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Corrosion of metal roof materials related to volcanic ash interactions
Natural Hazards
Abstract
Metal roofing material is commonly used for residential and industrial roofs in volcanically active areas. Increased corrosion of metal roofing from chemically reactive volcanic ash following ash deposition post-eruption is a major concern due to decreasing the function and stability of roofs. Currently, assessment of ash-induced corrosion is anecdotal, and quantitative data are lacking. Here, we systematically evaluate the corrosive effects of volcanic ash, specifically ash leachates, on a variety of metal roofing materials (i.e. weathered steel, zinc, galvanized steel, and Colorsteel©) utilizing weathering chamber experiments and direct acid treatments. Weathering chamber tests were carried out for up to 30 days, and visual, chemical, and surface analyses did not definitively identify significant corrosion in any of the test roofing metal samples. Direct concentrated acid treatments with hydrochloric (HCl), sulphuric (H2SO4), and hydrofluoric (HF) acids demonstrate that roofing materials are chemically resilient. Our experimental results suggest that ash-leachate-related corrosion is a longer-term process (>1 month), potentially related to a multitude of factors including increased ash leachate concentrations, the dissolution of the glass matrix of the ash, moisture retention at the ash-surface boundary, and potential reactions involving photo-oxidation. Overall, corrosion is not a simple process related to the short-term release of acid and/or salt leachates from the ash surface, but a product of dynamic interactions involving ash and water at the surface of metal roofing material for extended periods.
... Wilson et al. 2014;Jenkins et al. 2015). Buildings and building support systems can be damaged by even small amounts of tephra fall (≤ 10 mm thick) if heating, ventilation and air-conditioning equipment is clogged by ash or leachates lead to corrosion of metal roofs over the longer term (Miller et al. 2022;Oze et al. 2014). Thicknesses of 10-100 mm may cause collapse of structures which are not built to regulated building design standards (non-engineered buildings) or which are in poor condition (Hayes et al. 2019a;Jenkins et al. 2014), as we observed on La Palma, Canary Islands during the 2021 eruption of Cumbre Vieja. ...
... Hampton et al. 2015;Williams et al. 2019). In addition, if the deposit remains in place long term, corrosion may weaken metal roofs, as was reported in Montserrat (Sword-Daniels et al. 2014) and Rabaul, Papua New Guinea (Blong 2003), although laboratory tests indicate this is unlikely to occur over timescales less than one month (Oze et al. 2014). It would be useful to investigate how tephra fall may promote corrosion and lead to building failures beyond proximal areas, considering both the residue left after sliding (as we found in our dry-wet tests) and deposits thinner than 10 cm. ...
Following explosive eruptions, loading from tephra fall deposits can lead to roof collapse. However, the load may be reduced significantly by tephra sliding on pitched roofs. We present small-scale laboratory tests to investigate tephra sliding behaviour on metal, fibre cement sheet and tile roofing. We tested 10–30 cm thicknesses for dry and wet deposits of pumice, scoria and basaltic ash. We found that tephra did not slide on roof pitches ≤ 15° for coarse-grained deposits and ≤ 12° for dry ash. Thin deposits of wet ash were stable at pitches ≤ 30°. In addition, tephra was mainly shed on pitches ≥ 32° for metal roofs and ≥ 35° for fibre cement and tiles. Using these results, we have produced an initial set of sliding coefficients for tephra for simply pitched roofs that can be used to help prioritise roofs for clearing during an eruption and assist in designing roofs to withstand tephra fall.
... Typical effects of ash fall on drinking water supplies are the elevation of the metals Fe, Mn, and Al which produce unpleasant tastes but little direct health impact (Stewart et al., 2009). In addition, acidic coatings can accelerate corrosion of metal components such as roofing, fencing, and other exposed metal surfaces (Oze et al., 2014). High concentrations of readily water-soluble salts on volcanic ash can result in a conductive coating unless the particles are dry. ...
... Impacted zones can be dangerous and/or inaccessible for long periods of time. Experimental data (e.g., Oze et al., 2014) are also limited, and, where available, refer exclusively to materials, strengths, building codes and standards exhibited by the tested building stock. In the absence of empirical data, theoretical calculations of component, system or network response to hazard parameters can be prepared (e.g., Spence et al., 2005), but these are also subject to various uncertainties. ...
Originally prepared for the United Nations Office for Disaster Risk Reduction, this is the first comprehensive assessment of global volcanic hazards and risk, presenting the state of the art in our understanding of global volcanic activity. It examines our assessment and management capabilities, and considers the preparedness of the global scientific community and government agencies to manage volcanic hazards and risk. Particular attention is paid to volcanic ash, the most frequent and wide-ranging volcanic hazard. Of interest to government officials, the private sector, students and researchers, this book is a key resource for the disaster risk reduction community and for those interested in volcanology and natural hazards. A non-technical summary is included for policy makers. Regional volcanic hazard profiles, with invaluable information on volcanic hazards and risk at the local, national and global scale, are provided online. This title is available as an Open Access eBook via Cambridge Books Online.
... The corrosion of metallic roofs used in residential, administrative and industrial buildings in the study communities as a consequence of tephra may lead to a decrease in their function and stability (Oze et al., 2014). This corrosion is usually caused by the presence of ionic species in the tephra such as sodium (Na + ) and chloride (Cl − ), while the presence of calcium (Ca 2+ ) and some of its salts inhibit corrosion (Oze et al., 2014). ...
... The corrosion of metallic roofs used in residential, administrative and industrial buildings in the study communities as a consequence of tephra may lead to a decrease in their function and stability (Oze et al., 2014). This corrosion is usually caused by the presence of ionic species in the tephra such as sodium (Na + ) and chloride (Cl − ), while the presence of calcium (Ca 2+ ) and some of its salts inhibit corrosion (Oze et al., 2014). The 1999 MC tephra samples had CaO contents in the range of~0.3 to 23 wt%, Na 2 O (3 to 4 wt%) and chloride content of 1270 ppm (Suh et al., 2008), which may explain the presence of corroded roofs all over the pilot sites. ...
... Particulates serve as nucleation site for acidic gases such as SO 2 and NO 2 (Enghoff and Svensmark, 2008), increasing their aerodynamic diameter and settling velocities, and resulting in increased aesthetic impact. Various studies have confirmed that exposure to acidforming PM exacerbate metal corrosion beyond normal corrosion rate (Manning, 1988;Oze et al., 2014;Graedel, 1989;Larssen et al., 1999). Decrease in life span of paints through soiling, discolorations, loss of gloss, and loss of thickness of paint film layer by acid-forming particulates is discussed in the literature (Oze et al., 2014). ...
... Various studies have confirmed that exposure to acidforming PM exacerbate metal corrosion beyond normal corrosion rate (Manning, 1988;Oze et al., 2014;Graedel, 1989;Larssen et al., 1999). Decrease in life span of paints through soiling, discolorations, loss of gloss, and loss of thickness of paint film layer by acid-forming particulates is discussed in the literature (Oze et al., 2014). There are numerous reported adverse impacts of acid deposition on terrestrial and aquatic ecosystems (Cosby et al., 1985;Økland and Økland, 1986;Likens et al., 1996;Gilmour & Henry, 1991;Driscoll et al., 2001;Hutchinson and Havas, 2012;Reuss and Johnson, 2012). ...
Air pollution from airborne particulates is a global issue that has received some attention due to potential health issues and environmental impacts. Construction activities, agricultural operations, combustion of fossil fuels, and industrial and mining processes are significant sources of particulate pollution. The potential to cause health problems has been linked to size, concentration and chemical composition of suspended particles. Duration of exposure and receptor's susceptibility also determine potential to cause health effects. Particles that are 10 microns in diameter or smaller evade natural defence mechanisms and enter the lungs to cause serious health problems. Particulate matter is also found to reduce visibility, cause environmental and property damage and alter local weather. This paper reviews relevant literature on ambient air particles with specific focus on emission sources, potential threats and mitigation techniques. It is observed in the literature that particle pollution can lead to irritation of eyes, nose and throat; coughing, chest tightness and shortness of breath; reduced lung function; irregular heartbeat, asthma and heart attacks; and premature death in people with heart or lung disease.
... This can be attributed to the relatively low individual repair and replacement cost and is therefore of less concern for loss assessment. However, ash loads at or below structural damage thresholds have been reported to cause damage or disruption to non-structural roof elements, corrosion (to metal components), and damage to non-primed roof paint or stain (Blong, 1984;Matsumoto et al., 1988;Trebilco, 1997;Johnston et al., 2000;Becker et al., 2001;Blong, 2003;Wilson et al., 2012aWilson et al., , 2012bOze et al., 2014). Indirect costs also include roof and gutter clean up and repair, which can take considerable time and effort even after only a few millimeters of ashfall (Dillman and Roberts, 1982;Johnston et al., 2000;Becker et al., 2001;Spence at al., 2005;Sword-Daniels et al., 2011). ...
... Clean up of the gutter can be difficult and costly (e.g., Magill et al., 2013) and if done incorrectly may lead to abrasion and further damage to surfaces. If not cleaned for weeks to months, metal or painted gutters may be subject to corrosion (Becker et al., 2001;Oze et al., 2014). Roof and gutter cleaning can also lead to falls from roofs (Wardman et al., 2012;Magill et al., 2013) and result in injury or death. ...
