Ratiocalc: Software for processing data from multicomponent volcanic gas analyzers

Portable gas analyzers have become a powerful tool for the real-time monitoring of volcanic gas composition over the last decade. Gas analyzers make it possible to retrieve in real-time the chemical composition of a fumarole system or a plume in an open-conduit volcano via periodic field-deployments or at permanent stations. The core of a multicomponent volcanic gas analyzer (MultiGAS) consists of spectroscopic and electrochemical sensors that are used to determine the concentrations of the most abundant volcanic gases (H2O, CO2, SO2, H2S, H2, CO and HCl) in a diluted plume and their mutual molar ratios. Processing such data is often difficult due to the high sensitivity of the sensors to environmental conditions such as humidity, gas concentrations, and pressure, with all involving occasional instrumental drift. Analyses require accurate and time-consuming processing by an operator. This paper presents a stand-alone program for the processing of chemical data obtained using the MultiGAS, called Ratiocalc. The Ratiocalc program has a user-friendly interface to enable volcanologists to process large datasets in a simple and rapid manner, thereby reducing the processing time associated with volcano monitoring and surveying

A Low-Cost Smartphone Sensor-Based UV Camera for Volcanic SO2 Emission Measurements

Recently, we reported on the development of low-cost ultraviolet (UV) cameras, based on the modification of sensors designed for the smartphone market. These units are built around modified Raspberry Pi cameras (PiCams; ≈USD 25), and usable system sensitivity was demonstrated in the UVA and UVB spectral regions, of relevance to a number of application areas. Here, we report on the first deployment of PiCam devices in one such field: UV remote sensing of sulphur dioxide emissions from volcanoes; such data provide important insights into magmatic processes and are applied in hazard assessments. In particular, we report on field trials on Mt. Etna, where the utility of these devices in quantifying volcanic sulphur dioxide (SO2) emissions was validated. We furthermore performed side-by-side trials of these units against scientific grade cameras, which are currently used in this application, finding that the two systems gave virtually identical flux time series outputs, and that signal-to-noise characteristics of the PiCam units appeared to be more than adequate for volcanological applications. Given the low cost of these sensors, allowing two-filter SO2 camera systems to be assembled for ≈USD 500, they could be suitable for widespread dissemination in volcanic SO2 monitoring internationally

Interannual variations in the carbon to chlorophyll a ratios during the spring bloom in Prince William Sound, Alaska

Thesis (M.S.) University of Alaska Fairbanks, 2005The carbon to chlorophyll a ratio of phytoplankton during the spring bloom in Prince William Sound, Alaska was investigated for 3 seasons and related to major physical and chemical variables. Carbon to chlorophyll a ratios (C:Chl) were determined by two methods, based on particulate organic carbon to chlorophyll (POC:Chl) and phytoplankton cell carbon to chlorophyll (PCC:Chl). These ratios were compared to a more commonly used estimate, a fixed ratio of C:Chl, taken from literature, for the spring phytoplankton community. The hypothesis that the C:Chl ratios were significantly different between years was proven false. This research indicates that the C:Chl ratio is primarily determined by species composition of the phytoplankton community rather than external factors such as nutrients, temperature or salinity. In addition, this research indicates that the identification and enumeration method, although rarely used because it is the most time and labor intensive method, provides the best estimate of phytoplankton carbon. The mean PCC:Chl ratio for all three years was 18, and is the best fixed ratio to estimate spring phytoplankton carbon in Prince William Sound when an EI Niño is not present.Introduction -- Background : what factors determine the C:Chl ratio in a cell? -- What is the effect of cell size and chemical composition on C:Chl? -- What is the effect of temperature on C:Chl? -- What is the effect of nutrient concentrations on C:Chl? -- What is the effect of light on C:Chl? -- Summary -- Methods -- Results -- Discussion -- Comparison of carbon biomass values -- Effect of species composition on C:Chl -- Particulate organic carbon (POC) -- Particulate organic carbon to chlorophyll (POC:Chl) -- Phytoplankton cell carbon (PCC) -- Phytoplankton cell carbon to chlorophyll (PCC:Chl) -- Physical and chemical effects on C:Chl -- Temperature -- Salinity -- Nutrients -- Water Transparency -- Conclusions -- References

\u3cstrong\u3eHypocrisy on the High Seas: An Examination of the Conflicting Policy Goals and Actions of the International Community Regarding Illegal, Unreported, and Unregulated Fishing\u3c/strong\u3e

Fish and the fishing industry are one of the main sources of food protein and commerce in many areas of the world, whether it be from traditional and artisanal fishing practiced in Somalia and other undeveloped countries or large scale international commercial fishing from rich and industrialized nations. The world’s oceans are currently being plagued by overfishing both from legally authorized activities and Illegal, Unreported, and Unregulated Fishing. The purpose of this paper is to examine the problems plaguing the world’s fisheries with an eye towards the environmental damage and economic harm that stem from it. It is also to also examine the current systems in place working to combat Illegal, Unreported, and Unregulated Fishing on the international stage; and to attempt to form a comprehensive solution to the issues presented

On Determining Spontaneous Ignition in Porous Materials

A guide is developed that lays out the process of analyzing spontaneous ignition likelihood. The Frank-Kamenetskii (F-K) theory forms the basis of the approach. The Damkohler number, defined as the dimensionless heat generation parameter for a self-heating body, is described in terms of two key material constants and these materials are related to real incident spontaneous ignition scenarios. The Damkohler number is compared to the critical Damkohler number, value of heat generation at the onset of runaway condition, to determine if spontaneous ignition is likely. Corrections to the critical Damkohler number are described for cases of finite Biot number, low activation energy, and reactant consumption. Heat transfer analysis is needed in terms of a Biot number, and its calculation is described. A specific measurement of the heat transfer in an oven is described. Application of the spontaneous ignition hazard analysis for a real case is presented