turns out that economists have a great deal to say on the subject — first, about what motivates individuals to commit crime and second, about how society should allocate resources in order to reduce the damage caused by crime. In this chapter we will focus on the first of these issues.

Low-temperature (LTO) chemical vapor deposited (CVD) silicon dioxide was investigated for use as an insulator material in microfabricated ion engine accelerator grids. Both substrate (bulk) as well as surface breakdown experiments were performed. Oxide thicknesses for substrate breakdown tests ranged between 1 jim and 3.9 um. Surface breakdowns were performed over gap distances ranging between 5 um and 600 |im. Substrate breakdown strengths up to 600-700 V/p.m were measured, allowing for maximum stand-off voltages o f 2500 V. A slight decrease in breakdown field strength for larger thicknesses was observed. Temperature effects on substrate breakdown field strengths do exist, however, are small . Only a 15% drop in breakdown field strength was noted at 400 C vs. strengths measured at room temperature. Surface breakdown field strengths ranged as high as 140 V/|im , leading t o a stand-off capability of 700 V over a 5 |im oxide film. Tests were performed to study the influence of silicon oxide surface morphology on the surface breakdown strength and none was found.

Reaction of Sn(IV) with phosphonic acids results in the formation of tin phosphonates with a spherical morphology arising from the aggregation of nanosized individual particles. Under high magnification, the spheres are shown to be porous with surface areas of 200-515 m2/g, depending on the type of phosphonic acid and the synthesis conditions used. The pores are largely micro in nature but also somewhat dependent on the type of phosphonic acid utilized in the preparation. Both aliphatic and aromatic organic phosphonates form these spherical aggregates. Functional groups, such as amino and carboxyl, may be introduced as part of the phosphonic acid or subsequently by further reaction, leading to a large family of naturally formed nanoparticles with accompanying microporosity.

This paper presents the findings of a study to assess the effectiveness and sustainability of a GAVI (Global Alliance of Vaccines and Immunization) sponsored, time-limited Injection Safety (INS) support. The support came in two forms: 1) in-kind, in the form of AD syringes and safety boxes, and 2) in cash, for those countries that already had a secure, multi-year source of AD syringes and safety boxes, but proposed to use INS support to strengthen their injection safety activities. In total, GAVI gave INS support for a three-year period to 58 countries: 46 with commodities and 12 with cash support. To identify variables that might be associated with financial sustainability, frequencies and cross-tabulations were run against various programmatic and socio-economic variables in the 58 countries. All but two of the 46 commodity-recipient countries were able to replace and sustain the use of AD syringes and safety boxes after the end of their GAVI INS support despite the fact that standard disposable syringes are less costly than ADs (10-15 percent differential). In addition, all 12 cash-recipient countries continued to use AD syringes and safety boxes in their immunization programs in the years following GAVI INS assistance. At the same time, countries were often not prepared for the increased waste management requirements associated with the use of the syringes, suggesting the importance of anticipating challenges with the introduction of new technologies. The sustained use of AD syringes in countries receiving injection safety support from GAVI, in a majority of cases through government financing, following the completion of three years of time-limited support, represents an early indication of how GHPs can contribute to improved health outcomes in immunization safety in the world's poorest countries in a sustainable way.