Absent anoxic activity of PAO I on nitrate under different long-term operational conditions

2017 ◽  
pp. 127-156
Keyword(s):  
Operational Conditions

scholarly journals Optimising the performance of a lab-scale tidal flow reed bed system treating agricultural wastewater

2004 ◽  
Vol 50 (8) ◽  
pp. 65-72 ◽  
Author(s):  
Y.Q. Zhao ◽  
G. Sun ◽  
C. Lafferty ◽  
S.J. Allen
Keyword(s):  
Tidal Flow ◽  
High Strength ◽  
Pollutant Removal ◽  
Inorganic Pollutants ◽  
Operational Conditions ◽  
Agricultural Wastewater ◽  
Major Route ◽  
Reed Bed ◽  
Ammoniacal Nitrogen Removal

A gravel-based tidal flow reed bed system was operated with three different strategies in order to investigate its optimal performance for the treatment of a high strength agricultural wastewater. According to the three strategies, individual reed beds were saturated and unsaturated with the wastewater for different periods while reasonably stable hydraulic and organic loadings were maintained. Experimental results demonstrated that the system produced the highest pollutant removal efficiencies with a relatively short saturated period and long unsaturated period, highlighting the importance of oxygen transfer into reed bed matrices during the treatment. Significant removals of some major organic and inorganic pollutants were achieved under all three operational conditions. Nitrification was not the major route of ammoniacal-nitrogen removal when the system was under high organic loading. Due to the filtration of suspended solids and the accumulation of biomass, gradual clogging of the reed bed matrices took place, which caused concerns over the long-term efficiency of the tidal flow system.

scholarly journals Long-term investigation of phosphorus removal by iron electrocoagulation in small-scale wastewater treatment plants

2018 ◽  
Vol 78 (6) ◽  
pp. 1304-1311 ◽  
Author(s):  
I. Mishima ◽  
M. Hama ◽  
Y. Tabata ◽  
J. Nakajima
Keyword(s):  
Wastewater Treatment ◽  
Phosphorus Removal ◽  
Wastewater Treatment Plants ◽  
Phosphorus Release ◽  
Small Scale ◽  
Operational Conditions ◽  
Long Time ◽  
Negative Effect ◽  
Iron Electrolysis

Abstract Small-scale wastewater treatment plants (SWTPs), called Johkasou, are widely used as decentralized and individual wastewater treatment systems in sparsely populated areas in Japan. Even in SWTPs, nutrients should be removed to control eutrophication. An iron electrolysis method is effective to remove phosphorus chemically in SWTPs. However, it is necessary to determine the precise conditions under which phosphorus can be effectively and stably removed in full scale SWTPs for a long period. Therefore, long-term phosphorus removal from SWTPs was investigated and optimum operational conditions for phosphorus removal by iron electrolysis were analyzed in this study. Efficient phosphorus removal can be achieved for a long time by adjusting the amount of iron against the actual population equivalent. The change of the recirculation ratio had no negative effect on overall phosphorus removal. Phosphorus release to the bulk phase was prevented by the accumulated iron, which was supplied by iron electrolysis, resulting in stable phosphorus removal. The effect of environmental load reduction due to phosphorus removal by iron electrolysis was greater than the cost of power consumption for iron electrolysis.

scholarly journals Discrete-Event Simulation of the Establishment of a Bare Beachhead for Long-Term Joint Logistics over the Shore (JLOTS) Operations

2017 ◽  
Vol 5 (2) ◽  
pp. 123-128
Author(s):  
Marqus Burrell ◽  
Jeffrey Demarest ◽  
Sarah LaRue ◽  
Angelo Martinez ◽  
Wilson Meyer
Keyword(s):  
Discrete Event Simulation ◽  
Discrete Event ◽  
The United States ◽  
Operational Conditions ◽  
Freedom Of Movement ◽  
Event Simulation ◽  
Early Entry ◽  
Sea Transportation ◽  
Development Center

