A study of dynamic finite size scaling behavior of the scaling functions—calculation of dynamic critical index of Wolff algorithm

In this work we have studied the dynamic scaling behavior of two scaling functions and we have shown that scaling functions obey the dynamic finite size scaling rules. Dynamic finite size scaling of scaling functions opens possibilities for a wide range of applications. As an application we have calculated the dynamic critical exponent (z) of Wolff's cluster algorithm for 2-, 3- and 4-dimensional Ising models. Configurations with vanishing initial magnetization are chosen in order to avoid complications due to initial magnetization. The observed dynamic finite size scaling behavior during early stages of the Monte Carlo simulation yields z for Wolff's cluster algorithm for 2-, 3- and 4-dimensional Ising models with vanishing values which are consistent with the values obtained from the autocorrelations. Especially, the vanishing dynamic critical exponent we obtained for d=3 implies that the Wolff algorithm is more efficient in eliminating critical slowing down in Monte Carlo simulations than previously reported.     

Automatic realignment with electronic steering of free-space-optical transceivers in MANETs: A proof-of-concept prototype

Free-Space-Optical (FSO) communication has the potential to achieve very high wireless communication rates at tens of GHz. Although it has the advantage of high-speed optical modulation, FSO communication is prone to mobility and it requires establishment and maintenance of line-of-sight (LOS) between FSO transceivers since FSO transceivers are highly directional. We consider FSO structures with multiple transceivers placed on a spherical shape with angular diversity and tackle the problem of automatically detecting and maintaining LOS alignment among neighbor multi-transceiver FSO structures. We present a prototype implementation of such multi-transceiver electronically-steered communication structures. Our prototype uses a simple LOS detection and establishment protocol and assigns logical data streams to appropriate physical links. We show that by using multiple directional transceivers and an auto-alignment mechanism, it is possible to maintain optical wireless links in a mobile setting with minimal disruptions and overhead.     

Treatability of Organic Constituents in the Paşaköy Wastewater Treatment Plant Effluent by O3 and O3/H2O2

Effluent from the Pa?aköy Wastewater Treatment Plant was oxidized by using O₃ and O₃/H₂O₂. DOC, COD, UV₂₅₄, total coliform, dissolved ozone and some endocrine disrupting compounds were monitored during oxidation. Results showed that O₃ provided superior disinfection, however, lower reductions in DOC, COD and endocrine disrupting compounds were exhibited compared to O₃/H₂O_2. The highest removal efficiency of DOC, COD and endocrine disrupting compounds were achieved at 0.5 molar ratio of O₃/H₂O_2. The benefit of H₂O₂ addition for advanced oxidation reduced significantly when the mole ratio was increased to 2. Therefore, the mole ratio of H₂O₂ to O₃ is a critical parameter for the design of wastewater oxidation by O₃/H₂O₂.