scholarly journals Substrate colonization by an emulsion drop prior to spreading

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Suraj Borkar ◽  
Arun Ramachandran

AbstractIn classical wetting, the spreading of an emulsion drop on a surface is preceded by the formation of a bridge connecting the drop and the surface across the sandwiched film of the suspending medium. However, this widely accepted mechanism ignores the finite solubility of the drop phase in the medium. We present experimental evidence of a new wetting mechanism, whereby the drop dissolves in the medium, and nucleates on the surface as islands that grow with time. Island growth is predicated upon a reduction in solubility near the contact line due to attractive interactions between the drop and the surface, overcoming Ostwald ripening. Ultimately, wetting is manifested as a coalescence event between the parent drop and one of the islands, which can result in significantly large critical film heights and short hydrodynamic drainage times prior to wetting. This discovery has broad relevance in areas such as froth flotation, liquid-infused surfaces, multiphase flows and microfluidics.

2021 ◽  
Author(s):  
Klaus Abbink ◽  
Lu Dong ◽  
Lingbo Huang

Communication is one of the most effective devices in promoting team cooperation. However, asymmetric communication sometimes breeds collusion and hurts team efficiency. Here, we present experimental evidence showing that excluding one member from team communication hurts team cooperation; the communicating partners collude in profit allocation against the excluded member, and the latter reacts by exerting less effort. Allowing the partners to reach out to the excluded member partially restores cooperation and fairness in profit allocation, but it does not stop the partners from talking behind that member’s back even when they could have talked publicly. The partners sometimes game the system by tricking the excluded member into contributing but then grabbing all profits for themselves. This paper was accepted by Axel Ockenfels, behavioral economics and decision analysis.


2019 ◽  
Vol 65 (8) ◽  
pp. 3904-3927 ◽  
Author(s):  
Lucas C. Coffman ◽  
Alexander Gotthard-Real

Can an organization avoid blame for an unpopular action when an adviser advises it to do it? We present experimental evidence suggesting this is the case—advice to be selfish substantially decreases punishment of being selfish. Further, this result is true despite advisers’ misaligned incentives, known to all: Through a relational contract incentive, advisers are motivated to tell the decision makers what they want to hear. Through incentivized elicitations, we find suggestive evidence that advice moves punishment by affecting beliefs of how necessary the selfish action was. In follow-up treatments, however, we show advice does not decrease punishment solely through a beliefs channel. Advice not only changes beliefs about what happened, but also the perceived morality of it. Finally, in treatments in which advisers are available, the data suggest selfish decision makers act more selfishly. This paper was accepted by Axel Ockenfels, behavioral economics.


2004 ◽  
Vol 7 (2) ◽  
pp. 107-119 ◽  
Author(s):  
LAURA COLANTONI ◽  
JORGE GURLEKIAN

In this paper we present experimental evidence showing that Buenos Aires Spanish differs from other Spanish varieties in the realization of pre-nuclear pitch accents and in the final fall in broad focus declarative utterances. Whereas other Spanish varieties have been described consistently as showing late peak alignments, Buenos Aires Spanish displays early peak alignments. The alignment pattern found in Buenos Aires broad focus declarative utterances is not totally foreign to Spanish: it is attested in a quite different function, i.e. to signal contrastive focus. In addition, Buenos Aires Spanish also seems to differ from other Spanish varieties in the realization of the intonation contour in utterance-final intonational phrases, where a pronounced tendency for down-stepped peaks is observed. We argue that these patterns, which emerged at the turn of the twentieth century, and coincided with the peak of Italian immigration, are due to a combination of direct and indirect transfer from Italian. As a result, two intonational systems that were typologically similar before contact took place (Hualde, 2002) became more similar after contact, in what can be interpreted as a case of convergence.


2019 ◽  
Vol 116 (9) ◽  
pp. 3482-3487 ◽  
Author(s):  
Celso M. de Melo ◽  
Stacy Marsella ◽  
Jonathan Gratch

Recent times have seen an emergence of intelligent machines that act autonomously on our behalf, such as autonomous vehicles. Despite promises of increased efficiency, it is not clear whether this paradigm shift will change how we decide when our self-interest (e.g., comfort) is pitted against the collective interest (e.g., environment). Here we show that acting through machines changes the way people solve these social dilemmas and we present experimental evidence showing that participants program their autonomous vehicles to act more cooperatively than if they were driving themselves. We show that this happens because programming causes selfish short-term rewards to become less salient, leading to considerations of broader societal goals. We also show that the programmed behavior is influenced by past experience. Finally, we report evidence that the effect generalizes beyond the domain of autonomous vehicles. We discuss implications for designing autonomous machines that contribute to a more cooperative society.


1997 ◽  
Vol 484 ◽  
Author(s):  
M. Chauvet ◽  
S. A. Hawkins ◽  
G. J. Salamo ◽  
M. Segev ◽  
D. F. Bliss ◽  
...  

AbstractWe present experimental evidence for the observation of steady-state dark photorefractive screening solitons trapped in bulk InP:Fe.


2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Aaron Braver ◽  
Wm. G. Bennett

AbstractWhile a number of phonologists assume that phonotactics can provide clues to abstract morphological information, this possibility has largely gone unconsidered in work on Bantu noun classes. We present experimental evidence from isiXhosa (a Bantu language of the Nguni family, from South Africa), showing that speakers make use of root phonotactics when assigning noun classes to nonce words. Nouns in Xhosa bear class-indicating prefixes, but some of these prefixes are homophonous – and therefore ambiguous. Our findings show that when speakers are presented with words that have prefixes ambiguous between two classes, phonotactic factors can condition them to treat the nouns as one class or the other. This suggests that noun class (and other abstract morphological information) is not only stored in the lexicon, but is also redundantly indicated by phonotactic clues.


2004 ◽  
Vol 82 (10) ◽  
pp. 2931-2933 ◽  
Author(s):  
Mikito Kitayama ◽  
Kiyoshi Hirao ◽  
Motohiro Toriyama ◽  
Shuzo Kanzaki

2016 ◽  
Vol 113 (31) ◽  
pp. 8658-8663 ◽  
Author(s):  
Jillian J. Jordan ◽  
Moshe Hoffman ◽  
Martin A. Nowak ◽  
David G. Rand

Humans frequently cooperate without carefully weighing the costs and benefits. As a result, people may wind up cooperating when it is not worthwhile to do so. Why risk making costly mistakes? Here, we present experimental evidence that reputation concerns provide an answer: people cooperate in an uncalculating way to signal their trustworthiness to observers. We present two economic game experiments in which uncalculating versus calculating decision-making is operationalized by either a subject’s choice of whether to reveal the precise costs of cooperating (Exp. 1) or the time a subject spends considering these costs (Exp. 2). In both experiments, we find that participants are more likely to engage in uncalculating cooperation when their decision-making process is observable to others. Furthermore, we confirm that people who engage in uncalculating cooperation are perceived as, and actually are, more trustworthy than people who cooperate in a calculating way. Taken together, these data provide the first empirical evidence, to our knowledge, that uncalculating cooperation is used to signal trustworthiness, and is not merely an efficient decision-making strategy that reduces cognitive costs. Our results thus help to explain a range of puzzling behaviors, such as extreme altruism, the use of ethical principles, and romantic love.


2012 ◽  
Vol 25 (6) ◽  
pp. 705-725 ◽  
Author(s):  
Yongqi Wang ◽  
Martin Oberlack ◽  
Andreas Zieleniewicz

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