The United States military uses Joint Logistics Over-the-Shore (JLOTS) operations to move soldiers, vehicles, and equipment across the globe for military and humanitarian missions. These logistics operations can only be accomplished through cooperation between commanders in all services.  The U.S. Army Engineer Research and Development Center is developing a tool to analyze a set of early entry alternatives to optimize mission effectives and efficiencies in order to facilitate assured mobility and freedom of movement. This program is currently being developed under the name Planning Logistics Analysis Network System (PLANS). PLANS comprehensively covers air, land, and sea transportation infrastructure, regions of avoidance, and more. This research addresses a gap in strategic and operational planning by modeling the establishment of JLOTS operations on bare beach environments. The West Point developed discrete event simulation will determine the amount of time it takes to prepare a beach to sustain JLOTS operations under varying environmental and operational conditions.

The Analyses for the Casing Improvements of the MPM-20 Engine

2015 ◽  
Author(s):  
K. Ratkovská ◽  
J. Čerňan ◽  
M. Cúttová ◽  
K. Semrád
Keyword(s):  
Emission Spectra ◽  
Infrared Emission ◽  
Point Of View ◽  
Thermally Induced ◽  
Operational Conditions ◽  
Term Operation ◽  
Structural Modifications ◽  
Operational Issues ◽  
Combustor Liner

The operational issues of a small turbojet engine MPM – 20 are discussed. The engine was created by modifying the Soviet turbostarter TS – 20B/21 designed for short-term operation. It is necessary to make structural modifications that allow for the long-term operational premise of the engine. For this purpose, several analyses were focused on the thermally stressed parts. The first, a material analysis carried out on the outer casing of the combustion chamber and on the combustor liner reveals information about the mechanical properties of these structural nodes. It was necessary since there is no documentation of the engine with this information. Another analysis of the infrared emission spectra is important for monitoring operational conditions, especially from the temperature point of view. Subsequent stress analysis of the casing is based on results from previous analyses. It was used to observe the behaviour of the casing as operational conditions changed. This revealed a dangerous increase of thermally induced stress levels as temperature increased up to 150°C. Various structural modifications can be made in the future with these results, such as an application of a protective coating on the casing and combustor liner of the engine.

scholarly journals Short and long-term outcomes of video observed treatment in tuberculosis patients, the Republic of Moldova

2021 ◽  
Vol 15 (09.1) ◽  
pp. 17S-24S
Author(s):  
Svetlana Doltu ◽  
Ana Ciobanu ◽  
Yuliia Sereda ◽  
Ruth Persian ◽  
Luke Ravenscroft ◽  
...  
Keyword(s):  
Treatment Outcomes ◽  
Treatment Strategy ◽  
Term Outcome ◽  
Operational Conditions ◽  
Republic Of Moldova ◽  
Tb Treatment ◽  
Long Term Treatment ◽  
Short And Long Term ◽  
The Republic

Introduction: The Republic of Moldova is among the 18 high priority countries for tuberculosis (TB) in Europe. This study compared adherence and short and long-term TB treatment outcomes for TB patients who experienced asynchronous Video Observed Treatment (aVOT) during three months of outpatient treatment versus Directly Observed Treatment (DOT) in operational conditions in 2016-2017 in Chisinau. Methodology: We used secondary data from the 2016-2017 Randomized Clinical Trial (RCT) that piloted the aVOT Strategy in Chisinau and data from the national TB register. Relative risk was selected as a measure of association in analysis of treatment strategies (aVOT and DOT under operational conditions) and short and long-term treatment outcomes. Results: From 647 TB patients included in the study, 169 followed the treatment strategy in the RCT (83 in aVOT and 86 in DOT) and 478 were on DOT in operational conditions. Those in aVOT were more likely to have favourable short-term outcome than patients with DOT in operational conditions (RR 0.07; p < 0.001). TB recurrence as an indicator for the long-term outcome, was observed in group with DOT in operational conditions (40 cases, p = 0.006). Conclusions: This study demonstrated that the aVOT treatment strategy was associated with better adherence and both short and long-term TB treatment favourable outcomes. aVOT as a new patient-centred approach supporting TB patients on improving treatment adherence and outcomes might be recommended as an alternative to DOT strategy in the Republic of Moldova.

