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The electric arc furnace is the main process unit in scrap‐based steelmaking. Owing to its importance, numerous mathematical models for predicting the course of the electric arc furnace process have been developed. This article reviews mathematical process models proposed in the literature, identifying the most common modeling approaches, and uses mathematical descriptions for the main phenomena. Furthermore, the validation of such models is discussed in detail. Finally, the article identifies gaps in the existing knowledge and provides suggestions for the further development of mathematical process models.

OBJECTIVE: To determine the frequency, indications and complications associated with the use of faecal diversion systems (rectal tubes) in critically ill patients. DESIGN: A single centre observational study over 15 months. SETTING: Intensive care unit (ICU). PARTICIPANTS: Patients admitted during this period. MAIN OUTCOME MEASURES: Frequency of rectal tubes utilisation in ICU, as well as associated adverse events, with major events defined as lower gastrointestinal bleeding associated with defined blood transfusion of two or more units of red cells or endoscopy or surgical intervention. RESULTS: Of 3418 admission episodes, there were 111 episodes of rectal tubes inserted in 99 patients. Rectal tubes remained indwelling for a median of 5 days (range, 1-23) for a total of 641 patient-days. The most frequent indication for insertion was excessive bowel motions. A major adverse event was observed in three patients (3%; 0.5 events per 100 device days). Two patients underwent laparotomy and one patient sigmoidoscopy. These patients received between two and 23 units of packed red blood cells. Patients who had a rectal tube inserted had a substantially greater duration of ICU admission (mean, 14 days [SD, 14] v 2.8 days [SD, 3.7]) and hospital mortality (15% v 7.7%; risk ratio, 2.0; 95% CI, 1.2-3.4) as well as an overall higher Australian and New Zealand Risk of Death (ANZROD) score (mean, 27 [SD, 22] v 12.6 [SD, 20]). CONCLUSION: Rectal tubes appear to be frequently inserted and can lead to major adverse events in critically ill patients.

A simulator and an algorithm for the automatic creation of operation charts based on process conditions were developed on the basis of an existing comprehensive electric arc furnace process model. The simulator allows direct user input and real-time display of results during the simulation, making it usable for training and teaching of electric arc furnace operators. The automatic control feature offers a quick and automated evaluation of a large number of scenarios or changes in process conditions, raw materials, or equipment used. The operation chart is adjusted automatically to give comparable conditions at tapping and allows the assessment of the necessary changes in the operating strategy as well as their effect on productivity, energy, and resource consumption, along with process emissions.

Current chemistry climate models do not include polar emissions and chemistry of halogens. This work presents the first implementation of an interactive polar module into the very short-lived (VSL) halogen version of the Community Atmosphere Model with Chemistry (CAM-Chem) model. The polar module includes photochemical release of molecular bromine, chlorine, and interhalogens from the sea-ice surface, and brine diffusion of iodine biologically produced underneath and within porous sea-ice. It also includes heterogeneous recycling of inorganic halogen reservoirs deposited over fresh sea-ice surfaces and snow-covered regions. The polar emission of chlorine, bromine, and iodine reach approximately 32, 250, and 39 Gg/year for Antarctica and 33, 271, and 4 Gg/year for the Arctic, respectively, with a marked seasonal cycle mainly driven by sunlight and sea-ice coverage. Model results are validated against polar boundary layer measurements of ClO, BrO, and IO, and satellite BrO and IO columns. This validation includes satellite observations of IO over inner Antarctica for which an iodine “leapfrog” mechanism is proposed to transport active iodine from coastal source regions to the interior of the continent. The modeled chlorine and bromine polar sources represent up to 45% and 80% of the global biogenic VSL and VSL emissions, respectively, while the Antarctic sea-ice iodine flux is ~10 times larger than that from the Southern Ocean. We present the first estimate of the contribution of polar halogen emissions to the global tropospheric halogen budget. CAM-Chem includes now a complete representation of halogen sources and chemistry from pole-to-pole and from the Earth's surface up to the stratopause.

The 2006 WMO/UNEP Scientific Assessment of Ozone Depletion identified halogenated very short-lived substances (VSLS) as contributors to the atmospheric budget of halogens. As well, it raised a question regarding the extent of the contribution of halogenated VSLS to atmospheric Bry and Iy. Traditionally, scientists have been more concerned in determining the anthropogenic budget of halogenated compounds while nature is the major producer of such species. In order to have a complete atmospheric budget of halogenated VSLS, it is important to have a better understanding of what species are biogenically produced as well as their respective degradation pathways. Oceanic emissions of halocarbons may be a new link between climate change and the composition of the global atmosphere. The rates of halocarbon emissions are sensitive to sea-surface temperatures (SSTs), nutrient supply and upwelling; all of which are to be affected by climate change. Therefore, increases in SSTs will increase emission rates. On the one hand, seaweed has been identified as a major producer of biogenic polyhalogenated VSLS. Marine macroalgae (kelp) and phytoplankton emit halogen containing gases into the marine boundary layer, constituting 90 to 95% of the total global flux of volatile halocarbons to the atmosphere. On the other hand, the possibility of industrial scale marine kelp farming as a means of carbon sequestration (i.e. marine analogy of the Kyoto Protocol forest) is being pondered by countries with long coastlines and little land suitable for forestation. Would a Kyoto Protocol forest analog be the right strategy for climate change mitigation?With the use of a portable Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) spec- trometer, studies have been performed in the coast of New Zealand in order to determine the presence of BrO and IO during the spring and summer months of the Southern Hemisphere. MAX-DOAS uses scattered sunlight received from multiple viewing directio

