Ozone control strategy modeling and evaluation for Athens, Greece: ROG vs. NO x effectiveness and the impact of using different wind field preparation techniques

1995 ◽  
Vol 57 (1-4) ◽  
pp. 3-20 ◽  
Author(s):  
J. -M. Giovannoni ◽  
A. Clappier ◽  
A. Russell
Keyword(s):  
Control Strategy ◽  
Wind Field ◽  
Ozone Control ◽  
The Impact ◽  
Preparation Techniques

scholarly journals Quantitative impacts of meteorology and precursor emission changes on the long-term trend of ambient ozone over the Pearl River Delta, China and implications for ozone control strategy

2019 ◽  
Author(s):  
Leifeng Yang ◽  
Huihong Luo ◽  
Zibing Yuan ◽  
Junyu Zheng ◽  
Zhijiong Huang ◽  
...  
Keyword(s):  
Control Strategy ◽  
Pearl River Delta ◽  
Pearl River ◽  
The Past ◽  
Ambient Ozone ◽  
Ozone Control ◽  
Emission Changes ◽  
Ozone Episodes ◽  
The Impact ◽  
General Conditions

Abstract. China is experiencing increasingly serious ambient ozone pollution, including the economically developed Pearl River Delta (PRD) region. However, the underlying reasons for ozone increase remain largely unclear, leading to perplexity in formulating effective ozone control strategies. In this study, by developing a statistical analysis framework combining meteorological adjustment and source apportionment, we examine quantitatively the impacts of meteorology and precursor emissions from within and outside the PRD on the evolution of ozone during the past decade. We found that meteorological condition has mitigated ozone increase, and its variation can account for at most 15 % of annual ozone concentration in the PRD. Precursor emission from outside the PRD (non-local) makes the largest contribution to ambient ozone in the PRD and shows a consistently increasing trend, while that from within the PRD (local) shows a significant spatial heterogeneity and plays a more important role during ozone episodes over southwestern. Under general conditions, the impact on northeastern is positive but decreasing, and on southwestern is negative but increasing. During ozone episodes, the impact on northeastern is negative and decreasing, while on southwestern is positive but decreasing. Central and western PRD is the only area with increasing local ozone contribution. The spatial heterogeneity in both local ozone contribution and its trend under general conditions and ozone episodes are well interpreted by a conceptual model collectively taking into account ozone precursor emissions and their changing trends, ozone formation regimes, and the monsoonal and micro-scale synoptic conditions over different sub-regions of the PRD. In particular, we conclude that the inappropriate NOx / VOC control ratio within the PRD over the past years is most likely responsible for the ozone increase over southwestern, both under general conditions and during ozone episodes. By investigating the ozone evolution influenced by emission changes within and outside PRD during the past decade, this study highlights the importance of establishing a dichotomous ozone control strategy to tackle with general conditions and pollution events separately. NOx emission control should be further strengthened to alleviate peak ozone level during episodes. Detailed investigation is needed to retrieve appropriate NOx / VOC ratios for different emission and meteorological conditions, so as to maximize the ozone reduction efficiency in the PRD.

scholarly journals Onchocerciasis control in Ghana (1974–2016)

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Nana-Kwadwo Biritwum ◽  
Dziedzom K. de Souza ◽  
Odame Asiedu ◽  
Benjamin Marfo ◽  
Uche Veronica Amazigo ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Vector Control ◽  
Control Strategy ◽  
Financial Support ◽  
Control Programme ◽  
Ivermectin Treatment ◽  
Mobile Community ◽  
The Mean ◽  
The Impact ◽  
Onchocerciasis Control

