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71.
This study investigated the removal of two model pharmaceutically active compounds (PhAcs), viz., ibuprofen and triclosan, in lab‐scale engineered floodplain filtration (EFF) system. Biodegradation experiments were performed to acquire knowledge about the degradation of the targeted PhAcs, at an initial concentration of 350 µg/L. Biodegradation results showed that the two compounds were bio‐transformed to >70% after 15 days of incubation. Column tests were performed in a statistically significant manner to determine the adsorptive potential of the suggested filler layer in the EFF (C/C0), by varying the flow rate and initial concentration of the compound. It was observed based on the F and p‐values that the main effects (F = 3163, p < 0.005) were more significant than the interactive effects (F = 9561, p < 0.05) for both ibuprofen and triclosan removal. Besides, by performing the Student's “t” test, it was concluded that the flow rate plays a major role in determining the rapidness of achieving complete breakthrough than the initial concentration of both the compounds. The data obtained from column studies under biotic conditions indicated that the removal mechanism for PhAcs is mainly biotransformation based, and that an EFF system may be effectively used to remove these emerging compounds during ground water recharge for water recycling. 相似文献
72.
Rene Westerholt Bernd Resch Alexander Zipf 《International journal of geographical information science》2013,27(5):868-887
Georeferenced user-generated datasets like those extracted from Twitter are increasingly gaining the interest of spatial analysts. Such datasets oftentimes reflect a wide array of real-world phenomena. However, each of these phenomena takes place at a certain spatial scale. Therefore, user-generated datasets are of multiscale nature. Such datasets cannot be properly dealt with using the most common analysis methods, because these are typically designed for single-scale datasets where all observations are expected to reflect one single phenomenon (e.g., crime incidents). In this paper, we focus on the popular local G statistics. We propose a modified scale-sensitive version of a local G statistic. Furthermore, our approach comprises an alternative neighbourhood definition that enables to extract certain scales of interest. We compared our method with the original one on a real-world Twitter dataset. Our experiments show that our approach is able to better detect spatial autocorrelation at specific scales, as opposed to the original method. Based on the findings of our research, we identified a number of scale-related issues that our approach is able to overcome. Thus, we demonstrate the multiscale suitability of the proposed solution. 相似文献
73.
Ricardo Henrique Moreton Godoi Patricia Y. Hirata Andre V. L. Bitterncourt Ana F. L. Godoi Miguel Jafelicci Jr Francisco J. dos Santos Rafael Bini Liuz F. Zara Cynara L. N. Cunha Ana P. K Soares Eduardo F. Gobbi Sanja Potgieter‐Vermaak José E. F. C. Gardolinski José M. Reis Neto Giuliana Gatto Rotondo Rene van Grieken 《洁净——土壤、空气、水》2012,40(4):364-372
Suspended particles and dissolved substances in water provide reactive surfaces, influence metabolic activity and contribute to the net sediment deposition. It therefore plays an important part in the ecology and quality of the water mass. The water quality in reservoirs is crucial and it is naturally maintained by flushing and sedimentation, which continuously remove phosphorus from the water. In some reservoirs, however, these removal processes are countered by recycling of ions which could play a key role to start and/or maintain the eutrophic state. The combination of macro‐, trace‐ and microanalysis techniques can be useful to trace pollution sources through a chemical fingerprint, whether be during an acute environmental disaster or a long‐term release of pollutants. The water quality and total metal content of reservoir sediments were assessed in a reservoir, situated in the capital of the Paraná State, in the South‐Eastern part of Brazil. The goal of this paper was to determine the metal presence in the sediment and metal and ionic speciation in the Green River reservoir water. Water and bed sediment samples, collected from various sites during 2008 and 2009, were investigated using XRF, ICP‐OES, ICP‐MS, XRD and zeta potential measurements. Based on the results, the heavy metal concentration and chemical composition of the suspended matter in the water samples, as well as the sediment's chemical composition will be discussed. 相似文献
74.
Petrogenesis of group A eclogites and websterites: evidence from the Obnazhennaya kimberlite,Yakutia
Lawrence?A.?TaylorEmail author Gregory?A.?Snyder Randall?Keller David?A.?Remley Mahesh?Anand Rene?Wiesli John?Valley Nikolai?V.?Sobolev 《Contributions to Mineralogy and Petrology》2003,145(4):424-443
Mantle xenoliths from the Obnazhennaya kimberlite pipe, Yakutia, possess a large range of mineralogical and chemical compositions, from both group A and B eclogites. Major-element contents of the group A eclogites exhibit transitional features between the group B eclogites and peridotite. The Mg# of clinopyroxenes is 0.86–0.94, with 0.60–0.84 for garnets. Differences in concentration of LREEs exist between the Obnazhennaya group A and the well-studied group B eclogites from the Udachnaya kimberlite pipe. In general, garnets in the group A eclogites contain lower LREEs than those from the group B eclogites; however, the trend for clinopyroxene is reversed. High d 18O (5.46–7.81) values, and the positive Eu anomalies in the garnets and clinopyroxenes (Eu/Eu* 1.2–1.4) demonstrate the involvement of an oceanic crustal component in the formation of the group A eclogites. The group A eclogites formed between 21.0 and 37.6 kbar, and 711 and 923 °C, in a time interval of 1,071–1,237 Ma. An innovative model is proposed to explain the formation of the group A eclogites and websterites. It involves the reaction of a depleted mantle peridotite with TTG and carbonatite melts closely related to the subduction of oceanic crust. 相似文献
75.
