The water absorption effect on the hardness of composites polyester

2016 ◽  
Author(s):  
A. A. Mohammed ◽  
T. T. Issa
2012 ◽  
Vol 41 ◽  
pp. 1667-1673 ◽  
Author(s):  
Z. Salleh ◽  
Y.M. Taib ◽  
Koay Mei Hyie ◽  
M. Mihat ◽  
M.N. Berhan ◽  
...  

2021 ◽  
Vol 9 ◽  
Author(s):  
Li Li ◽  
Jia-Hui Cao ◽  
Xin-Yue Bao

Regular pattern is a typical feature of vegetation distribution and thus it is important to study the law of vegetation evolution in the fields of desertification and environment conservation. The saturated water absorption effect between the soil water and vegetation plays an crucial role in the vegetation patterns in semi-arid regions, yet its influence on vegetation dynamics is largely ignored. In this paper, we pose a vegetation-water model with saturated water absorption effect of vegetation. Our results show that the parameter 1/P, which is conversion coefficient of water absorption, has a great impact on pattern formation of vegetation: with the increase of P, the density of vegetation decrease, and meanwhile it can induce the transition of different patterns structures. In addition, we find that the increase of appropriate precipitation can postpone the time on the phase transition of the vegetation pattern. The obtained results systematically reveal the effect of saturated water absorption on vegetation systems which well enrich the findings in vegetation dynamics and thus may provide some new insights for vegetation protection.


2019 ◽  
Vol 970 ◽  
pp. 202-209
Author(s):  
Olga V. Muravieva ◽  
Robert R. Khasanov ◽  
Viktor A. Strizhak ◽  
Sergey S. Mkrtchyan

The article proposes the use of the acoustic waveguide method with normal Pochhammer waves to estimate the water absorption of composite fiberglass rebars. The results of experimental studies on the water absorption and temperature influence on the propagation velocity of rod and torsional waves in composite rebars samples with different physical and mechanical characteristics are presented. The sensitivity of the wave velocity parameter to water absorption and temperature fluctuations is estimated. The proposed acoustic waveguide method is characterized by high accuracy, reliability and efficiency.


2003 ◽  
Vol 36 (26) ◽  
pp. 9840-9850 ◽  
Author(s):  
E. Laredo ◽  
M. Grimau ◽  
F. Sánchez ◽  
A. Bello

This paper deals with the effect of moisture absorption on single coconut sheath fiber and single glass fibre. Additionally, the moisture effect in fibre reinforced unsaturated polyester composites like coconut sheath (CS) and Glass mat (GM) composite. Initially, CS and GM fibre reinforced polyester composite were produced through hand layup followed by compression moulding method. CS/UPR and GM/UPR composites were made through water treatment by dipping those composites in ordinary water for various time intervals at room temperature to study the water absorption effect. At different time periods, the absorption of water showed gradual increment. The effect of water gain in percentage for CS and GM was observed. From this experiment, it is concluded that the effect of water gain in CS/UPR composite is higher than GM/UPR composite.


Author(s):  
Alain Chalumeau ◽  
Antoine Felix-Henry

Thermal insulation of a flexible pipe for deepwater applications is generally obtained by spiraling syntactic foam extruded tapes around the pipe core, in between two thermoplastic sheaths. As water tightness of the insulating annulus can frequently not be guaranteed, water absorption and the effect on thermal properties of insulating material have to be determined, so as to be taken into account for Overall Heat Transfer Coefficient calculation of the flexible pipe. It is required to demonstrate the overall suitability of a specific insulating material for a given application. The first part of this paper describes accelerated fresh water absorption tests and subsequent thermal conductivity measurements, conducted on polypropylene syntactic foam filled with glass micro-spheres. Based on test data in the 50°C–100°C temperature range, a prediction model has been established to calculate water absorption for service life as long as 20 years. A relationship between thermal conductivity variation and water content has been demonstrated, so that thermal conductivity of material exposed to water can be calculated versus temperature and time of exposure, for design purpose. The second part describes the full scale thermal tests that have been performed by Technip, in order to compare the measured thermal properties and heat losses of the flexible pipes in vertical or horizontal positions, with the computer calculations. Finally, based on lab test ageing and full scale tests on non aged flexible pipe, Technip is able to predict the full thermal behaviour during all the lifetime of the pipe.


TAPPI Journal ◽  
2011 ◽  
Vol 10 (9) ◽  
pp. 7-13
Author(s):  
KHODADAD MALMIRCHEGINI ◽  
FARSHAD SARKHOSH RAHMANI

Flexography is an evolving printing technology that is suitable for printing on coated and uncoated paperboard and board, nonporous substrates including metalized and paperboard foils, and plastic films used especially in the packaging industry. This study evaluated the effect of paperboard and ink characteristics on flexographic print density in paperboard. Three commercial paperboards from different companies were prepared: brown kraft from Thailand, white kraft from Spain, and test liner from Iran. Four samples of process print inks from Iran were used in this investigation. Paperboard properties, such as roughness and water absorption, and ink characteristics, including solids content, PH and particle diameter, were measured. The inks were printed on paperboards using a roll no.15 applicator with a blade metering device, and the print densities were measured. Results showed that solids content, pH, and particle diameter of printing inks influenced print density, while the roughness and water absorption of the three types of paperboard had no significant influence on print density. Results also illustrated that two levels of ink viscosity (25–30 and 50–55 mPa·s) were insignificant to print density.


2012 ◽  
Vol 2 (11) ◽  
pp. 165-167
Author(s):  
B.O .Ugwuishiwu B.O .Ugwuishiwu ◽  
◽  
B.O. Mama B.O. Mama ◽  
N. M Okoye N. M Okoye

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