2,494 research outputs found
On-line monitoring of ozonation through estimation of Ct value, bromate and AOC formation with UV/Vis spectrometry
No full textThe application of ozone in water treatment serves many purposes, such as disinfection and degradation of organic micro-pollutants. To optimise the applied ozone dosage by on-line control, real-time information on the actual Ct value, the bromate and assimilable organic carbon concentration (AOC) is necessary. With UV/Vis spectroscopy, algorithms have been developed for the on-line determination of the Ct-value and the formation of bromate and AOC during ozonation. It was shown that these algorithms allow for the calculation of the optimal ozone dosage and provide a reliable indication of the amount of bromate and AOC formed during ozonation.Sanitary Engineerin
Excavations conducted at the site of Campbellfield pottery Glasgow Ceramic Resource Disc 9
No full textThe ceramic material listed, described, and photographed, on this ceramic resource disk is from an archaeological excavation carried out by AOC Archaeology Group for Coltart Early, on behalf of their client, on the site of the Campbellfield pottery in Glasgow. The ceramic material has been sorted by fabric type, decoration, and form, into (8 Folders and 84 Word Files), accession number (GM 2006.5.535). Many of the transfer printed patterns illustrated have been given temporary names by the author, who is happy to be contacted by other ceramic researchers able to fill in any gaps.
The ceramic material catalogued on this CD Rom is presently housed at the head offices of the AOC Archaeology Group, but will be transferred to Glasgow Museums Resource Centre, 200 Woodland Road, South Nitshill Industrial Estate, Glasgow G53 7NN: Tel 0141 276 9300 where it will be made available for stud
On-line monitoring of ozonation through estimation of Ct value and AOC formation with UV/Vis spectrometry
No full textThe application of ozone in water treatment serves many purposes, such as disinfection, degradation of organic micro-pollutants and oxidation of taste, odour and colour producing compounds. A commonly used method to determine the disinfection capacity of ozonation is calculating the exposure of pathogens to ozone, this capacity is expressed as the Ct value, a product of the residual concentration of the disinfectant (C) and contact time (t). Ozone reacts with natural organic matter (NOM), breaking high molecular weight compounds down into smaller fractions, resulting in an increase in carbon readily available for bacterial uptake. To estimate the regrowth potential of micro-organisms in (non-chlorinated) distribution systems, the assimilable organic carbon (AOC) concentration can be used as an indicator parameter. To optimise the applied ozone dosage by on-line control, real-time information on the actual Ct value and the AOC formation is necessary. Using in process UV/Vis spectroscopy, algorithms have been developed for the on-line determination of the Ct-value and the formation of AOC formation during ozonation. It was shown that these algorithms allow for the calculation of the optimal ozone dosage and provide a reliable indication of the amount of AOC formed.Water ManagementCivil Engineering and Geoscience
Change Characteristics of Women boxers’ Na+,K+- ATPase, ROS and T-AOC before the Match
No full textAbstractThe author tests 24 women boxers’ Na+, K+- ATPase, ROS and T-AOC before the match. The results show that women boxers’ Na+, K+- ATPase, ROS and T-AOC (P<0.01) have a rising trend compared with control group; serum CK-NAC and LDH-L are high control group obviously (P<0.05, P<0.01). Explanation: women boxers’ Na+, K+-ATPase activity in RBC Membrane keeps high level, which has a positive role for the athletes to keep a high athletics ability
Evaluation of a Multi-Agent System approach to airline disruption management
No full textEach day, airlines face disturbances that disrupt their carefully planned operations. Events like adverse weather conditions, sick crew members, or damaged aircraft often result in delays in the airline's schedule. An airline recovers from such disruptions through the role played by its Airline Operations Control (AOC). A Multi-Agent System (MAS) approach to airline disruption management was recently proposed under the acronym MASDIMA (Multi-Agent System for Disruption Management in AOC). The purpose of this paper is to evaluate this MAS supported AOC approach on its performance and its practical introduction. This is done using a scenario-based analysis to compare the MAS supported policy to human-team based AOC policies. A task-based analysis identifies how well AOC is able to cover a set of tasks using the MAS supported policy. The scenario-based analysis shows that the MAS supported AOC is able to find the optimal solution, and to do this significantly faster. The task-based analysis identified two main challenges for implementing the MAS supported AOC policy: i) to overcome the loss of experience that is caused by significantly automating humans roles in AOC, and ii) to reduce the workload for people that remain in AOC after its introduction. The paper concludes that implementing the MAS supported AOC policy leads to both better and faster resolutions, though the replacement of human roles also poses novel challenges that remain to be resolved: a potential increase in workload for the remaining human role and loss of experience in handling exceptional situations.Accepted Author ManuscriptAir Transport & Operation
Study on removing AOC value and inorganic salt using water treatment processes or adsorption method
No full textThis study is focused on investigating the variations of AOC level in a conventional water treatment plant (WTP) and solving excess amounts of inorganic salts in drinking water. In addition, we will conduct to evaluate the effects on adsorption capacity of GAC and description on behavior using adsorption models.
