Statistical Analysis of Long-Term Monitoring Data for Persistent Organic Pollutants in the Atmosphere at 20 Monitoring Stations Broadly Indicates Declining Concentrations

2014 ◽  
Vol 48 (21) ◽  
pp. 12492-12499 ◽  
Author(s):  
Deguo Kong ◽  
Matthew MacLeod ◽  
Hayley Hung ◽  
Ian T. Cousins
Keyword(s):  
Statistical Analysis ◽  
Organic Pollutants ◽  
Persistent Organic Pollutants ◽  
Monitoring Data ◽  
Long Term Monitoring ◽  
Term Monitoring ◽  
Monitoring Stations

scholarly journals Long-term monitoring of persistent organic pollutants (POPs) at the Norwegian Troll station in Dronning Maud Land, Antarctica

2013 ◽  
Vol 13 (14) ◽  
pp. 6983-6992 ◽  
Author(s):  
R. Kallenborn ◽  
K. Breivik ◽  
S. Eckhardt ◽  
C. R. Lunder ◽  
S. Manø ◽  
...  
Keyword(s):  
Long Range ◽  
Organic Pollutants ◽  
Persistent Organic Pollutants ◽  
Long Range Transport ◽  
Research Station ◽  
Range Transport ◽  
Dronning Maud Land ◽  
Long Term Monitoring ◽  
Term Monitoring

Abstract. A first long-term monitoring of selected persistent organic pollutants (POPs) in Antarctic air has been conducted at the Norwegian research station Troll (Dronning Maud Land). As target contaminants 32 PCB congeners, α- and γ-hexachlorocyclohexane (HCH), trans- and cis-chlordane, trans- and cis-nonachlor, p,p'- and o,p-DDT, DDD, DDE as well as hexachlorobenzene (HCB) were selected. The monitoring program with weekly samples taken during the period 2007–2010 was coordinated with the parallel program at the Norwegian Arctic monitoring site (Zeppelin mountain, Ny-Ålesund, Svalbard) in terms of priority compounds, sampling schedule as well as analytical methods. The POP concentration levels found in Antarctica were considerably lower than Arctic atmospheric background concentrations. Similar to observations for Arctic samples, HCB is the predominant POP compound, with levels of around 22 pg m−3 throughout the entire monitoring period. In general, the following concentration distribution was found for the Troll samples analyzed: HCB > Sum HCH > Sum PCB > Sum DDT > Sum chlordanes. Atmospheric long-range transport was identified as a major contamination source for POPs in Antarctic environments. Several long-range transport events with elevated levels of pesticides and/or compounds with industrial sources were identified based on retroplume calculations with a Lagrangian particle dispersion model (FLEXPART).

scholarly journals Long-term monitoring of persistent organic pollutants (POPs) at the Norwegian Troll station in Dronning Maud Land, Antarctica

2013 ◽  
Vol 13 (3) ◽  
pp. 6219-6246 ◽  
Author(s):  
R. Kallenborn ◽  
K. Breivik ◽  
S. Eckhardt ◽  
C. R . Lunder ◽  
S. Manø ◽  
...  
Keyword(s):  
Long Range ◽  
Organic Pollutants ◽  
Persistent Organic Pollutants ◽  
Long Range Transport ◽  
Research Station ◽  
Range Transport ◽  
Dronning Maud Land ◽  
Long Term Monitoring ◽  
Term Monitoring

Abstract. A first long-term monitoring of selected persistent organic pollutants (POPs) in Antarctic air has been conducted at the Norwegian Research station Troll (Dronning Maud Land). As target contaminants 32 PCB congeners, a- and g-hexachlorocyclohexane (HCH), trans- and cis-chlordane, trans- and cis-nonachlor, p,p'- and o,p-DDT, DDD, DDE as well as hexachlorobenzene (HCB) were selected. The monitoring program with weekly samples taken during the period 2007–2010 was coordinated with the parallel program at the Norwegian Arctic monitoring site (Zeppelin mountain, Ny-Ålesund, Svalbard) in terms of priority compounds, sampling schedule as well as analytical methods. The POP concentration levels found in Antarctica were considerably lower than Arctic atmospheric background concentrations. Similar as observed for Arctic samples, HCB is the predominant POP compound with levels of around 22 pg m−3 throughout the entire monitoring period. In general, the following concentration distribution was found for the Troll samples analyzed: HCB > Sum HCH > Sum PCB > Sum DDT > Sum chlordanes. Atmospheric long-range transport was identified as a major contamination source for POPs in Antarctic environments. Several long-range transport events with elevated levels of pesticides and/or compounds with industrial sources were identified based on retroplume calculations with a Lagrangian particle dispersion model (FLEXPART). The POP levels determined in Troll air were compared with 1 concentrations found in earlier measurement campaigns at other Antarctic research stations from the past 18 yr. Except for HCB for which similar concentration distributions were observed in all sampling campaigns, concentrations in the recent Troll samples were lower than in samples collected during the early 1990s. These concentration reductions are obviously a direct consequence of international regulations restricting the usage of POP-like chemicals on a worldwide scale.

