The temperature effects in aging index of asphalt during UV aging process

2015 ◽  
Vol 93 ◽  
pp. 1125-1131 ◽  
Author(s):  
Wenbo Zeng ◽  
Shaopeng Wu ◽  
Jin Wen ◽  
Zongwu Chen
Keyword(s):  
Temperature Effects ◽  
Aging Process ◽  
Uv Aging ◽  
Aging Index

Investigation of UV Absorber Residue Improving Aging Properties of Bitumen

2016 ◽  
Vol 847 ◽  
pp. 413-417 ◽  
Author(s):  
Li Gao ◽  
Jian Ying Yu ◽  
Min Wu ◽  
Li Hui Xue
Keyword(s):  
Aging Process ◽  
Retention Rate ◽  
Modified Bitumen ◽  
Uv Aging ◽  
Oxidative Aging ◽  
Uv Absorber ◽  
Aging Index ◽  
Modify Bitumen ◽  
Aging Properties ◽  
Aging Resistance

Ultraviolet (UV) absorber residue was used to modify bitumen. Effects of UV absorber residue on thermo-oxidative and UV aging properties of bitumen were evaluated by conventional physical properties and SARA (saturates, aromatics, resins and bitumenenes) analysis. The results showed that the viscosity aging index (VAI) and softening point increment (SPI) of bitumen decreased significantly due to introduction of the UV absorber residue, and the ductility retention rate (DRR) was evidently higher compared to the pristine bitumen. SARA show that UV absorber residue can effectively restrain the gelatinization of bitumen resulted from aging. As a consequence, the UV absorber residue modified bitumen displays enhanced aging resistance properties, which can be attributed to the physical sorption of activated carbon to lighter components in the thermo-oxidative aging process and the absorption of UV absorption residue to the ultraviolet light in the process of UV aging.

scholarly journals An Integrated Shadow-Adjusted Snow-Aging Index for Alpine Regions

2020 ◽  
Vol 12 (8) ◽  
pp. 1249
Author(s):  
Haixing Li ◽  
Jinrong Liu ◽  
Xiangxu Bu ◽  
Xuezhi Feng ◽  
Pengfeng Xiao
Keyword(s):  
Snow Cover ◽  
Aging Process ◽  
Field Measurements ◽  
Northwest China ◽  
Analytic Hierarchy ◽  
Alpine Regions ◽  
Aging Index ◽  
Optical Images ◽  
Searching Method ◽  
Steep Slopes

Detecting the variations in snow cover aging over undulating alpine regions is challenging owing to the complex snow-aging process and shadow effect from steep slopes. This study proposes a novel snow-cover status index, namely shadow-adjusted snow-aging index (SASAI), portraying the integrated aging process within the Manas River Basin in northwest China. The Environment Satellites HJ-1A/B optical images and in-field measurements were used during the snow ablation and accumulation periods. The in-field measurements provide a reference for building a candidate library of snow-aging indicators. The representative aging samples for training and validation were obtained using the proposed time-gap searching method combined with the target zones established based on the altitude of snowline. An analytic hierarchy process was used to determine the snow-aging index (SAI) using multiple optimal snow-aging indicators. After correction by the extreme value optimization algorithm, the SASAI was finally corrected for the effects of shading and assessed. This study provides both a flexible algorithm that indicates the characteristics of snow aging and speculation on the causes of the aging process. The separability of the SAI/SASAI and adaptability of this algorithm on multiperiod remote sensing images further demonstrates the applicability of the SASAI to all the alpine regions.

UV Aging Performance of Asphalt Containing LDHs

2014 ◽  
Vol 599 ◽  
pp. 265-270 ◽  
Author(s):  
Pan Fei Liu ◽  
Jun Zheng ◽  
Shao Peng Wu
Keyword(s):  
Aging Process ◽  
Complex Modulus ◽  
Short Term ◽  
Uv Aging ◽  
Oven Test ◽  
Aging Properties ◽  
Aging Resistance ◽  
Before And After ◽  
Double Hydroxides

In this paper the effect of Layered double hydroxides (LDHs) on aging properties of asphalts was studied. The thin film oven test TFOT tests and ultraviolet (UV) aging process were used to simulate short-term and long-term aging of asphalts, respectively. After aging, the physical properties and dynamic shear rheological behaviors of LDHs modified asphalts were investigated. The viscosity of LDHs modified asphalts was measured by Brookfield viscometer before and after UV aging. After UV aging, with an increase of LDHs, softening point and viscosity value of modified asphalts decreased, while both of ductility and penetration increased, compared to base asphalts. Temperature sweep tests showed that the complex modulus of LDHs modified asphalts was lower than that of base asphalt, while phase angle was higher. The results showed that LDHs improved the UV aging resistance of the asphalt, and it could prevent asphalt from UV aging.

