scholarly journals Aging Characteristics of Asphalt Binder under Strong Ultraviolet Irradiation in Northwest China

2021 ◽  
Vol 13 (19) ◽  
pp. 10753
Author(s):  
Ling Zou ◽  
Yan Zhang ◽  
Bangyi Liu
Keyword(s):  
Uv Radiation ◽  
Evaluation System ◽  
Evaluation Method ◽  
Asphalt Binder ◽  
Northwest China ◽  
Gansu Province ◽  
Uv Aging ◽  
Attenuation Index ◽  
Before And After ◽  
Asphalt Performance

Asphalt pavement is significantly affected by ultraviolet (UV) aging. Therefore, the establishment of an asphalt UV aging evaluation system is desirable for highway construction in areas which experience strong UV radiation. In this study, Dunhuang City in Gansu Province (northwest China) was used as the research site. Base and SBS modified asphalts were selected, and their performance changes before and after UV aging were studied. An asphalt UV aging evaluation system was established, including the conditions for an indoor, accelerated UV aging test as well as evaluation indicators. The results showed that the adverse effect of UV aging on asphalt performance was greater than that of RTFOT and PAV, and that the low-temperature performance of asphalt degraded most rapidly. SBS modified asphalt was more resistant to UV aging than base asphalt, while 60/80 pen grade base asphalt was found to be unsuitable for use on pavements which are exposed to strong UV radiation. The residual penetration, penetration attenuation index at 25 °C, and residual ductility of the asphalt were used as indicators to characterize the aging of asphalt, while the fracture energy method was used as a supplementary evaluation method.

scholarly journals Impact of Ultraviolet Radiation on the Aging Properties of SBS-Modified Asphalt Binders

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1111 ◽  
Author(s):  
Huanan Yu ◽  
Xianping Bai ◽  
Guoping Qian ◽  
Hui Wei ◽  
Xiangbing Gong ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Uv Radiation ◽  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Asphalt Binders ◽  
Shrinkage Stress ◽  
Uv Aging ◽  
Modified Asphalt ◽  
Aging Properties ◽  
Sbs Modified Asphalt

Styrene Butadiene Styrene (SBS) polymer-modified asphalt binders have become widely used in asphalt pavement because of their advantages in high- and low-temperature performance and fatigue resistance. Asphalt pavement is inevitably exposed to sunlight and ultraviolet (UV) radiation during its construction and service life. However, consideration of the aging effect of UV radiation is still limited in current pavement design and evaluation systems. In order to evaluate the impact of UV radiation on the aging properties of SBS-modified asphalt binders, UV aging tests were performed on Rolling Thin Film Oven Test (RTFOT)-aged samples with different UV radiation intensities and aging times. Sixteen different groups of tests were conducted to compare the rheological properties and functional group characteristics of SBS-modified asphalt binders. Dynamic Shear Rheometer (DSR), Bending Beam Rheometer (BBR), FTIR, and SEM tests were conducted to evaluate the aging mechanisms in various UV aging conditions. The results found that UV radiation seriously destroys the network structure formed by the cross-linking effect in SBS-modified asphalt binders, which aggravates the degradation of SBS and results in a great change of rheological properties after UV aging. The nature of SBS-modified asphalt binder aging resulted from the degradation of SBS and the changes of asphalt binder base composition, which lead to the transformation of colloidal structure and the deterioration of asphalt binder performance. The tests also found that continuous UV radiation can increase shrinkage stress in the asphalt binder surface and leads to surface cracking of the asphalt binder.

scholarly journals Study on the Fingerprints and Quality Evaluation of Angelica Sinensis Radix by HPLC Coupled With Chemometrics Based on Traditional Decoction Process of ACPTCM

Dose-Response ◽  
2020 ◽  
Vol 18 (3) ◽  
pp. 155932582095173
Author(s):  
Zhang Qian ◽  
Chen Yiyang ◽  
Ma Lixia ◽  
Jiang Yue ◽  
Chen Jun ◽  
...  
Keyword(s):  
Chinese Medicine ◽  
Traditional Chinese Medicine ◽  
Evaluation System ◽  
Quality Evaluation ◽  
Evaluation Method ◽  
Gansu Province ◽  
Angelica Sinensis ◽  
Chromatographic Fingerprint ◽  
Angelica Sinensis Radix ◽  
Decoction Process