Volcanic ash load is dependent on the migration and accumulation of ash on roofing surfaces and guttering, of which limited research has been conducted. This study investigates this knowledge gap through the empirical experimental testing of volcanic ash on variably pitched metal sheet roofs with modern PVC gutter systems, highlighting the relative importance of accumulation, migration, remobilization, saturation, and subsequent load.A testing rig delivered ash onto variably pitched roofs (pitches 15°, 25°, 30°, 35°, and 45°) with two 45° tests involving a wet surface with subsequent ashfall, and the second of ashfall with periods of wetting, followed by wetting until failure. In testing, dry ash on a dry roof accumulates at pitches up to 35°, above this pitch the percentage of ash accumulating reduces with greater percentages infilling guttering and or lost to the ground. With the introduction of a wet roof surface at 45° pitch, adherence of dry ash greatly increases, increasing accumulated ash thickness as compared to dry tests from 8% to 38%. For testing involving periods of wetting at 45° roof pitch, accumulation percentages further increased to 50%. Ash migrating from the roof surface filled guttering more rapidly at greater pitches, which once full resulted in further migrating ash to spill over the front or back gutter lips. Collapse of guttering did not occur during testing, but deformation and bracket detachment did occur at loads > 1 kPa.This study provides data on load calculations on roofing and PVC guttering through the quantification and utilization of relationships between ash fate, pitch, and the influence of water, in the development of two scenarios for both roof and gutter. These two scenarios then enable the estimation of ash accumulation and thus the load and collapse thresholds for roof and gutter at different roof pitch, which could be adopted for volcanic risk modeling or risk management.
... Blong 2003;Hayes et al. 2019;Spence et al. 1996). Although dedicated controlled experiments (Hampton et al. 2015;Oze et al. 2014;Williams et al. 2017Williams et al. , 2021 and theoretical studies (Perelli et al. 2023;Zuccaro et al. 2008) are increasingly being developed to complement dominantly empirical vulnerability models, the 2021 Tajogaite eruption highlights the need of site-specific methodologies to accurately capture the physical vulnerability at the local level to improve the accuracy of quantitative risk analyses. ...
The simultaneous or sequential occurrence of several hazards—be they of natural or anthropogenic sources—can interact to produce unexpected compound hazards and impacts. Since success in responding to volcanic crises is often conditional on accurate identification of spatiotemporal patterns of hazard prior to an eruption, ignoring these interactions can lead to a misrepresentation or misinterpretation of the risk and, during emergencies, ineffective management priorities. The 2021 eruption of Tajogaite volcano on the island of La Palma, Canary Islands (Spain), was an 86 day-long hybrid explosive-effusive eruption that demonstrated the challenges of managing volcanic crises associated with the simultaneous emission of lava, tephra and volcanic gases. Here, we present the result of a small-scale impact assessment conducted during three-field deployments to investigate how tephra fallout and lava flow inundation interacted to cause compound physical impact on buildings. The study area was a neighbourhood of 30 buildings exposed to tephra fallout during the entire eruption and by a late-stage, short-lived lava flow. Observations highlight, on one hand, the influence of clean-up operations and rainfall on the impact of tephra fallout and, on the other hand, the importance of the dynamics of lava flow emplacement in controlling impact mechanisms. Overall, results provide an evidence-based insight into impact sequences when two primary hazards are produced simultaneously and demonstrate the importance of considering this aspect when implementing risk mitigation strategies for future long-lasting, hybrid explosive-effusive eruptions in urban environments.
Supplementary Information
The online version contains supplementary material available at 10.1007/s00445-023-01700-w.
... Metallic materials installed on active volcanoes often suffer from corrosion caused by volcanic gases. Previous studies that employed experimental conditions simulating actual volcanic environments to examine the extent of volcanic gas corrosion that occurs when volcanic ash adheres to metallic materials have revealed that the amount of volcanic ash affects the extent of volcanic gas corrosion (Izumo et al. 1990;Oze et al. 2014). However, details of how metallic materials are corroded by longterm exposure to low volcanic gas concentrations in environments accessible to hikers and tourists are unknown. ...
The destruction caused by ballistic ejecta from the phreatic eruptions of Mt. Ontake in 2014 and Mt. Kusatsu-Shirane (Mt. Moto-Shirane) in 2018 in Japan, which resulted in numerous casualties, highlighted the need for better evacuation facilities. In response, some mountain huts were reinforced with aramid fabric to convert them into shelters. However, a number of decisions must be made when working to increase the number of shelters, which depend on the location where they are to be built. In this study, we propose a method of using high-strength steel to reinforce wooden buildings for use as shelters. More specifically, assuming that ballistic ejecta has an impact energy of 9 kJ or more, as in previous studies, we developed a method that utilizes SUS304 and SS400 unprocessed steel plates based on existing impact test data. We found that SUS304 is particularly suitable for use as a reinforcing material because it has excellent impact energy absorption characteristics due to its high ductility as well as excellent corrosion resistance. With the aim of increasing the structural strength of steel shelters, we also conducted an impact test on a shelter fabricated from SS400 deck plates (i.e., steel with improved flexural strength provided by work-hardened trapezoidal corrugated plates). The results show that the shelter could withstand impact with an energy of 13.5 kJ (2.66 kg of simulated ballistic ejecta at 101 m/s on impact). In addition, from the result of the impact test using the roof-simulating structure, it was confirmed the impact absorption energy is further increased when artificial pumice as an additional protective layer is installed on this structure. Observations of the shelter after the impact test show that there is still some allowance for deformation caused by projectile impact, which means that the proposed steel shelter holds promise, not only structurally, but also from the aspects of transportation and assembly. Hence, the usefulness of shelters that use steel was shown experimentally. However, shelter construction should be suitable for the target environment.
... Volcanic activity implies gas emission rich in sulphur compounds, as well as the expulsion of other materials, which can cause metallic corrosion. A number of researches address these interactions from a natural hazards point of view (OZE et al., 2014) or from a strict corrosion approach (WATANABE et al., 2006). These kinds of works do not attend heritage conservation views, which imply specifis needs. ...
Archaeometry is the application of Natural Sciences techniques, including Geography, to solve problems in Archaeology and Heritage Conservation. Corrosion constitutes the main deterioration process of metals, which is triggered by the properties of the surrounding matrix. This work focuses on atmospheric corrosion in Oaxaca, Mexico. Methods used included the creation of atmospheric corrosion stations where weight loss was measured and geo-localization of archaeo-metallurgical heritage was determined in the study area. A brief historical review of the cultural importance of metals in Mexico is also treated. Results for the three first months of measurement showed that atmospheric corrosion values are higher in the city centre, where heritage is more concentrated. Air pollution and increased temperatures attributed to global warming are considered to be relevant for explaining the data obtained. Further analysis of a full year cycle is expected to reinforce this argument. The methods used are shown to be useful heritage and urban management tools applicable to other geographic spaces.
... Experimental data (e.g. Oze et al., 2014) are also limited, and, where available, refer exclusively to materials and the building codes or standards of the tested component or system. In the absence of empirical or experimental data, theoretical calculations of the response of components, systems or networks to hazard parameters can add to the availability of quantitative vulnerability information (e.g. ...
Originally prepared for the United Nations Office for Disaster Risk Reduction, this is the first comprehensive assessment of global volcanic hazards and risk, presenting the state of the art in our understanding of global volcanic activity. It examines our assessment and management capabilities, and considers the preparedness of the global scientific community and government agencies to manage volcanic hazards and risk. Particular attention is paid to volcanic ash, the most frequent and wide-ranging volcanic hazard. Of interest to government officials, the private sector, students and researchers, this book is a key resource for the disaster risk reduction community and for those interested in volcanology and natural hazards. A non-technical summary is included for policy makers. Regional volcanic hazard profiles, with invaluable information on volcanic hazards and risk at the local, national and global scale, are provided online. This title is available as an Open Access eBook via Cambridge Books Online.
... Non-structural damage ranges from corrosion and abrasion of gutters and overhangs (~1 kg/m 2 ) to their potential destruction (≥ 100 kg/m 2 ) (Oze et al. 2014;Hampton et al. 2015). Structural damage, spanning partial to complete collapse of roofs and supporting structures, is highly dependent on the building type and ranges between 100 and 400 kg/m 2 (for roofs with timber support) to between 400 and 1400 kg/m 2 (for reinforced concrete roofs) (Pomonis et al. 1999;Spence et al. 2005;Jenkins et al. 2014a;Zuccaro et al. 2015). ...
We present an exposure analysis of infrastructure and lifeline to tephra fallout for a future large-scale explosive eruption of Sakurajima volcano. An eruption scenario is identified based on the field characterization of the last subplinian eruption at Sakurajima and a review of reports of the eruptions that occurred in the past six centuries. A scenario-based probabilistic hazard assessment is performed using the Tephra2 model, considering various eruption durations to reflect complex eruptive sequences of all considered reference eruptions. A quantitative exposure analysis of infrastructures and lifelines is presented primarily using open-access data. The post-event impact assessment of Magill et al. (Earth Planets Space 65:677–698, 2013) after the 2011 VEI 2 eruption of Shinmoedake is used to discuss the vulnerability and the resilience of infrastructures during a future large eruption of Sakurajima. Results indicate a main eastward dispersal, with longer eruption durations increasing the probability of tephra accumulation in proximal areas and reducing it in distal areas. The exposure analysis reveals that 2300 km of road network, 18 km² of urban area, and 306 km² of agricultural land have a 50% probability of being affected by an accumulation of tephra of 1 kg/m². A simple qualitative exposure analysis suggests that the municipalities of Kagoshima, Kanoya, and Tarumizu are the most likely to suffer impacts. Finally, the 2011 VEI 2 eruption of Shinmoedake demonstrated that the already implemented mitigation strategies have increased resilience and improved recovery of affected infrastructures. Nevertheless, the extent to which these mitigation actions will perform during the VEI 4 eruption presented here is unclear and our hazard assessment points to possible damages on the Sakurajima peninsula and the neighboring municipality of Tarumizu.
