Biological ice nucleation particles in the urban atmosphere of two megacities Beijing and Tianjin in North China

2020 ◽  
Author(s):  
Wei Hu ◽  
Shu Huang ◽  
Jie Chen ◽  
Jingchuan Chen ◽  
Xiangyu Pei ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Urban Areas ◽  
North China ◽  
Large Fraction ◽  
Ice Nucleation ◽  
Urban Atmosphere ◽  
Strong Wind ◽  
Air Masses ◽  
Peking University ◽  
The Impact

<p>Biological materials are the most active ice nucleating particles (INPs), which can nucleate ice at relatively warm temperatures, affecting cloud properties and regional or even global climate. However, the understanding on the impact of biological INPs in urban areas is quite limited. Beijing is the biggest megacity in North China suffered from severe air pollution. Tianjin is the biggest coastal megacity in North China and influenced by both continental/anthropogenic pollution and marine air masses, especially in summer. In this study, we collected aerosol samples on the urban campuses of Tianjin University (39.11°N, 117.17°E) from 01 to 08 July 2019 and PeKing University (39.99°N, 116.31°E) from 11 to 18 August 2019 with SKC Biosamplers. The concentration of INPs in aerosols has been investigated using the PeKing University Ice Nucleation Array (PKU-INA). The abundance of total bacteria in aerosols was enumerated using the LIVE/DEAD bacterial viability assay and an epifluorescence microscope (DM2500, Leica, Germany). The average concentration of INPs in Beijing (18 ± 23 L<sup>-</sup><sup>1</sup>) is higher than in Tianjin (8 ± 18 L<sup>-</sup><sup>1</sup>) at -19 °C. Heat-sensitive INPs inactivated by heat treatment (inactivating ice nucleation protein, 95°C, 15 min) and lysozyme-sensitive INPs (digested by lysozyme) were inferred to biological INPs and bacterial INPs, respectively. The contribution of biological INPs in Beijing (86 ± 14%) was higher than in Tianjin (72 ± 26%), but the proportion of bacterial INPs in Beijing (57 ± 20%) was lower than in Tianjin (64 ± 22%). In addition, we measured the ice nucleation activity of ice nucleating macromolecules (INMs) in filtrate (0.22 µm) and after heat treatment. INMs can be found both in Tianjin and Beijing and the majority of them can be inactivated by heat treatment, indicating most of them were likely proteinaceous materials. Also, we found a significant increase in the concentration of INPs during a rain period with strong wind in Tianjin, which implies rainfall and wind speed may significantly influence the abundance of INPs in this region. Backward air masses trajectories indicated that continental air masses can bring high bacterial INPs in Tianjin and Beijing. Interestingly, the air masses in Tianjin with low bacterial INP concentration were mainly from marine areas. These results imply that biological sources including bacteria may contribute a large fraction of INPs above -19 °C in Tianjin and Beijing in the summer of 2019, and biological INPs potentially play an important role in cloud formation and precipitation in Chinese urban areas.</p>

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...

scholarly journals Does Digital Inclusive Finance Promote Commercial Insurance Participation? -- An Empirical Study Based on the Digital Inclusive Finance Index and China Family Panel Studies Data

2021 ◽  
Author(s):  
Zaikun Hou ◽  
Wenjie Li ◽  
Wangchen Lu ◽  
Yue Gao
Keyword(s):  
Urban Areas ◽  
Financial Knowledge ◽  
Risk Averse ◽  
Commercial Insurance ◽  
Structural Differences ◽  
Central Regions ◽  
Peking University ◽  
Urban Rural ◽  
Panel Studies ◽  
The Impact

<p>This paper matches the "Peking University Digital Inclusive Finance Index" published by Peking University Digital Finance Research Center with the 2018 China Family Panel Studies (CFPS) database, and uses Probit and Logit models to empirically investigate the impact of digital inclusive finance on impact of household commercial insurance participation. The findings show that, first, the development of digital inclusive finance significantly increases commercial insurance participation, and this effect remains significant after adding control variables or changing models; second, the impact of digital inclusive finance on commercial insurance participation shows structural differences by urban-rural, regional, and risk preferences. At the urban-rural level, the impact of digital inclusive finance on commercial insurance participation is significantly higher in rural than in urban areas; at the regional level, the impact of digital inclusive finance is greater in western regions than in eastern and central regions; at the risk preference level, the impact of digital inclusive finance on commercial insurance participation is higher in risk-averse groups than in risk-averse groups. Based on the above findings, this paper proposes to accelerate the development of digital inclusive finance, especially focusing on the construction of digital inclusive finance in less developed regions; improve the financial market system, strengthen the supervision of insurance products; and increase the popularization of financial knowledge.</p>

scholarly journals Does Digital Inclusive Finance Promote Commercial Insurance Participation? -- An Empirical Study Based on the Digital Inclusive Finance Index and China Family Panel Studies Data