Objective: To establish a HPLC fingerprints evaluation method for Angelica Sinensis Radix (ASR) based on traditional decoction process of Ancient Classical Prescriptions of Traditional Chinese Medicine (ACPTCM). Methods: The fingerprints of 10 batches of ASR were further evaluated by chemometrics methods. The similarity analyzed with “Similarity Evaluation System for Chromatographic Fingerprint of Traditional Chinese Medicine 2004A,” and hierarchical clustering analysis (HCA) and principal component analysis (PCA) were performed by SPSS (version 22.0, SPSS Inc., Chicago, IL, USA). Results: There were 12 common peaks, and the similarity degrees of 10 batches of samples were more than 0.923 and showed that all the samples from different origins were of good consistency. The samples were divided into 4 clusters by HCA. The results of PCA showed that the 3 factors were chosen, the quality of samples could be evaluated basically. The comprehensive score results show that the ASR with Lot.Nos.DG-18007, DG-18008 in Weiyuan County, Gansu and DG-18009 produced in Minle County, Gansu Province rank among the top 3 in all samples. Conclusions: These results demonstrated that the combination of HPLC chromatographic fingerprint and chemometrics offers an efficient and reliable approach for quality evaluation of ASR from different sources as Ancient Classical Prescriptions ingredients.

scholarly journals Influence of Ultraviolet and Oxygen Coupling Aging on Rheological Properties and Functional Group Index of Warm Mix Asphalt Binder

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4216
Author(s):  
Hailian Li ◽  
Peipei Tong ◽  
Xijun Zhang ◽  
Xixiong Lin ◽  
Bo Li
Keyword(s):  
Infrared Spectrum ◽  
Rheological Properties ◽  
Functional Group ◽  
Asphalt Binder ◽  
Group Index ◽  
Uv Aging ◽  
Aging Period ◽  
Before And After ◽  
Time Required ◽  
Peak Value

Warm-mixed asphalt (WMA) has the characteristics of low mixing temperature and energy consumption, which makes it more suitable than hot-mixed asphalt for plateau regions (the altitude is above 500 m, and the terrain is relatively flat or has a wide area with certain undulations). However, WMA is subject to severe ultraviolet (UV) aging because the UV radiation in plateau areas is more intense. The asphalt’s aging changes its rheological properties inevitably, and thus degrades the asphalt pavement’s performance. Accordingly, the purpose of this paper is to investigate the effect of UV and oxygen coupling aging on WMA’s rheological properties and functional group index. Temperature and frequency sweep tests were performed with a dynamic shear rheometer. At the same time, the functional group index was used as an indicator to compare the changes in the WMA’s infrared spectrum before and after UV aging. The results showed that WMA’s elasticity increased and its viscosity decreased after aging with UV. Under the condition of UV–oxygen isolation, as the aging period increased, the WMA’s rutting factor increased gradually. The degree of improvement was greater than that under the condition of oxygen isolation. In contrast, the time required for the WMA’s complex shear modulus to recover under the condition of UV–oxygen coupling was delayed. An increase in the peak value of infrared spectrum indicates that the WMA has undergone oxygen aging. The presence and change in the carbonyl group reflects the degree of the WMA’s UV aging, and the UV aging condition had a greater effect on the peak values of the carbonyl and sulfoxide groups.

scholarly journals Recent advances in characterizing the “bee” structures and asphaltene particles in asphalt binders

2020 ◽  
Vol 13 (6) ◽  
pp. 697-706
Author(s):  
Yuhong Wang ◽  
Kecheng Zhao ◽  
Fangjin Li ◽  
Qi Gao ◽  
King Wai Chiu Lai
Keyword(s):  
Near Field ◽  
Asphalt Binder ◽  
Optical Microscope ◽  
Asphalt Binders ◽  
Zero Shear Viscosity ◽  
Surface Features ◽  
Asphaltene Content ◽  
Scanning Transmission ◽  
Before And After ◽  
Binder Aging

AbstractThe microscopic surface features of asphalt binders are extensively reported in existing literature, but relatively fewer studies are performed on the morphology of asphaltene microstructures and cross-examination between the surface features and asphaltenes. This paper reports the findings of investigating six types of asphalt binders at the nanoscale, assisted with atomic force microscopy (AFM) and scanning transmission electron microscopy (STEM). The surface features of the asphalt binders were examined by using AFM before and after being repetitively peeled by a tape. Variations in infrared (IR) absorbance at the wavenumber around 1700 cm−1, which corresponds to ketones, were examined by using an infrared s-SNOM instrument (scattering-type scanning near-field optical microscope). Thin films of asphalt binders were examined by using STEM, and separate asphaltene particles were cross-examined by using both STEM and AFM. In addition, connections between the microstructures and binder’s physicochemical properties were evaluated. The use of both microscopy techniques provide comprehensive and complementary information on the microscopic nature of asphalt binders. It was found that the dynamic viscosities of asphalt binders are predominantly determined by the zero shear viscosity of the corresponding maltenes and asphaltene content. Limited samples also suggest that the unique bee structures are likely related to the growth of asphaltene content during asphalt binder aging process, but more asphalt binders from different crude sources are needed to verify this finding.