... Recent studies have primarily focused on infrastructure vulnerability and related parameters (e.g. Jenkins et al., 2014, Oze et al., 2014, but also on more specific impacts of volcanic tephra on important electrical equipment such as high voltage power systems and even laptops exist (Wardman et al., 2012, Wardman et al., 2014. However, these previous studies did not consider the photovoltaic sector in detail, despite the high exposure to tephra fall. ...
Large volcanic eruptions may lead to significant tephra dispersion, crossing borders and affecting distant and industrial societies in various ways. While the effects of volcanic ash clouds on the aviation industry have been recognized, damaging effects on the photovoltaic energy sector are poorly investigated. Here we describe the influence of volcanic tephra deposition on photovoltaic (PV) modules that we experimentally analyzed and evaluated. A systematic set of experiments was conducted under controlled conditions using an artificial light source and measuring the electrical power generated from the PV-modules with the aim to determine the dependency of the amount of tephra covering a module and its subsequent loss in power production (measured in voltage and current) as well as the influence of the tephra grain size. We find that a mass of fine tephra has a stronger influence on the PV-modules power generation than the same mass of coarser particles. An application to the fine-grained 2010 Eyjafjallajökull eruption in Iceland and the resulting ash-cloud reveals that the power produced by PV-modules in continental Europe might have been affected significantly. Deposits were thick enough to cause complete failures of PV-modules up to a distance of about 300 km downwind. Although this distance is largely over the ocean in this particular case, our results imply that similar and larger eruptions of other volcanoes elsewhere might harm commercial or private energy production at distances of hundreds to thousands of kilometers from the volcano. Given that volcanic eruptions are frequent and the fact that the PV-industry is growing rapidly, negative impacts are expected in the future, requiring close tephra dispersion monitoring and PV-maintenance strategies.
... Experimental data (e.g. Oze et al., 2014) are also limited, and, where available, refer exclusively to materials and the building codes or standards of the tested component or system. In the absence of empirical or experimental data, theoretical calculations of the response of components, systems or networks to hazard parameters can add to the availability of quantitative vulnerability information (e.g. ...
All explosive volcanic eruptions generate volcanic ash, fragments of rock that are produced
when magma or vent material is explosively disintegrated. Volcanic ash is then convected
upwards within the eruption column and carried downwind, falling out of suspension and
potentially affecting communities across hundreds, or even thousands, of square kilometres.
Ash is the most frequent, and often widespread, volcanic hazard and is produced by all
explosive volcanic eruptions. Although ash falls rarely endanger human life directly, threats to
public health and disruption to critical infrastructure services, aviation and primary production
can lead to potentially substantial societal impacts and costs, even at thicknesses of only a few
millimetres. Communities exposed to any magnitude of ash fall commonly report anxiety about
the health impacts of inhaling or ingesting ash (as well as impacts to animals and property
damage), which may lead to temporary socio-economic disruption (e.g. evacuation, school and
business closures, cancellations). The impacts of any ash fall can therefore be experienced
across large areas and can also be long-lived, both because eruptions can last weeks, months or
even years and because ash may be remobilised and re-deposited by wind, traffic or human
activities.
Given the potentially large geographic dispersal of volcanic ash, and the substantial impacts that
even thin (a few mm in thickness) deposits can have for society, this chapter elaborates upon
the ash component of the overviews provided in Chapters 1 and 2. We focus on the hazard and
associated impacts of ash falls; however, the areas affected by volcanic ash are potentially much
larger than those affected by ash falling to the ground, as fine particles can remain aloft for
extended periods of time. For example, large portions of European airspace were closed for up
to five weeks during the eruption of Eyjafjallajökull, Iceland, in 2010 because of airborne ash
(with negligible associated ash falls outside of Iceland). The distance and area over which
volcanic ash is dispersed is strongly controlled by wind conditions with distance and altitude
from the vent, but also by the size, shape and density of the ash particles, and the style and
magnitude of the eruption. These factors mean that ash falls are typically deposited in the
direction of prevailing winds during the eruption and thin with distance. Forecasting ash
dispersion and the deposition ‘footprint’ is typically achieved through numerical simulation.
In this chapter, we discuss volcanic ash fall hazard modelling that has been implemented at the
global and local (Neapolitan area, Italy) scales (Section 3.2). These models are probabilistic, i.e.
they account for uncertainty in the input parameters to produce a large number of possible
outcomes. Outputs are in the form of hazard maps and curves that show the probabilities
associated with exceeding key hazard thresholds at given locations. As with any natural hazard,
these results are subject to uncertainty and the local case study describes how ongoing research
is working to better quantify this uncertainty through Bayesian methods and models. Further
to the ash fall hazard assessments, we discuss the key components required to carry these
hazard estimates forward to risk: namely identification of likely impacts and the response
(vulnerability) of key sectors of society to ash fall impact. The varied characteristics of volcanic
ash, e.g. deposit thickness and density, particle size and surface composition, the context, e.g.
timing and duration of ash fall, and resilience of exposed people and assets can all influence the
type and magnitude of impacts that may occur. We draw from data collected during and
following past eruptions and experimental and theoretical studies to highlight likely impacts for
key sectors of society, such as health, infrastructure and the economy (Section 3.3). In many
parts of the world, the failure, disruption or reduced functionality of infrastructure or societal
activities, e.g. ability to work or go to school, is likely to have a larger impact on livelihoods and
the local economy than direct damage to buildings. Broad relationships between ash thickness
(assuming a fixed deposit density) and key levels of damage is also outlined (Section 3.4);
however, vulnerability estimates are typically the weakest part of a risk model and detailed
local studies of exposed assets and their vulnerability should ideally be carried out before a
detailed risk assessment is undertaken.
Greater knowledge of ash fall hazard and associated impacts supports mitigation actions, crisis
planning and emergency management activities, and is an essential step towards building
resilience for individuals and communities. This chapter concludes with a discussion on where
some of the important advances in ash fall hazard and risk assessment may be achieved,
providing a roadmap for future research objectives.
Introduction
Localized corrosion in welds has always been a very common and difficult problem in many industrial fields. Preferential corrosion usually occurs in the weld zones with irregular shapes of metal welds due to the welding process.
Methods
To address the challenge of monitoring corrosion behavior at the weld zone in real-time, a novel Ag/AgCl flexible array, arranged in a 4×8 electrode configuration, has been developed. This array is employed for in situ monitoring of the corrosion process in Q235 steel welded joints (including single butt welds, double butt welds, and fillet welds) immersed in a 0.01 mol/L NaCl solution with a pH of 9. The measurement is conducted using a custom-made array electrode signal test system.
Results
The results demonstrate that the prepared electrode exhibits a highly responsive behavior to chlorine ions from 0.001 to 0.1 mol/L concentration and maintains excellent stability during 4000s. The weld zone shows higher corrosion activity and trends to generate pitting corrosion for all three welded joints in the first 15 min. With the increase of time, micro pitting corrosion dissolves and expands to macro point corrosion in the next 30 min.
Conclusion
The flexible reference array electrode proves to be a powerful tool for the in situ monitoring of carbon steel corrosion, offering a comprehensive depiction of the steel's corrosion status over time. Such insights are crucial for making accurate corrosion predictions and conducting service life evaluations of steel structures.
As a precise volume of volcanic ash-plume is essential to understand the dynamic of gas emission, exchanges and the eruptive dynamics, we have measured in 3D using photogrammetry a small-size volcanic plume at the summit of Yasur Volcano, Vanuatu. The objective was to collect the altitude and planform shape of the plume as well as the vertical variations of the shape and size. To reach this objective, the authors have used the Structure from Motion photogrammetric method applied to a series of photographs captured in a very short period of time around and above the plume. A total of 146 photographs at 3000x4000 pixel were collected as well as the geolocation, the pitch, tilt and orientation of the cameras. The results revealed a "mushroom"-like shape of the plume with a narrow ascending column topped by a turbulent mixing zone. The volume of the plume was calculated to be ~13,430 m 3 +/-512 m 3 (with the error being the cube of the linear error from the Ground Control Points) for a maximum height above the terrain of 63 m. The included error was also kept high because of the irregular distribution of the Ground Control Points that could not be collected in dangerous areas due to the ongoing eruption. Based on this research, it is therefore worth investigating the usage of multiple cameras to capture plumes in 3D over time and the method is also a good complement to the recent development of photogrammetry from space, which can tackle larger-scale eruption plumes.
All explosive eruptions produce volcanic ash, fragments of volcanic rock generated
when magma or vent material is explosively disintegrated during eruption. Volcanic
ash is convected upwards within the eruption column and carried downwind, falling
out of suspension and potentially affecting communities across hundreds of square
kilometers. Although ash falls rarely endanger human life directly, threats to public
health and disruption to critical infrastructure services, aviation, and primary
production (e.g. agriculture) can lead to significant societal impacts. Even relatively
small eruptions such as the Eyjafjallajo¨kull eruption in Iceland in 2010 (Volcanic
Explosivity Index of 4) can cause widespread disruption, damage, and economic loss.
Knowledge of the likely impacts can support mitigation actions, crisis planning, and
emergency management activities. This chapter presents an overview of ash fall
impacts for sectors of society including buildings, critical infrastructure, and agriculture;
and discuss associated socioeconomic factors. We also discuss the likely
response (vulnerability) of these key sectors to ash fall impacts. Broad relationships
between volcanic ash thickness and levels of damage and disruption have been outlined.