Abstract Background The control of onchocerciasis in Ghana started in 1974 under the auspices of the Onchocerciasis Control Programme (OCP). Between 1974 and 2002, a combination of approaches including vector control, mobile community ivermectin treatment, and community-directed treatment with ivermectin (CDTI) were employed. From 1997, CDTI became the main control strategy employed by the Ghana OCP (GOCP). This review was undertaken to assess the impact of the control interventions on onchocerciasis in Ghana between 1974 and 2016, since which time the focus has changed from control to elimination. Methods In this paper, we review programme data from 1974 to 2016 to assess the impact of control activities on prevalence indicators of onchocerciasis. This review includes an evaluation of CDTI implementation, microfilaria (Mf) prevalence assessments and rapid epidemiological mapping of onchocerciasis results. Results This review indicates that the control of onchocerciasis in Ghana has been very successful, with a significant decrease in the prevalence of infection from 69.13% [95% confidence interval) CI 60.24–78.01] in 1975 to 0.72% (95% CI 0.19–1.26) in 2015. Similarly, the mean community Mf load decreased from 14.48 MF/skin snip in 1975 to 0.07 MF/skin snip (95% CI 0.00–0.19) in 2015. Between 1997 and 2016, the therapeutic coverage increased from 58.50 to 83.80%, with nearly 100 million ivermectin tablets distributed. Conclusions Despite the significant reduction in the prevalence of onchocerciasis in Ghana, there are still communities with MF prevalence above 1%. As the focus of the GOCP has changed from the control of onchocerciasis to its elimination, both guidance and financial support are required to ensure that the latter goal is met.

scholarly journals Quadrature Voltage Compensation in the Isolated Multi-Modular Converter

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 529
Author(s):  
Cristian Verdugo ◽  
Jose Ignacio Candela ◽  
Pedro Rodriguez
Keyword(s):  
Control Strategy ◽  
Phase Voltage ◽  
Multilevel Converters ◽  
Photovoltaic Panels ◽  
Circulating Current ◽  
Three Phase ◽  
Voltage Compensation ◽  
Wide Range ◽  
Modular Converter ◽  
The Impact

Series connections of modules in cascaded multilevel converters are prone to power imbalances due to voltage differences on their DC side. When modules are connected to direct current (DC) sources, such as photovoltaic panels, the capability of withstanding power imbalances is crucial for generating the maximum power. In order to provide a possible solution for this requirement, this paper proposes a control strategy called Quadrature Voltage Compensation, which allows a wide range of power imbalances. The proposed control strategy regulates the power by introducing a circulating current between the arms and a phase angle in the output voltage. The impact of the circulating current and its effect on the phase voltage are studied. To highlight the features of the proposed strategy, an analytical model based on vector superposition is also described, demonstrating the strong capability of tolerating power differences. Finally, to validate the effectiveness of the Quadrature Voltage Compensation, simulation and experimental results are presented for a three-phase isolated multi-modular converter.

Identifying Challenges and Risks Associated with the Analysis of Major Mycotoxins in Feed and Botanicals

2019 ◽  
Vol 102 (6) ◽  
pp. 1689-1694
Author(s):  
Ujwal S. Patil ◽  
Sarah King ◽  
Sean Holleran ◽  
Kristen White ◽  
Cheryl Stephenson ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Weather Conditions ◽  
Herbal Products ◽  
Pros And Cons ◽  
Mycotoxin Analysis ◽  
Quantitative Results ◽  
Traditional Approaches ◽  
The Impact ◽  
Lc Tandem Ms ◽  
Preparation Techniques

Changing weather conditions have heightened the risk of growth of mycotoxigenic molds on crops and various agricultural commodities. Mycotoxins, which are linked to carcinogenic and nephrotoxic effects in animals and humans, have been traditionally analyzed by immunoassays, gas, and LC techniques with spectrophotometric detectors. This review discusses the current techniques and challenges in commercial settings associated with the analysis of mycotoxins in unique matrices such as animal feeds, herbal products, and dietary supplements containing botanicals. Because of the advantages and growing acceptance of LC-tandem MS (MS/MS) over traditional approaches, discussion is mainly based on LC-MS/MS-based approaches. Considering the impact of sample preparation on accuracy of quantitative results, discussion about pros and cons of recently introduced sample preparation techniques is integrated with analytical methods. A section of the review explains the importance and availability of reference materials for mycotoxins. The present discussion provides good insight into the current challenges and developments during mycotoxin analysis of feed and botanicals and addresses the need for researchers in terms of an official MS-based method.

