Study on the Main Characteristics of Reflective Cracking in the Asphalt Overlay on an Old Cement Pavement

2020 ◽  
Vol 980 ◽  
pp. 244-253
Author(s):  
Chun Fu Zhu ◽  
Pei Feng Cheng ◽  
Guang Yu Zhao
Keyword(s):  
Working Conditions ◽  
Coupling Effect ◽  
Shear Crack ◽  
Effect Of Temperature ◽  
Reflective Cracking ◽  
Effective Prevention ◽  
Finite Element Software ◽  
Asphalt Overlay ◽  
Prevention And Treatment ◽  
Reflection Crack

The purpose of this study is to explore the forms and characteristics of reflection crack in asphalt overlay of old cement pavement, so as to provide reference for effective prevention and treatment of reflection crack.By means of ANSYS finite element software, considering the coupling effect of temperature and vehicle in different working conditions, the influence of cooling on asphalt overlay was analyzed, and the location and form of crack were discussed.The analysis results show that tensile crack and shear crack are more likely to occur near the joint of old cement pavement, and shear crack is more likely to occur in areas outside the joint, about 1/2 wheel length from the joint of cement pavement.The prevention and treatment of crack at different locations should be carried out according to different working conditions.

scholarly journals Dynamic response of CRTS I double-block ballastless track under three-dimensional temperature and falling-shaft impact loadings

2021 ◽  
Vol 13 (3) ◽  
pp. 168781402110043
Author(s):  
Zhiping Zeng ◽  
Mengxuan Ye ◽  
Fushan Liu ◽  
Abdulmumin Ahmed Shuaibu ◽  
Weidong Wang ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Working Conditions ◽  
Coupling Effect ◽  
Three Dimensional ◽  
Impact Excitation ◽  
Effect Of Temperature ◽  
Large Temperature ◽  
Track Structure ◽  
Ballastless Track ◽  
The Impact

The CRTS I double-block ballastless track under the coupling effect of temperature and falling-shaft impact is more adaptable to actual operation. However, domestic and foreign research has only focused on either temperature or train loadings. In this study, the finite-element method was used to analyze the dynamic response of the double-block ballastless track structure. The results suggests that the displacement and acceleration characteristics of the ballastless track structure under different working conditions change significantly than no temperature gradient. Moreover, the vibration responses at the different working conditions under the impact excitation of a dropping wheelset show that. The findings of this study revealed that temperature has significant impact on falling-shaft which cannot be ignored, consequently it, paper provides referential information for the design, construction, operation and maintenance of the CRTS I double-block ballastless track structure under with large temperature difference.

MAPK: A Key Player in the Development and Progression of Stroke

2020 ◽  
Vol 19 (4) ◽  
pp. 248-256
Author(s):  
Yangmin Zheng ◽  
Ziping Han ◽  
Haiping Zhao ◽  
Yumin Luo
Keyword(s):  
Ischemic Stroke ◽  
Signaling Pathway ◽  
Complex Disease ◽  
Therapeutic Targets ◽  
Cell Types ◽  
Mapk Signaling ◽  
Mapk Signaling Pathway ◽  
Effective Prevention ◽  
Prevention And Treatment ◽  
Different Cell Types

Conclusion: Stroke is a complex disease caused by genetic and environmental factors, and its etiological mechanism has not been fully clarified yet, which brings great challenges to its effective prevention and treatment. MAPK signaling pathway regulates gene expression of eukaryotic cells and basic cellular processes such as cell proliferation, differentiation, migration, metabolism and apoptosis, which are considered as therapeutic targets for many diseases. Up to now, mounting evidence has shown that MAPK signaling pathway is involved in the pathogenesis and development of ischemic stroke. However, the upstream kinase and downstream kinase of MAPK signaling pathway are complex and the influencing factors are numerous, the exact role of MAPK signaling pathway in the pathogenesis of ischemic stroke has not been fully elucidated. MAPK signaling molecules in different cell types in the brain respond variously after stroke injury, therefore, the present review article is committed to summarizing the pathological process of different cell types participating in stroke, discussed the mechanism of MAPK participating in stroke. We further elucidated that MAPK signaling pathway molecules can be used as therapeutic targets for stroke, thus promoting the prevention and treatment of stroke.