2021 ◽  
Author(s):  
Zaikun Hou ◽  
Wenjie Li ◽  
Wangchen Lu ◽  
Yue Gao
Keyword(s):  
Urban Areas ◽  
Financial Knowledge ◽  
Risk Averse ◽  
Commercial Insurance ◽  
Structural Differences ◽  
Central Regions ◽  
Peking University ◽  
Urban Rural ◽  
Panel Studies ◽  
The Impact

<p>This paper matches the "Peking University Digital Inclusive Finance Index" published by Peking University Digital Finance Research Center with the 2018 China Family Panel Studies (CFPS) database, and uses Probit and Logit models to empirically investigate the impact of digital inclusive finance on impact of household commercial insurance participation. The findings show that, first, the development of digital inclusive finance significantly increases commercial insurance participation, and this effect remains significant after adding control variables or changing models; second, the impact of digital inclusive finance on commercial insurance participation shows structural differences by urban-rural, regional, and risk preferences. At the urban-rural level, the impact of digital inclusive finance on commercial insurance participation is significantly higher in rural than in urban areas; at the regional level, the impact of digital inclusive finance is greater in western regions than in eastern and central regions; at the risk preference level, the impact of digital inclusive finance on commercial insurance participation is higher in risk-averse groups than in risk-averse groups. Based on the above findings, this paper proposes to accelerate the development of digital inclusive finance, especially focusing on the construction of digital inclusive finance in less developed regions; improve the financial market system, strengthen the supervision of insurance products; and increase the popularization of financial knowledge.</p>

scholarly journals Gasoline aromatic: a critical determinant of urban secondary organic aerosol formation

2017 ◽  
Author(s):  
Jianfei Peng ◽  
Min Hu ◽  
Zhuofei Du ◽  
Yinhui Wang ◽  
Jing Zheng ◽  
...  
Keyword(s):  
Urban Areas ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Urban Atmosphere ◽  
Aerosol Formation ◽  
Vehicle Exhaust ◽  
Critical Determinant ◽  
Aromatic Content ◽  
Depth Study ◽  
The Impact

Abstract. Gasoline vehicle exhaust is an important contributor to secondary organic aerosol (SOA) formation in urban atmosphere. Fuel composition has considerable potential impact on gasoline SOA production, but this impact is still taken little account in the emission regulations due to the poor understanding of the link between fuel components and SOA production. Here, we present an in-depth study to investigate the impact of gasoline aromatic content on SOA production through chamber approach. A significant amplification factor of 3–6 for SOA productions from gasoline exhausts was observed as gasoline aromatic content rose from 29 % to 37 %. Considerably higher emissions of aromatic volatile organic compounds performed an essential role in the SOA production enhancement. Our findings indicate that gasoline aromatics have significant influence on ambient PM2.5 concentration in megacities and highlight that more stringent regulation on gasoline aromatic content will achieve unexpected benefit on air quality in urban areas.

scholarly journals Sensitivity of Radiative and Thermal Properties of Building Material in the Urban Atmosphere

2019 ◽  
Vol 11 (23) ◽  
pp. 6865 ◽  
Author(s):  
Marcos Vinicius Bueno de Morais ◽  
Viviana Vanesa Urbina Guerrero ◽  
Edmilson Dias de Freitas ◽  
Edson R. Marciotto ◽  
Hugo Valdés ◽  
...  
Keyword(s):  
Building Material ◽  
Urban Areas ◽  
Atmospheric Model ◽  
Sao Paulo ◽  
Urban Atmosphere ◽  
Radiative Properties ◽  
São Paulo ◽  
Cold Surface ◽  
Local Climate ◽  
The Impact

In the context of the impact of urbanization on climate change, this work aims to evaluate the sensitivity of the thermal and radiative properties of building surfaces in urban areas to the urban heat island intensity, a local scale meteorological phenomenon. For this, variations of albedo values, emissivity, thermal conductivity and heat capacity of roofs, streets and walls were simulated through an urban scheme coupled with the BRAMS mesoscale atmospheric model for the metropolitan area of São Paulo, considering two main urban types. The simulations show that, in general, looking for cold surface situations, the change of building material can contribute to a reduction of up to 3 °C for São Paulo. In addition, the role of orientation and the typological characteristics of constructions should be taken into account. In this sense, it is expected that this work guides civil engineers and builders to search for new materials in order to reduce the effects of urbanization on the local climate.

