105 research outputs found

    Integrated Management of Industrial and Municipal Wastewater in China. - Demonstration Project in Jiaxing, Zhejiang Province

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    Årsliste 2000The city of Jiaxing in Zhejiang Province is a medium-size, rapidly expanding Chinese city located in a flat landscape with numerous canals. These are used for navigation, fishing, aquaculture and as drinking and industrial water source, but also as recipients for domestic and industrial wastewater and runoff from agriculture, paved roads and solid waste landfills in the area. The canals are severely polluted. NIVA has been assisting Jiaxing Environmental Protection Bureau (JEPB) in finding solutions to the local wastewater problems. The industry in the area discharges substantial quantities of potentially toxic wastewater to the sewer systems. There are, however, good possibilities for cleaner production routines in various factories. Several measures facilitate the transport of sewage to the nearby Hangzhou Bay, and sewage treatment processes before final disposal have been identified. The project has identified current and future wastewater production and recipient status. Based on pilot-plant operation and computer models a complete system for sewage collection and treatment has been suggested. This is based on transport of untreated sewage to Hanfzhou Bay where the construction of a sewage treatment plant is planned. The treatment methodology is based on a flexible chemically enhanced primary treatment (CEPT), followed by a biological step at a later stage. The project findings put emphasis on knowledge transfer and strengthening of JEPB resources to find solutions to the water-related problems in the city. In addition a detailed abatement plan should be developed, taking existing water quality, user interests and future water quality objectives into account.Direktoratet for Utviklingshjelp (NORAD

    Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

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    The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR

    On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection

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    A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)

    Relationship of edge localized mode burst times with divertor flux loop signal phase in JET

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    A phase relationship is identified between sequential edge localized modes (ELMs) occurrence times in a set of H-mode tokamak plasmas to the voltage measured in full flux azimuthal loops in the divertor region. We focus on plasmas in the Joint European Torus where a steady H-mode is sustained over several seconds, during which ELMs are observed in the Be II emission at the divertor. The ELMs analysed arise from intrinsic ELMing, in that there is no deliberate intent to control the ELMing process by external means. We use ELM timings derived from the Be II signal to perform direct time domain analysis of the full flux loop VLD2 and VLD3 signals, which provide a high cadence global measurement proportional to the voltage induced by changes in poloidal magnetic flux. Specifically, we examine how the time interval between pairs of successive ELMs is linked to the time-evolving phase of the full flux loop signals. Each ELM produces a clear early pulse in the full flux loop signals, whose peak time is used to condition our analysis. The arrival time of the following ELM, relative to this pulse, is found to fall into one of two categories: (i) prompt ELMs, which are directly paced by the initial response seen in the flux loop signals; and (ii) all other ELMs, which occur after the initial response of the full flux loop signals has decayed in amplitude. The times at which ELMs in category (ii) occur, relative to the first ELM of the pair, are clustered at times when the instantaneous phase of the full flux loop signal is close to its value at the time of the first ELM

    Renseanlegg og system for avløp. Integrert modellering og beregning av totalutslipp

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    Kommunene har de senere år fått større ansvar for å fastsette mål for vannforekomster og å fremlegge dokumentasjon av utslipp. På den annen side har de fått større frihet til å velge tekniske løsninger som er tilpasset lokale forhold. Helhetlig planlegging vil være nødvendig for å finne fram til optimale tiltak ut fra fastsatte mål. Integrerte modeller for avløpsnett og renseanlegg, evt. også resipienten, vil være hensiktmessig verktøy i dette arbeidet. Tilgjengelige modeller og kompetanse i bruk av slike modeller er mangelvare i Norge. Derfor ble det tatt initativ til dette prosjektet. Derfor ble det tatt initativ til dette prosjektet. Prosjektets hovedmål har vært å gjennomgå, videreutvikle og beskrive nytten av å bruke kalibrerte EDB-modeller for dokumentasjon av totalutslipp og identifisere optimale tiltak i avløpssystemet. Prosjektet er gjennomført som et demostrasjons- og utviklingsprosjekt med praktiske eksempler med EDB-modellering og måleprogrammer i Lillehammer kommune og TAU/Tønsberg kommune. Basert på erfaringene fra prosjektet er det gitt erfaringer og råd til kommuner og konsulenter for gjennomføring av modellbygging, målinger og kalibrering av RA og ledningsnettmodeller

    Impact of nitrogen seeding on confinement and power load control of a high-triangularity JET ELMy H-mode plasma with a metal wall

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    This paper reports the impact on confinement and power load of the high-shape 2.5MA ELMy H-mode scenario at JET of a change from an all carbon plasma facing components to an all metal wall. In preparation to this change, systematic studies of power load reduction and impact on confinement as a result of fuelling in combination with nitrogen seeding were carried out in JET-C and are compared to their counterpart in JET with a metallic wall. An unexpected and significant change is reported on the decrease of the pedestal confinement but is partially recovered with the injection of nitrogen.Comment: 30 pages, 16 figure

    Prevention of colorectal cancer by combining early detection and chemoprevention

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    Colorectal cancer is a major cause of cancer-related mortality. Most colorectal cancers arise in precursor lesions over a number of years. The carcinogenetic pathway is modulated by a wide array of genetic and epigenetic factors. Two major approaches to halting carcinogenesis are chemoprevention and early detection. Chemoprevention is an attractive emerging option-advances in understanding the carcinogenetic pathways and progress in evaluating various putative agents are promising. However, several issues regarding efficacy, safety, and acceptability require answers before an ideal agent can come into widespread use. Early detection and removal of precursor lesions show promise in reducing disease burden. Although the concept has been around and has been widely advocated for several years, participation in screening remains low. The ideal test in terms of practicality, accuracy, and safety is still debated. This article reviews the recent literature related to screening and chemoprevention of colorectal cancer. Copyright © 2009 by Current Medicine Group LLC
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