scholarly journals Measuring and modeling moisture environment in underground metro stations during commissioning stage: A case study

Author(s):  
Yanzhe Yu ◽  
Shijun You ◽  
Huan Zhang ◽  
Tianzhen Ye ◽  
Yaran Wang ◽  
...  

Due to the humid underground environment, underground metro stations often have internal condensation issues, especially during the commissioning and initial operation phases, and these issues will have a negative impact on the equipment operation and building life. This study aims to solve the issue by 1) identifying common areas with condensation risks based on on-site measurements and numerical simulation methods, and 2) proposing effective dehumidification solutions for the moisture control of stations. By on-site investigating the characteristics of the station’s moisture environment and numerical assessing the effects of two different dehumidification strategies, it has been found that 1) for Tianjin, during most times in summer, the air temperature of the station in the commissioning phase was maintained relatively stable, but with significantly changing humidity; 2) the relative humidity on the platforms was higher than 80% for almost 30% of the testing time, and the surface of the upper structure of platform doors having a high risk of condensation; 3) the dehumidification effect of industrial dehumidifiers was found to be better than that of increasing exhaust air volume. The authors hope that the research could aid the decision on dehumidification strategies and provide guidance for further moisture control in underground stations. Practical Application This article analyzed the moisture environment of the underground metro stations in the commissioning phase and conducted a numerical approach to assess the condensation risk. Potential dehumidification solutions including increasing the exhaust air volume and using industrial dehumidifiers have been proposed, and their effects have been investigated and compared. The authors hope that this research can aid the decision on dehumidification strategies for facilities maintenance and provide a guidance to further moisture control in underground stations.

2020 ◽  
Vol 8 (3) ◽  
pp. 3-17
Author(s):  
Elena Blagoeva

The impact of the last global economic crisis (2008) on the European economy put a strain on higher education (HE), yet it also pushed the sector towards intensive reforms and improvements. This paper focuses on the “Strategy for the Development of Higher Education in the Republic of Bulgaria 2014-2020”. With a case study methodology, we explore the strategic endeavours of the Bulgarian government to comply with the European directions and to secure sustainable growth for the HE sector. Our research question is ‘How capable is the Bulgarian HE Strategy to overcome the economic and systemic restraints of Bulgarian higher education?’. Because the development of strategies for HE within the EU is highly contextual, a single qualitative case study was chosen as the research approach. HE institutions are not ivory towers, but subjects to a variety of external and internal forces. Within the EU, this is obviated by the fact that Universities obtain their funds from institutions such as governments, students and their families, donors, as well as EU-level programmes. Therefore, to explore how these pressures interact to affect strategic action on national level, the case method is well suited as it enabled us to study the phenomena thoroughly and deeply. The paper suggests the actions proposed within the Strategy have the potential to overcome the delay, the regional isolation and the negative impact of the economic crisis on the country. Nevertheless, the key elements on which the success or failure of this Strategy hinges are the control mechanisms and the approach to implementation. Shortcomings in these two aspects of strategic actions in HE seem to mark the difference between gaining long-term benefits and merely saving face in front of international institutions.


Author(s):  
Yunliang Meng ◽  
Sulaimon Giwa ◽  
Uzo Anucha

Our study investigated racial profiling of Black youth in Toronto and linked this racial profiling to urban disadvantage theory, which highlights neighbourhood-level processes. Our findings provide empirical evidence suggesting that because of racial profiling, Black youth are subject to disproportionately more stops for gun-, traffic-, drug-, and suspicious activity-related reasons. Moreover, they show that drug-related stop-and-searches of Black youth occur most excessively in neighbourhoods where more White people reside and are less disadvantaged, demonstrating that race-and-place profiling of Black youth exists in police stop-and-search practices. This study shows that the theoretical literature in sociology on neighbourhood characteristics can contribute to an understanding of the relationship between race and police stops in the context of neighbourhood. It also discusses the negative impact of racial profiling on Black youth.