scholarly journals The impact of implementing HIV prevention policies therapy and control strategy among HIV and AIDS incidence cases in Malaysia

2020 ◽  
Vol 5 ◽  
pp. 755-765
Author(s):  
Ofosuhene O. Apenteng ◽  
Prince P. Osei ◽  
Bismark Oduro ◽  
Mavis Pearl Kwabla ◽  
Noor Azina Ismail
Keyword(s):  
Hiv Prevention ◽  
Control Strategy ◽  
Hiv And Aids ◽  
Prevention Policies ◽  
And Control ◽  
The Impact

scholarly journals The impact of wind field spatial heterogeneity and variability on short-term wind power forecast errors

2019 ◽  
Vol 11 (3) ◽  
pp. 033304 ◽  
Author(s):  
Mao Yang ◽  
Luobin Zhang ◽  
Yang Cui ◽  
Qiongqiong Yang ◽  
Binyang Huang
Keyword(s):  
Spatial Heterogeneity ◽  
Wind Power ◽  
Wind Field ◽  
Forecast Errors ◽  
Short Term ◽  
Wind Power Forecast ◽  
The Impact

scholarly journals Coordinated Control for Driving Mode Switching of Hybrid Electric Vehicles

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Yanyan Zuo ◽  
Rui Sun ◽  
Jiuyu Zang ◽  
Mingyin Zheng
Keyword(s):  
Control Strategy ◽  
Coordinated Control ◽  
Switching Process ◽  
Mode Switching ◽  
Coupling Mechanism ◽  
Characteristic Analysis ◽  
Driving Mode ◽  
Power Coupling ◽  
Hybrid Electric ◽  
The Impact

Taking a hybrid electric vehicle using double-row planetary gear power coupling mechanism as a research object, this study proposes a coordinated control algorithm of “torque distribution, engine torque monitoring, and motor torque compensation” in an attempt to realize coordinated control for driving mode switching. Characteristic analysis of the power coupling mechanism was carried out, and the control strategy model in MATLAB/Simulink was built. Subsequently, the analysis of mode switching from the electric mode into joint driving mode was simulated. In addition, a multibody dynamics model of the power coupling mechanism was established and the simulation analysis during mode switching process was carried out. The results show that the proposed coordinated control strategy serves to effectively reduce the torque fluctuation and the impact degree during the mode switching process and improve the ride comfort of the vehicle. In the meantime, the time-domain and frequency-domain characteristics of gear meshing force and bearing restraint force indicate that the mode switching process of the dynamic coupling mechanism is quite stable and this control strategy contributes to improving the characteristics such as vibration and noise.

scholarly journals A Preventive Strategy of Voltage Stability based on Characteristic Analysis

2019 ◽  
Vol 115 ◽  
pp. 01001
Author(s):  
Zhen Hu ◽  
Ding Wang ◽  
Yangwu Shen ◽  
Daojun Chen ◽  
Yongyan Liu
Keyword(s):  
Control Strategy ◽  
Power Supply ◽  
Prevention And Control ◽  
Voltage Stability ◽  
Power Grid ◽  
Preventive Strategy ◽  
Characteristic Analysis ◽  
Node Voltage ◽  
And Control ◽  
The Impact

The purpose of voltage stability prevention and control strategy is to minimize the impact of expected accidents on the whole power grid while ensuring safe power supply. In this paper, it is expected that the accident has a large impact on the system voltage and makes the voltage margin of each node low. in order to not only adjust the node voltage, but also reduce the disturbance impact, a voltage stability prevention and control strategy is proposed based on the characteristic analysis.

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