Understanding these vulnerabilities is an essential step towards building
resilience for communities.
Effective natural hazard risk assessment requires the characterisation of both hazards and vulnerabilities of exposed elements. Volcanic hazard assessment is at an advanced state and is a considerable focus of volcanic scientific inquiry, whereas comprehensive vulnerability assessment is lacking. Cataloguing and analysing volcanic impacts provide insight on likely societal and physical vulnerabilities during future eruptions. This paper reviews documented disruption and physical damage of critical infrastructure elements resulting from four volcanic hazards (tephra fall, pyroclastic density currents, lava flows and lahars) of eruptions in the last 100 years. We define critical infrastructure as including energy sector infrastructure, water supply and wastewater networks, transportation routes, communications, and critical components. Common trends of impacts and vulnerabilities are summarised, which can be used to assess and reduce volcanic risk for future eruptions. In general, tephra falls cause disruption to these infrastructure sectors, reducing their functionality, while flow hazards (pyroclastic density currents, lava flows and lahars) are more destructive causing considerable permanent damage. Volcanic risk assessment should include quantification of vulnerabilities and we challenge the volcanology community to address this through the implementation of a standardised vulnerability assessment methodology and the development and use of fragility functions, as has been successfully implemented in other natural hazard fields.
Long-term volcanic activity at Soufrière Hills volcano, Montserrat (1995-ongoing) has created challenges for society and the resilience of the essential services (infrastructure) that support it. This paper explores the consequences, adaptations and resilience of essential services through interviews with their staff. We find that quick fixes for essential service reinstatement in the north of Montserrat have prevailed. Yet the legacy of this approach inhibits functionality through inadequate facilities and the perception of sites as temporary, stalling investment. Emigration resulted in staff shortages, retraining requirements, and challenges for the viability of specialist services. Low-impact hazards exacerbate shortcomings in essential services, causing power cuts, corrosion, and temporary closures of schools, clinics and the airport. Adaptations developed over time include changes to roofing materials, the addition of back-up systems, collaborative working and development of contingency plans. Resilience of essential services has improved through decentralisation, adaptations, and via strong community networks and tolerance of disruptions. Barriers to increasing resilience include the expense of some adaptations and the current reluctance to invest in essential services, hindering development. We offer some lessons for policy and practice to guide post-crisis redevelopment, through engagement with the community and by complementing community-level adaptations with investment to address long-term needs.
A corrosion test site was established at the Kilauea volcano in Volcanoes National Park on the island of Hawai'i in August of 2006. Atmospheric conditions including temperature, humidity, rainfall, solar radiation, wind speed, wind direction, time-of-wetness (TOW) and chloride deposition rate were monitored for a period of one year. Rainwater was collected and analyzed over a period of one year. 6061-T6 aluminum coupons were exposed at the site for 3, 6, and 12 months and corrosion data for 6061-T6 was generated. After one year, the corrosion rate of 6061-T6 at Kilauea was more than seven times higher than the corrosion rate of 6061-T6 at an industrial site on Oahu. Pure silver (Ag) coupons were exposed for thirteen months at the site and were characterized using x-ray diffraction (XRD) and energy dispersive x-ray analysis (EDXA) techniques. The only corrosion product detected with XRD on silver coupons exposed was silver chloride (AgCl). EDXA revealed approximately 0.25 wt% sulfur (S) on only one of thirteen coupons exposed. Chloride deposition rates derived from the increase in mass of silver coupons did not agree with monthly wet chloride candle data collected at the same location.
The photocatalyzed oxidative decompositions of solid particles of polyvinylchloride (PVC; size about 100 to 200 μm), of the polyvinylidene chloride copolymer (95% PVC/5% PVLC; size ∼ 400–600 μm), and a PVC film have been examined in suspensions of titania and zinc oxide illuminated by UV light and/or by natural sunlight. Dechlorination and evolution of carbon dioxide were monitored, the latter occurring by the intermediacy of acetic and formic acids. The photodegradation of polymer specimens was enhanced in TiO2/water media by such added oxidants as hydrogen peroxide and potassium persulfate. Photocorrosion of these particulates was also examined by scanning electron microscopy. © 1996 John Wiley & Sons, Inc.
Leaching of freshly erupted air-fall ash, unaffected by rain, from the May 18, 1980, eruption of Mount St. Helens volcano, Washington, shows that Ca2+, Na+, Mg2+, SO
42−, and Cl− are the predominant chemical species released on first exposure of the ash to water. Extremely high correlation of Ca with SO4 and Na with Cl in water leachates suggests the presence of CaSO4 and NaCl salts on the ash. The amount of water soluble material on ash increases with distance from source and with the weight fraction of small (less than 63 micrometers) ash particles of high-surface area. This suggests that surface reactions such as adsorption are responsible for concentrating the soluble material. CaSO4, NaCl, and other salts are probably formed as microscopic crystals in the high-temperature core of the eruption column and are then adsorbed by silicate ash particles.
The environmentally important elements Zn, Cu, Cd, F. Pb, and Ba are released by a water leach in concentrations which could pose short-term hazards to some forms of aquatic life. However, calculated concentrations are based on a water-to-ash ratio of 4:1 or less, which is probably an underestimation of the regionally operative ratio. A subsequent leach of ash by warm alkaline solution shows dramatic increases, in the amount of dissolved SiO2, U, and V, which are probably caused by increased dissolution of the glassy component of ash. Glass dissolution by alkaline ground water is a mechanism for providing these three elements to sedimentary traps where they may coaccumulate as uraniferous silica or U-V minerals.
Leaching characteristics of ash from Mount St. Helens are comparable to characteristics of ash of similar composition from volcanoes in Guatemala. Ashes from each locality show similar ions predominating for a given leachate and similar fractions of a particular element in the ash removed on contact with the leach solution.
Studies of the respiratory health effects of different types of volcanic ash have been undertaken only in the last 40years, and mostly since the eruption of Mt. St. Helens in 1980. This review of all published clinical, epidemiological and toxicological studies, and other work known to the authors up to and including 2005, highlights the sparseness of studies on acute health effects after eruptions and the complexity of evaluating the long-term health risk (silicosis, non-specific pneumoconiosis and chronic obstructive pulmonary disease) in populations from prolonged exposure to ash due to persistent eruptive activity. The acute and chronic health effects of volcanic ash depend upon particle size (particularly the proportion of respirable-sized material), mineralogical composition (including the crystalline silica content) and the physico-chemical properties of the surfaces of the ash particles, all of which vary between volcanoes and even eruptions of the same volcano, but adequate information on these key characteristics is not reported for most eruptions. The incidence of acute respiratory symptoms (e.g. asthma, bronchitis) varies greatly after ashfalls, from very few, if any, reported cases to population outbreaks of asthma. The studies are inadequate for excluding increases in acute respiratory mortality after eruptions. Individuals with pre-existing lung disease, including asthma, can be at increased risk of their symptoms being exacerbated after falls of fine ash. A comprehensive risk assessment, including toxicological studies, to determine the long-term risk of silicosis from chronic exposure to volcanic ash, has been undertaken only in the eruptions of Mt. St. Helens (1980), USA, and Soufrière Hills, Montserrat (1995 onwards). In the Soufrière Hills eruption, a long-term silicosis hazard has been identified and sufficient exposure and toxicological information obtained to make a probabilistic risk assessment for the development of silicosis in outdoor workers and the general population. A more systematic approach to multi-disciplinary studies in future eruptions is recommended, including establishing an archive of ash samples and a website containing health advice for the public, together with scientific and medical study guidelines for volcanologists and health-care workers.
Tephra in plumes can scavenge and thereby rapidly deposit volatiles including sulphur, halogen and metal species. These may then be leached (e.g. by rainfall), potentially releasing heavy loadings to soils and water bodies. Several eruptions have resulted in contamination of pasture, sometimes with serious impacts on livestock. Water quality has also been an issue in some areas affected by tephra fall. This work synthesises the literature on volcanic ash-leachates and considers the controls on volatile adsorption. General trends emerge for basaltic, intermediate and silicic tephra, as well as for variable particle size and transport distance. The applications of ash-leachate data to plume-gas geochemistry, calculation of volatile budgets and environmental impact assessment are evaluated. Comparisons for different eruptions are hampered by disparities in leachate analysis techniques. A standardised methodology is therefore proposed to facilitate future health impact assessment and volcanological interpretation of results from different sites.
On April 14, 2010, when meltwaters from the Eyjafjallajökull glacier mixed with hot magma, an explosive eruption sent unusually fine-grained ash into the jet stream. It quickly dispersed over Europe. Previous airplane encounters with ash resulted in sandblasted windows and particles melted inside jet engines, causing them to fail. Therefore, air traffic was grounded for several days. Concerns also arose about health risks from fallout, because ash can transport acids as well as toxic compounds, such as fluoride, aluminum, and arsenic. Studies on ash are usually made on material collected far from the source, where it could have mixed with other atmospheric particles, or after exposure to water as rain or fog, which would alter surface composition. For this study, a unique set of dry ash samples was collected immediately after the explosive event and compared with fresh ash from a later, more typical eruption. Using nanotechniques, custom-designed for studying natural materials, we explored the physical and chemical nature of the ash to determine if fears about health and safety were justified and we developed a protocol that will serve for assessing risks during a future event. On single particles, we identified the composition of nanometer scale salt coatings and measured the mass of adsorbed salts with picogram resolution. The particles of explosive ash that reached Europe in the jet stream were especially sharp and abrasive over their entire size range, from submillimeter to tens of nanometers. Edges remained sharp even after a couple of weeks of abrasion in stirred water suspensions.
