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941.
Questioning the excessive use of advanced treatment to remove organic micropollutants from wastewater 总被引:4,自引:0,他引:4
Pollution from endocrine disrupting compounds and related micropollutants is widely regarded as a major environmental issue on both a regional and a global scale, largely due to concerns over risks to human and ecological health. Between 2005 and 2010, the United Kingdom is conducting a demonstration program, costing approximately 40 million (approximately $80 million atthe time of writing), to evaluate technologies to remove these compounds from wastewater. However, while such advanced treatment techniques will undoubtedly reduce the discharges of micropollutants, they will also inevitably result in large financial costs, as well as environmentally undesirable increases in energy consumption and CO2 emissions. Here we calculate the price of treating urban sewage with two of the major options specifically proposed in the U.K. demonstration program: (i) granular activated carbon and ozone and (ii) membrane filtration and reverse osmosis. Economic analysis indicates thattreating wastewater with these advanced technologies may be economically and environmentally undesirable due to the increased energy consumption and associated economic costs and CO2 emissions. Since the costs of advanced treatment of sewage would most likely have to be passed on to customers (both domestic and industrial), we propose that national demonstration programs should not only compare and contrast the most advanced treatment methods but also consider alternative techniques, such as increased sludge ages and hydraulic retention times in conjunction with nutrient removal stages and the varying redox conditions associated with them, which potentially may be almost as effective but with much lower environmental and financial costs. 相似文献
942.
Effect of chromium(VI) on bacterial kinetics of heterotrophic biomass of activated sludge 总被引:3,自引:0,他引:3
The effect of hexavalent chromium, Cr(VI), on the maximum specific growth rate, mu(m) and biomass yield, Y(H), of heterotrophic biomass was studied in batch tests conducted under high (= 10) and low (= 1.5) substrate-to-biomass ratios (S0/X0). The effects of sludge age and biomass acclimatization to Cr(VI) on the bacterial kinetics were also studied. The mu(m) values were determined by measuring oxygen uptake rate (OUR) and volatile suspended solids (VSS) increase. Cr(VI) concentrations equal or greater than 10 mg l(-1) inhibited the growth of unacclimatized activated sludge and caused a significant decrease in mu(m) and Y(H) values. The acclimatization of biomass and the selection of a high operating sludge age reduced the inhibitory effect of Cr(VI). At a sludge age of 20 days, Cr(VI) concentrations of <10 mg l(-1) stimulated bacterial growth as evidenced by an increase in both the mu(m) and Y(H) values. Determining mu(m) values by OUR and VSS methods, revealed that the presence of Cr(VI) in unacclimatized biomass caused an inhibitory effect mostly on substrate oxidation, while in acclimatized biomass, anabolic pathways were inhibited more. 相似文献
943.
f-Value: measuring an article’s scientific impact 总被引:1,自引:0,他引:1
Eleni?FragkiadakiEmail author Georgios?Evangelidis Nikolaos?Samaras Dimitris?A.?Dervos 《Scientometrics》2011,86(3):671-686
The f-value is a new indicator that measures the importance of a research article by taking into account all citations received,
directly and indirectly, up to depth n. The f-value considers all information present in a Citation Graph in order to produce a ranking of the articles. Apart from
the mathematical equation that calculates the f-value, we also present the corresponding algorithm with its implementation,
plus an experimental comparison of f-value with two known indicators of an article’s scientific importance, namely, the number
of citations and the Page Rank for citation analysis. Finally, we discuss the similarities and differences among the indicators. 相似文献
944.
Pappas AC Zoidis E Georgiou CA Demiris N Surai PF Fegeros K 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2011,28(4):446-454
The aim of the study was to investigate the interactions between selenium (Se) and various trace elements, both toxic and essential, involved in the antioxidant system. A total of 128 day-old chicks (Gallus gallus, broilers) were used to investigate the effect of Se yeast supplementation on the accumulation of cadmium (Cd), copper (Cu) iron (Fe) and zinc (Zn). There were four replicates of four dietary treatments: T1 (basal diet with no added Se, analyzed to contain 0.21 mg kg(-1)), T2 (T1 with 0.15 mg kg(-1) Se added), T3 (T1 with 0.3 mg kg(-1) Se) and T4 (T1 with 3.0 mg kg(-1) Se). At week 4 and 6, two chickens per replicate pen were sacrificed for whole blood, breast muscle and liver sampling. Samples were analyzed by ICP-MS. Supplementation with Se-yeast, not only increased Se concentration but also reduced Cd concentration in the tissues. Selenium was negatively correlated with Cd and positively correlated with Zn, Cu and Fe. Cadmium was negatively correlated with Zn and Cu. Zinc was positively correlated with Cu. Iron was negatively correlated with Cu and uncorrelated with Zn and Cd. The balance between Se, Cu, Fe and Zn is important for proper antioxidant defense since they are an integral part of various antioxidant enzymes. 相似文献
945.