Microstructural and Mechanical Behaviour Evaluation of Mg-Al-Zn Alloy Friction Stir Welded Joint

2020 ◽  
Vol 17 (3) ◽  
pp. 8150-8159
Author(s):  
Kulwant Singh ◽  
Gurbhinder Singh ◽  
Harmeet Singh
Keyword(s):  
Heat Treatment ◽  
Friction Stir Welding ◽  
Magnesium Alloys ◽  
Mechanical Performance ◽  
Fuel Efficiency ◽  
Research Work ◽  
Grain Structure ◽  
Tensile Fracture ◽  
Friction Stir ◽  
The Impact

The weight reduction concept is most effective to reduce the emissions of greenhouse gases from vehicles, which also improves fuel efficiency. Amongst lightweight materials, magnesium alloys are attractive to the automotive sector as a structural material. Welding feasibility of magnesium alloys acts as an influential role in its usage for lightweight prospects. Friction stir welding (FSW) is an appropriate technique as compared to other welding techniques to join magnesium alloys. Field of friction stir welding is emerging in the current scenario. The friction stir welding technique has been selected to weld AZ91 magnesium alloys in the current research work. The microstructure and mechanical characteristics of the produced FSW butt joints have been investigated. Further, the influence of post welding heat treatment (at 260 °C for 1 h) on these properties has also been examined. Post welding heat treatment (PWHT) resulted in the improvement of the grain structure of weld zones which affected the mechanical performance of the joints. After heat treatment, the tensile strength and elongation of the joint increased by 12.6 % and 31.9 % respectively. It is proven that after PWHT, the microhardness of the stir zone reduced and a comparatively smoothened microhardness profile of the FSW joint obtained. No considerable variation in the location of the tensile fracture was witnessed after PWHT. The results show that the impact toughness of the weld joints further decreases after post welding heat treatment.

Urbanization of fauna on the example of marsh frog (Pelophylax ridibundus)

2015 ◽  
Vol 26 (3-4) ◽  
pp. 116-123
Author(s):  
A. P. Korzh ◽  
T. V. Zahovalko
Keyword(s):  
Urban Areas ◽  
Cognitive Modeling ◽  
Negative Impact ◽  
Natural Populations ◽  
Cellular Level ◽  
Anthropogenic Factors ◽  
Migration Routes ◽  
Corrective Effect ◽  
The Impact ◽  
The City

Recently, the number of published works devoted to the processes of synanthropization of fauna, is growing like an avalanche, which indicates the extreme urgency of this theme. In our view, the process of forming devices to coexist with human and the results of his life reflects the general tandency of the modern nature evolution. Urbanization is characteristic for such a specific group of animals like amphibians, the evidence of which are numerous literature data. Many researchers use this group to assess the bioindicative quality of the environment. For this aim a variety of indicators are used: from the cellular level of life of organization up to the species composition of the group in different territories. At the same time, the interpretation of the results is not always comparable for different areas and often have significantly different interpretations by experts. Urban environment, primarily due to the contamination is extremely aggressive to amphibians. As a consequence, the urban populations of amphibians may be a change in the demographic structure, affecting the reproductive ability of the population, the disappearance of the most sensitive species or individuals, resizing animals, the appearance of abnormalities in the development, etc. At the same time play an important amphibians in the ecosystems of cities, and some species in these conditions even feel relatively comfortable. Therefore, it is interesting to understand the mechanisms of self-sustaining populations of amphibians in urban environments. To assess the impact of natural and anthropogenic factors on the development of amphibian populations were used cognitive modeling using the program Vensim PLE. Cognitive map of the model for urban and suburban habitat conditions were the same. The differences concerned the strength of connections between individual factors (migration, fertility, pollution) and their orientation. In general, factors like pollution, parasites, predators had negative impact on the population, reducing its number. The birth rate, food and migration contributed to raising number of individuals. Some of the factors affected on the strength to of each other as well: the majority of the factors affected the structure of the population, had an influence on the fertility. Thanks to it the model reflects the additive effect of complex of factors on the subsequent status of the population. Proposed and analyzed four scenarios differing strength and duration of exposure. In the first scenario, a one-time contamination occurs and not subsequently repeated. The second and third scenario assumes half board contamination, 1 year (2 scenario) and two years (scenario 3). In the fourth scenario, the pollution affected the population of amphibians constantly. In accordance with the results of simulation, much weaker than the natural populations respond to pollution - have them as an intensive population growth and its disappearance at constant pollution is slow. Changes to other parameters of the model showed that this pollution is the decisive factor -only the constant action leads to a lethal outcome for the populations. All other components of the model have a corrective effect on the population dynamics, without changing its underlying trand. In urban areas due to the heavy impact of pollution maintaining the population is only possible thanks to the migration process – the constant replenishment of diminishing micropopulations of natural reserves. This confirms the assumption that the form of existence metapopulations lake frog in the city. In order to maintain the number of amphibians in urban areas at a high level it is necessary to maintain existing migration routes and the creation of new ones. Insular nature of the placement of suitable habitats in urban areas causes the metapopulation structure of the types of urbanists. Therefore, the process of urbanization is much easier for those species whicht are capable of migration in conditions of city. In the initial stages of settling the city micropopulationis formed by selective mortality of the most susceptible individuals to adverse effects. In future, maintaining the categories of individuals is provided mainly due to migration processes metapopulisation form of the species of existence is supported). It should be noted that the changes in the previous levels are always saved in future. In the case of reorganizations of individuals we of morphology can assume the existence of extremely adverse environmental conditions that threaten the extinction of the micropopulations. 

