1,898 research outputs found
Simulated low-gravity sloshing in spherical tanks and cylindrical tanks with inverted ellipsoidal bottoms
Simulated low gravity sloshing in spherical and cylindrical tanks with inverted ellipsoidal bottom
Equivalent mechanical model of propellant sloshing in the workshop configuration of the Saturn S-4B Final report
Mechanical model for propellant sloshing in irregular compartmentation of S-4B Workshop configuration during roll and lateral excitation
Low-gravity sloshing in rectangular tanks
Low-gravity sloshing in rectangular tank
Propellant dynamics in an aircraft-type launch vehicle
Liquid propellant sloshing in tilted axisymmetric cylindrical tanks for space shuttle application
Experimental and theoretical studies of liquid sloshing at simulated low gravities
Low gravity liquid sloshing in rigid cylindrical tan
Slosh force, natural frequency, and damping of low-gravity sloshing in oblate ellipsoidal tanks
Liquid sloshing under moderately low simulated gravity in oblate ellipsoidal tank geometrie
Nudging Cooperation in a Crowd Experiment
We examine the hypothesis that driven by a competition heuristic, people don't even reflect or consider whether a cooperation strategy may be better. As a paradigmatic example of this behavior we propose the zero-sum game fallacy, according to which people believe that resources are fixed even when they are not. We demonstrate that people only cooperate if the competitive heuristic is explicitly overridden in an experiment in which participants play two rounds of a game in which competition is suboptimal. The observed spontaneous behavior for most players was to compete. Then participants were explicitly reminded that the competing strategy may not be optimal. This minor intervention boosted cooperation, implying that competition does not result from lack of trust or willingness to cooperate but instead from the inability to inhibit the competition bias. This activity was performed in a controlled laboratory setting and also as a crowd experiment. Understanding the psychological underpinnings of these behaviors may help us improve cooperation and thus may have vast practical consequences to our society.Fil: Niella, Tamara. Universidad Torcuato di Tella; ArgentinaFil: Stier, Nicolas. Universidad Torcuato di Tella; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sigman, Mariano. Universidad Torcuato di Tella; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Experimental approaches to the difference in the Casimir force through the varying optical properties of boundary surface
We propose two novel experiments on the measurement of the Casimir force
acting between a gold coated sphere and semiconductor plates with markedly
different charge carrier densities. In the first of these experiments a
patterned Si plate is used which consists of two sections of different dopant
densities and oscillates in the horizontal direction below a sphere. The
measurement scheme in this experiment is differential, i.e., allows the direct
high-precision measurement of the difference of the Casimir forces between the
sphere and sections of the patterned plate or the difference of the equivalent
pressures between Au and patterned parallel plates with static and dynamic
techniques, respectively. The second experiment proposes to measure the Casimir
force between the same sphere and a VO film which undergoes the
insulator-metal phase transition with the increase of temperature. We report
the present status of the interferometer based variable temperature apparatus
developed to perform both experiments and present the first results on the
calibration and sensitivity. The magnitudes of the Casimir forces and pressures
in the experimental configurations are calculated using different theoretical
approaches to the description of optical and conductivity properties of
semiconductors at low frequencies proposed in the literature. It is shown that
the suggested experiments will aid in the resolution of theoretical problems
arising in the application of the Lifshitz theory at nonzero temperature to
real materials. They will also open new opportunities in nanotechnology.Comment: 23 pages of the text, 2 tables, and captions of 12 figures (to appear
in Phys. Rev. A
Religious pro-sociality? Experimental evidence from a sample of 766 Spaniards
This study explores the relationship between several personal religion-related variables and social behaviour, using three paradigmatic economic games: the dictator (DG), ultimatum (UG), and trust (TG) games. A large carefully designed sample of the urban adult population in Granada (Spain) is employed (N = 766). From participants' decisions in these games we obtain measures of altruism, bargaining behaviour and sense of fairness/equality, trust, and positive reciprocity. Three dimensions of religiosity are examined: (i) religious denomination; (ii) intensity of religiosity, measured by active participation at church services; and (iii) conversion out into a different denomination than the one raised in. The major results are: (i) individuals with “no religion” made decisions closer to rational selfish behaviour in the DG and the UG compared to those who affiliate with a “standard” religious denomination; (ii) among Catholics, intensity of religiosity is the key variable that affects social behaviour insofar as religiously-active individuals are generally more pro-social than non-active ones; and (iii) the religion raised in seems to have no effect on pro-sociality, beyond the effect of the current measures of religiosity. Importantly, behaviour in the TG is not predicted by any of the religion-related variables we analyse. While the results partially support the notion of religious pro-sociality, on the other hand, they also highlight the importance of closely examining the multidimensional nature of both religiosity and pro-social behaviour
Tumor Growth Enhances Cross-Presentation Leading to Limited T Cell Activation without Tolerance
Using a tumor model of spontaneously arising insulinomas expressing a defined tumor-associated antigen, we investigated whether tumor growth promotes cross-presentation and tolerance of tumor-specific T cells. We found that an advanced tumor burden enhanced cross-presentation of tumor-associated antigens to high avidity tumor-specific T cells, inducing T cell proliferation and limited effector function in vivo. However, contrary to other models, tumor-specific T cells were not tolerized despite a high tumor burden. In fact, in tumor-bearing mice, persistence and responsiveness of adoptively transferred tumor-specific T cells were enhanced. Accordingly, a potent T cell–mediated antitumor response could be elicited by intravenous administration of tumor-derived peptide and agonistic anti-CD40 antibody or viral immunization and reimmunization. Thus, in this model, tumor growth promotes activation of high avidity tumor-specific T cells instead of tolerance. Therefore, the host remains responsive to T cell immunotherapy
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