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A review on the role of green vegetation in improving urban environmental quality

The exacerbation of climate change impacts within metropolitan areas is a well-documented phenomenon, often leading to severe consequences that pose significant risks to human populations. The impact of urban vegetation and planting design on these factors can be observed. However, it is worth mentioning that while there is an extensive body of literature on the consequences of climate change, there is a relatively small number of studies specifically focused on examining the role of vegetation as a mitigating factor in urban environments. This review paper aims to critically examine existing studies pertaining to the role of urban vegetation in mitigating the detrimental effects of the urban environment. The objective is to offer practical recommendations that can be implemented by city planners. By conducting a comprehensive examination of the literature available in Scopus, Web of Science, and Google Scholar, employing specific keywords pertaining to urban vegetation and climate change, we have identified five prominent concerns pertaining to the urban environment. These concerns encompass particulate matter, gaseous pollution, noise pollution, water runoff, and the urban heat island effect. The present analysis highlights that the impact of urban vegetation on the negative consequences of climate change cannot be unequivocally classified as either positive or negative. This is due to the fact that the influence of urban greenery is intricately connected to factors such as the arrangement, makeup, and dispersion of vegetation, as well as the specific management criteria employed. Hence, this research has the potential to enhance comprehension of the multifaceted nature of urban green spaces and establish a solid groundwork for subsequent investigations.

Analytical study on the coupling coordination degree of tourism and urban development—Taking Shaanxi as an example

Tourism has been instrumental in fostering regional economic growth, enhancing the quality of life of residents, and boosting the image of urban areas in Shaanxi, thanks to the accelerated economic and social development of recent years. Nevertheless, the issue of aligning urban development and tourism in terms of space, resources, and the industrial chain remains a significant concern. This paper establishes an evaluation index system for tourism and urban development in the Shaanxi region from 2009 to 2019. It then employs the systematic coupling coordination model to conduct a comprehensive analysis of the coupling coordination degree of tourism and urban development in the region, as well as its various influencing factors. The study demonstrates that the coupling and coordination degree of tourism and urban development in the Shaanxi region exhibited a trend of continuous improvement from 2009 to 2019. The region underwent three stages of development: “uncoordinated development (2009–2011), transformation development (2012–2016), and coordinated development (2017–2019).” The coupling coordination level was elevated from “mild dissonance” to “intermediate coordination” in 2019. In contrast, the tourism economic development of Shaanxi cities remains unequal, as evidenced by the existence of two distinct categories of development: the “lagging tourism economy” and the “coordinated tourism economy.” The findings of this investigation indicate that the general trend of urban development and tourism in Shaanxi is favorable; however, the disparities in the progress of the tourism economy among cities necessitate additional regional coordination and cooperation. The theoretical support for the relevant research and a reference basis for tourism development planning and urban policy making are provided by the evaluation index system and the systematic coupling coordination model proposed in this paper. This will facilitate the sustainable and coordinated development of the tourism industry and cities in Shaanxi.

The utilizability of non-flammable R471A with low-GWP in air-conditioning systems

Atilla Gencer Devecioğlu, Vedat Oruç, Tuba Taneli

Article ID: 2283
Vol 4, Issue 1, 2023

DOI: https://doi.org/10.54517/ec.v4i1.2283

Received: 11 February 2023; Accepted: 30 March 2023; Available online: 16 April 2023;
Issue release: 30 June 2023

VIEWS - 4561 (Abstract)

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Abstract

The utilizability of non-flammable refrigerant R471A with low-GWP is theoretically investigated in an air-conditioning system. In this context, R410A, R32, and R471A are compared for the evaporation temperatures of 4, 8, and 12 ℃ with the condenser temperatures of 40 and 50 ℃. The results indicate that both the mass flow rate and power consumption of R471A are higher compared to R410A and R32. Although COP of R471A is determined to be smaller than R410A and R32 by about 19% and 22%, R471A can satisfy the restrictions for air-conditioning systems due to its considerable low-GWP compared to R410A and R32 (GWP of R471A is lower by 78% and 93% in comparison with R32 and R410A, respectively). Hence, it should be possible to suppress global warming through the reduction of carbon emissions as a result of using R471A in these systems. Additionally, since R471A is non-flammable, it can be safely used for systems requiring a high amount of refrigerant charge without violating the restrictions.

Keywords

R471A; carbon reduction; air-conditioning system; low-GWP refrigerant; non-flammable refrigerant

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