Impact of dust and sand storms on the aviation operation and assessment of conditions for their occurrence at aerodromes in European Russia

2020 ◽  
Vol 4 ◽  
pp. 78-95
Author(s):  
A.R. Ivanova ◽  
◽  
E.N. Skriptunova ◽  
N.I. Komasko ◽  
A.A. Zavialova ◽  
...  
Keyword(s):  
Seasonal Variations ◽  
Dust Storms ◽  
European Russia ◽  
Air Transport ◽  
Review Of Literature ◽  
Dust Transport ◽  
Air Masses ◽  
The Past ◽  
Sand Storm ◽  
The Impact

A review of literature on the impact of dust and sand storms on the air transport operation is presented. Observational data on dust storms at the aerodromes of European Russia for the period of 2001-2019 are analyzed. The seasonal variations in dust transport episodes at aerodromes and its relationship with visibility changes are discussed. The characteristics of dusty air masses and advection are given. It is concluded that the frequency of dust transfer episodes for the aerodromes under study has decreased over the past five years, except for Gumrak aerodrome (Volgograd). Keywords: dust storm, sand storm, aviation, visibility, seasonal variations, aerodrome оf European Russia

Impact of Elected Women Representatives of Panchayati Raj in Physical and Financial and Business Assets Development of Rural Women: A Study among the Rural Women’s of Tiruvannamalai District, Tamil Nadu[1]

2017 ◽  
Vol 4 (24) ◽  
Author(s):  
Kalaichelvi Sivaraman ◽  
Rengasamy Stalin
Keyword(s):  
Rural Women ◽  
Rural Areas ◽  
Urban Areas ◽  
Direct Democracy ◽  
Tamil Nadu ◽  
Local Level ◽  
Rural And Urban Areas ◽  
The Government ◽  
The Impact ◽  
Panchayati Raj

This research paper is the part of Research Project entitled “Impact of Elected Women Representatives in the Life and Livelihood of the Women in Rural Areas: With Special Reference to Tiruvannamalai District, Tamil Nadu” funded by University of Madras under UGC-UPE Scheme.The 73rd and 74th amendments of the Constitution of India were made by the government to strengthen the position of women and to create a local-level legal foundation for direct democracy for women in both rural and urban areas. The representation for women in local bodies through reservation policies amendment in Constitution of India has stimulated the political participation of women in rural areas. However, when it’s comes to the argument of whether the women reservation in Panchayati Raj helps or benefits to the life and livelihood development of women as a group? The answer is hypothetical because the studies related to the impact of women representatives of Panchayati Raj in the life and livelihood development of women was very less. Therefore, to fill the gap in existing literature, the present study was conducted among the rural women of Tiruvannamalai district to assess the impact of elected women representatives in the physical and financial and business development of the women in rural areas. The findings revealed that during the last five years because of the women representation in their village Panjayati Raj, the Physical Asset of the rural women were increased or developed moderately (55.8%) and Highly (23.4%) and the Financial and Business Asset of the rural women were increased or developed moderately (60.4%) and Highly (18.7%).

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