An iterative methodology for the prediction of dynamic vehicle–track interaction and long-term periodic rail wear

2018 ◽  
Vol 232 (6) ◽  
pp. 1718-1730 ◽  
Author(s):  
Andreas Carlberger ◽  
Peter T Torstensson ◽  
Jens CO Nielsen ◽  
Anders Frid
Keyword(s):  
General Purpose ◽  
Domain Model ◽  
Small Radius ◽  
Wear Depth ◽  
Commercial Software ◽  
Operational Conditions ◽  
Rail Corrugation ◽  
Rail Wear ◽  
Wide Range

In this study, a versatile numerical method for the prediction of long-term growth of rail roughness is presented and its functionality is demonstrated for the development of rail corrugation on small radius curves. The procedure includes two sub-modules: (1) a time-domain model for the simulation of dynamic vehicle–track interaction in a wide range of frequencies by using a commercial software for multibody dynamics and (2) a post-calculation of sliding wear based on the Archard’s model in combination with a non-Hertzian and transient wheel–rail contact model. The structural flexibility of the wheelset is accounted for by using the finite element method. The rail wear generated by a large number of passing trains is assessed by recurrently updating the rail surface based on the wear depth calculated in each post-processing step. The current work sets out from a previous study in which a model for the prediction of long-term growth of rail roughness on small radius curves was developed in a general-purpose programming language. By transferring the model into a commercial software, the aim is to develop an engineering tool that is more applicable for different operational conditions, such as various vehicle and track designs and track alignments. The proposed method is verified by comparing the simulation results against those obtained with the pre-existing software. Conditions similar to a 120 m radius curve on the Stockholm metro exposed to corrugation growth on the low rail are considered. The corrugation is found to be generated by the leading wheelsets. The prevailing wavelength-fixing mechanisms are identified and discussed.

Revealing the Microstructure-Related Light-induced Degradation for All-Polymer Solar Cells Based on Regioisomerized End-Capping Groups Acceptors

2022 ◽  
Author(s):  
Jing Guo ◽  
Tao Wang ◽  
Yao Wu ◽  
Rui Sun ◽  
Qiang Wu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
State Of The Art ◽  
Polymer Solar Cells ◽  
Power Conversion ◽  
The State ◽  
Operational Conditions ◽  
End Capping

Given the state-of-the-art impressive power conversion efficiency (PCE) of all-polymer solar cells (all-PSCs) surpassing 17%, it’s getting increasingly urgent to achieve highly stable devices under long-term operational conditions. Herein, the...

VeLoNOx™ Combustion System Operating Experience on Heavy Duty Gas Turbine

2010 ◽  
Author(s):  
Federico Bonzani ◽  
Carlo Piana ◽  
Domenico Zito
Keyword(s):  
Gas Turbine ◽  
Operating Experience ◽  
Combustion System ◽  
Heavy Duty ◽  
Operational Conditions ◽  
Commercial Operation ◽  
Heavy Duty Gas Turbine ◽  
Service Agreement ◽  
System Operating

In order to improve operability and flexibility, Ansaldo Energia has upgraded its top of the line AE94.3A gas turbine with a new combustion system called VeLoNOx™ (Very Low NOx) based on its own experience. This new combustion system meets the most stringent pollutant limitations (as of today) required by the governments all over EU, i.e. less than 15 ppm NOx emissions. The system has been first tested intensively on a single AE94.3A built by Ansaldo Energia. Due to the long term service agreement with the customer the whole operation has been constantly monitored and all most relevant operational conditions have been tested. Then has been installed on other engines. Up to now VeLoNOx™ combustion systems have been cumulating more than 25000 EOH on many sites, showing very good performances in line with expectations. Orders for many retrofit applications have been already awarded. This paper describes the performance of the system on the units of Ansaldo Energia fleet such as AE94.3A2 and AE94.3A4, focusing on the improvements carried out during commercial operation.

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