S. K. Behera M.Tech E. R. Rene M.Tech D. V. S. Murthy 《International Journal of Environmental Science and Technology》2007,4(2):247-252
Laboratory scale studies were conducted in an up-flow anoxic bioreactor using synthetic fertilizer wastewater for ascertaining the denitrification efficiency. The performance of the reactor was compared using ethanol and topioca starch as the carbon source. The initial No3-N concentrations (50–250 mg/L) and hydraulic retention time (FTRT, 12–24 h) were varied to evaluate the COD and No3-N removal. The results from this study shows that ethanol gave very good denitrification efficiency (78–98%) compared to topioca starch (68–96%). 相似文献
76.
The oceanic substratum of Northern Luzon: Evidence from xenoliths within Monglo adakite (the Philippines) 总被引:2,自引:0,他引:2
Betchaida D. Payot Sebastien Jego Rene C. Maury Mireille Polve Michel Gregoire Georges Ceuleneer Rodolfo A. Tamayo Jr Graciano P. Yumul Jr Herve Bellon Joseph Cotten 《Island Arc》2007,16(2):276-290
Abstract A 8.65 Ma adakitic intrusive sheet exposed near Monglo village in the Baguio District of Northern Luzon contains a suite of ultramafic and mafic xenoliths including in order of abundance: spinel dunites showing typical mantle-related textures, mineral and bulk rock compositions, and serpentinites derived from them; amphibole-rich gabbros displaying incompatible element patterns similar to those of flat or moderately enriched back-arc basin basalt magmas; and amphibolites derived from metabasalts and/or metagabbros of identical affinity. A single quartz diorite xenolith carrying a similar subduction-related geochemical signature has also been sampled. One amphibolite xenolith provided a whole-rock K–Ar age of 115.6 Ma (Barremian). We attribute the origin of this suite to the sampling by ascending adakitic magmas of a Lower Cretaceous ophiolitic complex located at a depth within the 30–35 km thick Luzon crust. It could represent an equivalent of the Isabela-Aurora and Pugo-Lepanto ophiolitic massifs exposed in Northern Luzon. 相似文献
77.
Type III bursts were observed between 3.5 MHz and 50 kHz by the University of Michigan radio astronomy experiment aboard the OGO-5 satellite.Decay times were measured and then combined with published data ranging up to about 200 MHz. The observed decay times increase with decreasing frequency but at a rate considerably slower than that expected from electron-proton Coulomb collisions. At 50 kHz values differ by about a factor of 100. Using Hartle and Sturrock's solar wind model, Coulomb collisional frequencies were computed and compared with the apparent collisional frequencies deduced from the observations. It was found that the ratio of observed to computed values varies with heliocentric distance according to an inverse 0.71 power. This is similar to an ad hoc function used by Wolff, Brandt, and Southwick to increase the electron-proton collisional energy exchange and make the solar wind theory agree with the measurements of electron and proton temperature near the Earth. These results may provide a clue about the nature of the non-collisional plasma wave damping process responsible for the short duration of type III bursts. 相似文献
78.
79.
Philippa Holmes James Rose Jonathan R. Lee Rene Barendregt Ian Candy James B. Riding Mark Lewis 《Proceedings of the Geologists' Association. Geologists' Association》2018,129(1):70-88
Although substantial work has been done on the pre-glacial terraces of East Anglia, very little systematic work has been done to understand the origin of river terraces in East Anglia that have formed since ice last covered the region. This paper records the results of studies of exposures and borehole records in ‘classical’ Quaternary terrace landforms that are considered to have formed since the Anglian (MIS 12) Glaciation, in the middle Waveney Valley. These features have been examined in terms of their morphological and sedimentological properties, in order to provide a detailed record of their form and composition, understand their processes of formation, and identify their stratigraphical status. The results show that the main body of the highest terrace (Homersfield Terrace, Terrace 3) is not composed of river sediments, but of shallow marine sediments, and is a remnant of early Middle Pleistocene Wroxham Crag. River sediments, in the form of Anglian age (MIS 12) glaciofluvial Aldeby Sands and Gravels also exist in the area as a channel fill, cut through the Wroxham Crag, and reflect outwash erosion and sedimentation from a relatively proximal ice margin to the west. The results mean that the interpretations previously presented for the terrace landforms of the middle Waveney valley are not applicable. The issue of why the terrace stratigraphy, hitherto identified in East Anglia cannot be related to that for the River Thames to the south and the rivers of Midland England to the west, still requires further research. 相似文献
80.
Reza Namdar Ghanbari Hector R. Bravo John J. Magnuson William G. Hyzer Barbara J. Benson 《Journal of Hydrology》2009,374(3-4):282-293
Ice duration has shortened and the ice-off date has become earlier for Lake Mendota from 1905 to 2000 as air temperatures have warmed and snowfall has increased. In addition, the ice record has cyclic components at inter-annual and inter-decadal scales. We examined the frequency domain relations between ice, local climate and the teleconnections, Southern Ocean Oscillation (SOI), Pacific Decadal Oscillation (PDO), North Atlantic Oscillation (NAO), and Northern Pacific Index (NP), through a three-tiered analysis of coherence. The coherence results provide evidence of linear relations between the three levels at inter-annual and inter-decadal frequencies. Of the three local climate variables analyzed, namely temperature, snowfall and snow depth, temperature is the variable that most significantly affects ice duration and ice-off date, at both inter-annual and inter-decadal frequencies. The most significant effect of teleconnections on local climate are the effects of PDO on snowfall and snow depth, and SOI on temperature, at inter-annual frequencies, and the effect of NAO on snowfall at inter-decadal frequencies. The teleconnections that most significantly affect ice-cover duration and ice-off date, particularly at inter-decadal frequencies, are the PDO and the NAO. The influence of PDO on ice-cover appears to be transmitted through temperature, while the influence of the NAO appears to be transmitted through temperature and snowfall. A cascading set of links between teleconnections, local climate, and lake ice explain some, but not all, of the dynamics in these time series. 相似文献