Indenture as a Self-Enforced Contract Device: An Experimental Test

We experimentally test the efficacy of indenture as a self-enforced contract device. In an indenture game, the principal signals the intention of payment-on-delivery, by tearing a banknote and giving the agent half of it as "prepayment"; the agent receives the completing half after delivering the service. By forward induction, cooperation is incentive-compatibly self-enforcing. The indenture performs very well, inducing a significantly higher level of cooperation than that in a three-stage centipede game, which we use to benchmark the natural rate of cooperation. The difference between cooperation rates in both games increases over time.Cooperation, experiment, contracts, indenture, reciprocity

Disgust as embodied moral judgment.

How, and for whom, does disgust influence moral judgment? In four experiments participants made moral judgments while experiencing extraneous feelings of disgust. Disgust was induced in Experiment 1 by exposure to a bad smell, in Experiment 2 by working in a disgusting room, in Experiment 3 by recalling a physically disgusting experience, and in Experiment 4 through a video induction. In each case, the results showed that disgust can increase the severity of moral judgments relative to controls. Experiment 4 found that disgust had a different effect on moral judgment than did sadness. In addition, Experiments 2-4 showed that the role of disgust in severity of moral judgments depends on participants' sensitivity to their own bodily sensations. Taken together, these data indicate the importance-and specificity-of gut feelings in moral judgments

The Economics of Solidarity: A Conceptual Framework

For many people "solidarity" has become a meaningless word used in slogans - too often used without leading to any economic consequences. We show in this paper conditions under which solidarity can be a powerful instrument. In a solidary action, an individual in a group contributes to a series of actions that aims for a reallocation of scarce resources. The willingness to contribute is mainly influenced by the efficiency of the objective of the solidary action, and is enhanced by feelings of mutual exchange (solidarity) within a group. --solidarity,altruism,dynamic,mutual

Understanding the magnetic resonance spectrum of nitrogen vacancy centers in an ensemble of randomly-oriented nanodiamonds

Nanodiamonds containing nitrogen vacancy (NV-) centers show promise for a number of emerging applications including targeted in vivo imaging and generating nuclear spin hyperpolarization for enhanced NMR spectroscopy and imaging. Here, we develop a detailed understanding of the magnetic resonance behavior of NV- centers in an ensemble of nanodiamonds with random crystal orientations. Two-dimensional optically detected magnetic resonance spectroscopy reveals the distribution of energy levels, spin populations, and transition probabilities that give rise to a complex spectrum. We identify overtone transitions that are inherently insensitive to crystal orientation and give well-defined transition frequencies that access the entire nanodiamond ensemble. These transitions may be harnessed for high-resolution imaging and generation of nuclear spin hyperpolarization. The data are well described by numerical simulations from the zero- to high-field regimes, including the intermediate regime of maximum complexity. We evaluate the prospects of nanodiamond ensembles specifically for nuclear hyperpolarization and show that frequency-swept dynamic nuclear polarization may transfer a large amount of the NV- center's hyperpolarization to nuclear spins by sweeping over a small region of its spectrum.Comment: 6 pages, 5 figure

Prediction of Random Incidence Transmission Loss based on Normal Incidence Four-Microphone Measurements

The use of the four-microphone standing wave tube to assess the acoustical properties of sound absorbing materials is becoming increasingly popular. The objective of the present work was to demonstrate that it is possible, under certain conditions, to predict the random incidence transmission loss of sound absorbing materials based on normal incidence measurements in a four-microphone standing wave tube. If a porous material may be modeled as being isotropic and either perfectly rigid or limp, it may be characterized as an effective fluid in terms of its complex density and wave number. The latter quantities may then be used in conjunction with plane wave theories to predict random incidence properties. That procedure is demonstrated here by using two different porous media. Good agreement was found between the estimated and directly measured random incidence transmission losses. The accuracy of the procedure may however, be limited at both low and high frequencies. At low frequencies, the estimated material properties may be affected by the constraint of the sample around its edge. At high frequencies, higher order mode propagation within the sample may affect the results owing to the typically subsonic wave speeds in porous media

