Supramolecular complexes of La@C82 with unsaturated thiacrown ethers

The paramagnetic La@C82-A(C2v) with unsaturated thiacrown ethers forms 1 : 1 host-guest complexes of [La@C82-A(C2v)]-[D]+ in solution as a result of electron transfer.     

Existence of an infinite particle limit of stochastic ranking process

We study a stochastic particle system which models the time evolution of the ranking of books by online bookstores (e.g., Amazon.co.jp). In this system, particles are lined in a queue. Each particle jumps at random jump times to the top of the queue, and otherwise stays in the queue, being pushed toward the tail every time another particle jumps to the top. In an infinite particle limit, the random motion of each particle between its jumps converges to a deterministic trajectory. (This trajectory is actually observed in the ranking data on web sites.) We prove that the (random) empirical distribution of this particle system converges to a deterministic space–time-dependent distribution. A core of the proof is the law of large numbers for dependent random variables.     

A Simple and Practical Method for Fluence Determination in Bench-Scale UV-LED Setups

In UV disinfection of water, the fluence of UV required to inactivate a target microorganism is determined based on the procedures developed for conventional mercury-based UV lamps with collimation. In this regard, a simple and practical method with a mathematical model and radiometry is proposed for determining the fluence rate with UV light-emitting diodes (UV-LEDs). This method was applied to a bench-scale UV-LED setup and validated by comparing the calculations with the measurements using either a spectroradiometer or a chemical actinometer. The results showed high accordance with spectroradiometer outputs with a linear regression equation y = 0.997x (x: model calculation, y: spectroradiometer output, r² = 0.999, P < 0.001 for n = 20) in an experiment varying the distance between the measurement points and the UV-LEDs. Meanwhile, the proposed method and chemical actinometry exhibited 98% concordance. Furthermore, this method was applied to determine the fluence-response profiles of Pseudomonas aeruginosa, and the results demonstrated that the proposed method was appropriate at two different distances between the UV-LEDs and the solutions. To conclude, the proposed method can determine the fluence in a UV-LED bench-scale setup in a simple and practical way, which would potentially promote the research and development of water treatment using UV-LEDs.