163,270 research outputs found
Acute and sub-lethal toxicity of landfill leachate towards two aquatic macro-invertebrates: demonstrating the remediation potential of air stripping
No full textA specific leachate that contained 1.036 mg l?1 of 2-chlorobiphenyl was used in the study (255 mg l?1 COD and 133 mg l?1 BOD5). Bench scale (20 l) air stripping trials were used to simulate on a small-scale the treatment potential of this method. Air stripping effectively reduced the leachates COD concentration. Regardless of the volume of air supplied (1–5 l of air per minute) the leachates COD reached a < 50 mg l?1 equilibrium after 96-h exposure, however, increasing the volume of air accelerated the process. In untreated leachate, the LC50 for Asellus aquaticus was 57% v/v leachate in deionised water and 5% for Gammarus pulex (96-h, static LC50 tests without nutrition and oxygen depleting conditions). After being exposed to air stripping, these values rose from 90% to below the LC50 threshold for Asellus when 1–5 l of air per minute were applied and 30–90% for Gammarus. Furthermore, in sub-lethal concentrations of air stripped leachate (leachate that had been exposed to 5-l of air per minute for 96-h) the population dynamics of both test species remained unaltered
[Report to Chief J. E. Curry, by an unknown author #1]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
[Report to Chief J. E. Curry, by an unknown author #2]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
An evaluation of mixed species in-situ and ex-situ feeding assays: The altered response of Asellus aquaticus and Gammarus pulex
No full textMixed species feeding assays were undertaken with pollution sensitive (Gammarus pulex) and tolerant (Asellus aquaticus) macro-invertebrates during August 2003 and April 2004. The purpose of this study was to establish if a test animals' response is comparable during in-situ and ex-situ toxicity tests. Seven test sites were established along an undisclosed stream, which received leachate discharge from an unlined, disused UK landfill site. Sampling points A–B were upstream of the contamination, C was adjacent to the influx and D–G were downstream of the leachate discharge (at 100 m intervals). During the in-situ and ex-situ tests, 2-week-old male laboratory bred A. aquaticus and G. pulex were used as test animals. The animals were transplanted to the seven sampling points for the duration of the in-situ tests, whilst water samples from each site were returned to the laboratory for ex-situ testing. The results show that the animals' mortality and feeding rates followed similar trends during the in-situ and ex-situ tests, however, the animals' response was amplified during the in-situ tests. It was also observed that the effects were greater in April, compared to August that may be attributed to a higher frequency of rainfall during spring, which could have flushed a greater proportion of the contaminant load from the waste mass and as a consequence, higher levels of pollution may have leached into the stream from the landfill site. The study, therefore, concludes that in-situ toxicity tests are a more precise monitoring technique, in comparison to ex-situ assays.<br/
Acute and sub-lethal toxicity of landfill leachate towards two macro-invertebrates: assessing the remediation potential of constructed wetlands
No full textAspecific leachate that contained 1.036 mgl–1 of 2-chlorobiphenyl was used in the study (255 mgl–1 COD and 133 mgl–1 BOD5). When operated on a 10 day hydraulic retention time (RT), reed beds planted with Juncus effusus removed 60% of the leachates COD, compared to 25% in unplanted beds. The constructed wetlands proved effective at reducing the level of acute toxicity to A. aquaticus and G. pulex. In untreated leachate, the LC50 for A. aquaticus was 57% v/v leachate in deionized water and 5% for G. pulex. When reed beds were operated on a 1–10 day RT, the LC50 for Asellus increased from 69% to below the LC50 threshold. The Gammarus LC50 also rose from 10% to 50%. The maximum toxicity reduction achieved by unplanted beds was 10% towards A. aquaticus and 5% for G. pulex, when operated on a 10 day RT. However, in sub-lethal concentrations of reed bed effluent (100%, 80% and 60% dilutions, obtained from planted beds on a 10 day RT), the final length of Asellus was significantly reduced, in comparison to a deionized water control. It is also speculated that chronic leachate stress may have affected the fecundity of Gammarus, however, insufficient data was collected to statistically validate this hypothesis
Soft-Keyboard for the disabled
No full textThis paper discusses an investigation carried out in designing and evaluating a neurorehabiliatory communication interfaces for nonverbal Quadriplegic and other clinically brain injured persons. Research was conducted where brain-injured persons communicated using a brain-body interface and a computer program with simple text such as Yes, No, Thanks etc. This research was further developed into a soft keyboard, which gave a brain-injured person an interface to create simple sentences. The users used the soft keyboard with a brain body interface. This paper reports on the soft keyboard developed and the experimental results of this research
Murder on the mountain: author talk with Peter J. Wosh
No full textAuthor talk by Peter J. Wosh on May 5th, 2022, on his book, "Murder on the Mountain: crime, passion, and punishment in gilded age New Jersey.
Mr. Melvin J. Collier, RWWL AUC, June 2011
No full textThis video is a conversation with Mr. Melvin J. Collier. Mr. Collier talks about his book, "From Mississippi to Africa: A Journey of Discovery". Daniel Le, AUC Woodruff Library, is the interviewer
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