Abstract. To obtain a thorough knowledge of PM2. 5 chemical composition and its impact on aerosol optical properties across China, existing field studies conducted after the year 2000 are reviewed and summarized in terms of geographical, interannual and seasonal distributions. Annual PM2. 5 was up to 6 times the National Ambient Air Quality Standards (NAAQS) in some megacities in northern China. Annual PM2. 5 was higher in northern than southern cities, and higher in inland than coastal cities. In a few cities with data longer than a decade, PM2. 5 showed a slight decrease only in the second half of the past decade, while carbonaceous aerosols decreased, sulfate (SO42−) and ammonium (NH4+) remained at high levels, and nitrate (NO3−) increased. The highest seasonal averages of PM2. 5 and its major chemical components were typically observed in the cold seasons. Annual average contributions of secondary inorganic aerosols to PM2. 5 ranged from 25 to 48 %, and those of carbonaceous aerosols ranged from 23 to 47 %, both with higher contributions in southern regions due to the frequent dust events in northern China. Source apportionment analysis identified secondary inorganic aerosols, coal combustion and traffic emission as the top three source factors contributing to PM2. 5 mass in most Chinese cities, and the sum of these three source factors explained 44 to 82 % of PM2. 5 mass on annual average across China. Biomass emission in most cities, industrial emission in industrial cities, dust emission in northern cities and ship emission in coastal cities are other major source factors, each of which contributed 7–27 % to PM2. 5 mass in applicable cities. The geographical pattern of scattering coefficient (bsp) was similar to that of PM2. 5, and that of aerosol absorption coefficient (bap) was determined by elemental carbon (EC) mass concentration and its coating. bsp in ambient condition of relative humidity (RH) = 80 % can be amplified by about 1.8 times that under dry conditions. Secondary inorganic aerosols accounted for about 60 % of aerosol extinction coefficient (bext) at RH greater than 70 %. The mass scattering efficiency (MSE) of PM2. 5 ranged from 3.0 to 5.0 m2 g−1 for aerosols produced from anthropogenic emissions and from 0.7 to 1.0 m2 g−1 for natural dust aerosols. The mass absorption efficiency (MAE) of EC ranged from 6.5 to 12.4 m2 g−1 in urban environments, but the MAE of water-soluble organic carbon was only 0.05 to 0.11 m2 g−1. Historical emission control policies in China and their effectiveness were discussed based on available chemically resolved PM2. 5 data, which provides the much needed knowledge for guiding future studies and emissions policies.
El objetivo es determinar los factores facilitadores y de barrera que permitan a los pequeños y medianos productores de zarzamora en Los Reyes, Michoacán, México, escalar su posición en las cadenas de valor global. Se utiliza el estudio de caso mediante 20 entrevistas. Los resultados indican que los productores tienen una fuerte dependencia comercial y financiera; que los niveles de colaboración entre productores son bajos; y que se requiere instaurar redes de colaboración entre agricultores locales. El aporte consiste en contribuir a la construcción de un marco teórico para incrementar el aprovechamiento de los recursos locales.
Cities. Urban geography, Urban groups. The city. Urban sociology
Haitham Nobanee, Diem Thi Hong Vo, Hai Hong Trinh
et al.
This study presents a comprehensive bibliometric and systematic literature review analysis of the literature on the Big Mac Index (BMI) to identify its foundational aspects and summarize key findings. The BMI, an informal measure of purchasing power parity, has garnered scholarly interest in discussions about currency valuations, trade imbalances, and cross-country cost of living. This index encompasses a rich set of fields, including pricing drugs, cigarette/smoking across countries, professors’ salaries, income inequality, and wages. The study provides the first bibliometric analysis in this field, revealing that the number of published articles and citations is relatively low, highlighting the undervaluation of the pricing of different products and services across countries. After several screening steps, 54 articles met the criteria for examination using VOSviewer. The study offers insights into the evolution of BMI literature and highlights leading authors, documents, countries, institutions, and journals. The results indicate that Tobacco Control is the top journal publishing paper and the top-cited journal article on BMI, with the United States leading in contributions. The paper presents potential future research directions in the field of BMI.
Cities. Urban geography, Urbanization. City and country
Anna Calvén, Thomas Beery, Hannah Kristofers
et al.
During the COVID-19 pandemic, participation in outdoor recreation increased in several countries, with nature taking on an expanded role as a social space for meetings and activities with food. This development may have created opportunities for nature-based hospitality providers to navigate the pandemic crisis. This review examines how food and eating were part of outdoor recreation and nature-based tourism during COVID-19, focusing on hospitality providers in rural Sweden. A literature search was performed for research articles, newspapers, and magazine articles. The results show creativity in adapting to new outdoor and nature tourism situations. The main findings that emerged focused on local and national guests, preventing the spread of infection, food as part of the experience in nature, experience packages, comfort, local food, food trucks and takeaway food, and other hospitality industry changes. Trends observed before COVID-19 but accelerating during the pandemic were also highlighted. Further research is needed to improve our understanding of food as part of outdoor recreation and nature-based tourism and how this knowledge can support sustainable thinking in the hospitality sector while contributing to resilient rural development.