2005 ◽  
Vol 51 (12) ◽  
pp. 325-329 ◽  
Author(s):  
X. Wang ◽  
X. Bai ◽  
J. Qiu ◽  
B. Wang

The performance of a pond–constructed wetland system in the treatment of municipal wastewater in Kiaochow city was studied; and comparison with oxidation ponds system was conducted. In the post-constructed wetland, the removal of COD, TN and TP is 24%, 58.5% and 24.8% respectively. The treated effluent from the constructed wetland can meet the Chinese National Agricultural and Irrigation Standard. The comparison between pond–constructed wetland system and oxidation pond system shows that total nitrogen removal in a constructed wetland is better than that in an oxidation pond and the TP removal is inferior. A possible reason is the low dissolved oxygen concentration in the wetland. Constructed wetlands can restrain the growth of algae effectively, and can produce obvious ecological and economical benefits.


2012 ◽  
Vol 253-255 ◽  
pp. 1913-1917
Author(s):  
Ze Bin Zhao

In order to reduce the negative impact of urban traffic air pollution, this paper firstly analyzes the relationship between urban traffic air pollution and vehicle speed, after providing the relationship model, the paper establishes a comprehensive pricing model of urban traffic air pollution based on bi-level programming, the model considers the traffic air pollution pricing, and includes the factors of congestion pricing, bus fee, pricing revenue redistribution on improvement of public transport services and the expansion of road capacity. The case study shows that the implementation of comprehensive pricing of urban traffic air pollution can reduce traffic pollution and unreasonable traffic flow, which is conducive to the sustainable development of the city.


2021 ◽  
Vol 19 (1) ◽  
pp. 462-470
Author(s):  
Marta Bożym ◽  
Beata Klojzy-Karczmarczyk

Abstract Environmental pollution by mercury is a local problem in Poland and concerns mainly industrial sites. Foundry waste are usually characterized by low mercury content compared to other heavy metals. Spent foundry sands with low content of Hg are the main component of foundry waste. However, Hg may be present in foundry dust, which may also be landfilled. Due to Hg toxicity, even a minimal content may have a negative impact on biota. This study focuses on assessing the mercury content of landfilled foundry waste (LFW), to assess its toxicity. Currently tested waste is recovered and reused as a road aggregate. The results were compared with the mercury content of local soils as the reference level. Waste samples were taken from foundry landfill. The mercury content, fractional composition, organic matter (OM) and total organic carbon content, pH and elementary composition of waste were analysed. It was found that the mercury content in LFW was very low, at the level of natural content in soils and did not pose a threat to the environment. The statistical analysis shows that mercury was not associated with OM of the waste, in contrast to soils, probably due to different types of OM in both materials.


Author(s):  
Rade M. Ciric ◽  
Sasa N. Mandic

AbstractThe Republic of Serbia must make significant efforts to promote and exploit renewable energy sources and increase energy efficiency in all energy sectors to ensure energy security and economic competitiveness, reduce the negative impact on the environment from energy production and use, and contribute to global efforts to reduce greenhouse gases. Within the paper several issues of integration of recently realized CHP plant are introduced and discussed. Firstly, the legal and energy policy issues in the Republic of Serbia regarding connecting CHP to the grid are presented. The challenges and technical solutions for CHP connection to the grid, as well as power quality issues and the role of the CHP plant during the restoration of power supply during the maintenance of the substation and unplanned loss of high voltage supply, are presented and discussed. Finally, the impact of prospective massive integration of CHP on the energy balance and CO2 emission reduction in the province of Vojvodina in Serbia is investigated and discussed. Since it is the first CHP plant realized in Serbia, it is crucial that experience be shared to all potential stakeholders in the future energy efficiency projects.