scholarly journals Prevalence of gastrointestinal parasites in free-range yaks (Bos grunniens) in Gansu Province, Northwest China

2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Si-Yuan Qin ◽  
Ming-Yang Yin ◽  
Guang-Yao Song ◽  
Qi-Dong Tan ◽  
Jin-Lei Wang ◽  
...  
Keyword(s):  
Northwest China ◽  
Gansu Province ◽  
Gastrointestinal Parasites ◽  
Economic Losses ◽  
Parasitic Infections ◽  
Cattle Industry ◽  
Free Range ◽  
Bos Grunniens ◽  
High Prevalence ◽  
Different Seasons

Abstract Background Little information about the prevalence of gastrointestinal parasites in yaks (Bos grunniens) in northwest China is available. Therefore, the objective of the study was to quantify faecal egg counts of gastrointestinal parasites (helminths and coccidia) in free-range yaks from Gannan Tibetan Autonomous Prefecture, Gansu Province, Northwest China. Results Parasites were detected in 290 of 733 (39.56%) faecal samples. The results showed that Strongylidae, Trichuris spp. and Eimeria spp. were detected all year round, Strongyloides papillosus was detected in autumn and summer, and Nematodirus spp. was detected in both autumn and spring. In contrast, Fasciola spp. was only detected in spring. The prevalence rates of parasitic infections in different seasons were significantly different. Conclusions To our knowledge, this is the first investigation of gastrointestinal parasites in yaks (Bos grunniens) in Gansu, China. The results demonstrated a high prevalence of gastrointestinal parasitic infections, specifically GN infections, in yaks in GTAP and these infections can cause economic losses to the local cattle industry.

scholarly journals Color Image Evaluation for Small Space Based on FA and GEP

2014 ◽  
Vol 2014 ◽  
pp. 1-11
Author(s):  
Li Deng ◽  
Sui-Huai Yu ◽  
Wen-Jun Wang ◽  
Jun-Xuan Chen ◽  
Guo-Chang Liu
Keyword(s):  
Evaluation System ◽  
Frequency Conversion ◽  
Evaluation Method ◽  
Color Image ◽  
Gene Expression Programming ◽  
Image Evaluation ◽  
Evaluation Tool ◽  
Small Space ◽  
Entropy Weight ◽  
Fast Evaluation

Aiming at the problem that color image is difficult to quantify, this paper proposes an evaluation method of color image for small space based on factor analysis (FA) and gene expression programming (GEP) and constructs a correlation model between color image factors and comprehensive color image. The basic color samples of small space and color images are evaluated by semantic differential method (SD method), color image factors are selected via dimension reduction in FA, factor score function is established, and by combining the entropy weight method to determine each factor weights then the comprehensive color image score is calculated finally. The best fitting function between color image factors and comprehensive color image is obtained by GEP algorithm, which can predict the users’ color image values. A color image evaluation system for small space is developed based on this model. The color evaluation of a control room on AC frequency conversion rig is taken as an example, verifying the effectiveness of the proposed method. It also can assist the designers in other color designs and provide a fast evaluation tool for testing users’ color image.

Research in Geological Environmental Evaluation System of Transmission Line

2014 ◽  
Vol 641-642 ◽  
pp. 1238-1245
Author(s):  
Zi Xia Feng ◽  
Bin Bin Zhao ◽  
Lei He ◽  
Chen Fang
Keyword(s):  
Transmission Lines ◽  
Evaluation System ◽  
Evaluation Method ◽  
Rapid Development ◽  
Evaluation Research ◽  
Planning Period ◽  
Environmental Evaluation ◽  
Life Cycle Design ◽  
Power Construction ◽  
Whole Life Cycle

With the rapid development of electric power construction , transmission lines and the surrounding geological environment influence each other that has become increasingly serious, however, there is not formed yet a set of complete and more scientific geological environmental evaluation system in transmission lines at present. In this paper, on the basis of using the experience of other industries of geological environmental evaluation research , study and put forward the geological environmental evaluation method specifically for transmission lines. Evaluation system is established for transmission lines in planning period and construction period , and also put forward the corresponding evaluation index. The research conclusion can provides theoretical support and maintenance for transmission lines of the whole life cycle design,and it also provides reference in designing transmission lines plan and preventing, and controlling geological environmental problems of transmission lines for the decision-making department.