Plinian and subplinian volcanic eruptions can be accompanied by tephra falls which may last hours or days, posing threats to people, buildings and economic activity. Numerous historical examples exist of tephra damage and tephra casualties. The mechanisms and consequences of roof collapse from static tephra load are an important area of tephra damage requiring more research.
This paper contributes to this work by estimating the structural vulnerability of buildings to tephra load based on both analytical studies and observed damage. New studies are presented of roof strengths in the area around Mt. Vesuvius in southern Italy and of field surveys undertaken in other European volcanic locations to assess building vulnerability to tephra fall.
The results are a proposed set of new European tephra fall roof vulnerability curves in areas potentially threatened by explosive volcanic eruptions along with comments on the human casualty implications of roof collapse under tephra loading. Some mitigation recommendations are provided.
Continuous low-level basaltic volcanic activity, from Yasur Volcano in Tanna, and Marum and Benbow vents on Ambrym, occurred for as long as records have been kept in Vanuatu. The potential chronic health implications for the inhabitants of these two areas were investigated in a preliminary environmental sampling program. The focus was particularly on fluoride and other volcanic gas-derived chemical contamination in areas surrounding the volcanic centres. Little immediate contamination of the environment was evident for areas affected by volcanic ash and gas on Tanna, with water fluoride concentrations being elevated (to 0.42 mg x l(-1)) only within a lake adjacent to the active volcanic cone. Selected re-sampling in April 2001 following the long active phase of Yasur, revealed higher F levels in surface waters (to 1.05 mg x l(-1)). Analysis of cow rib bone and teeth indicated a possible long-term accumulation of F in grazing animals, which probably consume F-bearing volcanic ash and gas hydrates on the surface of plant leaves. No human impacts (including stress and respiratory problems) were noted, probably due to the constant and familiar low-level activity, plus the coarse nature of most ash ejecta. Ambrym appears to be a more F-concentrated system than Tanna, with volcanic ash containing 281 total and 36.7-43.6 soluble mg F x kg(-1) (cf. 178 total and 7.3-9.1 soluble mg F x kg(-1) on Tanna), and water levels reaching up to 2.8 mg F x l(-1) in rainwater tanks. The drinking water F levels on Ambrym are higher than WHO recommended levels, despite the being sampled during a substantial lull in eruptive activity, and signal potential for chronic dental and skeletal fluorosis.
Corrosion tests where heating and cooling are repeated between 40°C and 20°C in a SO2 gas atmosphere (150-200 ppm) were carried out on carbon steel (SS 41), copper, aluminium, and zinc-plated steel covered with volcanic ash. Corrosion phenomena were investigated by measurement of mass loss and electron probe microanalysis. For SS 41, aluminium, and zinc-plated steel, the corrosion is accelerated by ash when it is thick on the surface. The copper specimen corrodes faster in the case of no volcanic ash, while in the presence of volcanic ash corrosion is accelerated as the ash layer becomes thicker. These effects are attributed to capillary condensation and the water-retaining effects of ash.
The 2011 eruption of Shinmoedake, Japan, deposited tephra across Miyazaki prefecture impacting both urban and rural environments. We provide an overview of the impacts, management and recovery of a modern city, infrastructure networks and a diverse agricultural region following this moderate sized explosive eruption, focusing on four key sectors. Cleanup of tephra was time consuming, physically demanding and costly for residents, businesses and municipal authorities. The agricultural sector sustained large initial impacts with smothering, loading and abrasion of crops, soils and greenhouses. However, extreme concerns at the time of the eruption were not realised, with farming operations experiencing limited long-term effects. There were few disruptions to electrical networks due to resilient insulator design, a successful cleaning program, relatively coarse tephra and dry conditions. Cancellations and delays occurred on three rail lines resulting primarily from mechanical failure of track switches and loss of electrical contact between train wheels and tracks. Both residents and organisations exhibited high levels of adaptive capacity in response to the event and utilised regional and national networks to obtain information on past events and recovery strategies. The combination of relatively short eruption duration, well resourced and coordinated organisations and resilient infrastructure networks contributed to a strong recovery.
Laptop computers are vital components of critical infrastructure sectors and a common tool in broader society. As they become more widely used, their exposure to volcanic hazards will increase. Therefore, understanding how laptops will function in volcanic environments is necessary to provide suitable mitigation options. In this study, laptop computers were subjected to volcanic ash and gas in both laboratory and field settings. None of the laptops sustained permanent damage in laboratory experiments; however, ash contamination did reduce the functionality of keyboards, CD drives, and cooling fans. Several laptops shut down temporarily due to overheating following ash contamination. In field experiments, laptops were exposed to high concentrations of volcanic gases at White Island, New Zealand. These laptops did not sustain permanent damage as only a small amount of gas was able to enter the laptops. However, metal components on the outside of the laptop did sustain minor corrosion. Re-examination of the laptops after 6 months indicated they were in full working order. Printed circuit boards suffered significant corrosion damage and ceased working only when in direct and sustained contact with volcanic gases. Simple mitigation techniques such as isolating laptops inside heavy duty polyethylene bags were effective. Overall, our experiments demonstrate that laptops have a relatively low risk of damage from volcanic ash and gas exposure, but have a low-medium risk of loss of functionality in ash environments. We think this has implications for other electronic equipment used extensively in critical infrastructure services.
The Earth’s history is punctuated by large explosive eruptions that eject large quantities of magma and silicate rock fragments into the atmosphere. These tephra particles can sometimes be dispersed across millions of square kilometres or even entire continents. The interaction of tephra with or in receiving environments may induce an array of physical, chemical and biological effects. The consequences for affected systems and any dependent communities may be chronic and localised in the event of frequent, small eruptions, while larger and rarer events may have acute, regional-scale impacts. It is, therefore, necessary to document the range of possible impacts that tephra may induce in receiving environments and any resulting effects in interconnected systems. We collate results from many studies to offer a detailed multidisciplinary and interdisciplinary review of the immediate post-eruptive effects of tephra emission into the atmosphere, onto vegetation, soil or ice/snow surfaces and in aquatic systems. We further consider the repercussions that may be induced in the weeks to years afterwards. In the atmosphere, tephra can influence cloud properties and air chemistry by acting as ice nuclei (IN) or by offering sites for heterogeneous reactions, respectively. Tephra on vegetation causes physical damage, and sustained coverage may elicit longer-term physiological responses. Tephra deposits on soils may alter their capacity to exchange gas, water and heat with the atmosphere or may have a specific chemical effect, such as nutrient input or acidification, on sensitive soils. Tephra deposition onto snow or ice may affect ablation rates. Rivers and lakes may experience turbidity increases and changes in their morphology as a result of fallout and prolonged (months or years) erosion from the tephra-covered catchment. In the first weeks after deposition, tephra leaching may affect river chemistry. The abundance and speciation of phytoplankton populations in lakes may be altered by tephra-induced changes in water chemistry or sediment–water nutrient cycling. In the oceans, tephra deposition may fertilise Fe-limited waters, with potential impacts on the global carbon cycle. Embracing the full complexity of environmental effects caused by tephra fall demands a renewed investigative effort drawing on interdisciplinary field and laboratory studies, combined with consideration of the interconnectivity of induced impacts within and between different receiving environments.
This volume examines the diverse effects of volcanic eruptions on people and their activities using examples and case studies. Eight broad groups of volcanic hazards - lava flows, ash (tephra) falls, pyroclastic flows, lahars (mudflows), volcanogenic earthquakes, volcanogenic tsunami, atmospheric phenomena such as shock waves and lightening strikes, and acid rains and gases - are identified and discussed. The social effects of eruptions are discussed, including human perceptions, mental health problems, evacuation, panic, rumors, disaster relief, religious beliefs, and longer-term social changes. Attention is also given to the effects of volcanic hazards on agriculture and other forms of economic activity. Throughout the book suggestions are made indicating ways in which casualties and damage may be reduced.
Volcanic ash samples from the May 18, 1980, Mount St. Helens eruption were analyzed for major, minor, and trace composition by a variety of analytical techniques. Results indicate that the basic composition of the ash consists of approximately 65% SiO2, 18% Al2O3, 5% FetO3, 2% MgO, 4% CaO, 4% Na2O, and 0.1% S. Thirty seven trace metals are reported including Ba, Cu, Mn, Sr, V, Zn, and Zr. A change in the chemical composition of the ash as a function of distance from the volcano is related to a similar change in physical characteristics of the ash. Water soluble components were also determined after column leaching experiments were performed. Concentration levels of soluble salts were found to be moderately high (1500-2000 mug/g) with molar ratios suggesting the presence of NaCl, KCl, CaSO4, and MgSO4. Heavy metals such as Cu, Co, Mn, and Zn were found at appreciable concentrations (10-1000 mug/g). Unexpectedly high concentration levels of ammonium (45 mug/g) and nitrate (100 mug/g) ions as well as dissolved organic carbon (130 mug/g) were observed in several ash leachates. Results for fluoride and boron show low average levels ~5 and ~0.5 mug/g, respectively.