2021 ◽  
Vol 13 (1) ◽  
pp. 421
Author(s):  
Marzena Tomaszewska ◽  
Beata Bilska ◽  
Agnieszka Tul-Krzyszczuk ◽  
Danuta Kołożyn-Krajewska

The problem of food waste in food services, which is global and essentially affects the entire world, is a major challenge for the hospitality industry. At the same time, it should be noted that this problem has not been sufficiently studied, which makes it difficult to reduce it effectively. The study was carried out in four hotels in late 2019 and early 2020. In order to determine the scale of food waste, the diary method was used, which consists of systematically recording, for seven days, in forms prepared for workstations, the weight of all food products and unused food, including the stage of the technological process. In the hotels under study, most food was wasted in the serving department, i.e., in the buffet in the dining room or in the form of plate waste (on average 72.55% of wasted food). After taking into account the number of hotel guests served, it was found that in the investigated facilities, an average of 0.046 kg was wasted from each serving offered to guests in the form of plate waste, which constituted 5.8% of its weight. In sum, it should be stated that in order to reduce food waste, it is necessary to educate both food services staff and consumers. Employees should be trained in the proper handling of food. Consumer education, on the other hand, should be directed toward raising awareness of the negative impact of food waste, such as that on the natural environment. In addition, it should indicate what action everyone can take to limit this negative phenomenon, whether at home, in the workplace, or in a food service establishment.


2021 ◽  
pp. 152700252110084
Author(s):  
Levi Pérez

It is common for elite players to represent their respective countries in international competitions. However, there is a potential cost to the club team derived from that situation (risk of injury, fatigue, psychological momentum, etc.). This paper evaluates the impact of players’ absence on European football teams’ performance by focusing on the Africa Cup of Nations as the case study. The results indicate that the sending of players to the African tournament has a relatively small negative impact on teams’ performance. But this cannot be generalized to all the leagues and loses significance when corrected by players’ abilities.


Materials ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 234
Author(s):  
Matthias Richter ◽  
Wolfgang Horn ◽  
Elevtheria Juritsch ◽  
Andrea Klinge ◽  
Leon Radeljic ◽  
...  

Indoor air quality can be adversely affected by emissions from building materials, consequently having a negative impact on human health and well-being. In this study, more than 30 natural building materials (earth dry boards and plasters, bio-based insulation materials, and boards made of wood, flax, reed, straw, etc.) used for interior works were investigated as to their emissions of (semi-)volatile organic compounds ((S)VOC), formaldehyde, and radon. The study focused on the emissions from complete wall build-ups as they can be used for internal partition walls and the internal insulation of external walls. Test chambers were designed, allowing the compounds to release only from the surface of the material facing indoors under testing parameters that were chosen to simulate model room conditions. The emission test results were evaluated using the AgBB evaluation scheme, a procedure for the health-related evaluation of construction products and currently applied for the approval of specific groups of building materials in Germany. Seventeen out of 19 sample build-ups tested in this study would have passed this scheme since they generally proved to be low-emitting and although the combined emissions of multiple materials were tested, 50% of the measurements could be terminated before half of the total testing time.


2001 ◽  
Vol 44 (6) ◽  
pp. 109-117 ◽  
Author(s):  
M. A. Mathegana ◽  
L. K. Chauke ◽  
F. A.O. Otieno

The primary purpose of an improved water supply and sanitation is the achievement of acceptable health and hygiene standards as well as the sustainable improvement of the environment. Many governments recognize this and so they budget for large sums of money to improve these services to the communities. The purpose of this study was to investigate the different gaps in environmental health and hygiene practices with the aim of suggesting a strategy of improving this in the Northern Province of South Africa. To do this, 231 households and 30 schools were surveyed. Workshops and visits to different government departments were also used. This paper reports the results from this study which indicate that the situation in schools was not any better than that in households, with more than 90% of the villages still dependent on the unimproved pit latrines and 56,6% relying on standpipes which were (70% of the time) non-operational. The main problems identified seem to those associated with implementation and maintenance. The study concludes that with proper training of the water committees and their active involvement with the government and NGOs, environmental health and hygiene problems can be minimized or eliminated.


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