Charge of a quasiparticle in a superconductor

Non-linear charge transport in SIS Josephson junctions has a unique signature in the shuttled charge quantum between the two superconductors. In the zero-bias limit Cooper pairs, each with twice the electron charge, carry the Josephson current. An applied bias $V_{SD}$ leads to multiple Andreev reflections (MAR), which in the limit of weak tunneling probability should lead to integer multiples of the electron charge $ne$ traversing the junction, with $n$ integer larger than $2{\Delta}/eV_{SD}$ and ${\Delta}$ the superconducting order parameter. Exceptionally, just above the gap, $eV_{SD}>2{\Delta}$, with Andreev reflections suppressed, one would expect the current to be carried by partitioned quasiparticles; each with energy dependent charge, being a superposition of an electron and a hole. Employing shot noise measurements in an SIS junction induced in an InAs nanowire (with noise proportional to the partitioned charge), we first observed quantization of the partitioned charge $q=e^*/e=n$, with $n=1-4$; thus reaffirming the validity of our charge interpretation. Concentrating next on the bias region $eV_{SD}{\approx}2{\Delta}$, we found a reproducible and clear dip in the extracted charge to $q{\approx}0.6$, which, after excluding other possibilities, we attribute to the partitioned quasiparticle charge. Such dip is supported by numerical simulations of our SIS structure

drivers attitude towards caffeine chewing gum as countermeasure to driver task related fatigue

Abstract: Driver fatigue is one of the major contributors to road accidents. In this study, we refer to task-related fatigue, in contrast to sleep-related fatigue. Sleep-related fatigue decrements in driving performance are related to the circadian rhythm, sleep disorders, and sleep deprivation or restriction. Task-related fatigue depends on driving conditions: active and passive task-related fatigue may arise according to the combination of driving task and driving environment. Active task-related fatigue is related to overload driving conditions, and passive task-related fatigue with underload ones. Several countermeasures have been proposed to face the problem of driver fatigue, such as taking a nap or caffeine beverages. The intake of caffeine has shown the enhancement of vigilance and choice reaction time. Those enhancements have an effect within 5-10 min in a caffeine chewing gum compared with 30 to 45 min in coffee. The enhancement in alertness within 5 min is crucial and potentially can reduce sleep related car accidents. Recent study showed that the caffeine effect is directly related to driving performance in monotonous conditions. In this study, two groups of drivers were asked to provide their preferences on several products that might positively affect their driving performance on long and monotonous conditions. The first group composed of participants that drove a driving simulator and actually consumed the products. The second group was composed of questionnaire responders that were presented with animations replicating the first group's actual driving. Both groups' participants preferred to consume coffee or regular chewing-gum over caffeine chewing gum when asked at the beginning of the experiment (or survey). Drivers that actually consumed the products changed their attitude in favour of caffeine chewing-gum. On the other hand, the drivers that participated in the survey did not change their attitude, but rather changed their attitude with regards to the safety in using caffeine chewing-gum

Nudging Parents to Improve Children\u27s Oral Health: A Field Study

This brief presents the results from a field experiment that tested strategies for improving parental participation in an oral health promotion workshop. In this study, daycare centers, in which a team of dental hygienists provided oral health workshops for parents, were randomly assigned to one of six experimental conditions. Specifically, daycare centers were randomly assigned to introduce the Teeth Brushing Board (TBB)—i.e., an interactive poster board to report whether parents brushed their child’s teeth the previous day—into daycare classrooms in the two weeks before the oral health workshop. Further, parents were randomly assigned to receive invitation letters to the workshop with different messages (neutral, negative accountability, or positive accountability). The evidence shows that 41.3% of parents attended the oral health workshop, with none of the interventions significantly changing parents’ attendance rates relative to the control condition (i.e., neutral letter, no interactive board). Research Brief 21-0

