35 research outputs found

    The Role of Oxygen at the Second Discharge Plateau of Nickel Hydroxide

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    It was shown that the appearance of a secondary discharge plateau approximately 400 mV below the primary plateau can result from the reduction of oxygen. During the galvanostatic discharge of planar nickel-hydroxide films at room temperature and in 3 weight percent KOH solutions, the second discharge plateau was observed only in the presence of dissolved oxygen in the electrolyte. When the solution was deoxygenated, no residual capacity could be extracted from the films even at low discharge rates or from overcharged films. In addition, the duration of the second plateau is inversely proportional to the square of the discharge current, which is indicative of a diffusion-controlled process. The nickel hydroxide active material, rather than the electrolyte, seems to be the primary reservoir for the oxygen that is reduced on the second plateau

    Dry Gas Seals: General (Installation, Operation, Troubleshooting, and Retrofitting), Controls

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    Discussion GroupSuggested Topics for Dry Gas Seals Discussion group: • DGS operating characteristics • Unidirectional versus bidirectional • Seals faces and seats, O rings materials • Explosive decompression • Primary seal gas supply control system Primary seal failure detection • Primary seal gas vent to flare control system • Secondary seal failure detection • Tertiary seal types, carbon rings versus labyrinth • Buffer gas and associated control • Separation gas, air or nitrogen and associated controls • Tandem versus double seals application • Field problems and experiences • Challenges in Dry Gas Seal retrofits • Operation and spares maintenance, shelf life and requalification. • Dry Gas seals reliability and availability. • Dew point monitoring and control • Seal Gas Conditioning systems • Seal Gas Boosters and Heaters • API 614 – 5th Edition, current and advancements in Dry Gas seals & System

    Return and Volatility Spillovers of Asian Pacific Stock Markets’ Energy Indices

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    The aim of the study was to investigate the presence of volatility among the Energy Indices of Asia Pacific Stock Markets. To test the volatility among the daily returns of Energy Indices of Asia Pacific Stock Markets, the study selected five sample Asian Pacific stock markets’ Energy Indices on the basis of availability of data. The findings of descriptive statistics and the ADF Test revealed, that the daily returns of the sample energy indices of Asian Pacific stock markets were not normally distributed and achieved stationarity at level difference, over the research period. Hence the data may be used for additional analysis. The data were then analysed, by using the GARCH (1,1) model to assess the considerable volatility of daily returns of sample energy indices and the study, which revealed that during the study period, all of the sample energy indices were volatile

    Dry Gas Seals: General (Installation, Operation, Troubleshooting, and Retrofitting), Controls

    Get PDF
    Discussion GroupSuggested Topics for Dry Gas Seals Discussion group: • DGS operating characteristics • Unidirectional versus bidirectional • Seals faces and seats, O rings materials • Explosive decompression • Primary seal gas supply control system Primary seal failure detection • Primary seal gas vent to flare control system • Secondary seal failure detection • Tertiary seal types, carbon rings versus labyrinth • Buffer gas and associated control • Separation gas, air or nitrogen and associated controls • Tandem versus double seals application • Field problems and experiences • Challenges in Dry Gas Seal retrofits • Operation and spares maintenance, shelf life and requalification. • Dry Gas seals reliability and availability. • Dew point monitoring and control • Seal Gas Conditioning systems • Seal Gas Boosters and Heaters • API 614 – 5th Edition, current and advancements in Dry Gas seals & System

    Community-developed checklists for publishing images and image analysis

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    Images document scientific discoveries and are prevalent in modern biomedical research. Microscopy imaging in particular is currently undergoing rapid technological advancements. However for scientists wishing to publish the obtained images and image analyses results, there are to date no unified guidelines. Consequently, microscopy images and image data in publications may be unclear or difficult to interpret. Here we present community-developed checklists for preparing light microscopy images and image analysis for publications. These checklists offer authors, readers, and publishers key recommendations for image formatting and annotation, color selection, data availability, and for reporting image analysis workflows. The goal of our guidelines is to increase the clarity and reproducibility of image figures and thereby heighten the quality of microscopy data is in publications.Comment: 28 pages, 8 Figures, 3 Supplmentary Figures, Manuscript, Essential recommendations for publication of microscopy image dat

    On the inadequacy of environment impact assessments for projects in Bhagwan Mahavir Wildlife Sanctuary and National Park of Goa, India : a peer review

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    The Environment Impact Assessment (EIA) is a regulatory framework adopted since 1994 in India to evaluate the impact and mitigation measures of projects, however, even after 25 years of adoption, EIAs continue to be of inferior quality with respect to biodiversity documentation and assessment of impacts and their mitigation measures. This questions the credibility of the exercise, as deficient EIAs are habitually used as a basis for project clearances in ecologically sensitive and irreplaceable regions. The authors reiterate this point by analysing impact assessment documents for three projects: the doubling of the National Highway-4A, doubling of the railway-line from Castlerock to Kulem, and laying of a 400-kV transmission line through the Bhagwan Mahavir Wildlife Sanctuary and National Park in the state of Goa. Two of these projects were recently granted ‘Wildlife Clearance’ during a virtual meeting of the Standing Committee of the National Board of Wildlife (NBWL) without a thorough assessment of the project impacts. Assessment reports for the road and railway expansion were found to be deficient on multiple fronts regarding biodiversity assessment and projected impacts, whereas no impact assessment report was available in the public domain for the 400-kV transmission line project. This paper highlights the biodiversity significance of this protected area complex in the Western Ghats, and highlights the lacunae in biodiversity documentation and inadequacy of mitigation measures in assessment documents for all three diversion projects. The EIA process needs to improve substantially if India is to protect its natural resources and adhere to environmental protection policies and regulations nationally and globally

    Training the brain to survive stroke.

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    Presently, little can be done to repair brain tissue after stroke damage. We hypothesized that the mammalian brain has an intrinsic capacity to adapt to low oxygen which would improve outcome from a reversible hypoxic/ischemic episode. Acclimation to chronic hypoxia causes increased capillarity and tissue oxygen levels which may improve the capacity to survive ischemia. Identification of these adaptations will lead to protocols which high risk groups could use to improve recovery and reduce costs.Rats were exposed to hypoxia (3 weeks living at ½ an atmosphere). After acclimation, capillary density was measured morphometrically and was increased by 30% in the cortex. Novel implantable oxygen sensors showed that partial pressure of oxygen in the brain was increased by 40% in the normal cortex. Infarcts were induced in brain with 1 h reversible middle cerebral artery occlusions. After ischemia (48 h) behavioural scores were improved and T2 weighted MRI lesion volumes were reduced by 52% in acclimated groups. There was a reduction in inflammation indicated by reduced lymphocytes (by 27-33%), and ED1 positive cells (by 35-45%).It is possible to stimulate a natural adaptive mechanism in the brain which will reduce damage and improve outcome for a given ischemic event. Since these adaptations occur after factors such as HIF-1α have returned to baseline, protection is likely related more to morphological changes such as angiogenesis. Such pre-conditioning, perhaps with exercise or pharmaceuticals, would not necessarily reduce the incidence of stroke, but the severity of damage could be reduced by 50%
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