Seasonal variation and size distribution of bioaerosols in an air-conditioned auditorium – a case study

2011 ◽  
pp. 31-40
Keyword(s):  
Seasonal Variation ◽  
Size Distribution

scholarly journals Size-Segregated Atmospheric Humic-Like Substances (HULIS) in Shanghai: Abundance, Seasonal Variation, and Source Identification

Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 526
Author(s):  
Tianming Sun ◽  
Rui Li ◽  
Ya Meng ◽  
Yu Han ◽  
Hanyun Cheng ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Size Distribution ◽  
Principal Component ◽  
Water Soluble ◽  
Atmospheric Particulate Matter ◽  
Biomass Combustion ◽  
Vehicle Exhaust ◽  
Total Suspended Particulates ◽  
Condensation Mode ◽  
Water Soluble Organic Carbon

Humic-like substances (HULIS) are of great interest due to their optical and chemical characteristics. In this study, a total of 180 samples of atmospheric particulate matter (PM) of different sizes were collected from summer 2018 to spring 2019, in order to analyze the size distribution, to investigate the seasonal variation and then to identify the key sources of HULIS. The annual mean concentration of HULIS in the total suspended particulates reached 5.12 ± 1.42 μg/m3. The HULIS concentration was extremely higher in winter (8.35 ± 2.06 μg/m3) than in autumn (4.88 ± 0.95 μg/m3), in summer (3.62 ± 1.68 μg/m3) and in spring (3.36 ± 0.99 μg/m3). The average annual ratio of water-soluble organic carbon (WSOC) to OC and the ratio of HULIS to WSOC reached 0.546 ± 0.092 and 0.56 ± 0.06, respectively. Throughout the whole year, the size distributions of WSOC and HULIS-C were relatively smooth. The peaks of WSOC appeared at 1.8~3.2 μm and 0.56~1.0 μm, while the peaks of HULIS-C were located at 3.2~5.6 μm, 1.0~1.8 μm and 0.18~0.32 μm. The distribution of the HULIS particle mode was similar in spring, summer and autumn, while there was a lower proportion of the coarse mode and a higher proportion of the condensation mode in winter. By using the comprehensive analysis of principal component analysis (PCA), air mass backward trajectories (AMBTs) and fire point maps, key sources of WSOC and HULIS in Shanghai were identified as biomass combustion (48.42%), coal combustion (17.49%), secondary formation (16.07%) and vehicle exhaust (5.37%). The remaining part might be contributed by crustal dust sources, marine sources and/or other possible sources. This study provides new insight into the characteristics and size distribution of HULIS in Shanghai, thereby providing a practical base for further modeling.

Are seasonal lakes as productive as permanent lakes? A case study from Ireland

2010 ◽  
Vol 67 (8) ◽  
pp. 1291-1302 ◽  
Author(s):  
Helder Cunha Pereira ◽  
Norman Allott ◽  
Catherine Coxon
Keyword(s):  
Seasonal Variation ◽  
Linear Regression ◽  
Chlorophyll A ◽  
Algal Biomass ◽  
P Limitation ◽  
Underlying Causes ◽  
Western Ireland ◽  
Log Linear ◽  
First Time

This paper compares, for the first time, nutrient levels and chlorophyll a measured in a set of seasonal lakes with those reported for permanent lakes in the literature. Twenty-two turloughs (karstic seasonal lakes) in western Ireland were sampled monthly from the onset of flooding (October) until they dried out (6 to 9 months). The turloughs showed similar levels of nutrients and chlorophyll a to those reported for Irish and international lakes. Chlorophyll a peaked between November and February in the majority of turloughs, sometimes with values higher than those measured in mesotrophic lakes in summer. A significant log-linear regression was found between total phosphorus and chlorophyll a, which suggests P limitation of algal biomass in the majority of the turloughs. The regression characteristics were not significantly different than those described in similar studies of permanent lakes. Patterns in seasonal variation of nutrients are also presented, their underlying causes being discussed in relation to their transport within catchments. Our results show that despite being predominantly winter phenomena, turloughs can be as productive as permanent lakes.

scholarly journals Seasonal Variation Analysis Method of GHG at Municipal Solid Waste Incinerator

2020 ◽  
Vol 12 (18) ◽  
pp. 7425
Author(s):  
Seongmin Kang ◽  
Joonyoung Roh ◽  
Eui-chan Jeon
Keyword(s):  
Seasonal Variation ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Ghg Emissions ◽  
Co2 Concentration ◽  
Waste Incineration ◽  
Seasonal Effect ◽  
Waste Incinerator ◽  
Waste Composition

The greenhouse gas emissions of the waste incineration sector account for approximately 43% of the total GHG emissions and represent the majority of the CO2 emissions from waste in Korea. Improving the reliability of the GHG inventory of the waste incineration sector is an important aspect for the examination of global GHG emission management according to the Paris Agreement. In this study, we introduced a statistical approach to analyze seasonal changes through analysis of waste composition and CO2 concentration in Municipal Solid Waste incinerators and applied the methodology to one case study facility. The analysis results in the case study showed that there was no seasonal variation in waste composition and CO2 concentrations, except for wood. Wood is classified as biomass, and the GHG emissions caused by biomass incineration are reported separately, indicating that the effect of an MSW incinerator on GHG emissions is not significant. Therefore, the seasonal effect of CO2 concentration or waste composition may not be an impact when calculating GHG emissions from case study facilities’ MSW incinerators. This study proposed an approach for analyzing factors that affect the GHG inventory reliability by analyzing seasonal characteristics and variation through the statistical analysis, which are used for the calculation of the GHG emissions of an MSW incinerator.

Seasonal variation of antibiotics concentration in the aquatic environment: a case study at Jianghan Plain, central China

2015 ◽  
Vol 527-528 ◽  
pp. 56-64 ◽  
Author(s):  
Linlin Yao ◽  
Yanxin Wang ◽  
Lei Tong ◽  
Yonggang Li ◽  
Yamin Deng ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Aquatic Environment ◽  
Central China ◽  
Jianghan Plain

scholarly journals Suspended Sediment Analysis: Case Study of Berounka Sources

Geografie ◽  
1997 ◽  
Vol 102 (2) ◽  
pp. 130-138
Author(s):  
Zdeněk Kliment ◽  
Jan Kopp
Keyword(s):  
Seasonal Variation ◽  
Sediment Transport ◽  
Suspended Sediment ◽  
Inorganic Material ◽  
Suspended Sediments ◽  
Suspended Load ◽  
Suspended Sediment Transport ◽  
Sediment Analysis ◽  
Load Characteristics

The article examines suspended sediment transport in Mže, Radbuza, and Úhlava Rivers over the period 1989-95. Data on suspended sediments was collected at five observing sites. The research has been carried out in collaboration with Czech Hydrometeorological Institute, Plzeň. Apart from the suspended load characteristics also the seasonal variation of suspended sediments, siltation of Hracholusky and České Údolí Lakes, and the share of inorganic material in suspended sediments have been examined.

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