Velocity Distribution and Cumulants in the Unsteady Uniform Longitudinal Flow of a Granular Gas

The uniform longitudinal flow is characterized by a linear longitudinal velocity field $u_x(x,t)=a(t)x$, where $a(t)={a_0}/({1+a_0t})$ is the strain rate, a uniform density $n(t)\propto a(t)$, and a uniform granular temperature $T(t)$. Direct simulation Monte Carlo solutions of the Boltzmann equation for inelastic hard spheres are presented for three (one positive and two negative) representative values of the initial strain rate $a_0$. Starting from different initial conditions, the temporal evolution of the reduced strain rate $a^*\propto a_0/\sqrt{T}$, the non-Newtonian viscosity, the second and third velocity cumulants, and three independent marginal distribution functions has been recorded. Elimination of time in favor of the reduced strain rate $a^*$ shows that, after a few collisions per particle, different initial states are attracted to common "hydrodynamic" curves. Strong deviations from Maxwellian properties are observed from the analysis of the cumulants and the marginal distributions.Comment: 8 pages; 4 figures; contributed paper at the 28th International Symposium on Rarefied Gas Dynamics (Zaragoza, Spain, July 9-13, 2012

A non-welfarist solution for two-person bargaining situations.

In this paper we present a non-welfarist solution which is applicable to a broad spectrum of twoagent bargaining problems, such as exchange economies, location problems and division problems. In contrast to welfarist bargaining solutions, it depends only on the agents' preferences. not on their specific utility representation, and takes explicitly into account the underlying space of alternatives. We offer a simple sequential move mechanism, without chance moves, that implements our solution in subgame perfect equilibrium. Moreover, an axiomatic characterization of the solution is provided. It is shown that the solution coincides with the Kalai-Rosenthal bargaining solution after choosing a suitable utility representation of the preferences. When applied to exchange economies with equal initial endowments for both agents, the solution generates envy-free, Pare to efficient egalitarian equivalent allocations.Bargaining; Nash program; Welfarism; Non-welfarism; Exchange economies; Location problems; Implementation;

On the emergence of large and complex memory effects in nonequilibrium fluids

Control of cooling and heating processes is essential in many industrial and biological processes. In fact, the time evolution of an observable quantity may differ according to the previous history of the system. For example, a system that is being subject to cooling and then, at a given time $t_{w}$ for which the instantaneous temperature is $T(t_w)=T_{\mathrm{st}}$, is suddenly put in contact with a temperature source at $T_{\mathrm{st}}$ may continue cooling down temporarily or, on the contrary, undergo a temperature rebound. According to current knowledge, there can be only one "spurious" and small peak/low. However, our results prove that, under certain conditions, more than one extremum may appear. Specifically, we have observed regions with two extrema and a critical point with three extrema. We have also detected cases where extraordinarily large extrema are observed, as large as the order of magnitude of the stationary value of the variable of interest. We show this by studying the thermal evolution of a low density set of macroscopic particles that do not preserve kinetic energy upon collision, i.e., a granular gas. We describe the mechanism that signals in this system the emergence of these complex and large memory effects, and explain why similar observations can be expected in a variety of systems.Comment: 15 pages, 5 figure

The age-metallicity relationship in the Fornax spheroidal dwarf galaxy

We produce a comprehensive field star age-metallicity relationship (AMR) from the earliest epoch until ~ 1 Gyr ago for three fields in the Fornax dSph galaxy by using VI photometric data obtained with FORS1 at the VLT. We find that the innermost one does not contains dominant very old stars (age > 12 Gyr), whereas the relatively outer field does not account for representative star field populations younger than ~ 3 Gyr. When focusing on the most prominent stellar populations, we find that the derived AMRs are engraved by the evidence of a outside-in star formation process. The studied fields show bimodal metallicity distributions peaked at [Fe/H] = (-0.95 +- 0.15) dex and (-1.15 or -1.25 +- 0.05) dex, respectively, but only during the first half of the entire galaxy lifetime. Furthermore, the more metal-rich population appears to be more numerous in the outer fields, while in the innermost Fornax field the contribution of both metallicity populations seems to be similar. We also find that the metallicity spread ~ 6 Gyr ago is remarkable large, while the intrinsic metallicity dispersion at ~ 1-2 Gyr results smaller than that for the relatively older generations of stars. We interpret these outcomes as a result of a possible merger of two galaxies that would have triggered a star formation bursting process that peaked between ~ 6 and 9 Gyr ago, depending on the position of the field in the galaxy.Comment: 7 pages, 5 figures, MNRAS, in pres

Influence of age of child on differences in marital satisfaction of males and females in East Asian countries

Using individual-level data for China, Korea, and Japan for 2006, this research examines how the age of children influences marital satisfaction for males and females in East Asian countries. Our results show that the marital satisfaction of males is barely affected by a child of the relationship, whereas the marital satisfaction of females with a young child is lower than that of females who do not have a child. This result holds for countries at different development stages. There is also a gender differential regarding the effect of young children on marital satisfaction. Furthermore, the more developed the country, the greater this difference becomes.Marital satisfaction, child, East Asian countries, ordered probit.

Determinants of Suicides in Denmark: Evidence from Time Series Data

This research examines empirically the determinants of suicides in Denmark over the period 1970-2006. To our knowledge, there exist no previous study that estimates a dynamic econometric model of suicides on the basis of time series data and cointegration framework at disaggregate level. Our results indicate that suicide is associated with a range of socio-economic factors but the strength of the association can differ by gender. In particular, we find that a rise in real per capita income and fertility rate decreases suicides for males and females. Divorce is positively associated with suicides and this effect seems to be stronger for men. A fall in unemployment rates seems to lower significantly suicides in males and females. Policy implications of suicides are discussed with some appropriate recommendations.Suicide, Denmark, Time Series, Cointegration

Does corruption affect suicide? Empirical evidence from OECD countries

The question to what extent corruption influences suicide remains still unanswered. This paper examines the effect of corruption on suicide using a panel data approach for 24 OECD countries over the period 1995-1999. Our results indicate suicide rates are lower in countries with lower levels of corruption. We also find evidence that this effect is approximately three times larger for males than for females. It follows that corruption has a detrimental effect on societal well-being.Corruption, Panel data, Suicide, Well- Being, OECD

Does corruption affect suicide? Empirical evidence from OECD countries

Panel data regressions for 24 OECD countries showed that the less corrupt a society is, the lower the total suicide rate. This effect was approximately three times larger for males than for females. It follows that corruption has a detrimental effect on social well-being.Corruption, Panel data, Suicide, OECD

Trust and Fertility: Evidence from OECD countries

Using panel data for 24 (OECD) countries during the period 1980–2004 this study examines how social trust affects fertility. The major finding through the random effects approach is that the social trust increases the fertility rate. A 1% rise in the trust rate leads to an increase in fertility by 0.01 points. The results presented here suggest that in developed countries, trust underlies the desirable circumstances for child rearing.Trust, fertility, OECD, inequality, female labor participation.

Influence of age of child on differences in marital satisfaction of males and females in East Asian countries

Using individual-level data from China, Korea, and Japan for 2006, this research examines how the age of children of the relationship influences marital satisfaction for males and females in East Asian countries. Our results show that the marital satisfaction of males is barely affected by a child of the relationship, whereas the marital satisfaction of females with a young child is lower than that of females who do not have a child. This result holds for countries of different development stages. There is also a gender differential regarding the effect of young children on marital satisfaction. Furthermore, the more developed the country, the greater this difference becomes.Marital satisfaction, child, East Asian countries, probit