Urbanisation and digitalisation are two significant trends in social development nowadays. The ‘smart city’ has been introduced to address the conflict between citizens’ needs and urban services. However, while much attention has been directed towards the technological aspects, fewer studies have explored their urban impacts. This article presents a systematic review of the existing empirical literature on smart cities in urban space, aiming to investigate the trends of the research, and emphasise obstacles and potential opportunities for smart cities in urban space. The review covers 53 articles obtained from the Web of Science (WoS) and Scopus databases and followed the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement. The findings reveal three main trends (smart city as a technique, as a tool, and as a way), five major obstacles (technological hegemony; surveillance and privacy; data integration difficulties; marginalisation and regional inequality; technocracy and discrimination), and four potential opportunities (interdisciplinary collaboration; platform integrations; inclusive citizen engagement; localised adaptive approaches) related to the objectives. Furthermore, the article highlights several recommendations related to context-based responsive planning strategies for local needs; a comprehensive examination of user perception frameworks; the integration of participatory approaches for more inclusive cities, and standardised measurement protocols for information exchange. This review contributes to policymakers and urban planners in their practices, provides valuable guidance to academics in various fields, and delivers implications for applying smart city concepts in the Global South and other developing countries.
Cities. Urban geography, Urban groups. The city. Urban sociology
Carlos Sambricio (ed.), La cultura arquitectónica en los años de la Transición, Sevilla, Editorial Universidad de Sevilla (Colección Arquitectura, nº 46), 2022, 389 páginas, ISBN: 978-84-472-2418-0.
Este artículo explora el futuro del desarrollo sustentable México al 2030 a través de planificación de escenarios; basado en métodos cualitativos de prospectiva: el método Delphi, análisis de impacto cruzado y planificación de escenarios. Los datos primarios provienen de entrevistar a treinta expertos. Los resultados indican convergencia de opinión de expertos respecto a incertidumbres que incluyen mayor riesgo político, empeoramiento de seguridad pública y lento crecimiento económico. Usando metodología de matriz cruzada, se desarrollaron cuatro escenarios que presentan diferentes futuros potenciales para 2030. El más probable es que México incumpla los Objetivos de la Agenda 2030 de la ONU.
Cities. Urban geography, Urban groups. The city. Urban sociology
Samuel Yakubu, Kayode Samuel, Anthony Kola-Olusanya
et al.
Mobility plays a crucial role in joining activity's locations to each other, enabling social contact, and facilitating the movement of people and goods from and to various locations. This study investigates the mobility characteristics of peri-urban communities in selected cities of Southwest Nigeria. We selected 505 respondents from the 11 peri-urban communities for the questionnaire survey using a stratified sampling technique. The data were summarised using frequency, mean and mode while ANOVA and Chi-square were used to test for the significant difference in inter-community and gender variations in mobility variables. Findings revealed a substantial variation in the distance separating the peri-urban communities and the city centres. Most of the respondents (81.4%) indicated that the roads in their communities were not paved, with adverse effects on their mobility. The peri-urban communities are served by informal transit modes, with more than 33% of the respondents relying on motorcycles for their mobility needs. Mobility characteristics among the peri-urban dwellers vary from one community to another and between gender. Over 80% of respondents work within the peri-urban interface, indicating increasing decentralisation of activities. The peri-urban dwellers are mobility-starved due to failed infrastructure and informal transit services. The government at all levels (Federal, State and Local) should prioritise improving road infrastructures and public transport services that enhance sustainable mobility at the city peripheries.
Cyber security is one of the main issues that is discussed today everywhere in the world. The development of technology has grown rapidly and it is important that this development should be done simultaneously with the increase in security. When we talk about the network, we must also consider its "Security". On the other hand, Python is a language which, especially in recent times, has received a great development and now we can say that it enjoys such a wide community. Our goal in this article is the advantages that this programming language offers in cases of cyber security issues. It has everything that cyber security professionals need to protect against cyber vulnerabilities and threats. It allows developers to do anything that relates to cyber security by detecting threats to system fixes. Python is a high-level, general-purpose, interpreted programming language for analyzing small networks. So, the implications of the study are for cybersecurity professionals and developers. They use the NetworkX grid tools imported into python. NetworkX provides many functions and generation facilities to read and write graphics in many formats. By analyzing these network nodes graphs, are identified the nodes that can be "bad". With Python scripts, you can scan ports and compromised device. In order to achieve this, we have obtained two concrete dataset which were obtained respectively from a public and a private network. After analyzing the graphs, the weaknesses of the network and unidentified devices in the network are identified, creating the possibility of taking appropriate measures to protect against cyber-attacks.
