Effects of Bitumen Modification on Pavement Performance Subjected to High Vehicular Speed and Extreme Temperature Conditions: A Review

Bitumen is used worldwide in the construction of flexible pavements and because of its wide applicability its performance is needed to be improved in all regards like, Chemical, and thermal stability, fatigue life, moisture susceptibility, mechanical strength, temperature susceptibility, rutting resistance, ageing resistance, tensile strength, viscosity, stiffness etc. In this connection, researchers have used various modifiers to improve the pavement performance. The present paper provides a brief review of different modifiers in road making industry. Some popular polymer modifiers like low density polythene, high density polythene, polypropylene, ethyl vinyl acetate, styrene butadiene styrene and industrial waste are reviewed in terms of their role in bitumen modification. It also discusses enhancement in properties of bitumen after modification in order to improve properties of pavement. Through the reviewed literature, it is found that the addition of the polymers to bitumen tends to enhance fatigue and cracking resistance mainly. The future development and recommendation in modifiers for bitumen modification are also suggested in the end.

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Efficient p-n junction-based thermoelectric generator that can operate at extreme temperature conditions

Journal of Physics D Applied Physics ◽

10.1088/1361-6463/aa9b6a ◽

2017 ◽

Vol 51 (1) ◽

pp. 014005 ◽

Cited By ~ 8

Author(s):

Ruben Chavez ◽

Sebastian Angst ◽

Joseph Hall ◽

Franziska Maculewicz ◽

Julia Stoetzel ◽

...

Keyword(s):

Thermoelectric Generator ◽

Extreme Temperature ◽

Temperature Conditions

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Evaluating Growth and Photosynthesis of Kimchi Cabbage According to Extreme Weather Conditions

Agronomy ◽

10.3390/agronomy10121846 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1846

Author(s):

Seung Hwan Wi ◽

Hee Ju Lee ◽

Sewoong An ◽

Sung Kyeom Kim

Keyword(s):

Net Photosynthetic Rate ◽

Air Temperature ◽

Photosynthetic Rate ◽

Extreme Temperature ◽

Extreme Weather ◽

High Temperature Treatment ◽

Growth Stages ◽

Temperature Conditions ◽

Extreme High Temperature ◽

Gas Exchange System

The aim of this study was to develop and validate growth and photosynthetic models of Kimchi cabbages under extreme temperature conditions at different growth stages. Kimchi cabbage plants were subjected to low and high air temperatures 7–10 days after transplanting (DAT) and 40–43 DAT using extreme weather simulators. Except during these periods, the air temperature, relative humidity, solar radiation, and precipitation were set according to previous meteorological data. The experiments were performed over two years: in the first year, data were used to develop the models; the second-year experimental data were used for validation. The growth parameters and relative growth rate of Kimchi cabbage decreased due to low and high air temperature treatments. Photosynthetic CO2 response curves, which were measured using a portable gas exchange system, were used to calculate three biochemical parameters from measured data: photochemical efficiency, carboxylation conductance, and dark respiration. These parameters were used to develop the photosynthetic models (modified Thornley’s models) representing predictions of net photosynthetic rate by CO2 concentration and growth stage. The simulated photosynthetic rate with extreme high temperature treatment (35/31 °C) was 19.7 μmol m−2 s−1 which was evaluated approximately 3% deduction compared with control. Results of this study indicate that the growth and photosynthetic models developed here could be applied to evaluate retarded growth and net photosynthetic rate under extreme temperature conditions.

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