CFD Analysis of Pollutant Removal Mechanism in Urban Street Canyons

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Designers of collaboration mandates for sustainable natural resource management must address public agencies’ concerns about losing autonomy and influence

With climate change now influencing entire regions, there is a greater need for organizational collaboration to manage natural resources sustainably. Using California’s Sustainable Groundwater Management Act, which mandates collaboration between groundwater sustainability agencies, as a case study, Brian An and Shui-Yan Tang examine what drives integrative collaborations between agencies. They find that agencies are more likely to joint integrative collaborations if their mission addresses a broader focus, their core stakeholder groups have less concentrated interests in the policy issue, and their organizational culture is less rigid and risk averse

A multiple type bike repositioning problem

This paper investigates a new static bicycle repositioning problem in which multiple types of bikes are considered. Some types of bikes that are in short supply at a station can be substituted by other types, whereas some types of bikes can occupy the spaces of other types in the vehicle during repositioning. These activities provide two new strategies, substitution and occupancy, which are examined in this paper. The problem is formulated as a mixed-integer linear programming problem to minimize the total cost, which consists of the route travel cost, penalties due to unmet demand, and penalties associated with the substitution and occupancy strategies. A combined hybrid genetic algorithm is proposed to solve this problem. This solution algorithm consists of (i) a modified version of a hybrid genetic search with adaptive diversity control to determine routing decisions and (ii) a proposed greedy heuristic to determine the loading and unloading instructions at each visited station and the substitution and occupancy strategies. The results show that the proposed method can provide high-quality solutions with short computing times. Using small examples, this paper also reveals problem properties and repositioning strategies in bike sharing systems with multiple types of bikes.published_or_final_versio

Editorial for IEEE access special section on theoretical foundations for big data applications : challenges and opportunities

Big data is one of the hottest research topics in science and technology communities, and it possesses a great application potential in every sector for our society, such as climate, economy, health, social science, and so on. Big data usually includes data sets with sizes beyond the ability of commonly used software tools to capture, curate, and manage. We can conclude that big data is still in its infancy stage, and we will face many unprecedented problems and challenges along the way of this unfolding chapter of human history

Membrane in M5-branes Background

In this paper, we investigate the properties of a membrane in the M5-brane background. Through solving the classical equations of motion of the membrane, we can understand the classical dynamics of the membrane in this background.Comment: 15 pages, typos correcte

In the early global fight against COVID-19, quick mask mandates were most effective

Before the development of an effective vaccine, policymakers had to use other approaches such as mask mandates and stay-at-home orders to slow the spread of COVID-19. In new research covering 164 countries, Brian An, Simon Porcher, Shui-Yan Tang, and Eunji Emily Kim examine the effectiveness of these measures aimed at stopping the spread of COVID-19, finding that mask mandates, if adopted early, were the most effective. They also find that countries with less individualistic cultures, and those with better healthcare capacity prior to the pandemic, were more likely to adopt early mask mandates

Measurement of Surface Machining Damage in Ceramics

Machining damage in hot pressed (NCI32) silicon nitride, due to surface grinding and polishing, has been simulated by dragging a Knoop indentor across the surface of optically polished samples. The reflection coefficient of the cracks thus generated was measured versus frequency, and was found to be in excellent agreement with the theoretical calculations of Achenbach and Brind1. We found that the long slot-like cracks were closed at the top (about 20% of the total crack depth), which was due to the residual stress introduced when the samples were scratched. By taking into consideration the crack closure, and with the results of our scattering measurements, we were able to make failure stress predictions with an accuracy of better than 10%

Do climate change regulatory pressures increase corporate environmental sustainability performance? The moderating roles of foreign market exposure and industry carbon intensity

This study focuses on climate change regulatory pressures at the national/regional level, which can be considered emergent institutions – newly established and subject to change – in contrast to established institutions. We explore their impact on the environmental sustainability performance of multinational enterprises, advancing beyond the extant literature's focus on their binary compliance reactions. Utilizing a sample of Standard & Poor's 1200 firms, our findings indicate that variations in climate change regulatory pressures at the national/regional level can account for differences in environmental sustainability performance at the corporate level. Moreover, this relationship is moderated by two critical firm characteristics: foreign market exposure and industry carbon intensity. Foreign market exposure, particularly in the context of developing countries, can diminish the positive effects of a home country's climate change regulatory pressures, while industry carbon intensity can amplify these effects

Plasmoid ejection and secondary current sheet generation from magnetic reconnection in laser-plasma interaction

Reconnection of the self-generated magnetic fields in laser-plasma interaction was first investigated experimentally by Nilson {\it et al.} [Phys. Rev. Lett. 97, 255001 (2006)] by shining two laser pulses a distance apart on a solid target layer. An elongated current sheet (CS) was observed in the plasma between the two laser spots. In order to more closely model magnetotail reconnection, here two side-by-side thin target layers, instead of a single one, are used. It is found that at one end of the elongated CS a fan-like electron outflow region including three well-collimated electron jets appears. The ($>1$ MeV) tail of the jet energy distribution exhibits a power-law scaling. The enhanced electron acceleration is attributed to the intense inductive electric field in the narrow electron dominated reconnection region, as well as additional acceleration as they are trapped inside the rapidly moving plasmoid formed in and ejected from the CS. The ejection also induces a secondary CS