Results of an aqueous source term model for a radiological risk assessment of the Drigg LLW Site, U.K.

A radionuclide source term model has been developed which simulates the biogeochemical evolution of the Drigg low level waste (LLW) disposal site. The DRINK (DRIgg Near field Kinetic) model provides data regarding radionuclide concentrations in groundwater over a period of 100,000 years, which are used as input to assessment calculations for a groundwater pathway. The DRINK model also provides input to human intrusion and gaseous assessment calculations through simulation of the solid radionuclide inventory. These calculations are being used to support the Drigg post closure safety case. The DRINK model considers the coupled interaction of the effects of fluid flow, microbiology, corrosion, chemical reaction, sorption and radioactive decay. It represents the first direct use of a mechanistic reaction-transport model in risk assessment calculations

Use of Desulfovibrio and Escherichia coli Pd-nanocatalysts in reduction of Cr(VI) and hydrogenolytic dehalogenation of polychlorinated biphenyls and used transformer oil

BACKGROUND Desulfovibrio spp. biofabricate metallic nanoparticles (e.g. ‘Bio-Pd’) which catalyse the reduction of Cr(VI) to Cr(III) and dehalogenate polychlorinated biphenyls (PCBs). Desulfovibrio spp. are anaerobic and produce H2S, a potent catalyst poison, whereas Escherichia coli can be pre-grown aerobically to high density, has well defined molecular tools, and also makes catalytically-active ‘Bio-Pd’. The first aim was to compare ‘Bio-Pd’ catalysts made by Desulfovibrio spp. and E. coli using suspended and immobilised catalysts. The second aim was to evaluate the potential for Bio-Pd-mediated dehalogenation of PCBs in used transformer oils, which preclude recovery and re-use.\ud RESULTS Catalysis via Bio-PdD. desulfuricans and Bio-PdE. coli was compared at a mass loading of Pd:biomass of 1:3 via reduction of Cr(VI) in aqueous solution (immobilised catalyst) and hydrogenolytic release of Cl- from PCBs and used transformer oil (catalyst suspensions). In both cases Bio-PdD. desulfuricans outperformed Bio-Pd E. coli by ~3.5-fold, attributable to a ~3.5-fold difference in their Pd-nanoparticle surface areas determined by magnetic measurements (Bio-PdD. desulfuricans) and by chemisorption analysis (Bio-PdE. coli). Small Pd particles were confirmed on D. desulfuricans and fewer, larger ones on E. coli via electron microscopy. Bio-PdD. desulfuricans-mediated chloride release from used transformer oil (5.6 $\pm$ 0.8 $\mu$g mL-1 ) was comparable to that observed using several PCB reference materials. \ud CONCLUSIONS At a loading of 1:3 Pd: biomass Bio-PdD. desulfuricans is 3.5-fold more active than Bio-PdE. coli, attributable to the relative catalyst surface areas reflected in the smaller nanoparticle sizes of the former. This study also shows the potential of Bio-PdD. desulfuricans to remediate used transformer oil

Temperature mapping and thermal lensing in large-mode, high-power laser diodes

The authors use high-resolution charge-coupled device based thermoreflectance to derive two dimensional facet temperature maps of a λ = 1.55 μmλ=1.55μm InGaAsP/InPInGaAsP∕InP watt-class laser that has a large (>5×5 μm2)(>5×5μm2) fundamental optical mode. Recognizing that temperature rise in the laser will lead to refractive index increase, they use the measured temperature profiles as an input to a finite-element mode solver, predicting bias-dependent spatial mode behavior that agrees well with experimental observations. These results demonstrate the general usefulness of high-resolution thermal imaging for studying spatial mode dynamics in photonic devices.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87806/2/201110_1.pd

Are mungbean-compatible wild bradyrhizobia more resilient to abiotic stress?