Staying alive: A 21st century agenda for mental health, child protection and forensic services

2021 ◽  
pp. 263440412110078
Author(s):  
Patricia M Crittenden ◽  
Andrea Landini ◽  
Susan J Spieker
Keyword(s):  
Mental Health ◽  
Mental Health Professionals ◽  
Child Protection ◽  
Mental Health Treatment ◽  
Developmental Process ◽  
Diagnostic Methods ◽  
Effective Prevention ◽  
Common Basis ◽  
Prevention And Treatment ◽  
Protective Strategies

Mental health treatment, child protection and forensic services for criminality need major reorganisation in conceptualisation and service provision. This need results from the failure of current diagnostic methods, administrative organisations and treatment approaches to reduce the prevalence of mental illness, child maltreatment or criminal behaviour. We propose that defining these problems as individual deficits and responding to them by category of harm (to self, progeny and others, respectively) stands in the way of effective prevention and treatment. We address four topics: (1) the common basis of all of these problems in unprotected and uncomforted exposure to danger, (2) the developmental process of psychological maladaptation that occurs interpersonally in endangered families, (3) the behavioural expression of psychological development as protective strategies that can be adaptive or maladaptive, depending upon the context in which they are used, and (4) proposals for systemic change that could improve prevention and treatment. These proposals include using functional formulations to guide treatment planning, single portal entry to assessment and services, integrated universal transdisciplinary training followed by specialisation for all mental health professionals, delivering customised treatment through transitional attachment relationships and consolidating disparate disciplines in ‘departments of human adaptation’.

The Influence of the Leading Wheel Structural Change on Stress of Multi-Rope Friction Hoist

2013 ◽  
Vol 670 ◽  
pp. 48-53 ◽  
Author(s):  
Guang Lin Zhou ◽  
W.J. Chu
Keyword(s):  
Finite Element ◽  
Structural Change ◽  
Service Life ◽  
Working Conditions ◽  
Weld Bead ◽  
Rational Structure ◽  
Open Problems ◽  
Finite Element Software ◽  
Stress Fluctuation

To avoid the open problems of the leading wheel and get a more rational structure, the paper uses PRO / E and the finite element software to analyze the leading wheel of JKM-3.25/4 multi-rope friction hoist. The results show that in the leading wheel the rib plates between the channel steel and wheel hub are removed or added the same ones will have little effect on the overall force situation, and only affect the stress of the weld bead. To solve the problem of open weld of rib plates, can consider the rib plates to be removed. When the radial angle between support wheel and drum is bigger than 6°, the overall force of the leading wheel is affected seriously. But when the radial angle is 5°, the amplitude of stress fluctuation is the minimum, which can improve the leading wheel working conditions and increase the service life of the leading wheel. Therefore the suggestion is to take the radial angle of 5° when to design the new multi-rope hoist. Study conclusions provide the theoretical supports for the leading wheel of multi-rope friction design and technical renovation.

The Interaction of Temperature and Bending Load on Structural Performance of Chinese Larch Wood

2012 ◽  
Vol 531-532 ◽  
pp. 122-126
Author(s):  
Hai Bin Zhou ◽  
Chuan Shuang Hu ◽  
Jian Hui Zhou
Keyword(s):  
Elevated Temperatures ◽  
Coupling Effect ◽  
Structural Performance ◽  
Effect Of Temperature ◽  
Short Exposure ◽  
Short Exposure Time ◽  
Larch Wood ◽  
Timber Construction ◽  
Bending Load ◽  
Stress Levels

Wood is being used extensively in timber construction in China. In fire-resistant design for timber construction, the main goal is to ensure that enough structural integrity is maintained during a fire to prevent structure collapse. It is important to understand its structural performance when exposed to elevated temperatures and loaded by stress levels. To study the interaction effect of Chinese larch wood, a total of 72 small clear wood samples were observed under constant stress levels when the wood temperature was elevated. The results indicated that Chinese larch wood was more susceptible to the coupling effect of temperature and stress. The interaction promoted a temporary stable flexural structure to collapse during a short exposure time.

scholarly journals EFFECTIVE PREVENTION AND TREATMENT OF CHRONIC HEPATITIS B IN THE CONTEMPORARY PRACTICE OF HEPATOLOGY

2017 ◽  
pp. 47-51
Author(s):  
R. G. MYAZIN
Keyword(s):  
Chronic Hepatitis ◽  
Hepatitis B ◽  
Chronic Hepatitis B ◽  
Long Term Conditions ◽  
Effective Prevention ◽  
Results Of Treatment ◽  
Prevention And Treatment ◽  
The One ◽  
Contemporary Practice

Modern approaches to the prevention and treatment of chronic hepatitis B are based on the use of vaccination of the population, on the one hand, and rational choice of antiviral therapy schemes in patients - on the other. This allows the physician to predict results of treatment and preventive measures. Modern analogues of nucleosides, in particular, Entecavir, has high efficacy, good tolerance and high safety profile when used in long term conditions.