Volcanic ash contamination of high voltage (HV) power networks compromises the reliability of society’s electricity supply. Ash-induced insulator flashover is a common problem on transmission networks during explosive eruptions, which is attributed to the high conductivity (σ), low resistivity (ρ) of volcanic ash. However, there have been few studies which have investigated the electrical conductivity of volcanic ash and how it may be influenced by different volcanological and environmental factors. In this study we have used a simple and rapid testing method to measure the influence of ash composition, grain size, soluble salt content, compaction and moisture (water) content on ash conductivity. We also developed physically, chemically and electrically equivalent ash proxies to be used for current and future laboratory experimentation. Results indicate that dry volcanic ash is non-conducting (ρ>1.56×107 Ωm), however, the conductivity of volcanic ash increases abruptly with the adsorption of water. Further increase in conductivity has been observed with increasing soluble salt content and compaction. All grain sizes (<32 um to 1.4 mm) can exhibit high conductivity values (p < 100 Ωm) and therefore have similar potential to cause flashover on HV insulation. The methodology development and results herein represent a benchmark for in-field testing during volcanic crises and for future studies.
Average chemical compositions are given for the common plutonic rock types and their volcanic equivalents. An attempt has been made also to give the general average chemical compositions of silicic, intermediate, subsilicic and ultramafic igneous rocks
Photocatalysis application in effluent decontamination is becoming one of the most promising green chemistry technologies. In this paper, natural volcanic ash particles have been characterized and used either as photocatalysts or as a support for a titania-containing photocatalyst. The natural material alone displayed good photocatalyst behaviour as a consequence of the presence of some titanium compounds in its composition. The original ashes were further loaded with TiO2 through hydrolysis of TiOSO4 under hydrothermal conditions. Activity tests of these Ti-loaded materials in the photocatalytic decomposition and elimination of phenol-type organic pollutants in water displayed good activity which makes them candidates to be used as photocatalysts for waste water treatment.
Anodic and cathodic polarization of zinc was carried out in 0.1 M sodium chloride (NaCl) solution with pH ranging from 1 to 13. The electrochemical data was then contrast to thermodynamic chemical equilibrium diagrams. The analysis shows that, in general, variations in corrosion of zinc with pH are associated with the cathodic currents. In acidic solutions, the active form of corrosion occurring is controlled by the kinetics of the cathodic reaction (predominantly hydrogen evolution). In the pH range (7 to 10), the lowered cathodic reaction rate reduces overall zinc corrosion rates. The surface oxides thermodynamically predicted to form in this pH (7 to 10) do not form an effective corrosion protection barrier. In alkaline conditions corrosion occurs chiefly by the formation of zinc hydroxide complexes or zinc oxides that could protect the surface depending on local pH and potential at the metal surface. This work expands the knowledge on zinc electrode kinetics over a wide range of pH and augments the existing literature on zinc corrosion.
The dissolution mechanisms of multioxide silicate minerals and glasses differ from those of single (hydr)oxides because their dissolution may require the breaking of more than one metal-oxygen bond type. A general kinetic description of major rock forming multioxide silicate dissolution is developed in the present study by assuming the following: (1) the relative rates at which various metal-oxygen bonds are broken within a multioxide structure are consistent with the relative dissolution rates of the single (hydr)oxides; (2) the difference in the rates of breaking each metal-oxygen bond type is sufficiently large such that the reaction breaking one bond type can attain equilibrium before breaking substantial quantities of slower breaking metal-oxygen bonds; and (3) those metal oxygen bonds that break before the final destruction of the structure liberate metal atoms via metal-proton exchange reactions.Multioxide dissolution proceeds via a series of metal-proton exchange reactions until the mineral or glass structure is destroyed. This metal-proton exchange reaction sequence is shown to be consistent with leached layer compositions at acidic conditions. The last metal-proton exchange reaction in the series is slowest and thus rate controlling. Of these slowest exchanging metals, those partially freed from the structure by being adjacent to previously exchanged metals are liberated faster than those completely attached to the mineral or glass and thus constitute the rate-controlling precursor complex. The identity and reactions forming this precursor complex are used within the context of transition-state theory to derive equations that describe accurately the dissolution rates of the major rock-forming multioxide silicate minerals and glasses as a function of solution composition over the full range of chemical affinity.
Kagoshima has an active volcano, Sakurajima, at the southern edge of Japan, which belches out smoke and ash almost every day. The volcanic ash falls over Kagoshima, a city of more than 530 000 people, situated only 10 km from Sakurajima. Therefore, indoor air pollution due to the volcanic ash is a serious local problem. In these circumstances, a natural ventilation system with an ash-resistant device was developed, and its performance was tested. It has been proved from exposure tests that the amount of ash entering a room is reduced to about of that from ventilation systems in general use.
Corrosion products that had been formed on copper and silver plates exposed in Miyake Island, where suffered a volcanic eruption in 2000, were analyzed by X-ray techniques to get better understanding of copper and silver corrosion in harsh environment. The exposure experiment was carried out from September 2004 to April 2005. Many kinds of patina were found on copper such as cuprite (Cu2O), posnjakite (Cu4SO4(OH)6·H2O), brochantite (Cu4SO4(OH)6), antlerite (Cu3SO4(OH)4), and geerite (Cu8S5). For silver, silver chloride (AgCl) and silver sulfide (Ag2S) were formed. Although the volcanic activity had greatly subsided, the atmospheric corrosion of copper and silver plates exposed on Miyake Island was mainly affected by volcanic gases, wet–dry cycles in the environment, and sea-salt aerosols.
VolcaNZ is a probabilistic volcanic loss model developed for the Auckland Region in New Zealand that currently considers tephra fall hazards from the Auckland Volcanic Field (AVF), Tuhua volcano, Okataina volcanic centre, Taupo volcano, Tongariro volcanic centre and Egmont volcano. In this first version of the model, structural and non-structural damage to residential building envelopes and associated cleanup costs are calculated using Monte Carlo simulation.VolcaNZ assigns a Minimum and Maximum Damage Value to groups of buildings for every simulation, dependent on tephra thickness. A Central Damage Value, representing loss as a percentage of total replacement cost, is then randomly selected between these limits. Even with small-thickness falls, non-structural damage is expected to roof and wall coatings, air-conditioning units, aerials and satellite dishes due to the corrosive and abrasive properties of tephra. An average loss of 1 billion losses, due to structural damage, occur at about 35,000 years and this increases to about 160 million for ARIs above about 600 years. Between 600 and 3000 years, cleanup loss is approximately 450 million at a return period of 1 million years. At ARIs between 600 and 3000 years, total loss is approximately 10 billion at 100,000 years and over $26 billion at 1 million years. Because we only consider residential building damage and associated cleanup, these values greatly underestimate total loss from the next volcanic event to impact Auckland. Loss calculations will be improved by adding additional hazard and loss modules to VolcaNZ, resulting in a complete catastrophe loss model.
Samples of ash from the 18 May 1980 eruption of Mount St. Helens were collected from several locations in eastern Washington
and Montana. The ash was subjected to a variety of analyses to determine its chemical, physical, mineralogical, and biological
characteristics. Chemically, the ash samples were of dacitic composition. Particle size data showed bimodal distributions
and differed considerably with location. However, all samples contained comparable amounts of particles less than 3.5 micrometers
in diameter (respirable fraction). Mineralogically, the samples ranged from almost totally glassy to almost totally crystalline.
Crystalline samples were dominated by plagioclase feldspar (andesine) and orthopyroxene (hypersthene), with smaller amounts
of titanomagnetite and hornblende. All but one of the samples contained from less than 1 percent to 3 percent free crystalline
silica (quartz, trydimite, or cristobalite) in both the bulk samples and 1 to 2 percent in the fractions smaller than 3.5
micrometers. The long-lived natural radionuclide content of the ash was comparable to that of crustal material; however, relatively
large concentrations of short-lived radon daughters were present and polonium-210 content was inversely correlated with particle
size. In vitro biological tests showed the ash to be nontoxic to alveolar macrophages, which are an important part of the
lungs' natural clearance mechanism. On the basis of a substantial body of data that has shown a correlation between macrophage
cytotoxicity and fibrogenicity of minerals, the ash is not predicted to be highly fibrogenic.
This paper describes a multiscale (from global to micron) model for the prediction of atmospheric corrosion. The model has a modular structure, in which the higher scales set the boundary conditions for the lower scales, and the lower scales alter some of the constants in the upper scales. The model has primarily been designed for Australian conditions and so focuses on corrosion by marine aerosols. The upper level modules look at aerosol production by oceans and surf beaches, salt transport and deposition, and cleaning events such as rain and wind, to provide an estimate of salt retention on surfaces. Separate modules that define surface temperature, surface relative humidity, and wetting and drying of deposited hygroscopic salts, enable the prediction of the (three-hourly) ‘state’ of a surface, where ‘state’ is defined as dry, wet from rain or wet from the wetting of hygroscopic salts. The state model is combined with a damage model to estimate the progression of damage with time. Currently, damage models are either probabilistic (define the occurrence, growth or death of pits as probability functions) or empirical (define a single relationship between mass loss in a given state on the basis of measured data) in nature, but new experimental and modelling research is being undertaken to develop first-principle models of corrosion under established oxide films.
Damage information on 173 buildings was collected in the immediate aftermath of the September 1994 eruption which destroyed large sections of Rabaul town, Papua New Guinea. The extent of damage is presented on a five-point scale and related to construction characteristics and tephra load. Total roof loads in Rabaul town ranged from 2 to 16 kN m-2 (about 100- to 950-mm tephra thickness). Most buildings which collapsed completely experienced loads >7.5 kN m-2, but many buildings sustained half this load with little more than cosmetic damage. Timber-framed buildings suffered more than buildings with at least some concrete block walls. However, some old, steel-framed buildings experienced severe damage with tephra loads as low as 2 kN m-2. Comparisons with tephra loads and building damage elsewhere are limited but suggest that Rabaul buildings experiencing roof loads of 2-5 kN m-2 generally survived reasonably well. However, the comparisons are unsatisfactory because of inadequate data on tephra unit weights, roof design, building ages, the quality of workmanship, and the natural variability of construction materials, particularly timber. The Rabaul data suggest that concrete block walls increase building resistance to tephra loads but it is doubtful that conventional residential buildings can be designed to sustain tephra loads exceeding 7 kN m-2. The Rabaul experience also indicates that building codes for volcanic areas need to consider mudfills and post-eruption corrosion of sheet metal roofs and wall cladding. Most importantly, had the majority of buildings in Rabaul survived the September 1994 tephra falls, wet season mudflows a few months later would still have made most of the town unsafe and uninhabitable.
