Reducing risk in basin scale CO2 sequestration: a framework for integrated monitoring design

Injection of CO(2) into geological structures is a key technology for sequestering CO(2) emissions captured from the combustion of fossil fuels. Current projects inject volumes on the order of megatonnes per year. However, injection volumes must be increased by several orders of magnitude for material reductions in ambient concentrations. A number of questions surrounding safety and security of injection have been raised about the large scale deployment of geological CO(2) sequestration. They are site specific and require an effective monitoring strategy to mitigate risks of concern to stakeholders. This paper presents a model-based framework for monitoring design that can provide a quantitative understanding of the trade-offs between operational decisions of cost, footprint size, and uncertainty in monitoring strategies. Potential risks and challenges of monitoring large scale CO(2) injection are discussed, and research areas needed to address uncertainties are identified. Lack of clear guidance surrounding monitoring has contributed to hampering the development of policies to promote the deployment of large scale sequestration projects. Modeling provides an understanding of site specific processes and allows insights into the complexity of these systems, facilitating the calibration of an appropriate plan to manage risk. An integrated policy for risk-based monitoring design, prior to large scale deployment of sequestration will ensure safe and secure storage through an understanding of the real risks associated with large scale injection.     

Measurement and scaling of air-surface mercury exchange from substrates in the vicinity of two Nevada gold mines

The state of Nevada has extensive mineral resources, and is the largest producer of gold in the USA as well as fourth in world gold production. Mercury (Hg) is often present in the hydrothermal systems that produce gold deposits, and can be found in elevated concentrations in gold ore. As a result, mining of gold ore in Nevada has been shown to release Hg to the atmosphere from point and non-point sources. This project focused on measurement of air-soil Hg exchange associated with undisturbed soils and bedrock outcrops in the vicinity of two large gold mines. Field and laboratory data collected were used to identify the important variables controlling Hg flux from these surfaces, and to estimate a net flux from the areas adjacent to the active mines as well as that occurring from the mined area pre-disturbance. Mean daily flux by substrate type ranged from 9 ng m^− 2 day^− 1 to 140 ng m^− 2 day^− 1. Periods of net deposition of elemental Hg were observed when air masses originating from a mine site moved over sampling locations. Based on these observations and measured soil Hg concentrations we suggest that emissions from point and non-point sources at the mines are a source of Hg to the surrounding substrates with the amount deposited not being of an environmental concern but of interest mainly with respect to the cycling of atmospheric elemental Hg. Observations indicate that while some component of the deposited Hg is sequestered in the soil, this Hg is gradually released back to the atmosphere over time. Estimated pre-disturbance emissions from the current mine footprints based on field data were 0.1 and 1.7 kg yr^− 1, compared to that estimated for the current non-point mining sources of 19 and 109 kg yr^− 1, respectively.     

Effect of a new rifamycin derivative, rifalazil, on liver microsomal enzyme induction in rat and dog

1. The effect of a new rifamycin derivative, rifalazil (KRM-1648), on liver microsomal enzyme induction was studied in rat and dog with repeated oral administration of the compound. Relative liver weight, cytochrome b5 and P450 contents, enzyme activities of NADPH-cytochrome c reductase, aniline hydroxylase, p-nitroanisole O-demethylase, aminopyrine N-demethylase, and erythromycin N-demethylase were measured. 2. In rat, rifalazil treatment at 300 mg/kg/day for 10 days increased cytochrome b5 content but it did not affect liver weight, P450 content or enzyme activities. In contrast, rifampicin and rifabutin increased relative liver weights, cytochrome contents and enzyme activities under similar conditions. 3. In dog, rifalazil did not affect any parameters at 30 or 300 mg/kg/day for 13 weeks. 4. These findings indicate that rifalazil is not an enzyme inducer in rat and dog. This property differs from other rifamycin derivatives such as rifampicin and rifabutin.     

Grafted GaAlAs rib waveguides on an InP substrate

Rib waveguides were fabricated on a 1.4 mu m thick GaAlAs epilayer granted on the surface of a semi-insulating InP substrate by epitaxial lift-off. Single-mode waveguides with propagation losses (<7 dB/cm) lower than heteroepitaxially grown counterparts have been achieved. TEM analysis on the GaAlAs/InP interface indicates surface scattering as one of the main loss mechanisms.<>     

Antitumor killer lymphocytes in the peripheral blood of a patient with transitional cell carcinoma of the bladder

Despite the trend in the use of electromechanical left ventricular assist devices (LVAD), the highly compact, long lasting, and endurance characteristics of the new pneumatic system has its place in the treatment of end-stage chronic heart failure. The ProCor Model 1 LVAD has an implantable pump which is small in size and has a double pusher plate design. The portable power pack is small, too. It is easy to carry, and it is synchronized to the ECG to pump during the patient's diastolic period. Constant driving conditions are set as follows: frequency rate, 60 bpm; systolic percentage, 25 (250 ms); dP/dt, 1,800 (45 ms) mm Hg.s; and driving pressure, 250 mm Hg to have a basic 3.500 L/min pump output for prolonged circulatory assistance. The 6 mm internal diameter (ID) percutaneous multipurpose pneumatic tube contains within its wall both a spiral of MP35N alloy wire connected to the myocardial lead for ECG sensing and a spiral serving as mass ready to be used for cardiac pacing with an external pacemaker when necessary. The aortic porcine bioprosthesis maintains the aortic root and the sinus ridge.     

Reduction of gaseous contamination by UV/photoelectron method

We have previously reported that UV/photoelectron method, in which particles are charged by photoelectrons emitted from the UV irradiated metal surface and collected on the electrodes by the electric field, is effective to collect particles in the gas phase. This paper represents that the UV/photoelectron method is effective not only to collect particles but also to reduce the gaseous contamination such as hydrocarbon or organic compounds and water molecules. By using the UV/photoelectron method the carbon atom concentration on the Si surface is reduced to 1/4 compared with that stored in the clean room for the storage period of about 40 h. The oxygen concentration is reduced to 1/7 in the same condition     

Cloning and nucleotide sequence of fosfomycin biosynthetic genes of Streptomyces wedmorensis

The biosynthetic pathway for production of the antibiotic fosfomycin by Streptomyces wedmorensis consists of four steps including the formation of a C-P bond and an epoxide. Fosfomycin production genes were cloned from genomic DNA using S. wedmorensis mutants blocked at different steps of the biosynthetic pathway. Four genes corresponding to each of the biosynthetic steps were found to be clustered in a DNA fragment of about 5 kb. Nucleotide sequencing of a large fragment revealed the presence of ten open reading frames, including the four biosynthetic genes and six genes with unknown functions.