The Fukushima nuclear accident in March 2011 has released a large amount of radioactive pollutants to the environment. Of the pollutants, iodine-129 is a long-lived radionuclide and will remain in the environment for millions of years. This work first report levels and inorganic speciation of (129)I in seawater depth profiles collected offshore Fukushima in June 2011. Significantly elevated (129)I concentrations in surface water were observed with the highest (129)I/(127)I atomic ratio of 2.2 × 10(-9) in the surface seawater 40 km offshore Fukushima. Iodide was found as the dominant species of (129)I, while stable (127)I was mainly in iodate form, reflecting the fact that the major source of (129)I is the direct liquid discharges from the Fukushima NPP. The amount of (129)I directly discharged from the Fukushima Dai-ichi nuclear power plant to the sea was estimated to be 2.35 GBq, and about 1.09 GBq of (129)I released to the atmosphere from the accident was deposited in the sea offshore Fukushima. A total release of 8.06 GBq (or 1.2 kg) of (129)I from the Fukushima accident was estimated. These Fukushima-derived (129)I data provide necessary information for the investigation of water circulation and geochemical cycle of iodine in the northwestern Pacific Ocean in the future.

Iodine-129, the long-lived radioisotope of iodine, occurs naturally, but anthropogenic generated 129 I has dominated the environment in the past 60 years. Due to active chemical and environmental properties of iodine and the enhanced analytical capacity for 129 I measurement, the application of 129

-Wireless multi-hop, mesh networks are being considered as a candidate to backhaul data traffic from access networks to the wired Internet. To enhance system performance, scheduling algorithms for wireless mesh networks are desirable to take advantage of multi-user diversity resulted from timevarying channel condition and space-varying path loss. Although many existing scheduling algorithms or medium access protocols have been adopted for the wireless mesh networks, they do not perform well, given that the algorithms are devised for wireless access. In this paper, we study the computational complexity in finding the optimal schedule for a mesh network with time-division-duplexing (TDD) operations. We propose a novel heuristic distributed scheduling framework for wireless mesh networks with open definitions of utility function. Performance analysis shows that our proposed framework is of polynomial-time complexity. Simulation results compare our framework with the tree-structural approach, and reveal that our proposed framework is highly capable of selecting and scheduling links with high utility in a fully distributed manner.

Cross-layer design for quality of service (QoS) in wireless mesh networks (WMNs) has attracted much research interest recently. Such networks are expected to support various types of applications with different and multiple QoS and grade-of-service (GoS) requirements. In order to achieve this, several key technologies spanning all layers, from physical up to network layer, have to be exploited and novel algorithms for harmonic and efficient layer interaction must be designed. Unfortunately most of the existing works on cross-layer design focus on the interaction of up to two layers while the GoS concept in WMNs has been overlooked. In this paper, we propose a unified framework that exploits the physical channel properties and multi-user diversity gain of WMNs and by performing intelligent route selection and connection admission control provides both QoS and GoS to a variety of underlying applications. Extensive simulation results show that our proposed framework can successfully satisfy multiple QoS requirements while it achieves higher network throughput and lower outage as compared to other scheduling, routing and admission control schemes.

Wireless multi-hop, mesh networks are being considered as a candidate to backhaul data traffic from access networks to the wired Internet. These mesh networks are referred to as wireless backhaul networks. Existing medium access control (MAC) protocols and scheduling algorithms are devised for wireless access. So although they have been adopted for the wireless backhaul networks, they do not yield good performance. In this paper, we propose a novel distributed scheduling algorithm, composed of a framework and a new utility function definition, for wireless backhaul networks. We show by analysis and simulation that in a long run the algorithm converges to the desired throughput allocation, which can be specified by the routing protocol in use to guarantee quality of service. Moreover, in terms of interference, we show that our framework maintains strong temporal correlation of interference, which is required to ensure proper channel predictions for scheduling gain and for distributed power control. Finally, simulation results reveal that the new algorithm takes advantage of the multi-user diversity in achieving high overall network throughput, when compared with the tree-structure algorithm.