Mathematical and experimental investigation of water migration in plant xylem

Plant can take water from soil up to several metres high. However, the mechanism of how water rises against gravity is still controversially discussed despite a few mechanisms have been proposed. Also, there still lacks of a critical transportation model because of the diversity and complex xylem structure of plants. This paper mainly focuses on the water transport process within xylem and a mathematical model is presented. With a simplified micro channel from xylem structure and the calculation using the model of water migration in xylem, this paper identified the relationship between various forces and water migration velocity. The velocity of water migration within the plant stem is considered as detail as possible using all major forces involved, and a full mathematical model is proposed to calculate and predict the velocity of water migration in plants. Using details of a specific plant, the velocity of water migration in the plant can be calculated, and then compared to the experimental result from Magnetic Resonance Imaging (MRI). The two results match perfectly to each other, indicating the accuracy of the mathematical model, thus the mathematical model should have brighter future in further applications

The rank reversal problem in multi-criteria decision making : a literature review

Despite the importance of multicriteria decision-making (MCDM) techniques for constructing effective decision models, there are many criticisms due to the occurrence of a problem called rank reversal. Nevertheless, there is a lack of a systematic literature review on this important subject which involves different methods. This study reviews the pertinent literature on rank reversal, based on 130 related articles published from 1980 to 2015 in international journals, which were gathered and analyzed according to the following perspectives: multicriteria technique, year and journal in which the papers were published, co-authorship network, rank reversal types, and research goal. Thus our survey provides recommendations for future research, besides useful information and knowledge regarding rank reversal in the MCDM field

A model describing photosynthesis in terms of gas diffusion and enzyme kinetics

A model predicting net photosynthesis of individual plant leaves for a variety of environmental conditions has been developed. It is based on an electrical analogue describing gas diffusion from the free atmosphere to the sites of CO 2 fixation and a Michaelis-Menten equation describing CO 2 fixation. The model is presented in two versions, a simplified form without respiration and a more complex form including respiration. Both versions include terms for light and temperature dependence of CO 2 fixation and light control of stomatal resistance. The second version also includes terms for temperature, light, and oxygen dependence of respiration and O 2 dependence of CO 2 fixation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47495/1/425_2004_Article_BF00387066.pd

A simulation of the finish-line system of a major running race

The finish-line system of a major road race is investigated by means of a simulation model. In an attempt to help race management identify conditions that may lead to congestion of runners at this point. Based on the results of the model, race management was presented with a simple tool which could be used in situ to analyse a given situation, identify if congestion was likely to occur, and then consider corrective action

Nuclear spring? : new research shows that the Australian public may accept nuclear energy if it will help tackle climate change

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Nuclear power in australia : a comparative analysis of public opinion regarding climate change and the fukushima disaster

A nation-wide survey was conducted in 2010 to investigate the Australian public's attitudes to nuclear power in relation to climate change and in comparison to other energy alternatives. The survey showed a majority of respondents (42%) willing to accept nuclear power if it would help tackle climate change. Following the disaster at the Fukushima Daiichi Nuclear Power Complex in Japan, an event triggered by the 11 March 2011 Tohoku earthquake and tsunami, it was expected that support for nuclear power in Australia would change. In light of this, a follow-up survey was conducted in 2012. Indeed, the post-Fukushima results show a majority of respondents (40%) were not willing to accept nuclear power as an option to help tackle climate change, despite the fact that most Australians still believed nuclear power to offer a cleaner, more efficient option than coal, which currently dominates the domestic production of energy. Expanding the use of renewable energy sources (71%) remains the most popular option, followed by energy-efficient technologies (58%) and behavioural change (54%). Opposition to nuclear power will continue to be an obstacle against its future development even when posed as a viable solution to climate change.10 page(s