Network Design Model with Evacuation Constraints Under Uncertainty

Abstract: Nepal earthquake, have shown the need for quick response evacuation and assistance routes. Evacuation routes are, mostly, based on the capacities of the roads network. However, in extreme cases, such as earthquakes, roads network infrastructure may adversely affected, and may not supply their required capacities. If for various situations, the potential damage for critical roads can be identify in advance, it is possible to develop an evacuation model, that can be used in various situations to plan the network structure in order to provide fast and safe evacuation. This paper focuses on the development of a model for the design of an optimal evacuation network which simultaneously minimizes construction costs and evacuation time. The model takes into consideration infrastructures vulnerability (as a stochastic function which is dependent on the event location and magnitude), road network, transportation demand and evacuation areas. The paper presents a mathematic model for the presented problem. However, since an optimal solution cannot be found within a reasonable timeframe, a heuristic model is presented as well. The heuristic model is based on evolutionary algorithms, which also provides a mechanism for solving the problem as a stochastic and multi-objective problem

Simulation of tourists' wayfinding during evacuation based on experiments in Kyoto

24th EURO Working Group on Transportation Meeting, EWGT 2021, 8-10 September 2021, Aveiro, PortugalTourists are often more vulnerable than residents in sudden disaster situations due to lack of knowledge regarding evacuation routes and safe areas. To establish protocols and the schemes for tourist evacuation to safe areas, it is necessary to gather their likely behavior during an evacuation. Since there are few actual data available we conducted a VR (Virtual Reality) experiment assuming a sudden disaster situation and estimated tourists’ route choice based on the experiment. In the experiment pictures of intersection in the touristic Higashiyama area of Kyoto, Japan, where shown to participants and they could choose the direction they want to proceed until reaching an open space or designated shelter. As a result, we could quantify the impact of road width and, to some degree, network structure. The results reveal the tendency to select wide roads and to proceed straight. If the participants were put under time pressure these tendencies are intensified. Utilizing these results we constructed an evacuation simulation. We estimated the distribution and amount of tourists using data obtained from a mobile phone service provider. We conducted the simulation using VisWalk with various guidance situations and compared those results. The results illustrate potential capacity bottlenecks of designated shelter locations and the importance to provide route guidance and certain points in the network

Stochastic Multi-Objective Evacuation Model Under Managed and Unmanaged policies

Abstract Natural and man-created disasters, such as hurricanes, earthquakes, tsunamis, accidents and terrorist attacks, require evacuation and assistance routes. Evacuation routes are mostly based on the capacities of the road network. However, in extreme cases, such as earthquakes, road network infrastructure may adversely be affected, and may not supply their required capacities. If for various situations, the potential damage for critical roads can be identified in advance, it is possible to develop an evacuation model, that can be used in various situations. This paper focuses on the development of a model for the design of an optimal evacuation network which simultaneously minimizes retrofit costs of critical links (bridges, tunnels, etc.) and evacuation time. The model considers infrastructures' vulnerability (as a stochastic function which is dependent on the event location and magnitude), road network, transportation demand and evacuation areas. Furthermore, the model evaluates the benefits of managed evacuation (system optimum) when compared to unmanaged evacuation (user equilibrium). The paper presents a mathematic model for the presented problem. However, since an optimal solution cannot be found within a reasonable timeframe, a heuristic model is presented as well. This heuristic model is based on evolutionary algorithms, which also provides a mechanism for solving the problem as a multi-objective stochastic problem. Using a real-world data, the algorithm is evaluated and compared to the unmanaged evacuation conditions. The results clearly demonstrate the advantages of managed evacuation, as the average travel time can be reduced by 5% to 30%

Non-local Supercurrent of Quartets in a Three-Terminal Josephson Junction

We report an observation of a new, non dissipative and non local supercurrent, carried by quartets; each consisting of four entangled electrons. The supercurrent is a result of a novel Andreev bound state (ABS), formed among three superconducting terminals. While in a two-terminal Josephson junction the usual ABS, and thus the DC Josephson current, exist only in equilibrium, in the present realization the ABS exists also in the strongly nonlinear regime (biased terminals). The presence of supercurrent carried by quartets was established by performing non-local conductance and cross-correlation of current fluctuations measurements, in different devices made of aluminum-InAs nanowire junctions. An extensive and detailed theoretical study is intertwined with the experimental results