Experimental Research on Physical Parameters Inside Hardy-Plant Leaves
Xin Xuan,
Fan Jingwen,
Li Qingling
Issue:
Volume 2, Issue 3, September 2016
Pages:
13-20
Received:
22 June 2016
Accepted:
9 November 2016
Published:
10 December 2016
Abstract: With the development of bio-heat transfer technology, the research into the thermal effect mechanism of hardy plants, as well as the heat exchange between the plant and the surroundings has become another emerging issue in the field of heat transfer. Specific heat capacity and thermal conductivity are two important physical parameters during the study of material thermal properties, which play important roles in the analysis of mechanism of heat and mass transfer within plants. In this paper, the leaves of Camellia, Tarajo holly and Jasper were selected as the research object and the specific heat capacity of their detached leaves were measured by DSC, the thermal conductivity of leaf tissue was measured based on thermal probe method of hotline source instantaneous model. Conclusions are as follows: the specific heat and thermal conductivity of hardy plant leaves surged within a narrow temperature range around 0°C and peaked at 0°C, but the peak value of different plants was quite different. Each physical parameter values measured from experiments were within the permissible range, it was also verified that the experimental equipment and methods used before were reasonable and operational.
Abstract: With the development of bio-heat transfer technology, the research into the thermal effect mechanism of hardy plants, as well as the heat exchange between the plant and the surroundings has become another emerging issue in the field of heat transfer. Specific heat capacity and thermal conductivity are two important physical parameters during the st...
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Review on Impact of Climate Change on Weed and Their Management
Issue:
Volume 2, Issue 3, September 2016
Pages:
21-27
Received:
18 May 2016
Accepted:
22 July 2016
Published:
21 December 2016
Abstract: The global climate is changing; along with measuring temperature and CO2 level changes that are considered major drivers of climate change, there is also increasing attention being given to its impact on agricultural production systems (including weeds). Climate conditions exert a significant influence on the spread, population dynamics, life cycle duration, infestation pressure and the overall occurrence of the majority of agricultural pests. Weeds are among the agricultural pest that can be influenced by climate change. It is expected that climate change will bring about a shift in the floral composition of several ecosystems at higher latitudes and altitudes, as changes in temperature and humidity will be reflected on flowering, fruiting and seed dormancy. Changes in atmospheric CO2 levels, rainfall, temperature and other growing conditions will affect weed species ‘distribution and their competitiveness within a weed population and within crop. Any factor which increases environmental stress on crops may make them more vulnerable to attack by insects and plant pathogens and less competitive with weeds. Many of these weeds reproduce by vegetative means and recent evidence indicates that as a group, these weeds may show a strong response to recent increases in atmospheric CO2. Changing and increment of temperature is one main characteristics of climate change which may affect existing plants (weeds shift) and allow some other plants (weeds) to replace native and will be expand in to new areas which is not existed before. Even under drought condition some weeds produce allele-chemical that made weeds to thrive well and compete with crop. An increase in root: stem, with increases in the growth of roots or rhizomes, particularly of perennial weeds, may make it harder to control some weeds that regrow from root fragments left after mechanical tillage. The direct impacts of climate change will be either on the biology of the biological control agent and/or on the ability of the host plant to resist, tolerate or compensate for the presence of the herbivore or plant pathogen. Increased temperature would be expected to increase the rate of life cycles of both the biological control agents and the weeds. Increased water stress will affect the host plant’s development, and through this, the development of biological control agents, so they might be less effective in drier situations.
Abstract: The global climate is changing; along with measuring temperature and CO2 level changes that are considered major drivers of climate change, there is also increasing attention being given to its impact on agricultural production systems (including weeds). Climate conditions exert a significant influence on the spread, population dynamics, life cycle...
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