scholarly journals The impact of chlorine chemistry combined with heterogeneous N<sub>2</sub>O<sub>5</sub> reactions on air quality in China

2021 ◽  
Author(s):  
Xiajie Yang ◽  
Qiaoqiao Wang ◽  
Nan Ma ◽  
Weiwei Hu ◽  
Yang Gao ◽  
...  
Keyword(s):  
Air Quality ◽  
North China Plain ◽  
Heterogeneous Reaction ◽  
Data Sets ◽  
The North ◽  
Multiple Data ◽  
Multiple Data Sets ◽  
The Sichuan Basin ◽  
The Impact

Abstract. The heterogeneous reaction of N2O5 on Cl-containing aerosols (N2O5 − ClNO2 chemistry) plays a key role in chlorine activation, NOx recycling and consequently O3 formation. In this study, we use the GEOS-Chem model with additional anthropogenic and biomass burning chlorine emissions combined with updated parameterizations for N2O5 − ClNO2 chemistry (i.e. the uptake coefficient of N2O5 (γN2O5) and the ClNO2 yield (φClNO2)) to investigate the impacts of chlorine chemistry on air quality in China, the role of N2O5 − ClNO2 chemistry, as well as their sensitivities to chlorine emissions and parameterizations for γN2O5 and φClNO2. The model evaluation with multiple data sets observed across China demonstrated significant improvement especially regarding the simulation of Cl−, N2O5 and ClNO2 with the updates in chlorine emissions and N2O5 − ClNO2 chemistry. Total tropospheric chlorine chemistry could increase annual mean MDA8 O3 by up to 4.5 ppbv but decrease PM2.5 by up to 7.9 μg m−3 in China, 83 % and 90 % of which could be attributed to the effect of N2O5 – ClNO2 chemistry. The heterogeneous uptake of N2O5 on chloride-containing aerosol surfaces is an important loss pathway of N2O5 as well as a important source of O3, and hence is particularly useful in elucidating the commonly seen ozone underestimations. The importance of chlorine chemistry largely depends on both chlorine emissions and the parameterizations for N2O5 – ClNO2 chemistry. With the additional chlorine emissions annual mean maximum daily 8-hour average (MDA8) O3 in China could be increased by up to 3.5 ppbv. The corresponding effect on PM2.5 concentrations varies largely with regions, with an increase of up to 4.5 μg m−3 in the North China Plain but a decrease of up to 3.7 μg m−3 in the Sichuan Basin. On the other hand, even with the same chlorine emissions, the effects on MDA8 O3 and PM2.5 in China could differ by 48 % and 27 %, respectively between different parameterizations.

Antebellum Farm-Settlement Patterns: A Three-Level Approach to Assessing the Effects of Soils

2010 ◽  
Vol 41 (3) ◽  
pp. 393-420 ◽  
Author(s):  
Robert E. Mitchell
Keyword(s):  
Settlement Patterns ◽  
Economic Benefits ◽  
Data Sets ◽  
Old Northwest ◽  
The North ◽  
Multiple Data ◽  
Central United States ◽  
Multiple Data Sets ◽  
The Individual ◽  
Motivating Factor

Different soil classes offered varying economic results for farmers. The use of multiple data sets to analyze the connection between soils, economic benefits, and settlement patterns at three geographical levels—the five states of the Old Northwest, the sixty-eight counties in Michigan's Lower Peninsula, and the individual farms in one mid-Michigan county—tends to confirm that soils were a significant motivating factor in the locational decisions of antebellum farmers at the state, county, and intra-county levels of the north-central United States during the mid-nineteenth century.

scholarly journals Assessing boreal forest fire smoke aerosol impacts on U.S. air quality: A case study using multiple data sets

2011 ◽  
Vol 116 (D22) ◽  
pp. n/a-n/a ◽  
Author(s):  
David J. Miller ◽  
Kang Sun ◽  
Mark A. Zondlo ◽  
David Kanter ◽  
Oleg Dubovik ◽  
...  
Keyword(s):  
Air Quality ◽  
Boreal Forest ◽  
Forest Fire ◽  
Data Sets ◽  
Smoke Aerosol ◽  
Multiple Data ◽  
Fire Smoke ◽  
Multiple Data Sets

scholarly journals Recent ozone trends in the Chinese free troposphere: role of the local emission reductions and meteorology