AOC is indicating the level of organic carbon in drinking water. Controlling the level of AOC could reduce the amounts of organic nutrients for microorganisms for protecting re-growth of bacterial in finished water and distribution system.
The results of test showed the percent of AOC contained in raw water of WTP was majorly by part of AOC-P17. In measurement of AOC variation in water treatment process, it was found AOC was effectively removed. But the pre-chlorination disinfection process could increase the level of AOC, this was probable reason causing the level of AOC over 50 ppb in finished water in the WTP.
The results of adsorption of perchlorate in water using GAC and SWCNTs showed both adsorption equilibriums were achieved in approximately 8 hr. These adsorption datas were fitted with three models such as modified Freundlich, pseudo-first-order, and pseudo-second-order. The modified Freundlich model produced the best fit to describe the kinetic adsorption processes. The adsorption capacity increased as the concentration of perchlorate increased and as the ionic strength of the solution decreased. Maximum perchlorate adsorption capacities of 10.03\ue213.64\ue2\ue2mg/g were attained within a temperature range of 5\ue245\uc2\ub0C on the SWCNTs; and maximum perchlorate adsorption capacities of 28.21 \ue2 33.87\ue2\ue2mg/g were attained within a temperature range of 5\ue245\uc2\ub0C on the GAC. The isothermal adsorption data were fitted with Langmuir and Freundlich models. Thermodynamic parameters were also calculated in results and discussions in this text, including equilibrium rate constant, standard free energy change, standard enthalpy change, and standard entropy change. Both two adsorption processes were found spontaneous exothermic reaction on the SWCNTs and GAC. In summary, the adsorption isotherm studies demonstrated that low solution pH values, low solution ionic strength, and low temperature conditions could facilitate the adsorption of perchlorate on the GAC
Evaluating ozone dose for AOC removal in two-step GAC filters
No full textUpgrading an existing post-ozonation plant with two-step granular activated carbon (GAC) filtration for assimilable organic carbon (AOC) removal was studied. The effects of ozone dose on AOC formation and its removal in the subsequent two-step GAC filtration was studied using chemically pretreated 2 to 14° C humic lake water. Two parallel pilot-plant trains with different ozone doses (0 to 1.2 mgO3/mgTOC) and a short-term ozonation study were performed. The optimum ozone dose for maximum AOC formation was 0.4–0.5 mgO3/mgTOC. The AOC-P17 of ozonated water was three-fold higher and AOC-NOX over ten-fold higher than in non-ozonated water, while the following biofiltration (first step) removed 51% and 72% of AOC-P17 and AOC-NOX, respectively. The adsorber (second step) contributed to less than 10% of the overall AOC reduction. It appeared that biofiltration is a feasible method in upgrading water treatment plants for AOC removal even when treating cold humic waters, while the subsequent adsorber seems to have less significance for AOC removal.</jats:p
Nature, the co-author of its products?: An analysis of the recent controversy over “rejected” AOC wines in France
No full textProducers defending terroir have called for and obtained a reform of the AOC (French GI) regulation which they deem to be incapable of containing “dangerous shifts” in the interpretation of terroir. An analysis of their accusations shows that the intellectual property dimension of AOCs is returning to the forefront of concerns. The “terroir” quality of AOCs is the multifaceted result of a duet between the vintner and his vineyard, allowing greater creativity. The present reform embraces this change by adding to regulations specifying the means, an accreditation more receptive to innovation. However, it runs into difficulties over the assessment of typicity upon which