scholarly journals Gaseous Oxidized mercury dry deposition measurements in the Four Corners area, U.S.A., after large power plant mercury emission reductions

Author(s):  
Mark E. Sather ◽  
Shaibal Mukerjee ◽  
Luther Smith ◽  
Johnson Mathew ◽  
Clarence Jackson ◽  
...  
2013 ◽  
Vol 4 (2) ◽  
pp. 168-180 ◽  
Author(s):  
Mark E. Sather ◽  
Shaibal Mukerjee ◽  
Luther Smith ◽  
Johnson Mathew ◽  
Clarence Jackson ◽  
...  

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Mark E. Sather ◽  
Shaibal Mukerjee ◽  
Kara L. Allen ◽  
Luther Smith ◽  
Johnson Mathew ◽  
...  

Gaseous oxidized mercury (GOM) dry deposition measurements using aerodynamic surrogate surface passive samplers were collected in central and eastern Texas and eastern Oklahoma, from September 2011 to September 2012. The purpose of this study was to provide an initial characterization of the magnitude and spatial extent of ambient GOM dry deposition in central and eastern Texas for a 12-month period which contained statistically average annual results for precipitation totals, temperature, and wind speed. The research objective was to investigate GOM dry deposition in areas of Texas impacted by emissions from coal-fired utility boilers and compare it with GOM dry deposition measurements previously observed in eastern Oklahoma and the Four Corners area. Annual GOM dry deposition rate estimates were relatively low in Texas, ranging from 0.1 to 0.3 ng/m2h at the four Texas monitoring sites, similar to the 0.2 ng/m2h annual GOM dry deposition rate estimate recorded at the eastern Oklahoma monitoring site. The Texas and eastern Oklahoma annual GOM dry deposition rate estimates were at least four times lower than the highest annual GOM dry deposition rate estimate previously measured in the more arid bordering western states of New Mexico and Colorado in the Four Corners area.


Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1900
Author(s):  
Vitor Augusto Machado Jorge ◽  
Pedro Daniel de Cerqueira Gava ◽  
Juan Ramon Belchior de França Silva ◽  
Thais Mancilha ◽  
Waldir Vieira ◽  
...  

Hydroelectric power plants often make use of tunnels to redirect the flow of water to the plant power house. Such tunnels are often flooded and can span considerable distances. Periodical inspections of such tunnels are highly desirable since a tunnel collapse will be catastrophic, disrupting the power plant operation. In many cases, the use of Unmanned Underwater Vehicles (UUVs) equipped with mechanical profiling sonars is a suitable and affordable way to gather data to generate 3D mapping of flooded tunnels. In this paper, we study the resolution of 3D tunnel maps generated by one or more mechanical profiling sonars working in tandem, considering synchronization and occlusion problems. The article derives the analytical equations to estimate the sampling of the underwater tunnels using mechanical profiling sonars (scanning sonars). Experiments in a simulated environment using up to four sensors simultaneously are presented. We also report experimental results obtained by a UUV inside a large power plant tunnel, together with a first map of this environment using a single sonar sensor.


2012 ◽  
Vol 2 (8) ◽  
pp. 1-9
Author(s):  
Saroj Koul

Subject area Operations and human resourcing. Study level/applicability This case study is intended for use in graduate, executive level management and doctoral programs. The case study illustrates a combined IT and HR driven participative management control system in a flexible organization structure. It is intended for a class discussion rather than to illustrate either effective or ineffective handling of an administrative situation. Case overview The case describes the situation of managing unskilled workforces (≥14,000 workers) during the construction phase of the 4 × 250MW power plants both for purposes of turnout as well as due compensation, in the event of an accident. The approved labour forces appointed for 45 × 8 h. Man-days after a rigorous fitness test and approvals of the safety officer are allocated housing and other necessary amenities and a commensurate compensation system. Expected learning outcomes These include: illustrating typical organizational responsibility structure at a construction site of a large power plant; illustrating the planning and administrative control mechanism in implementing strategy at a construction site of a large power plant; offering students the opportunity to understand and view a typical operational (project) structure; allowing students to speculate adaptations in the wake of an ever-changing business and company environment; and providing an opportunity to introduce a power scenario in India, Indian labour laws and radio frequency identification technology and to relate this to the case in context. Supplementary materials Teaching notes are available; please consult your librarian for access.


1990 ◽  
Vol 11 (4) ◽  
pp. 19-31 ◽  
Author(s):  
BENJAMIN G. LEVICH ◽  
Y. KISHINEVSKY
Keyword(s):  

2007 ◽  
Vol 7 (3) ◽  
pp. 781-801 ◽  
Author(s):  
B. de Foy ◽  
W. Lei ◽  
M. Zavala ◽  
R. Volkamer ◽  
J. Samuelsson ◽  
...  

Abstract. Emissions of air pollutants in and around urban areas lead to negative health impacts on the population. To estimate these impacts, it is important to know the sources and transport mechanisms of the pollutants accurately. Mexico City has a large urban fleet in a topographically constrained basin leading to high levels of carbon monoxide (CO). Large point sources of sulfur dioxide (SO2) surrounding the basin lead to episodes with high concentrations. An Eulerian grid model (CAMx) and a particle trajectory model (FLEXPART) are used to evaluate the estimates of CO and SO2 in the current emission inventory using mesoscale meteorological simulations from MM5. Vertical column measurements of CO are used to constrain the total amount of emitted CO in the model and to identify the most appropriate vertical dispersion scheme. Zenith sky UV spectroscopy is used to estimate the emissions of SO2 from a large power plant and the Popocatépetl volcano. Results suggest that the models are able to identify correctly large point sources and that both the power plant and the volcano impact the MCMA. Modelled concentrations of CO based on the current emission inventory match observations suggesting that the current total emissions estimate is correct. Possible adjustments to the spatial and temporal distribution can be inferred from model results. Accurate source and dispersion modelling provides feedback for development of the emission inventory, verification of transport processes in air quality models and guidance for policy decisions.


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