2021 ◽  
Vol 21 (20) ◽  
pp. 16001-16025
Author(s):  
Gaëlle Dufour ◽  
Didier Hauglustaine ◽  
Yunjiang Zhang ◽  
Maxim Eremenko ◽  
Yann Cohen ◽  
...  
Keyword(s):  
Anthropogenic Emissions ◽  
P Value ◽  
Data Sets ◽  
Free Troposphere ◽  
Ozone Monitoring Instrument ◽  
Multiple Data ◽  
Ozone Trends ◽  
Sensitivity Studies ◽  
Multiple Data Sets

Abstract. Free tropospheric ozone (O3) trends in the Central East China (CEC) and export regions are investigated for 2008–2017 using the IASI (Infrared Atmospheric Sounding Interferometer) O3 observations and the LMDZ-OR-INCA model simulations, including the most recent Chinese emission inventory. The observed and modelled trends in the CEC region are −0.07 ± 0.02 and −0.08 ± 0.02 DU yr−1, respectively, for the lower free troposphere (3–6 km column) and −0.05 ± 0.02 and −0.06 ± 0.02 DU yr−1, respectively, for the upper free troposphere (6–9 km column). The statistical p value is smaller to 0.01 for all the derived trends. A good agreement between the observations and the model is also observed in the region, including the Korean Peninsula and Japan and corresponding to the region of pollution export from China. Based on sensitivity studies conducted with the model, we evaluate, at 60 % and 52 %, the contribution of the Chinese anthropogenic emissions to the trend in the lower and upper free troposphere, respectively. The second main contribution to the trend is the meteorological variability (34 % and 50 %, respectively). These results suggest that the reduction in NOx anthropogenic emissions that has occurred since 2013 in China led to a decrease in ozone in the Chinese free troposphere, contrary to the increase in ozone at the surface. We designed some tests to compare the trends derived by the IASI observations and the model to independent measurements, such as the In-service Aircraft for a Global Observing System (IAGOS) or other satellite measurements (Ozone Monitoring Instrument (OMI)/Microwave Limb Sounder (MLS)). These comparisons do not confirm the O3 decrease and stress the difficulty in analysing short-term trends using multiple data sets with various sampling and the risk of overinterpreting the results.

Ultrasonic characterization of anisotropic rocks: Impact of transducers’ size and geometry on data interpretation

Geophysics ◽  
2020 ◽  
Vol 85 (4) ◽  
pp. C99-C105
Author(s):  
Yevhen Kovalyshen ◽  
Joel Sarout ◽  
Jeremie Dautriat ◽  
Bruce Maney ◽  
Maxim Lebedev
Keyword(s):  
Finite Size ◽  
Data Interpretation ◽  
Point Sources ◽  
Data Sets ◽  
Ultrasonic Characterization ◽  
Multiple Data ◽  
Anisotropic Rocks ◽  
Multiple Data Sets ◽  
The Impact

Typical ultrasonic laboratory measurements of rock physical properties are conducted with ultrasonic transducers that are relatively large compared to the rock sample. We have determined the impact of the transducer size on the resulting velocity estimations. To improve data interpretation, we explore two complementary avenues: (1) explicitly account for the finite size of the transducers as part of the data interpretation/correction workflow, rather than assuming point sources, and (2) reducing the effective size of the transducers at the hardware design level. Both approaches as well as their combination have been tested successfully on multiple data sets including artificial homogeneous and isotropic samples as well as natural anisotropic rocks such as shales.

scholarly journals SRGM with Imperfect Debugging using Capability Analysis of Log-Logistic Model

2012 ◽  
Vol 2 (2) ◽  
pp. 30-33
Author(s):  
Dr.O. Naga Raju ◽  
D. Rakesh ◽  
K.V. SubbaReddy
Keyword(s):  
Time Frame ◽  
Complex Model ◽  
Data Sets ◽  
Key Factors ◽  
Validity Analysis ◽  
Failure Data ◽  
Multiple Data ◽  
Capability Analysis ◽  
Multiple Data Sets ◽  
The Impact

Analyze the predict capability of some SRGMs to understand the different parameters to facilitate the estimate process. The predict validity analysis will be on two key factors, one pertaining to the degree of fitment on available failure data and the other for its prediction capability. The validity analysis will be to arrive at trade off in choosing a simple model as compared to complex model by determining their performances across multiple data sets. Data for the predict validity analysis has been taken from different time periods to understand the impact of these models across various technologies and process during the time frame.

scholarly journals Size-resolved characterization of organic aerosol in the North China Plain: new insights from high resolution spectral analysis

2021 ◽  
Author(s):  
Weiqi Xu ◽  
Chun Chen ◽  
Yanmei Qiu ◽  
Conghui Xie ◽  
Yunle Chen ◽  
...  
Keyword(s):  
Radiative Forcing ◽  
North China Plain ◽  
North China ◽  
Fine Particles ◽  
Large Fraction ◽  
Organic Aerosol ◽  
Size Distributions ◽  
The North ◽  
The Impact

Organic aerosol (OA), a large fraction of fine particles, has a large impact on climate radiative forcing and human health, and the impact depends strongly on size distributions. Here we...