Bradyrhizobia required by mungbean for nitrogen fixation can be impacted by abiotic stresses, reducing nitrogen fixation and yield. Wild bradyrhizobia were collected from ten sites in the dry tropics of Queensland and compared with the commercial strain for performance of inoculated mungbeans, under neutral and acid soil conditions. We found thirteen of the fifteen strains tested promoted growth at least as well as the commercial strain under both acid and neutral conditions. Two significantly outperformed the commercial strain under neutral conditions. This study suggests that gains could be made in mungbean performance through use of better-adapted bradyrhizobia

Optic neuropathy associated with systemic sarcoidosis

Objective: To identify and follow a series of 52 patients with optic neuropathy related to sarcoidosis. Methods: Prospective observational cohort study. Results: The disorder was more common in women and affected a wide age range. It was proportionately more common in African and Caribbean ethnic groups. Two clinical subtypes were identified: the more common was a subacute optic neuropathy resembling optic neuritis; a more slowly progressive optic neuropathy arose in the remaining 17%. Sixteen (31%) were bilateral. Concurrent intraocular inflammation was seen in 36%. Pain arose in only 27% of cases. An optic perineuritis was seen in 2 cases, and predominate involvement of the chiasm in one. MRI findings showed optic nerve involvement in 75% of cases, with adjacent and more widespread inflammation in 31%. Treatment with corticosteroids was helpful in those with an inflammatory optic neuropathy, but not those with mass lesions. Relapse of visual signs arose in 25% of cases, necessitating an increase or escalation of treatment, but relapse was not a poor prognostic factor. Conclusions: This is a large prospective study of the clinical characteristics and outcome of treatment in optic neuropathy associated with sarcoidosis. Patients who experience an inflammatory optic neuropathy respond to treatment but may relapse. Those with infiltrative or progressive optic neuropathies improve less well even though the inflammatory disorder responds to therapy

Millisecond accuracy video display using OpenGL under Linux

To measure people’s reaction times to the nearest millisecond, it is necessary to know exactly when a stimulus is displayed. This article describes how to display stimuli with millisecond accuracy on a normal CRT monitor, using a PC running Linux. A simple C program is presented to illustrate how this may be done within X Windows using the OpenGL rendering system. A test of this system is reported that demonstrates that stimuli may be consistently displayed with millisecond accuracy. An algorithm is presented that allows the exact time of stimulus presentation to be deduced, even if there are relatively large errors in measuring the display time

The Unseen Face of E-Business Project Development

The purpose of this paper is intent on identify and analyze the unseen factors of successful or failure of e-business project development. The IT managers must take into account both all costs involved in e-business development and all phases (analysis, design, testing, implementation, maintenance and operation) according to principle of project management for software/systems life cycle development. There are many solutions to exceed these factors of failure among could be counted outsourcing, a good project management, involvement of senior management, a real cost estimation etc.Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 zostało dofinansowane ze środków MNiSW w ramach działalności upowszechniającej nauk

The implications of an idealised large-scale circulation for mechanical work done by tropical convection

A thermodynamic analysis is presented of an overturning circulation simulated by two cloud resolving models, coupled by a weak temperature gradient parametrisation. Taken together, they represent two separated regions over different sea surface temperatures, and the coupling represents an idealised large-scale circulation such as the Walker circulation. It is demonstrated that a thermodynamic budget linking net heat input to the generation of mechanical energy can be partitioned into contributions from the large-scale interaction between the two regions, as represented by the weak temperature gradient approximation, and from convective motions in the active warm region and the suppressed cool region. Model results imply that such thermodynamic diagnostics for the aggregate system are barely affected by the strength of the coupling, even its introduction, or by the SST contrast between the regions. This indicates that the weak temperature gradient parametrisation does not introduce anomalous thermodynamic behaviour. We find that the vertical kinetic energy associated with the large-scale circulation is more than three orders of magnitude smaller than the typical vertical kinetic energy in each region. However, even with very weak coupling circulations, the contrast between the thermodynamic budget terms for the suppressed and active regions is strong and is relatively insensitive to the degree of the coupling. Additionally, scaling arguments are developed for the relative values of the terms in the mechanical energy budget

Bells and whistles of convection parameterization

The present workshop constitutes the 5th in the annual series on “Concepts for Convective Parameterizations in Large-Scale Models”. The purpose of the workshop series has been to discuss the fundamental theoretical issues of convection parameterization with a small number of European scientists. The workshop series has been funded by European Cooperation in the Field of Scientific and Technical Research (COST) Action ES0905. The theme of the workshop for the year 2012 was decided from a main conclusion of the previous workshop, which focused on the convective organization problem, seeking a means for implementing such effects into convection parameterizations (Yano et al. 2012). As it turned out, in order to discuss this implementation issue in any concrete manner, we have first to know very well the bells and whistles of convection parameterizations. This was the purpose of the 5th workshop. The title of the workshop is rather metaphorically tagged as “Bulk or Spectrum?”, because this is a typical decision we have to face at the outset of any parameterization development. The following report discusses selected issues of bells and whistles addressed during the meeting