Monitoring permanent CO2 storage by in situ mineral carbonation using a reactive tracer technique

AbstractIn situ mineral carbonation provides the most effective and permanent solution for geologic CO2 storage. Basaltic rocks have the potential to store large volumes of CO2 as (Ca, Mg, Fe) carbonates [1]. Existing monitoring and verification techniques for geologic CO2 storage are insufficient to quantitatively characterize solubility and mineral trapping in a geologic reservoir. We developed and tested a new reactive tracer technique for quantitative monitoring and detection of dissolved and chemically transformed CO2. The technique involves the active tagging of the injected CO2 with low levels of radiocarbon (14C) as a reactive tracer in combination with the injection of non-reactive tracers such as sulfurhexafluoride (SF6) and trifluoromethylsulphur pentafluoride (SF5CF3). The tracer technique has been applied at the CarbFix pilot injection site in Hellisheidi, Iceland as part of a comprehensive geochemical monitoring program during two injection phases; Phase III and IV. SF6 and SF5CF3 confirm the arrival of the injected CO2 and CO2+H2S solutions at the first observation well HN04, which is 125m west of the injection well at 520 m depth. The initial breakthrough of the migrating dissolved CO2 front occurred 63 and 62 days after injection began as evidenced by an initial peak in the SF6, SF5CF3, 14C, and dissolved inorganic carbon (DIC) concentrations. The major increase in the non-reactive tracer concentrations occurred several months after the initial breakthrough, although no major concentration increase has been observed for 14C and DIC suggesting that mineral reactions are dominant during CO2 injection

ADC measurements on the Unity MR-linac - A recommendation on behalf of the Elekta Unity MR-linac consortium

Background and purpose: Diffusion-weighted imaging (DWI) for treatment response monitoring is feasibleon hybrid magnetic resonance linear accelerator (MR-linac) systems. The MRI scanner of the ElektaUnity system has an adjusted design compared to diagnostic scanners. We investigated its impact onmeasuring the DWI-derived apparent diffusion coefficient (ADC) regarding three aspects: the choice ofb-values, the spatial variation of the ADC, and scanning during radiation treatment. The aim of this studyis to give recommendations for accurate ADC measurements on Unity systems.Materials and methods: Signal-to-noise ratio (SNR) measurements with increasing b-values were done todetermine the highest bvalue that can be measured reliably. The spatial variation of the ADC wasassessed on six Unity systems with a cylindrical phantom of 40 cm diameter. The influence of gantry rotationand irradiation was investigated by acquiring DWI images before and during treatment of 11 prostatecancer patients.Results: On the Unity system, a maximum b-value of 500 s/mm2 should be used for ADC quantification, asa trade-off between SNR and diffusion weighting. Accurate ADC values were obtained within 7 cm fromthe iso-center, while outside this region ADC values deviated more than 5%. The ADC was not influencedby the rotating linac or irradiation during treatment.Conclusion: We provide Unity system specific recommendations for measuring the ADC. This willincrease the consistency of ADC values acquired in different centers on the Unity system, enabling largecohort studies for biomarker discovery and treatment response monitoring.Biological, physical and clinical aspects of cancer treatment with ionising radiatio

Sonic diaspora, vibrations and rhythm: thinking through the sounding of the Jamaican dancehall session

The propagation of vibrations may provide a better way of understanding diasporic spread than the conventional focus on the circulation of products (Hall 1980, Appadurai 1986, 1996, Gilroy 1993a, Brah 1996). Jamaican sound systems operate as a broadcast medium and a source of CDs, DVDs and other commercial products (Henriques 2007a). But the dancehall sound system session also propagates a broad spectrum of frequencies diffused through a range of media and activities - described as “sounding” (following Small’s 1998 concept of “musicking”). These include the material vibrations of the signature low-pitched auditory frequencies of Reggae as a bass culture (Johnson 1980), at the loudness of “sonic dominance” (Henriques 2003). Secondly a session propagates the corporeal vibrations of rituals, dance routines and bass-line “riddims” (Veal 2007). Thirdly it propagates the ethereal vibrations (Henriques 2007b), “vibes” or atmosphere of the sexually charged popular subculture by which the crowd (audience) appreciate each dancehall session as part of the Dancehall scene (Cooper 2004). The paper concludes that thinking though vibrating frequencies makes it easier to appreciate how audiences with no direct or inherited connection with a particular music genre can be energetically infected and affected - to form a sonic diaspora

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

The power of popular publicity: new social media and the affective dynamics of the sport racism scandal

Sociologists have tended to take insufficient account of the importance of emotions to the social power of the institution of media, particularly as altered by the emergence of social media in the current media ecology. This paper compensates for this neglect by means of a brief illustrative case study of the effect of social media on the public reception of the 2011 Sepp Blatter racism scandal and of other ‘race-related’ scandals in the UK. In proposing media scandals’ wider sociological significance regarding the dynamic, multi-accented relationships between emotions and power, it analyses how England’s prevailing climate of ‘postcolonial guilt’ was reinforced and conveyed through social media networks

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02

Wholesale pricing in a small open economy

This paper addresses the empirical analysis of wholesale profit margins using data of the Dutch wholesale sector, 1986. At the heart of the analysis is the typical nature of wholesale production: wholesalers do not produce a tangible product, but offer a service capacity. This has an immediate impact on the identification, interprelation and measurement of determinants of profit variations. A model is set up to explain variations in wholesale profit margins, which is inspired by two widely applied approaches to industry pricing: the behavioural mark-up model and the marginalist price-cost model