Photooxidation of polyurethane (PU) and its composites with anatase and rutile titanium dioxide nanoparticles induced by ultraviolet exposure was investigated in this work. Anatase was found to be a photosensitiser that accelerates photooxidation of PU, while rutile acted as an effective stabilizer retarding photooxidation of PU. With a rise in the TiO2 nanoparticle content, both photosensitivity of PU/anatase TiO2 nanocomposite and photostability of PU/rutile TiO2 nanocomposite increase. The photocatalytic degradation mechanism of PU and its nanocomposites are briefly discussed. The results are believed to facilitate proper application of TiO2 nanoparticles for different purposes.
The reactions occurring between gases/aerosols and silicate ash particles in volcanic eruption plumes remain poorly understood, despite the fact that they are at the origin of a range of volcanic, environmental, atmospheric and health effects. In this study, we apply X-ray photoelectron spectroscopy (XPS), a surface-sensitive technique, to determine the chemical composition of the near-surface region (2–10 nm) of nine ash samples collected from eight volcanoes. In addition, atomic force microscopy (AFM) is used to image the nanometer-scale surface structure of individual ash particles isolated from three samples. We demonstrate that rapid acid dissolution of ash occurs within eruption plumes. This process is favoured by the presence of fluoride and is believed to supply the cations involved in the deposition of sulphate and halide salts onto ash. AFM imaging also has permitted the detection of extremely thin (< 10 nm) coatings on the surface of ash. This material is probably composed of soluble sulphate and halide salts mixed with sparingly soluble fluoride compounds. The surface approach developed here offers promising aspects for better appraising the role of gas/aerosol–ash interaction in dictating the ability of ash to act as sinks for various volcanic and atmospheric chemical species as well as sources for others.
Pourbaix diagrams (potential/pH diagrams) for zinc at 25–300°C have been revised. The diagrams were calculated for three concentrations, 10−5, 10−6 and 10−8molal, the latter for use in high purity water such as in nuclear power reactors. Extrapolation of thermochemical data to elevated temperatures has been performed with the revised model of Helgeson-Kirkham-Flowers, which also allows uncharged aqueous complexes, such as Zn(OH)2(aq), to be handled. The calculations show that the hydroxide of zinc does not passivate at the concentration of 10−6M, due to the uncharged zinc(II) complex, Zn(OH)2(aq). However, at concentrations ≥ 10−5.7 M zinc passivates by formation of ZnO, which is stable in the temperature interval investigated.
In recent years, there has been a tremendous amount of research and development in the area of photocatalysis (heterogeneous and homogeneous), a process included in a special class of oxidation techniques defined as Advanced Oxidation Processes (AOPs), all characterized by the same chemical feature, production of OH radicals. This paper reviews the use of sunlight to produce the OH radicals by TiO2 photocatalysis and photo-Fenton process. The reacting systems necessary for performing solar photocatalysis are described. The paper also summarizes most of the research carried out related to solar photocatalytic degradation of water contaminants, and how it could significantly contribute to the treatment of persistent toxic compounds. It outlines how to enhance the process efficiency by integration with biotreatment. Various solar reactors for photocatalytic water treatment mainly based on non-concentrating collectors built during the last few years are also described in detail in this review, as well as the use of the solar photocatalytic processes to inactivate microorganisms present in water, placing special emphasis on experimental systems made to optimize this disinfection technique.
The atmospheric corrosion of zinc and mild steel was investigated in the laboratory at relative humidities of 65%, 80% and 90% in unpolluted atmospheres and at a relative humidity of 80% in atmospheres containing HCl and SO2 pollutant gases. In order to investigate the effect of atmospheric particulates on corrosion rates, metal samples were contaminated with three coal and three oil fly-ashes from different industrial sources. Control specimens were either uncontaminated or contaminated with small glass beads of similar size to the fly-ashes < 45 μm. In unpolluted atmospheres, particulate contamination increased corrosion in approximate proportion to the quantity of leachable ionic species present in the fly-ash. Additionally, glass beads slightly increased corrosion rates probably due to differential aeration effects and an increased local time-of-wetness in the vicinity of the beads. In polluted environments, the corrosion rates of the specimens increased and the additional effect of fly-ash contamination on the corrosion rates was consequently decreased in proportion to the presentation rate of pollutant. There was no significant additional increase in corrosion rates with SO2 pollutant and fly-ash contamination, indicating that effects due to catalytic oxidation of SO2 to sulphuric acid or sulphates were not significant. Overall, this study provides strong evidence that the atmospheric corrosion rates of metals are dependent on the conductance of the thin-film surface electrolyte and that the first-order effect of contaminant particles is to increase solution conductance and hence corrosion rates.
Volcanic formations in the central Andes overlie extensive amounts of ancient evaporites of Cenozoic age. Recycling of buried salts in present closed basins through the hydrological cycle is a well-known process. Another salt recycling process through volcanic activity has been detected in a recent eruption of the Lascar volcano in northern Chile. About 109 metric tons of air-fall tephra was deposited over the surrounding closed basins. Leaching experiments were carried out on ashes deposited near the summit and in a lower neighbouring valley. Summit ash leachates are almost pure CaSO4 solutions, whereas the valley ashes leachates are enriched in minor components. Leachates of the summit ash are near-neutral, whereas those of the valley ash have pH as high as 10.5. Sulfur isotope composition of the leached sulfate is consistent with the volcanic recycling of Tertiary gypsum present in the sedimentary section beneath the volcanic cordillera. As a rough estimate, about 700,000 tons of easily soluble CaSO4 were added in only three days to the surrounding closed basins. The high pH of the valley ash leachates is due to the hydration of alkali and alkaline-earth metal oxides formed during pyrolysis of vegetation by hot ash. Efflorescent salts encrusted on plants and dissolution of volcanic glass provided some of the minor components. The almost pure CaSO4 composition of the leach waters is compositionally distinct from any present inflow waters in the central Andes. Addition of CaSO4 may explain some of the differences between the observed brine compositions and those predicted by simulating the evaporation of regular inflows. The recycling of sedimentary gypsum is probably not restricted to Lascar volcano. The recycling of ancient salts, and possibly also the pyrolysis of vegetation, may have been crucial processes in the salt balance of closed basins during the intense volcanic activity of the Tertiary.
An aggressive, photocatalytically initiated, free-radical degradation mechanism promoted by specific components of modern sunscreen formulations is proposed for appearance of unsightly defects on prepainted steel sheets installed in roofing applications. The effect has been confirmed and reproduced in both laboratory and exterior exposure tests. X-ray diffraction (XRD) studies reveal the presence of a potent photocatalyst in several sunscreen formulations. Electron spin resonance (ESR) studies confirm the photocatalytic activity through monitoring production of hydroxyl radicals, HO, using the spin trapping technique. The model shows that surface coatings with an inherent roughness are highly susceptible to this effect. In practical terms, it is estimated that the weathering (in terms of deterioration of appearance properties) of the coating has been accelerated 100-fold by this photocatalytic degradation mechanism. Benchmark surface coatings for this application sector, based upon ‘fluoropolymer’ technologies, are also severely damaged in a short space of time.
Far-from-equilibrium, steady-state dissolution rates at pH 4 of a suite of natural glasses, ranging from basaltic to rhyolitic in composition, have been determined as a function of aqueous fluoride concentrations up to 1.8 × 10−4 mol/kg in mixed-flow reactors. Dissolution rates of each of these glasses increase monotonically with increasing aqueous fluoride concentration. Measured dissolution rates are found to be consistent with both the Furrer and Stumm (1986) surface coordination model and the Oelkers (2001) multi-oxide dissolution model. Application of the latter model yields the following equation that can describe all measured rates as a function of both glass and aqueous solution composition:
where r+,geo represents the far-from-equilibrium dissolution rate, normalized to geometric surface area, SiO2(wt.%) refers to weight percent of SiO2 in the glass, and ai denotes the activity of the subscripted aqueous species. Computed glass dissolution rates increase with increasing aqueous fluoride concentration due to the formation of aqueous Al-fluoride complexes, which decrease aAl3+. This rate expression can be used to predict far-from-equilibrium dissolution rates of natural glasses in a variety of natural environments. Comparison of rate predictions with the composition of natural fluids suggests that the presence of aqueous fluoride can enhance natural glass dissolution rates by an order of magnitude or more in a variety of geochemical systems.