Analysis of Jib Strength and Broken Jib Accident of High Pedestal Jib Crane from the Perspective of Mechanics

2012 ◽  
Vol 164 ◽  
pp. 322-325 ◽  
Author(s):  
Qing Dun Zeng ◽  
Fang Liu
Keyword(s):  
Finite Element ◽  
Working Conditions ◽  
Tensile Force ◽  
Compressive Force ◽  
Guangdong Province ◽  
Solid Model ◽  
Finite Element Software ◽  
Actual Working

According to an example of the broken jib accident of a high pedestal jib crane (HM2564) in a Shipyard Co., Ltd. in Guangdong province, this paper used a finite element software ANSYS to establish a solid model for the jib frame of the crane, calculated the stresses of jib system under various actual working conditions and checked the strengths. Simultaneously, the reasons of broken jib were quantitatively analyzed from the perspective of mechanics. The results show that the strengths of the jib system meet the requirements of safe use under all kinds of working conditions, but the related hoistman incorrectly operated the facility, cables can’t be winded normally in pulleys, thus resulting in that the tensile force of a cable was directly applied on the main jib by pulley spindle and the failure of the jib frame occurred under heavy compressive force of lifting cables.

Research on Loading Test Scheme of Vehicular Bridge-Footbridge Combined Double-Deck Cable-Stayed Bridges

2013 ◽  
Vol 361-363 ◽  
pp. 1081-1085
Author(s):  
Meng Yan ◽  
Yong Qing Yang ◽  
Yuan Yuan ◽  
Xiang Lin Zeng
Keyword(s):  
Coupling Effect ◽  
Test Methods ◽  
Test Scheme ◽  
Bridge Structure ◽  
Loading Test ◽  
Finite Element Software ◽  
Working Stress ◽  
Upper Deck ◽  
Dynamic Performances ◽  
Capacity Loading

In order to check whether the bridge structure is in good working condition, meeting the requirements of carrying capacity and traffic capacity, loading test should be conducted to the Huiketing No.1 Bridge in Mianyang city. The bridge is a double-deck cable-stayed bridge, the upper deck of which works as a footbridge and is connected by 6 chain poles to the lower deck which works as a vehicular bridge. Since the bridge structure is novel, the working stress state is complicated and the coupling effect of the two decks is notable, little referential experience could be found from other bridges. The loading test uses sandbags as equivalent to pedestrian loads on the footbridge and adopts heavy trucks to imitate the design vehicle loads on the vehicular bridge. According to the structural symmetry of the whole bridge and the analysis of its static and dynamic performances in the finite element software, the optimized loading project is finalized. Test methods and analysis results of this footbridge can be used as reference in loading test of similar bridges in the future.

Life-Cycle Cost Analysis of Mitigating Reflective Cracking

2003 ◽  
Vol 1823 (1) ◽  
pp. 73-79 ◽  
Author(s):  
Susan Tighe ◽  
Ralph Haas ◽  
Joseph Ponniah
Keyword(s):  
Service Life ◽  
Life Cycle Cost ◽  
Cost Savings ◽  
Economic Benefits ◽  
Crack Spacing ◽  
Reflective Cracking ◽  
International Roughness Index ◽  
Pavement Rehabilitation ◽  
Asphalt Overlay ◽  
Benefit Cost

Reflective cracking is a major and costly problem in many countries. It occurs in the top (overlay) layers above existing cracks in the lower (existing) pavement. This type of cracking can lead to premature deterioration of the pavement structure through the infiltration of moisture and debris. Although extensive research has been directed toward mitigation of the problem, work needs to be done, as it still appears to be a major problem. The problem is related in part to the fact that most of the work being done involves rehabilitation. One of the most common types of pavement rehabilitation is the use of an asphalt overlay. The focus of the present analysis is the economic benefits of reducing and treating reflective cracking before the placement of an asphalt overlay. A methodology for converting crack spacing to roughness is also presented. This information is used to examine how cracking is related to the measured international roughness index values. A model relating the amount of cracking to the loss of serviceability or a reduction in service life is presented. That model indicates that a reduction of transverse crack spacing from 5 to 20 m should result in a 5-year extension of service life, with a cost savings of $25,000 (2002 U.S. dollars) per two-lane kilometer. Measurement and treatment of cracking can also yield significant benefits. Benefit–cost ratios from the measurement of cracking can range from about 5 to 50, while proper and timely crack treatment (routing and sealing) can result in an extension of pavement life by 2 years and cost savings of $7,000 per lane kilometer.

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