NIWA operates a network of zenith-sky viewing DOAS (Differential Optical Absorption Spec- troscopy) instruments to measure NO2 and BrO. The longest existing time series (1981 present) of NO2 has been measured at Lauder (45oS), New Zealand and the trend of this long- term data set has been studied extensively. Here we present a summary of stratospheric NO2 trends observed at several Northern and Southern Hemisphere stations (including Lauder) and an update of our understanding of the observed hemispheric asymmetry. These trends provide an important anchor for the interpretation of NO2 trends measured by satellites.BrO observations are currently made by NIWA at two Southern Hemisphere sites, Lauder and Arrival Heights (78oS) with each data set spanning more than 15 years. The zenith sky BrO observations are complemented with direct sun observations at Lauder since 2001and with MAX-DOAS (Multi-axis Differential Optical Absorption Spectroscopy) observations at Arrival Heights (78oS) since 1998. A retrieval technique to separate the tropospheric and stratospheric partial columns of BrO was developed for the combination of zenith sky and direct sun measurements with the zenith sky observations providing predominantly the information on the stratospheric partial column and the direct sun observations providing the tropospheric contribution. This retrieval has now been applied to Lauder BrO UV-visible measurements for the whole time period (2001 - present) and the updated results including an upper limit of BrO in the troposphere and the stratospheric bromine loading will be presented.The retrieval method has now also been extended so that it can be applied to zenith sky data only. Furthermore, an independent retrieval algorithm has been developed including a forward model capable of dealing with multiple scattering (Monte Carlo radiative transfer model) to enable us to retrieve altitude information in the boundary layer and lower troposphere. This retrieval method has been

We will present a newly developed algorithm for the retrieval of tropospheric trace gas profiles from MAX-DOAS measurements. A Monte Carlo radiative transfer model, NIMO (NIWA Monte Carlo model) is used to calculate the weighting functions and forward model DSCDs (Differential Slant Column Densities). NIMO uses the local estimation technique to substantially speed up the determination of DSCDs for any given set of measurement ge- ometries, enabling use of the model online rather than using pre-calculated lookup tables. The optimal estimation method is used to retrieve profiles for either single or multiple scan sequences or over prescribed time intervals. This inversion method is used to derive NO2 profiles from MAX-DOAS measurements made during the CINDI campaign at Cabauw, Netherlands, in June/July 2009. BrO profiles retrieved from sea-ice MAX-DOAS measure- ments, made during two Antarctic springtime campaigns in 2006 and 2007, are also presented.

As noted in the WMO/UNEP Scientific Assessment of Ozone Depletion: 2006, halogenated very short-lived substances (VSLS) contribute to the atmospheric budget of halogens and thereby lead to substantial decreases in ozone and increases in surface UV radiation in the tropics and mid-latitudes. Halogenated VSLS are primarily of natural origin; oceanic emissions constitute the largest source providing 90-95% of the total global flux to the atmosphere. Macro algae in the ocean appear to be an important source of polyhalogenated VSLS. Oxidation of halogenated VSLS in the atmosphere (i.e. photolysis and reactions with OH) produces halogen oxide radicals (e.g. ClO, BrO, IO) which have been suggested as the main component of gas-phase halogens. Countries with long coastlines and little land suitable for forestation are investigating the possibility of industrial scale marine kelp farming as a means of carbon sequestration. This marine analogy of the Kyoto Protocol forest has been thought as a means to contribute to climate change mitigation. Knowledge of how natural emissions of VSLS will respond to both the drivers of climate change (e.g. changes in CO2 and land use) and to the consequences of climate change (e.g. changes in sea surface temperature and wind stress) is very limited. As a result, it is imperative that observational studies are performed to quantify the contributions of these natural VSLS to halogen loading in the troposphere and, subsequently, in the stratosphere. For this, transport and degradation processes of the source gases and product gases need to be studied and quantified. A key question surfacing from the WMO Assessment is to what extent halogenated VSLS contribute to atmospheric Bry and Iy. During a field campaign conducted during the spring of 2009, measurements of BrO and IO were made along the coastline of the South Island of New Zealand using a portable Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) spectrometer with the aim o

This paper will report on the progress of a large three year Australian Research Council (ARC) grant awarded to a multidisciplinary team of researchers in Victoria, Australia. The research, A multi-disciplinary investigation of how trauma and chronic illness impact on schooling, identity and social connectivity commenced in 2007 and is known as Keeping Connected (2007). The research is a collaborative grant in partnership with the Royal Children’s Hospital Education Institute, in association with the Melbourne Graduate School of Education, University of Melbourne and the Centre for Adolescent Health, Royal Children’s Hospital. The research aims to investigate qualitatively, longitudinally and through multiple perspectives how young people construct/reconstruct identity and relationships with schooling following disruption associated with chronic illness. Using a mixed methodology, but with a central focus on longitudinal qualitative studies from the perspective of the young people, the study aims to identify key elements of disruption or continued connection, and will illuminate identity issues of people facing this disruption at different age and schooling points. The research outcomes will support education and health practices and provide a differently focused empirical contribution to the literature on education and social connection. The paper works at mixing methods qualitatively, rather than focusing on the overall mixed method design of the study. Assemblages of social capital theory and sociomateriality may be a useful standpoint for the development of our empirical contribution.