An analytic approximation to the Diffusion Coefficient for the periodic Lorentz Gas

An approximate stochastic model for the topological dynamics of the periodic triangular Lorentz gas is constructed. The model, together with an extremum principle, is used to find a closed form approximation to the diffusion coefficient as a function of the lattice spacing. This approximation is superior to the popular Machta and Zwanzig result and agrees well with a range of numerical estimates.Comment: 13 pages, 4 figure

Building a Sustainable Business in China's Small and Medium-sized Enterprises (SMEs)

Given the SMEs a heterogeneous group in the Chinese society due to their inherent characteristics, this paper takes a preliminary step to look into the complicated and dynamic environment for engaging China's SMEs in corporate sustainability. It aims to provide insight into how China's SMEs perceive and practice sustainability, and to explore key drivers and barriers behind their environmental and social engagement. Findings reveal an apparent contradiction in the current status of China's SMEs towards sustainability: a high level of concern vs. a low level of engagement. The most important motivator appears to be improving corporate image, followed by governmental legislation. While barriers hindering SMEs' sustainable engagement vary, predominant problems involve a lack of awareness and perception, insufficient financial resources and insufficient or ill-suited external support. Accordingly, the paper highlights three areas for China's SMEs' further improvements: education, communication and cooperation

Air Pollution Damage to Crop Yield and Quality in Developing Countries ¿ the Case for Secondary Air Pollution Standards in China.

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Diesel exhaust rapidly degrades floral odours used by honeybees

Honeybees utilise floral odours when foraging for flowers; we investigated whether diesel exhaust pollution could interrupt these floral odour stimuli. A synthetic blend of eight floral chemicals, identified from oilseed rape, was exposed to diesel exhaust pollution. Within one minute of exposure the abundances of four of the chemicals were significantly lowered, with two components rendered undetectable. Honeybees were trained to recognise the full synthetic odour mix; altering the blend, by removing the two chemicals rendered undetectable, significantly reduced the ability of the trained honeybees to recognize the altered odour. Furthermore, we found that at environmentally relevant levels the mono-nitrogen oxide (NOx) fraction of the exhaust gases was a key facilitator of this odour degradation. Such changes in recognition may impact upon a honeybee's foraging efficiency and therefore the pollination services that they provid