Vibration Serviceability of Long Span Cable Bridges using Long-term Monitoring Data

2019 ◽  
Author(s):  
Eui-seung Hwang ◽  
Sun-Kon Kim ◽  
Do-Young Kim ◽  
Ki-Jung Park
Keyword(s):  
Monitoring Data ◽  
Suspension Bridges ◽  
Span Length ◽  
Bridge Design ◽  
Long Span ◽  
Vibration Serviceability ◽  
Long Term Monitoring ◽  
Deflection Limit ◽  
Term Monitoring

<p>Along with building slender and longer span structures, vibration serviceability becomes more important considerations in bridge design and maintenance. In this study, vibration serviceability and deflection limit for long span cable bridges are investigated using long-term monitoring data such as accelerations and displacements of bridges. Exampled bridges are Yi Sun-Sin Grand Bridge (suspension bridge, main span length=1,545m) and 2<sup>nd</sup> Jindo Grand Bridge (cable stayed bridge, main span length=344m). Long-term data are analyzed and compared with various design codes, guidelines, and other research results. Probability of exceedance are calculated for each criterion. Regarding on deflection limits, Korean Bridge Design Code (Limit State Design) specifies L/400 and L/350 for cable stayed and suspension bridges, respectively. Saadeghvaziri suggested deflection limit based on natural frequency, acceleration limit of 0.5 m/s² and vehicle speed. Various human comfort criteria on vibration are also applied including ISO standards. The results of this study are expected to be useful reference for the design, the proper planning and deflection review of the long span cable bridges around the world. Further researches are required to find the optimum deflection or vibration criteria for long span bridge and their effects on bridge clearance and elevation.</p>

Proposed evaluation methods for vibration serviceability of long span cable bridges

2021 ◽  
Author(s):  
E.-S. Hwang ◽  
M. T. Hwang ◽  
D. Y. Kim ◽  
K. J. Park
Keyword(s):  
Heavy Traffic ◽  
Damping Ratio ◽  
Flexible Structures ◽  
Evaluation Methods ◽  
Monitoring Data ◽  
Long Span ◽  
Vibration Serviceability ◽  
Long Term Monitoring ◽  
Term Monitoring

<p>Vibration serviceability becomes more important considerations in design and maintenance, especially for slender and flexible structures such as long span cable bridges. In this study, various evaluation methods for vibration serviceability for long span cable bridges are proposed. These methods are based on short and long-term monitoring data such as accelerations and displacements of bridges. Proposed methods include (1) method of evaluating vibration amplitude based on Reiher-Meister curves, (2) method of evaluating variations in natural frequencies and damping ratio,</p><p>(3) method of weighted rms(root-mean-square) acceleration based on ISO 2631-1, and (4) probabilistic analysis using long-term monitoring data. These methods are applied to example cable bridge and cases of normal traffic, heavy traffic, windy condition and sudden abnormal vibration are considered. The results of this study are expected to be implemented to real bridge monitoring system for real-time and periodic evaluation of vibration serviceability.</p>

scholarly journals Long-term monitoring data logs of a recirculating artificial seawater based colonial ascidian aquaculture

Data in Brief ◽  
2021 ◽  
Vol 38 ◽  
pp. 107372
Author(s):  
Marta K. Wawrzyniak ◽  
Lluìs Albert Matas Serrato ◽  
Simon Blanchoud
Keyword(s):  
Artificial Seawater ◽  
Monitoring Data ◽  
Colonial Ascidian ◽  
Long Term Monitoring ◽  
Term Monitoring

scholarly journals Reliability of long-term monitoring data

2013 ◽  
Vol 4 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Peter Anderegg ◽  
Rolf Brönnimann ◽  
Urs Meier
Keyword(s):  
Monitoring Data ◽  
Long Term Monitoring ◽  
Term Monitoring
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