The development of nurses’ foundational values

2021 ◽  
pp. 096973302110032
Author(s):  
Sastrawan Sastrawan ◽  
Jennifer Weller-Newton ◽  
Gabrielle Brand ◽  
Gulzar Malik
Keyword(s):  
Professional Training ◽  
Reference Points ◽  
Constructivist Grounded Theory ◽  
Professional Values ◽  
Data Sets ◽  
Value System ◽  
Institutional Values ◽  
Multiple Data ◽  
Human Ethics ◽  
Multiple Data Sets

Background: In the ever-changing and complex healthcare environment, nurses encounter challenging situations that may involve a clash between their personal and professional values resulting in a profound impact on their practice. Nevertheless, there is a dearth of literature on how nurses develop their personal–professional values. Aim: The aim of this study was to understand how nurses develop their foundational values as the base for their value system. Research design: A constructivist grounded theory methodology was employed to collect multiple data sets, including face-to-face focus group and individual interviews, along with anecdote and reflective stories. Participants and research context: Fifty-four nurses working across various nursing settings in Indonesia were recruited to participate. Ethical considerations: Ethics approval was obtained from the Monash University Human Ethics Committee, project approval number 1553. Findings: Foundational values acquisition was achieved through family upbringing, professional nurse education and organisational/institutional values reinforcement. These values are framed through three reference points: religious lens, humanity perspective and professionalism. This framing results in a unique combination of personal–professional values that comprise nurses’ values system. Values are transferred to other nurses either in a formal or informal way as part of one’s professional responsibility and customary social interaction via telling and sharing in person or through social media. Discussion: Values and ethics are inherently interweaved during nursing practice. Ethical and moral values are part of professional training, but other values are often buried in a hidden curriculum, and attained and activated through interactions during nurses’ training. Conclusion: Developing a value system is a complex undertaking that involves basic social processes of attaining, enacting and socialising values. These processes encompass several intertwined entities such as the sources of values, the pool of foundational values, value perspectives and framings, initial value structures, and methods of value transference.

scholarly journals Impact of crop field burning and mountains on heavy haze in the North China Plain: A case study

2016 ◽  
Author(s):  
X. Long ◽  
X. X. Tie ◽  
J. J. Cao ◽  
R. J. Huang ◽  
T. Feng ◽  
...  
Keyword(s):  
Air Pollution ◽  
North China Plain ◽  
North China ◽  
Wind Condition ◽  
Beijing City ◽  
The North ◽  
The North China Plain ◽  
Crop Field ◽  
The Impact ◽  
Field Burning

Abstract. Crop field burning (CFB) has important effects on air pollution in China, but it is seldom quantified and reported in a regional scale, which is of great importance for the control strategies of CFB in China, especially in the North China Plain (NCP). With the provincial statistical data and open crop fires captured by satellite (MODIS), we extracted a detailed emission inventory of CFB during a heavy haze event from 6th to 12th October 2014. A regional dynamical and chemical model (WRF-Chem) was applied to investigate the impact of CFB on air pollution in NCP. The model simulations were compared with the in situ measurements of PM2.5 (particular matter with radius less than 2.5 μm) concentrations. The model evaluation shows that the correlation coefficients (R) between measured and calculated values exceeds 0.80 and absolute normalized mean bias (NMB) is no more than 14 %. In addition, the simulated meteorological parameters such as winds and planetary boundary layer height (PBLH) are also in good agreement with observations. The model was intensive used to study (1) the impacts of CFB and (2) the effect of mountains on regional air quality. The results show that the CFB occurred in southern NCP (SNCP) had significant effect on PM2.5 concentrations locally, causing a maximum of 35 % PM2.5 increase in SNCP. Because of south wind condition, the CFB pollution plume is subjective a long transport to northern NCP (NNCP-with several mega cities, including Beijing of the capital city in China), where there are no significant CFB occurrences, causing a maximum of 32 % PM2.5 increase in NNCP. As a result, the heavy haze in Beijing is enhanced by the CFB occurred in SNCP. Further more, there are two major mountains located in the western and northern NCP. Under the south wind condition, these mountains play important roles in enhancing the PM2.5 pollution in NNCP through the blocking and guiding effects. This study suggests that the PM2.5 emissions in SNCP region should be significantly limited in order to reduce the occurrences of heavy haze events in NNCP region, including the Beijing City.

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