Nikolaos Katsarakis Aristodemos Pnevmatikakis Zheng-Hua Tan Ramjee Prasad 《Wireless Personal Communications》2014,78(3):1789-1810
Visual face tracking is an important building block for all intelligent living and working spaces, as it is able to locate persons without any human intervention or the need for the users to carry sensors on themselves. In this paper we present a novel face tracking system built on a particle filtering framework that facilitates the use of non-linear visual measurements on the facial area. We concentrate on three different such non-linear visual measurement cues, namely object detection, foreground segmentation and colour matching. We derive robust measurement likelihoods under a unified representation scheme and fuse them into our face tracking algorithm. This algorithm is complemented with optimum selection of the particle filter’s object model and a target handling scheme. The resulting face tracking system is extensively evaluated and compared to baseline ones. 相似文献
946.
Nikolaos Stamatis John S Arkoudelos 《Journal of the science of food and agriculture》2007,87(6):1164-1171
The self‐life, quality and safety of refrigerated sardine fillets (Sardina pilchardus) were determined at 3 °C in atmospheric air, vacuum and modified atmosphere (50% CO2/50% N2) packaging conditions. Microbiological, physico‐chemical and sensory parameters were utilised as quality indicators. The microbial flora of sardine comprised—according to order of occurrence—Shewanella putrefaciens, pseudomonads, Brochothrix thermosphacta, lactic acid bacteria and, finally, Enterobacteriaceae. Bacteria grew most quickly in sardines stored in air, followed by those in vacuum packaging, and the lowest counts were found in modified atmosphere packaging. The concentrations of moisture, ash, protein, fat and polyunsaturated fatty acids were not affected during the storage period compared to the pH values and the concentrations of lactate and ammonia that showed significant differences. Copyright © 2007 Society of Chemical Industry 相似文献
947.
948.
Evan Ribnick Ravishankar Sivalingam Nikolaos Papanikolopoulos Kostas Daniilidis 《Computer Vision and Image Understanding》2012,116(7):815-826
We have shown previously that it is possible to accurately reconstruct periodic motions in 3D from a single camera view, using periodicity as a physical constraint from which to perform geometric inference. In this paper we explore the suitability of the reconstruction techniques for real human motion. We examine the degree of periodicity of human gait empirically, and develop algorithmic tools to address some of the challenges arising from this type of motion, including reconstructing motions that deviate from pure periodicity, properly handling the trajectories of multiple points on an articulated body, and proposing a distance function for measuring the difference between two reconstructions. Importantly, we illustrate the usefulness of these techniques by applying them to the tasks of view-invariant activity classification, clinical gait analysis and person identification. 相似文献
949.
Michael J. Thomson Sudip Biswas Nikolaos Tsakirpaloglou Endang M. Septiningsih 《International journal of molecular sciences》2022,23(12)
Advances in molecular technologies over the past few decades, such as high-throughput DNA marker genotyping, have provided more powerful plant breeding approaches, including marker-assisted selection and genomic selection. At the same time, massive investments in plant genetics and genomics, led by whole genome sequencing, have led to greater knowledge of genes and genetic pathways across plant genomes. However, there remains a gap between approaches focused on forward genetics, which start with a phenotype to map a mutant locus or QTL with the goal of cloning the causal gene, and approaches using reverse genetics, which start with large-scale sequence data and work back to the gene function. The recent establishment of efficient CRISPR-Cas-based gene editing promises to bridge this gap and provide a rapid method to functionally validate genes and alleles identified through studies of natural variation. CRISPR-Cas techniques can be used to knock out single or multiple genes, precisely modify genes through base and prime editing, and replace alleles. Moreover, technologies such as protoplast isolation, in planta transformation, and the use of developmental regulatory genes promise to enable high-throughput gene editing to accelerate crop improvement. 相似文献
950.
Nikolaos Politakos Iñaki ZalakainBorja Fernandez d'Arlas Arantxa EceizaGalder Kortaberria 《Materials Chemistry and Physics》2013
In this work two systems consisting on polyaniline (Pani) doped with simple and small gap C60 fullerenes have been prepared and characterized. Composites with different doping amounts of 1,2,4 and 8 wt% have been analyzed in order to evaluate their structure together with their optical and electrical properties and the effect of fullerene type and amount on them. The shift and change of shape in Fourier transform infrared spectroscopy (FTIR) bands and solid 13C NMR spectroscopy signals showed the presence of interactions between matrix and fullerenes by electron density transfer among them. Optical properties have also been analyzed in terms of ultraviolet (UV) spectroscopy. The blue shift of several bands confirmed the charge transfer. Obtained structures have been analyzed by optical microscopy (OM) showing the different way in which both types of fullerenes have been incorporated into the polymer chains. Finally, conductivity has been measured by the four probe technique, relating obtained values with the structure of the composite and the different degree of crystallinity of simple and small gap fullerenes. 相似文献