A Laboratory Engine Test Method and Its Application to Evaluation of High Temperature Oil Thickening Problems in Gasoline Engines

1972 ◽  
Author(s):  
J. V. D. Wilson ◽  
G. J. J. Jayne ◽  
E. G. Thomas
Keyword(s):  
High Temperature ◽  
Test Method ◽  
Engine Test ◽  
Gasoline Engines ◽  
Oil Thickening

scholarly journals Evaluation of Micro-Mechanism and High- and Low-Temperature Rheological Properties of Disintegrated High Volume Crumb Rubber Asphalt (DHVRA)

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1145
Author(s):  
Wei Li ◽  
Sen Han ◽  
Xiaokang Fu ◽  
Ke Huang
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Rheological Properties ◽  
Particle Diameter ◽  
Gel Permeation Chromatography ◽  
High Volume ◽  
Crumb Rubber ◽  
Test Method ◽  
Polar Component ◽  
Temperature Performance

The aims of this paper are to prepare disintegrated high volume crumb rubber asphalt (DHVRA) with low viscosity, good workability and low-temperature performance by adding disintegrating agent (DA) in the preparation process, and to further analyze the disintegrating mechanism and evaluated high-temperature and low-temperature rheological properties. To obtain DHVRA with excellent comprehensive performance, the optimum DA dosage was determined. Based on long-term disintegrating tests and the Fluorescence Microscopy (FM) method, the correlations between key indexes and crumb rubber (CR) particle diameter was analyzed, and the evaluation indicator and disintegrating stage division standard were put forward. Furthermore, Fourier transform infrared spectroscopy (FT-IR) and Gel Permeation Chromatography (GPC) was used to reveal the reaction mechanism, and the contact angle test method was adopted to evaluate the surface free energy (SFE). In addition, the high-temperature and low-temperature rheological properties were measured, and the optimum CR content was proposed. Results indicated that the optimum DA dosage was 7.5‰, and the addition of DA promoted the melt decomposition of CR, reduced the viscosity and improved the storage stability. The 135 °C rotational viscosity (RV) of DHVRA from mixing for 3 h could be reduced to 1.475 Pa·s, and the softening point difference was even less than 2 °C. The linear correlation between 135 °C RV and the diameter of CR particle in rubber asphalt system was as high as 0.968, and the viscosity decay rate (VDR) was used as the standard to divide the disintegrating process into a fast disintegrating stage, stable disintegrating stage and slight disintegrating stage. Compared to common rubber asphalt (CRA), DHVRA has an absorption peak at 960 cm−1 caused by trans olefin = C-H, and higher molecular weight and polar component of surface energy. Compared with CRA, although the high-temperature performance of DHVRA decreases slightly, the low-temperature relaxation ability can be greatly improved.

Influence of High-Temperature Bias Stress on Room-Temperature VT Drift Measurements in SiC Power MOSFETs

2019 ◽  
Vol 963 ◽  
pp. 757-762
Author(s):  
Daniel B. Habersat ◽  
Aivars Lelis ◽  
Ronald Green
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
State Of The Art ◽  
Charge Trapping ◽  
High Temperature Stress ◽  
Test Method ◽  
Power Mosfets ◽  
Temperature Bias ◽  
Bias Stress

Our results reinforce the notion of the need for an improved high-temperature gate bias (HTGB) test method — one which discourages the use of slow (greater than ~1 ms) threshold-voltage (VT) measurements at elevated temperatures and includes biased cool-down if room temperature measurements are performed, to ensure that any ephemeral effects during the high-temperature stress are observed. The paper presents a series of results on both state-of-the-art commercially-available devices as well as older vintage devices that exhibit enhanced charge-trapping effects. Although modern devices appear to be robust, it is important to ensure that any new devices released commercially, especially by new vendors, are properly evaluated for VT stability.

scholarly journals Dynamic Water Effect on the High Temperature Stability of Asphalt Mixture

2012 ◽  
Vol 5 ◽  
pp. 352-357 ◽  
Author(s):  
Ming Hao Hou ◽  
Yi Qiu Tan ◽  
Bin Hu
Keyword(s):  
High Temperature ◽  
Asphalt Mixture ◽  
Temperature Stability ◽  
High Viscosity ◽  
Test Method ◽  
Water Effect ◽  
High Temperature Stability ◽  
Air Voids ◽  
Working Together ◽  
Better Than

This paper introduces dynamic water effect into the test, develops a laboratory test device for simulating the dynamic water effect on asphalt pavement, and puts forward a test method of dynamic water effect working together with load, water and temperature. Based on this method, the high temperature stability of seven kinds of asphalt mixtures with the factors of asphalt grade, gradation and air voids are studied. The research shows that the effect of dynamic water can take adverse effect for the high temperature stability of asphalt mixture. The effect degree is different under different factors. It is the most disadvantaged when the air voids of the mixture is near 10%, the skeleton structure gradation of mixture is better than the suspended structure at the most disadvantage air voids, and the mixture made of high viscosity asphalt is more affected when the temperature is higher.

High-Temperature Interlaminar Tension Test Method Development for Ceramic Matrix Composites

2013 ◽  
Author(s):  
Todd Engel
Keyword(s):  
High Temperature ◽  
Method Development ◽  
Standardized Test ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Test Method ◽  
Test Technique ◽  
Structural Applications

Ceramic Matrix Composite (CMC) materials are an attractive design option for various high-temperature structural applications. In particular, the use of CMC materials as a replacement for state-of-the-art nickel-based superalloys in hot gas path turbomachinery components offers the potential for significant increases in turbine system efficiencies, due largely to reductions in cooling requirements afforded by the increased temperature capabilities inherent to the ceramic material. However, two-dimensional fabric-laminated CMCs typically exhibit low tensile strengths in the thru-thickness (interlaminar) direction, and interply delamination is a concern for some targeted applications. Currently, standardized test methods only address the characterization of interlaminar tensile strengths at ambient temperatures; this is problematic given that nearly all CMCs are slated for service in high-temperature operating environments. This work addresses the development of a new test technique for the high-temperature measurement of interlaminar tensile properties in CMCs, allowing for the characterization of material properties under conditions more analogous to anticipated service environments in order to yield more robust component designs.

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