Deposition of volcanic ash into aqueous environments leads to dissolution of adsorbed metal salts and aerosols, increasing the bioavailability of key nutrients. Volcanogenic fertilization events could increase marine primary productivity, leading to a drawdown of atmospheric CO2. Here we conduct flow-through experiments on unhydrated volcanic ash samples from a variety of locations and sources, measuring the concentrations and fluxes of elements into de-ionized water and two contrasting ocean surface waters. Comparisons of element fluxes show that dissolution of adsorbed surface salts and aerosols dominates over glass dissolution, even in sustained low pH conditions. These surface ash-leachates appear unstable, decaying in situ even if kept unhydrated. Volcanic ash from recent eruptions is shown to have a large fertilization potential in both fresh and saline water. Fluorine concentrations are integral to bulk dissolution rates and samples with high F concentrations display elevated fluxes of some nutrients, particularly Fe, Si, and P. Bio-limiting micronutrients are released in large quantities, suggesting that subsequent biological growth will be limited by macronutrient availability. Importantly, acidification of surface waters and high fluxes of toxic elements highlights the potential of volcanic ash-leachates to poison aqueous environments. In particular, large pH changes can cause undersaturation of CaCO3 polymorphs, damaging populations of calcifying organisms. Deposition of volcanic ash can both fertilize and/or poison aqueous environments, causing significant changes to surface water chemistry and biogeochemical cycles.
Unexpectedly high aluminium concentrations beside fluoride and essential elements are released from metal salts adsorbed to volcanic ash. Through simulation of the mixing of pristine volcanic ash leachate with fresh water and seawater using PHREEQC, we found an increased potential toxicity in fresh waters through the combination of high aluminium and fluoride concentrations. Owing to the mixing of acid ash leachate with fresh water, aluminofluoride complexes (AlFx+ 3−x) persist in aqueous systems with low turnover rates, and could be toxic to both plants and animals. In contrast, due to the well-buffered and relatively high pH in seawater, the speciation of the ash leachate/seawater mixture shows that complexes of fluoride and aluminium (i.e. AlFx+ 3−x) will not dominate in a well-mixed marine system; instead, Al(OH)x+ 3−x species will occur at greatest concentration. Consequently, compared with fresh water environments, the mixing of ash leachate with seawater indicates reduced toxic effects due to decreased formation of AlFx+ 3−x complexes and the low solubility of Al-hydroxides. In addition, the deposition of volcanic aerosols may enhance biological activity in the marine environment by providing micronutrients as some oceanic phytoplankton species tolerates extreme concentrations of fluoride (F).
A novel approach to measure the corrosion effects of aerosols as a function of their aerodynamic size and chemical composition was used to study the effects of atmospheric aerosols on mild steel at a rural coastal site. The technique uses collocated micro-orifice uniform deposition impactor samplers to deposit ambient atmospheric particles on exposure steel coupons and collect aerosol samples for ionic analyses. Rusts were found on the coupons with aerosols but none on the blank coupons even the blanks were incubated at the same conditions. FTIR analysis shows that the composition of rusts changes gradually with the aerosol particle size.
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In recent years, semiconductor photocatalytic process has shown a great potential as a low-cost, environmental friendly and sustainable treatment technology to align with the "zero" waste scheme in the water/wastewater industry. The ability of this advanced oxidation technology has been widely demonstrated to remove persistent organic compounds and microorganisms in water. At present, the main technical barriers that impede its commercialisation remained on the post-recovery of the catalyst particles after water treatment. This paper reviews the recent R&D progresses of engineered-photocatalysts, photoreactor systems, and the process optimizations and modellings of the photooxidation processes for water treatment. A number of potential and commercial photocatalytic reactor configurations are discussed, in particular the photocatalytic membrane reactors. The effects of key photoreactor operation parameters and water quality on the photo-process performances in terms of the mineralization and disinfection are assessed. For the first time, we describe how to utilize a multi-variables optimization approach to determine the optimum operation parameters so as to enhance process performance and photooxidation efficiency. Both photomineralization and photo-disinfection kinetics and their modellings associated with the photocatalytic water treatment process are detailed. A brief discussion on the life cycle assessment for retrofitting the photocatalytic technology as an alternative waste treatment process is presented. This paper will deliver a scientific and technical overview and useful information to scientists and engineers who work in this field.
Electronic materials and devices corrode in the same ways as automobiles, bridges, and pipelines, but their typically small dimensions make them orders of magnitude more susceptible to corrosion failure. As elsewhere, the corrosion involves interactions with the environment. Under control, these interactions can be put to use, as in the formation of protective and functional oxide films for superconducting devices. Otherwise, they cause damage, as in the electrolytic dissolution of conductors, even gold, in the presence of humidity and ionic contamination from atmospheric particles and gases. Preventing corrosion entails identifying the damaging interactions and excluding species that allow them to occur.
The effect of fly ash particulates on the atmospheric corrosion of zinc and mild steel The immediate environmental effects of tephra emission The interaction of modern sunscreen formulations with surface coatings
- A Askey
- Lyon
- Sb
- Ge Thompson
- Johnston
- Jb
- Wood
- Gc
- Pw Sage
- Cooke
Askey A, Lyon SB, Thompson GE, Johnston JB, Wood GC, Sage PW, Cooke MJ (1993) The effect of fly ash particulates on the atmospheric corrosion of zinc and mild steel. Corros Sci 34:1055–1081 Ayris PM, Delmelle D (2013) The immediate environmental effects of tephra emission. Bull Volcanol 74:1905–1936 Barker PJ, Branch A (2008) The interaction of modern sunscreen formulations with surface coatings. Prog Org Coat 62:313–320
Recent developments in photocatalytic water treatment technology: a review Multiscale modelling of the corrosion of metals under atmospheric corrosion Corrosion of electronic materials and devices
- Jin B Mn
- Chow Cwk
- Saint
- Is Cole
- Muster Tj
- Azmat Ns
- Ms Venkatraman
- Cook
- Cronin
- Sj
- Sharp
MN, Jin B, Chow CWK, Saint C (2010) Recent developments in photocatalytic water treatment technology: a review. Water Res 44:2997–3027 Cole IS, Muster TJ, Azmat NS, Venkatraman MS, Cook A (2011) Multiscale modelling of the corrosion of metals under atmospheric corrosion. Electrochim Acta 56:1856–1865 Comizzoli RB, Frankenthal RP, Milner PC, Sinclair JD (1986) Corrosion of electronic materials and devices. Science 234:340–345 Cronin SJ, Sharp DS (2002) Environmental impacts on health from continuous volcanic activity at Yasur (Tanna) and Ambrym, Vanuatu. Int J Environ Health Res 12:109–123
Corrosion testing and atmospheric monitoring in an active volcanic environment Photocatalyzed degradation of polymers in aqueous semiconductor suspensions. I. Photooxidation of solid particles of polyvinylchloride
- Ga
- N Mullet
- Srinivasan
- Suzuki Hihara Lh H
- K Nohara
- S Horikoshi
- Y Hisamatsu
- E Pelizzetti
- Serpone
GA, Mullet N, Srinivasan R and Hihara LH (2007) Corrosion testing and atmospheric monitoring in an active volcanic environment. Proceedings of the 2007 Tri-Service Corrosion Conference, US Department of Defense Hidaka H, Suzuki Nohara K, Horikoshi S, Hisamatsu Y, Pelizzetti E, Serpone N (1996) Photocatalyzed degradation of polymers in aqueous semiconductor suspensions. I. Photooxidation of solid particles of polyvinylchloride. J Polym Sci A Polym Chem 34(7):1311–1316
Corrosion of metals in volcanic environments Physical and social impacts of past and future volcanic eruptions in New Zealand Rapid releases of metal salts and nutrients following the deposition of volcanic ash into aqueous environments
- S H Sueyoshi
- K Kitamura
- Ohzono
S, Sueyoshi H, Kitamura K, Ohzono Y (1990) Corrosion of metals in volcanic environments. Corros Eng 39:271–281 Johnston DM (1997) Physical and social impacts of past and future volcanic eruptions in New Zealand. PhD thesis, Massey University, New Zealand Jones MT, Gislason SR (2008) Rapid releases of metal salts and nutrients following the deposition of volcanic ash into aqueous environments. Geochim Cosmochim Acta 72:3661–3680
Influence of eruptions from Mt Sakurajima on the deterioration of materials Environmental chemistry of soils Average chemical compositions of some igneous rocks
- H Okabyashi
- T Mochihara
H, Okabyashi T., Mochihara M (1988) Influence of eruptions from Mt Sakurajima on the deterioration of materials. In proceedings Kagoshima international conference on Volcanoes, Kago-shima, Japan, pp 732–735 McBride MB (1994) Environmental chemistry of soils. Oxford University Press, New York, p 406 Nockolds SR (1954) Average chemical compositions of some igneous rocks. Geol Soc Am Bull 65:1007
Volcanic ash leachates: a review and recommendations for sampling methods The effect of fluoride on the dissolution rates of natural glasses at pH 4 and 25 °C
- Witham Cs
- C Oppenheimer
- D Horwell Cj Wolff-Boenisch
- Gislason
- Sr
Witham CS, Oppenheimer C, Horwell CJ (2005) Volcanic ash leachates: a review and recommendations for sampling methods. J Volcanol Geoth Res 141:299–326 Wolff-Boenisch D, Gislason SR, Oelkers E (2004) The effect of fluoride on the dissolution rates of natural glasses at pH 4 and 25 °C. Geochim Cosmochim Acta 68:4571–4582 Nat Hazards
Corrosion of Zinc as a function of pH Investigating the electrical con-ductivity of volcanic ash and its effect on HV power systems
- Birbilis N Venkatraman
- Cole Ms
- Ish
- H
- Wilson Tm Jb
- Bodger
- Cole Jw Ps
- Johnston
S, Birbilis N, Venkatraman MS, Cole IS (2012) Corrosion of Zinc as a function of pH. Corrosion 68:H1–H9 Wardman JB, Wilson TM, Bodger PS, Cole JW, Johnston DM (2012) Investigating the electrical con-ductivity of volcanic ash and its effect on HV power systems. Phys Chem Earth 45:128–145