| 1. |
- Szymanski, J. J., et al.
(author)
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A study of the decay mu –> e gamma by the MEGA experiment
- 1996
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In: Proceedings, 9th Meeting, DPF'96, Minneapolis, USA, August 11-15, 1996. Vol. 1, 2.. ; , s. 1450-1452
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Conference paper (peer-reviewed)
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| 2. |
- Cooper, M. D., et al.
(author)
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Construction and performance of MEGA's low-mass, high-rate cylindrical MWPCs
- 1998
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In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 417:1, s. 24-49
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Journal article (peer-reviewed)abstract
- A design for extremely low mass, high-resolution multiwire proportional chambers (MWPC) was achieved by the MEGA collaboration in its experiment to search for the lepton family number violating decay μ → eγ. To extend the present branching ratio limit by over an order of magnitude, these MWPCs were operated in high particle fluxes. They showed minimal effects of aging, and evidenced spatial and energy resolutions for the orbiting positrons from muon decay which were consistent with our design parameters. The unique features of these chambers, their assembly into the MEGA positron spectrometer, and their performance during the experiment are described in this paper.
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| 3. |
- Rappe, C., et al.
(author)
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PCDDs and PCDFs in soil and river sediment samples from a rural area in the United States of America
- 1997
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In: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 34:5-7, s. 1297-1314
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Journal article (peer-reviewed)abstract
- In 1994, we collected 36 soil samples and 61 sediment samples from southern Mississippi, USA. Each sample was analyzed for PCDDs and PCDFs by HRMS using either a polar or a non-polar HRGC column. Although most Cl-4 - Cl-8 PCDDs and PCDFs were detected in each sample, PCDD levels (particularly Cl-7 - Cl-8) were higher in sediment than soil samples. The PCDF pattern in two sediment samples indicated a possible PCB source. The concentrations of 2,3,7,8-tetra CDD and 2,3,7,8-tetra CDF were somewhat higher upstream of a pulp mill than downstream from the mill.
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| 4. |
- Fiedler, Heidelore, 1953-, et al.
(author)
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PCDD, PCDF, and PCB in farm-raised catfish from southeast United States - Concentrations, sources, and CYP1A induction
- 1998
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In: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 37:9-12, s. 1645-1656
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Journal article (peer-reviewed)abstract
- Nine catfish fillets, three catfish nuggets, two feed samples, and one pond sediment were analyzed for PCDD, PCDF, and-PCB. Farm-raised catfish from Mississippi, Alabama, and Arkansas contained significant levels of 2,3,7,8-substituted PCDD and PCDF. In addition, a large number of non-2,3,7,8-substituted congeners were present in all samples. The catfish fillets and catfish nuggets also contained high concentrations of dioxin-like PCB, as well as a number of non-dioxin-like PCB. The TEQ based on PCDD and PCDF ranged from 9.5 to 43.0 pg/g lipid and the TEQ based on PCB ranged from 0.45 to 4.9 pg/g lipid for all catfish samples. The dioxin-like PCB contributed 4-16% to the total TEQ (PCDD/PCDF/PCB) for the catfish samples. The major source for the PCDD, PCDF, and PCB appears to be from feed and not from pond sediment. Immunoreactive CYP1A protein was elevated 2.5 fold in the pond-raised catfish compared to the aquarium-raised one. The results of this study suggest that the PCDD/PCDF are more important than the PCB in the CYP1A induction.
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| 5. |
- Rappe, C., et al.
(author)
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PCDDs and PCDFs in municipal sewage sludge and effluent from POTW in the State of Mississippi, USA
- 1998
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In: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 36:2, s. 315-328
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Journal article (peer-reviewed)abstract
- During the summer 1995, we collected sewage sludge and effluent samples from 17 publicly-owned treatment works (POTW) in the State of Mississippi, USA. Most PCDDs and PCDFs were detected in the sludge, and the hepta- and octaCDD congeners typically were dominant. One plant had an octaCDD value in sludge exceeding 400,000 pg/g d.m. The primary source probably is pentachlorophenol. An earlier US EPA finding of 116 pg/g d.m. 2,3,7,8-tetraCDD in sludge from the Corinth POTW was not confirmed in this study, where only 0.3 pg/g d.m. was measured. Most effluent samples were below the detection limit of approximately 10 pg/L for the tetra- through hexachlorinated congeners. The New Augusta POTW had the highest octaCDD value in effluent (2500 pg/L). This plant is a point source to the Leaf River.
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| 6. |
- Fiedler, Heidelore, 1953-, et al.
(author)
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Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/PCDF) in food samples collected in southern Mississippi, USA
- 1997
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In: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 34:5-7, s. 1411-1419
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Journal article (peer-reviewed)abstract
- n 1994, we analyzed 43 foodstuff samples from local supermarkets in southern Mississippi, USA, for PCDD/PCDF. 2,3,7,8-Cl4DD could be quantified in 31 of these samples. On a lipid basis, levels in meat (0.53-1.10 pg I-TEQ/g) and dairy products (0.42-1.10 pg I-TEQ/g) were slightly lower than those reported from other industrialized countries. While levels in dairy samples from the United States and Europe are comparable, there is a difference in the contribution of individual congeners to the I-TEQ: for example, in milk samples from Germany approximately 40% of the I-TEQ is due to the presence of 2,3,4,7,8-Cl5DF while in the Mississippi samples this congener only contributes 16%. The highest concentrations of PCDD/PCDF in our study were detected in the farm-raised catfish (10.2-27.8 pg I-TEQ/g). A unique finding was that in addition to the 2,3,7,8-substituted PCDD/PCDF the catfish samples contained many non-2,3,7,8-substituted congeners. This is unusual because vertebrate animals selectively eliminate or metabolize the non-2,3,7,8-substituted congeners.
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