Characterizing the Economic and Environmental Benefits of LNG Heavy-Duty Trucks: A Case Study in Shenzhen, China

Heavy-duty trucks (HDTs) in road freight are a primary contributor of PM2.5 and NOX emissions in many cities. Shenzhen, a megacity of China, has already made great efforts to promote the green transport transition, including via the Liquefied Natural Gas (LNG) HDTs program, which may be the largest alternative fuel vehicle promotion program in the world. In order to fully understand the actual efficiency of such program, the economic and environmental impacts of LNG HDTs were analyzed in this study. The results revealed that, while the capital cost of LNG HDTs is higher than that of diesel HDTs, the aggregated cost during the entire operation period of LNG HDTs is 10% to 17% lower than that of diesel HDTs. By replacing existing diesel HDTs mode (including China-I to China-V) with LNG HDTs (100%), environmental impact analysis showed that PM2.5 and NOX emissions could be reduced by 96.7% and 73.2% in the city level, respectively. Moreover, the environmental benefits of using purely LNG HDTs versus just China-V diesel HDTs were also compared, which indicated that LNG substitution is superior to China-V, with a reduction of 20.9% for PM2.5 and 35.4% for NOX, respectively. Overall, the effectiveness of the promotion of LNG HDTs is notable in Shenzhen, and these findings could provide references for other cities to promote LNG HDTs and beyond.

Changing Suburban Daily Mobilities in Response to a Mobility Intervention: A Qualitative Investigation of an E-bike Trial

This paper explores how local mobility interventions can bring about changes in daily mobilities and presents a qualitative study of an intervention introducing electric bikes (e-bikes) to suburban commuters in Norway. Our research shows promising evidence that e-bikes could play a crucial role in achieving a sustainable transport transition and that interventions are essential to stimulate the upscaling and mainstreaming of this emerging low-energy transport mode. In order to understand the scheme’s capacity to change mobility outcomes, this paper considers (i) how this low-energy mobility intervention was conceived and undertaken by its initiators, as well as how it was experienced by its participants; and (ii) how new e-bike practices are intertwined with existing daily activities and mobility systems. Theoretically, this paper draws on the staging mobilities framework and conceptualizes situational mobilities as involving the dimensions of embodiment, social interaction, and materiality. With this twofold objective, this paper generates crucial knowledge that is required to understand the capacity of mobility interventions to trigger a sustainable transport transition. This study explores the potential of combining mobile methods (GPS-tracking), qualitative GIS, and visual methods (photo- and map-elicitation) in interviews, and participant observations.

Electric field tuned anisotropic to isotropic thermal transport transition in monolayer borophene without altering its atomic structure

Thermal anisotropy/isotropy can be tuned robustly by external electric field without altering atomic structure.

Movement of accessible plasma membrane cholesterol by the GRAMD1 lipid transfer protein complex

Cholesterol is a major structural component of the plasma membrane (PM). The majority of PM cholesterol forms complexes with other PM lipids, making it inaccessible for intracellular transport. Transition of PM cholesterol between accessible and inaccessible pools maintains cellular homeostasis, but how cells monitor the accessibility of PM cholesterol remains unclear. We show that endoplasmic reticulum (ER)-anchored lipid transfer proteins, the GRAMD1s, sense and transport accessible PM cholesterol to the ER. GRAMD1s bind to one another and populate ER-PM contacts by sensing a transient expansion of the accessible pool of PM cholesterol via their GRAM domains. They then facilitate the transport of this cholesterol via their StART-like domains. Cells that lack all three GRAMD1s exhibit striking expansion of the accessible pool of PM cholesterol as a result of less efficient PM to ER transport of accessible cholesterol. Thus, GRAMD1s facilitate the movement of accessible PM cholesterol to the ER in order to counteract an acute increase of PM cholesterol, thereby activating non-vesicular cholesterol transport.

Obduracy and Change in Urban Transport—Understanding Competition Between Sustainable Fuels in Swedish Municipalities

Within the renewable transport transition, a number of alternative technologies have emerged creating competing visions of how to reduce fossil fuel dependence. This paper examines the dynamics of competing fuels in two Swedish municipalities where electric buses have emerged, threatening incumbent biogas-based bus systems. While in Linköping, actors are resistant to the promise of electrification, in Malmö the shift to electrify urban buses has already begun. Here, the theoretical perspectives of obduracy and sociotechnical imaginaries are used to analyze obduracy and change in Linköping and Malmö, showing how the local contexts of these two municipalities influence obduracy or willingness to change. In Linköping, perceived connections between the biogas-based bus system and local infrastructures of renewable waste management and organic food production cause actors to place biogas buses at the center of a sustainable future region, while in Malmö linkages to the gas network (which also distributes natural gas) cause actors to question the sustainability of the fuel in use and opens up the city to welcome new electric vehicle tests. These examples show how fuel alternatives interact with each other in the wider renewable energy transition.