Effect of a lignin-based polyurethane on adhesion properties of asphalt binder during UV aging process

2020 ◽  
Vol 247 ◽  
pp. 118547 ◽  
Author(s):  
Chao Peng ◽  
Shifan Huang ◽  
Zhanping You ◽  
Fang Xu ◽  
Lingyun You ◽  
...  
Keyword(s):  
Aging Process ◽  
Asphalt Binder ◽  
Uv Aging ◽  
Adhesion Properties

Investigation of Anti-UV Aging of Bitumen Modified with Layered Double Hydroxides

2014 ◽  
Vol 599 ◽  
pp. 187-192 ◽  
Author(s):  
Xiao Juan Jia ◽  
Jian Ying Yu ◽  
Song Xu ◽  
Wei Dan ◽  
Li Hui Xue
Keyword(s):  
Layered Double Hydroxides ◽  
Chemical Compositions ◽  
Ftir Analysis ◽  
Modified Bitumen ◽  
Uv Aging ◽  
Aging Index ◽  
Modify Bitumen ◽  
Penetration Ratio ◽  
Double Hydroxides ◽  
Changing Rate

Layered double hydroxides (LDHs) were used to modify bitumen. Effect of LDHs on physical properties and chemical compositions of bitumen was investigated. Fourier transform infrared (FTIR) spectroscopy was carried out to analyze the structural change of LDHs modified bitumen after UV aging. The results show that LDHs is effective in improving the UV aging resistance of bitumen since the viscosity aging index (VAI) and softening point increment (SPI) of bitumen decrease while the retained penetration ratio (RPR) increases with increasing LDHs contents. The carbonyl and sulfoxide of LDHs modified bitumen presented a smaller increase after UV aging in comparison with unmodified bitumen according to FTIR analysis, and the changing rate of carbonyl and sulfoxide index of aromatics and asphaltenes reduced obviously compared with the slight changes of saturates and resins after the introduction of LDHs during UV aging, which demonstrated that LDHs mainly inhibit the oxidation of aromatics and asphaltenes during the UV aging.

Quantifying the Dynamics of Polystyrene Microplastics UV-Aging Process

2021 ◽  
Author(s):  
Ziyi Liu ◽  
Yanjie Zhu ◽  
Shangsi Lv ◽  
Yuxian Shi ◽  
Shuofei Dong ◽  
...  
Keyword(s):  
Aging Process ◽  
Uv Aging

Characterization of carbides in M50NiL

1991 ◽  
Vol 49 ◽  
pp. 606-607
Author(s):  
L. S. Lin ◽  
K. P. Gumz ◽  
A. V. Karg ◽  
C. C. Law
Keyword(s):  
Temperature Effects ◽  
Base Composition ◽  
Lattice Parameter ◽  
Control Surface ◽  
Carbide Formation ◽  
Particle Sizes ◽  
Low Carbon ◽  
Fee Structure ◽  
Heat Treated

Carbon and temperature effects on carbide formation in the carburized zone of M50NiL are of great importance because they can be used to control surface properties of bearings. A series of homogeneous alloys (with M50NiL as base composition) containing various levels of carbon in the range of 0.15% to 1.5% (in wt.%) and heat treated at temperatures between 650°C to 1100°C were selected for characterizations. Eleven samples were chosen for carbide characterization and chemical analysis and their identifications are listed in Table 1.Five different carbides consisting of M6C, M2C, M7C3 and M23C6 were found in all eleven samples examined as shown in Table 1. M6C carbides (with least carbon) were found to be the major carbide in low carbon alloys (<0.3% C) and their amounts decreased as the carbon content increased. In sample C (0.3% C), most particles (95%) encountered were M6C carbide with a particle sizes range between 0.05 to 0.25 um. The M6C carbide are enriched in both Mo and Fe and have a fee structure with lattice parameter a=1.105 nm (Figure 1).

Images of Aging in the Psychotherapeutic Context

GeroPsych ◽  
2015 ◽  
Vol 28 (2) ◽  
pp. 47-55 ◽  
Author(s):  
Eva-Marie Kessler ◽  
Catherine E. Bowen
Keyword(s):  
Old Age ◽  
Diagnostic Tests ◽  
Aging Process ◽  
Developmental Psychology ◽  
Mental Representations ◽  
Later Life ◽  
Future Research ◽  
Psychotherapeutic Process ◽  
Images Of Aging ◽  
Client Communication

Both psychotherapists and their clients have mental representations of old age and the aging process. In this conceptual review, we draw on available research from gerontology, social and developmental psychology, and communication science to consider how these “images of aging” may affect the psychotherapeutic process with older clients. On the basis of selected empirical findings we hypothesize that such images may affect the pathways to psychotherapy in later life, therapist-client communication, client performance on diagnostic tests as well as how therapists select and apply a therapeutic method. We posit that interventions to help both older clients and therapists to reflect on their own images of aging may increase the likelihood of successful treatment. We conclude by making suggestions for future research.

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