Percolation on hyperbolic lattices

The percolation transitions on hyperbolic lattices are investigated numerically using finite-size scaling methods. The existence of two distinct percolation thresholds is verified. At the lower threshold, an unbounded cluster appears and reaches from the middle to the boundary. This transition is of the same type and has the same finite-size scaling properties as the corresponding transition for the Cayley tree. At the upper threshold, on the other hand, a single unbounded cluster forms which overwhelms all the others and occupies a finite fraction of the volume as well as of the boundary connections. The finite-size scaling properties for this upper threshold are different from those of the Cayley tree and two of the critical exponents are obtained. The results suggest that the percolation transition for the hyperbolic lattices forms a universality class of its own.Comment: 17 pages, 18 figures, to appear in Phys. Rev.

Anomalous response in the vicinity of spontaneous symmetry breaking

We propose a mechanism to induce negative AC permittivity in the vicinity of a ferroelectric phase transition involved with spontaneous symmetry breaking. This mechanism makes use of responses at low frequency, yielding a high gain and a large phase delay, when the system jumps over the free-energy barrier with the aid of external fields. We illustrate the mechanism by analytically studying spin models with the Glauber-typed dynamics under periodic perturbations. Then, we show that the scenario is supported by numerical simulations of mean-field as well as two-dimensional spin systems.Comment: 6 pages, 5 figure

Re-exploration of subjective well-being determinants: Full-model approach with extended cross-contextual analysis

Despite the numerous studies on the determinants of subjective wellbeing (SWB), there are still under-researched areas as follows: a full-model approach allowing un-confounded and robust estimations, extension of cross-contextual approaches, and an account of recent changes in Hofstede value dimensions. The present study aims to overcome those limitations with analyses of 59 countries from 1981 to 2013, rendering the following main findings. Individual education’s effect was methodologically affected by the reference category level of dummy variables. I found weak influence of GPRGE (governance, political rights, and gender equality) and individualism, which were associable with the ambivalent nature of intellectual autonomy. Regarding cross-contextual effects, I found that people from underdeveloped societies keep more to current pleasure, and that demand for welfare is higher in affluent and individualistic societies. A culture of uncertainty avoidance reduced the effect of national employment, because of its demotivating aspects in the workplace. Overall, variables related with hedonism, social relation, and wealth showed coherently strong effects, but social progress factors had weak relevance.Keywords: life satisfaction, happiness, robust effects, cross-contextual approach, Hofstede value dimensions, social qualit

End-of-Life Management of Crystalline Silicon Photovoltaic Module

PV manufacturing has been growing over the past 10 years and further annual growth of 15% is expected until 2020. A study on positioning a grand plan for solar power shows how vast PV arrays and other renewable energies can provide significant amount of electricity and total energy needs by 2050. Various new PV technologies have been introduced in the market and existing technologies have undergone further development. How all these developments will affect the fate of the end-of-life PV modules is uncertain. In addition, the market price of some rare earth materials utilized in the manufacturing of the various PV technologies has exponentially increased in the past five years. Therefore, it is necessary to set a proactive strategic recycling plan for the treatment of the disposed PV wastes

Residual discrete symmetry of the five-state clock model

It is well-known that the $q$-state clock model can exhibit a Kosterlitz-Thouless (KT) transition if $q$ is equal to or greater than a certain threshold, which has been believed to be five. However, recent numerical studies indicate that helicity modulus does not vanish in the high-temperature phase of the five-state clock model as predicted by the KT scenario. By performing Monte Carlo calculations under the fluctuating twist boundary condition, we show that it is because the five-state clock model does not have the fully continuous U(1) symmetry even in the high-temperature phase while the six-state clock model does. We suggest that the upper transition of the five-state clock model is actually a weaker cousin of the KT transition so that it is $q \ge 6$ that exhibits the genuine KT behavior.Comment: 13 pages, 17 figure