Study of highway asphalt pavement recycling maintenance scheme decision system and decision method

2021 ◽  
pp. 1-10
Author(s):  
Hongjun Jing ◽  
Ping Yao ◽  
Lichen Song ◽  
Jiahao Zhang ◽  
Yanlong Zhao ◽  
...  
Keyword(s):  
Decision Making ◽  
Evaluation System ◽  
Evaluation Method ◽  
Comprehensive Evaluation ◽  
Asphalt Pavement ◽  
Economic Benefits ◽  
Highway Maintenance ◽  
Decision System ◽  
Recovery Index ◽  
Pavement Recycling

With modern economic and social development, the technical and economic requirements of highway maintenance and construction projects have become increasingly complicated. Meticulous and in-depth investigation and demonstration guided by scientific theories and methods are of considerable importance to highway maintenance scheme decision. As basis for the selection of highway asphalt pavement recycling maintenance scheme, the factors influencing the decision are analytically demonstrated and an evaluation system is proposed, including three major decision indexes: applicability of recycling mode, recycled pavement quality recovery index, and economic benefit. According to the principles of data statistics and analysis, this study proposes a calculation method for the recycled pavement quality recovery index, analyzes the economic benefits of decision schemes using economic models such as recycling ratio and cost, and puts forward an optimal evaluation method of engineering cost and its fuzzy score intervals. Index weights are calculated through the analytic hierarchy process, and the comprehensive decision evaluation system and comprehensive evaluation method are established. Subsequently, the decision-making method is analyzed on the basis of the decision system by combining the related data. Results show maximum weight of the pavement quality recovery index and minor differences among four recycling schemes in the quality recovery index and applicability. The decision-making results are simplified with clear hierarchical feature because of the fuzzy score intervals of each index. Findings can provide a reference for the asphalt pavement recycling scheme decision.

scholarly journals Study on layout optimization of sewage outfalls: a case study of wastewater treatment plants in Xiamen

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cui Wang ◽  
Zhouhua Guo ◽  
Qingsheng Li ◽  
Jing Fang
Keyword(s):  
Wastewater Treatment ◽  
Water Reuse ◽  
Evaluation System ◽  
Evaluation Method ◽  
Wastewater Treatment Plants ◽  
Comprehensive Evaluation ◽  
Ecological Impact ◽  
Layout Optimization ◽  
Marine Environmental

AbstractIn order to protect the offshore environment and strengthen the comprehensive rectification of sewage outfalls, an evaluation method of regional sewage outfalls by combining the marine numerical simulation and comprehensive evaluation technology was constructed, considering the marine environmental capacity and the ecological impact of sewage discharge from outfalls on the marine eco-environment sensitive areas. Then the layout rationality of each outfall was evaluated and the discharge scale was optimized with a case study of existing sewage outfalls in Xiamen. The results show that, the comprehensive evaluation score of Yundang outfall was 3 points in 2025, evaluated as the outfall with irrational layout. In 2035, the comprehensive evaluation scores of Fenglin and Dalipu outfalls were 3 and 2 points respectively, evaluated as the outfall with irrational discharge scale. It is suggested to control the scale of expansion or increase the reclaimed water reuse rate in Jimei and Gaoqi Wastewater Treatment Plants. This method has enriched the evaluation system for layout optimization of sewage outfalls, providing scientific supports for comprehensive improvement of sewage outfalls and marine environmental management.

scholarly journals Application of Analytical Hierarchy Process in Teaching Quality Analysis of English Writing

2020 ◽  
Vol 15 (14) ◽  
pp. 137
Author(s):  
Xiaoqin Zhang ◽  
Shengxin Wang ◽  
Yanling Cao ◽  
Guangqi Chen
Keyword(s):  
Analytical Hierarchy Process ◽  
Evaluation System ◽  
Evaluation Method ◽  
Evaluation Model ◽  
Teaching Quality ◽  
Quality Analysis ◽  
English Writing ◽  
Evaluation Systems ◽  
Hierarchy Process

There are two major problems in the evaluation of the teaching quality of English writing: the weak logic of the evaluation system and the low reliability of the evaluation model. To solve the problems, this paper put forward an evaluation method for the teaching quality of English writing based on the analytical hierarchy process (AHP). Firstly, the authors reviewed the current evaluation methods for the teaching quality of English writing. Next, hierarchical evaluation systems were established for the teaching quality of English writing from the perspectives of teachers and students, respectively. After that, the AHP method and the grey theory were introduced to set up an evaluation model for the teaching quality of English writing. Finally, several strategies were presented to improve the teaching quality of English writing. The proposed evaluation systems and model enriched the theories on teaching quality evaluation of English writing, and promoted the teaching quality of English writing.

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