the AOC quality guarantee has to be based. This paper concludes with a discussion of the reasons for these difficulties and suggestions for an assessment1 better suited to the multifaceted nature of typicity.Des producteurs défenseurs des terroirs ont demandé et obtenu une réforme des AOC qu'ils jugent incapables de contenir de « dangereuses derives » de l‘interprétation du terroir. L'analyse de leurs accusations fait apparaître un tetour sur le devant de la scène du register de la propriété intellectuelle des AOC: leur qualité de terroir est le résultat pluriel d'un duo d'auteurs, le vigneron et son vignoble, à la créativité renforcée. La réforme en cours épouse ce changement en ajoutant à l'obligation de moyens de la réglementation une habilitation plus ouverte à l'innovation. Mails elle achoppe sur la question de l’épreuve de la typicité sur laquelle doit prendre appui la garantie de qualité des AOC. Nous discutons pour finir les raisons de ces difficultés et proposons une épreuve ajustée à la nature plurielle de la typicité
Assimilable Organic Carbon (Aoc) And Biodegradable Dissolved Organic Carbon (Bdoc): Complementary Measurements
No full textThe objective of this study was to evaluate the necessity of measuring both assimilable organic carbon (AOC) and biodegradable dissolved organic carbon (BDOC) as indicators of bacterial regrowth potential. AOC and BDOC have often been measured separately as indicators of bacterial regrowth, or together as indicators of bacterial regrowth and disinfection by-product formation potential, respectively. However, this study proposes that both AOC and BDOC should be used as complementary measurements of bacterial regrowth potential. In monitoring of full-scale membrane filtration, it was determined that nanofiltration (NF) removed over 90% of the BDOC while allowing the majority of the AOC through. Heterotrophic plate counts (HPC) remained low during the entire period of monitoring due to high additions of disinfectant residual. In a two-year monitoring of a water treatment plant that switched its treatment process from chlorination to chlorination and ozonation, it was observed that the plant effluent AOC increased by 127% while BDOC increased by 49% after the introduction of ozone. Even though AOC is a fraction of BDOC, measuring only one of these parameters can potentially under- or over-estimate the bacterial regrowth potential of the water. Copyright © 2001 Elsevier Science Ltd
Assimilable organic carbon (AOC) and biodegradable dissolved organic carbon (BDOC): Complementary measurements
No full textThe objective of this study was to evaluate the necessity of measuring both assimilable organic carbon (AOC) and biodegradable dissolved organic carbon (BDOC) as indicators of bacterial regrowth potential. AOC and BDOC have often been measured separately as indicators of bacterial regrowth, or together as indicators of bacterial regrowth and disinfection by-product formation potential, respectively. However, this study proposes that both AOC and BDOC should be used as complementary measurements of bacterial regrowth potential. In monitoring of full-scale membrane filtration, it was determined that nanofiltration (NF) removed over 90% of the BDOC while allowing the majority of the AOC through. Heterotrophic plate counts (HPC) remained low during the entire period of monitoring due to high additions of disinfectant residual. In a two-year monitoring of a water treatment plant that switched its treatment process from chlorination to chlorination and ozonation, it was observed that the plant effluent AOC increased by 127% while BDOC increased by 49% after the introduction of ozone. Even though AOC is a fraction of BDOC, measuring only one of these parameters can potentially under- or over-estimate the bacterial regrowth potential of the water. (C) 2001 Elsevier Science Ltd. All rights reserved
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