Rheology of Ring Polymer Melts: From Linear Contaminants to Ring/Linear Blends

Ring polymers remain a major challenge to our current understanding of polymer dynamics. Experimental results are difficult to interpret because of the uncertainty in the purity and dispersity of the sample. Using both equilibrium and non-equilibrium molecular dynamics simulations we have systematically investigated the structure, dynamics and rheology of perfectly controlled ring/linear polymer blends with chains of such length and flexibility that the number of entanglements is up to about 14 per chain, which is comparable to experimental systems examined in the literature. The smallest concentration at which linear contaminants increase the zero-shear viscosity of a ring polymer melt of these chain lengths by 10% is approximately one-fifth of their overlap concentration. When the two architectures are present in equal amounts the viscosity of the blend is approximately twice as large as that of the pure linear melt. At this concentration the diffusion coefficient of the rings is found to decrease dramatically, while the static and dynamic properties of the linear polymers are mostly unaffected. Our results are supported by a primitive path analysis.Comment: 5 pages, 4 figures, accepted by PR

Analisa Kelayakan Investasi Asphalt Mixing Plant

Proyek konstruksi merupakan proses dimana rencana/desain dan spesifikasi paraperencana dikonversikan menjadi struktur dan fasilitas fisik. Dalam setiap proyek yang dikerjakan, pasti dibutuhkan suatu alat. Beberapa Perusahaan kontraktor memilih untuk membeli alat sebagai pilihan untuk berinvestasi. Dalam penelitian ini, akan dibahas mengenai kelayakan investasi peralatan yang berkaitan dengan pekerjaan pengaspalan jalan, yaitu Asphalt Mixing Plant. Metode analisa kelayakan yang akan digunakan adalah metode Net Present Value. Penelitian ini bertujuan untuk mengetahui kelayakan investasi dari Asphalt Mixing Plant

The representative deficit in different European Party Systems: an analysis of the elections to the European Parliament 2009-2014

This paper explores the extent to which different party systems in Europe effectively represent their citizens. We argue that many European countries suffer from a “representative deficit”, which occurs when a significant portion of citizens have to vote for a political party whose stated views are actually quite different from their own. We measure the extent of this deficit in different European countries using data from EU Profiler and euandi, two Voting Advice Applications which served millions of users during the EP elections in 2009 and 2014 respectively. We find wide variation in the extent to which political parties are accurately tuned in to the preferences of their voters, a variation which is not clearly linked to the number of political parties or the proportionality of the electoral system. We attempt to explain some of this variation, and explore the reasons why some party systems offer better representation than others

Measurement of Untruncated Nuclear Spin Interactions via Zero- to Ultra-Low-Field Nuclear Magnetic Resonance

Zero- to ultra-low-field nuclear magnetic resonance (ZULF NMR) provides a new regime for the measurement of nuclear spin-spin interactions free from effects of large magnetic fields, such as truncation of terms that do not commute with the Zeeman Hamiltonian. One such interaction, the magnetic dipole-dipole coupling, is a valuable source of spatial information in NMR, though many terms are unobservable in high-field NMR, and the coupling averages to zero under isotropic molecular tumbling. Under partial alignment, this information is retained in the form of so-called residual dipolar couplings. We report zero- to ultra-low-field NMR measurements of residual dipolar couplings in acetonitrile-2-$^{13}$C aligned in stretched polyvinyl acetate gels. This represents the first investigation of dipolar couplings as a perturbation on the indirect spin-spin $J$-coupling in the absence of an applied magnetic field. As a consequence of working at zero magnetic field, we observe terms of the dipole-dipole coupling Hamiltonian that are invisible in conventional high-field NMR. This technique expands the capabilities of zero- to ultra-low-field NMR and has potential applications in precision measurement of subtle physical interactions, chemical analysis, and characterization of local mesoscale structure in materials.Comment: 6 pages, 3 figure