Iran has one of the oldest civilizations in the world, and many elements of today’s urban planning and design have their origins in the country. However, mass country-city migration from the 1960s onwards brought enormous challenges for the country’s main cities in the provision of adequate housing and associated services, resulting in a range of sub-standard housing solutions, particularly in Tehran, the capital city. At the same time, and notably in the past decade, Iran’s main cities have had significant involvement in the smart city movement. The Smart Tehran Program is currently underway, attempting to transition the capital towards a smart city by 2025. This study adopts a qualitative, inductive approach based on secondary sources and interview evidence to explore the current housing problems in Tehran and their relationship with the Smart Tehran Program. It explores how housing has evolved in Tehran and identifies key aspects of the current provision, and then assesses the main components of the Smart Tehran Program and their potential contribution to remedying the housing problems in the city. The article concludes that although housing related issues are at least being raised via the new smart city technology infrastructure, any meaningful change in housing provision is hampered by the over centralized and bureaucratic political system, an out of date planning process, lack of integration of planning and housing initiatives, and the limited scope for real citizen participation.
Cobalt-based sulfides have emerged as promising candidates for next-generation high-performance anode materials for lithium-ion batteries (LIBs) due to their high theoretical specific capacity and reversible conversion reaction mechanisms. However, their practical application is hindered by volume expansion effects and relatively low rate performance. Guided by theoretical principles, this study synthesizes nanoscale Bi/CoS-C and Bi/Co4S3-C (denoted as Bi/CS-C) composite materials using Co and Bi2S3 as precursors via a solid-state ball milling method. The electrochemical properties of these materials were systematically investigated. When employed as anodes for LIBs, Bi/CoS-C and Bi/CS-C exhibit excellent rate capabilities. At current densities of 0.1, 0.5, 1, 4, and 10 A/g, the reversible capacities of Bi/CoS-C were 939.2, 730.7, 655.6, 508.1, and 319 mAh/g, respectively. In contrast, Bi/CS-C exhibited reversible capacities of 760.4, 637.6, 591.9, 484.3, and 295.4 mAh/g, respectively. Moreover, Co4S3, as an active component, enables superior long-cycle performance compared to CoS. After 300 cycles at 0.2 A/g, the Bi/CoS-C and Bi/CS-C electrodes retained capacities of 193.1 and 788.8 mAh/g, respectively. This study demonstrates that nanostructure design and carbon-based composite materials can effectively mitigate the volume expansion issue of cobalt-based sulfides, thereby enhancing their rate performance and cycling stability. This strategy provides new insights for the development of high-performance anode materials for lithium-ion batteries and is expected to accelerate their practical application in next-generation energy storage devices.
Heat removal has become an increasingly crucial issue for microelectronic chips due to increasingly high speed and high performance. One solution is to increase the thermal conductivity of the corresponding dielectrics. However, traditional approach to adding solid heat conductive nanoparticles to polymer dielectrics led to a significant weight increase. Here we propose a dielectric polymer filled with heat conductive hollow nanoparticles to mitigate the weight gain. Our mesoscale simulation of heat conduction through this dielectric polymer composite microstructure using the phase-field spectral iterative perturbation method demonstrates the simultaneous achievement of enhanced effective thermal conductivity and the low density. It is shown that additional heat conductivity enhancement can be achieved by wrapping the hollow nanoparticles with graphene layers. The underlying mesoscale mechanism of such a microstructure design and the quantitative effect of interfacial thermal resistance will be discussed. This work is expected to stimulate future efforts to develop light-weight thermal conductive polymer nanocomposites.
Recently, the government of Ethiopia has been engaged in modernizing the trans-regional Ethio-Djibouti railway infrastructure using the Belt and Road Initiative. This railway corridor has been serving as the main get way for the landlocked Ethiopia to the port. This article creates an insight about the implications of the Ethio-Djibouti railway corridor by exploring the question: what kinds of urban form and morphological changes evolved due to the railway corridor? To examine the impact of this railway corridor, the article employed stratified sampling and multiple criteria intermediate cities selection method. Accordingly, four (Bishoftu, Mojo, Adama, and Dire Dawa) intermediate cities were selected as case study. The article points out that the railway corridor conceived different kinds of linear urban centers around stations. The identified four intermediate cities attract industries and logistic centers. Those industries, logistic centers, and new railway stations often established at the periphery of intermediate cities resulted labour influx from rural and nearby small urban centers and urban expansion that caused a rural-urban continuum of ribbon settlement and strengthen trade gate way for the landlocked Ethiopia that caused trans-regional integration.
E-commerce is increasingly developing as a platform large and small companies use to carry out online transactions with consumers. However, the development of e-commerce is also fraught with new environmental problems. Various problems occur, such as data leaks and fraud in buying and selling transactions. This research aims to deepen the study of the e-commerce environment from the perspective of local policymakers, and this research completes a study on the analysis of e-commerce problems and solutions from the perspective of policy actors. The development of e-commerce still has an unsafe environment; the potential for fraud and data leakage is still significant, and a government response is needed, such as creating new regulations or revising existing regulations. This research uses qualitative analysis with a content analysis approach and national online news media as research data and information sources. Nvivo 12 Plus software was used to identify problems and solutions offered by actors in their narratives in the media. The results of this research show that data leaks and e-commerce have the potential to threaten the country’s resilience, conventional businesses are threatened with closure, and policymakers are shifting responsibility for overcoming e-commerce problems. Current regulations still need to be made appropriately to overcome e-commerce problems.
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