Social sciences (General), Cities. Urban geography
shahrivar rostaei, Akbar Asghari zamani, forough andesta
Introduction: A neighborhood is a social-spatial concept. neighborhood management methods include the three dimensions of physical quality, social arrangement, and governance manners. Concerning the third dimension, recent decades have witnessed a shift from centralized towards decentralization processes and network society.Data and Method: The present study had a fundamental goal and used an explorative-explanatory approach. This study used a systematic and structured view to review the theoretical literature on neighborhood management and related concepts. Using, the MICMAC software, the study analyzed the extent to which factors affected and were affected by each other. In the end, driving factors were extracted. For this, 61 factors in five categories of network structure, network society policies, urban governance, governance capacity, and social capital were identified, and provided to 15 experts in the form of a 61*61 matrix, using questionnaires, and via a purposive sampling method.Results: Results indicated that 19 driving factors contributed to investigating the neighborhood management of the urban governance of the city of Tabriz, out of which the factor “revision of the laws and urban development plans” was more important, while the factors “active adaptation to the environment”, “the non-exclusive right of special groups”, “the content of laws enacted”, “the enjoyment of the open urban culture”, “focus on the “solidarity between people to produce knowledge” took the next ranks.Conclusion: The results were found to be used as a framework to investigate the neighborhood management position in urban governance. In this connection, urban development plans and rules, and their revision contributed to this.
La presente investigación tuvo como objetivo comparar los aditivos químicos Consolid 444 y Con-Aid para mejorar la capacidad de soporte de un suelo arcilloso. Las muestras fueron extraídas del tramo de la carretera Pedro Ruiz–San Carlos entre los km 3+000 y 4+000, provincia de Bongará, Perú; asimismo se realizaron ensayos de laboratorio para determinar las propiedades físicas y mecánicas del suelo estabilizado y sin estabilizar. Los resultados obtenidos indicaron que el suelo natural fue clasificado como CL según SUCS, y AASHTO como A-7-6 (17), además con la adición de 0,035% para el aditivo Consolid 444 y 2 ml para el aditivo Con-Aid, se logró un incremento de CBR al 95 % de 5,49% a 28,65% y 24,32% respectivamente. Por otro lado, se verificó que el valor de CBR aumentó, al incrementar los periodos de curado a los 7, 14 y 28 días para ambos aditivos. En conclusión, los aditivos Consolid 444 y Con-Aid mejoraron el comportamiento mecánico del suelo arcilloso, logrando subrasantes excelentes
BackgroundA growing body of research suggests that the suburbanization of food retailers in North America and the United Kingdom in recent decades has contributed to the emergence of urban 'food deserts', or disadvantaged areas of cities with relatively poor access to healthy and affordable food. This paper explores the evolution of food deserts in a mid-sized Canadian city (London, Ontario) by using a geographic information system (GIS) to map the precise locations of supermarkets in 1961 and 2005; multiple techniques of network analysis were used to assess changing levels of supermarket access in relation to neighbourhood location, socioeconomic characteristics, and access to public transit.ResultsThe findings indicate that residents of inner-city neighbourhoods of low socioeconomic status have the poorest access to supermarkets. Furthermore, spatial inequalities in access to supermarkets have increased over time, particularly in the inner-city neighbourhoods of Central and East London, where distinct urban food deserts now exist.ConclusionContrary to recent findings in larger Canadian cities, we conclude that urban food deserts exist in London, Ontario. Policies aimed at improving public health must also recognize the spatial, as well as socioeconomic, inequities with respect to access to healthy and affordable food. Additional research is necessary to better understand how supermarket access influences dietary behaviours and related health outcomes.
El objeto de este trabajo es presentar la posible ubicación del vado y del azud de Alarilla (Fuentidueña de Tajo, Madrid). Estas infraestructuras, de alto valor estratégico y territorial durante la Edad Media, se encuentran desaparecidas en las riberas del Tajo. Para ello, se han utilizado tanto fuentes históricas, como metodologías del ámbito de la geografía, la geomorfología de campo y laboratorio, y la geoarqueología. Esta multidisciplinariedad ha ayudado a obtener los respectivos emplazamientos con cierta precisión. La localización del vado y el azud nos ayuda a entender la vertebración de un territorio que ya ha sido profundamente transformado por el ser humano y el clima desde el siglo XI al XIV. Una vez localizados, procedimos a valorar su evolución hasta su desaparición.
Geography. Anthropology. Recreation, Human ecology. Anthropogeography
Peer-to-peer electricity trading is the exchange of electricity between interconnected participants, such as distributed energy generators, consumers and prosumers. While the term ‘peer-to-peer electricity trading’ is common in scientific discussions, the term is rarely used in policy language. However, with an increase of distributed energy resources and the need for effective management mechanisms, policy documents of the EU and China in recent years have supported the concept without explicitly using the term. This paper uses qualitative content analysis and examines six relevant policy documents of the EU and China that were issued between 2016 and 2019 to determine to what extent they reflect the concept of the ‘peer-to-peer electricity trading’ in language and content. Key terms, similarities, and differences in the conceptualisation of peer-to-peer electricity trading in the EU and China are identified. The results show that while the conditions and focus of the documents are different in the EU and China, the concept of peer-to-peer trading is a running theme in both regions.
Cities. Urban geography, Urbanization. City and country