scholarly journals Pengaruh Penuaan Aspal Pada Karakteristik Campuran Beton Aspal Lapis Aus AC – WC

2020 ◽  
pp. 47-56
Author(s):  
M. Mashuri ◽  
R. Rahman
Keyword(s):  
Environmental Factors ◽  
Air Temperature ◽  
Asphalt Concrete ◽  
Aging Process ◽  
Short Term ◽  
The Road ◽  
Service Period ◽  
Asphalt Content ◽  
Pavement Layers

The aging process of asphalt in the pavement layers of asphalt concrete road occurs when mixing in the Asphalt Mixing Plant and during the road service period. The asphalt aging process when mixing is called short-term aging and aging during the road service period is called long-term aging. AC - WC mixture is a wear layer and it is on the top layer of the surface which allows characteristics change that are influenced by several environmental factors (air, temperature and sunlight). This study aims to know the effect of asphalt aging on the characteristics of AC - WC mixture with Marshall method on some asphalt content  that are 4.5%, 5.0%, 5.5%, 6.0%, 6, 5% and 7.0%. For testing on short-term aging (Short - Term Oven Aging, STOA) is by testing the mixture specimen AC - WC at 135o C before solidified for 4 hours and for long-term aging (Long - Term Oven Aging, LTOA) was carried out by testing the mixture specimen AC - WC at 85o C for 2 - 5 days. The results of this study found that asphalt aging had an effect on the characteristics of AC - WC mixture. Values of density, VFB, stability, flow tend to decrease with age. While VIM and VMA values tend to increase with age. Aging caused the mixture to became more rigid.

A Closer Look at the Culture of Infidelity

2020 ◽  
pp. 180-200
Author(s):  
Steven M. Ortiz
Keyword(s):  
Professional Sports ◽  
Short Term ◽  
The Road ◽  
Emotional Relationships ◽  
The World ◽  
On The Road ◽  
The One ◽  
Communication Methods

This chapter takes a deeper look at the culture of infidelity that pervades the world of professional sports, why wives share a universal fear that their husbands will be unfaithful, and how they are affected by the possibility or actuality that their husbands will engage in sexual or emotional relationships with other women. Three patterns of infidelity are identified in the context of the sport marriage: the one-time encounter, the short-term affair, and the long-term affair. The concept of suspicion work is introduced to examine how wives try to manage the fear that their husbands may succumb to temptation and to specify how denial can be part of this process. The chapter discusses re-entry routines and communication methods some couples use when husbands return from travel, and the boundaries of fidelity and forgiveness wives establish as they attempt to cope with the realities of their husbands’ lives on the road.

scholarly journals The Dimension of Time in Host-Microbiome Interactions

mSystems ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Giulia T. Uhr ◽  
Lenka Dohnalová ◽  
Christoph A. Thaiss
Keyword(s):  
Microbial Community ◽  
Environmental Factors ◽  
Temporal Dynamics ◽  
Therapeutic Strategies ◽  
Intestinal Microbiome ◽  
Short Term ◽  
Intestinal Microbial Community ◽  
Intermediate States ◽  
Different Time Scales

ABSTRACT The intestinal microbiota contains trillions of commensal microorganisms that shape multiple aspects of host physiology and disease. In contrast to the host’s genome, the microbiome is amenable to change over the course of an organism’s lifetime, providing an opportunity to therapeutically modulate the microbiome’s impact on human pathophysiology. In this Perspective, we highlight environmental factors that regulate the temporal dynamics of the intestinal microbiome, with a particular focus on the different time scales at which they act. We propose that the identification of transient and intermediate states of microbiome responses to perturbations is essential for understanding the rules that govern the behavior of this ecosystem. The delineation of microbiome dynamics is also helpful for distinguishing cause and effect in microbiome responses to environmental stimuli. Understanding the dimension of time in host-microbiome interactions is therefore critical for therapeutic strategies that aim at short-term or long-term engineering of the intestinal microbial community.

scholarly journals Assessing the Ageing Impact on Fatigue Life of Asphalt Concrete

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Saad Issa Sarsam
Keyword(s):  
Fatigue Life ◽  
Asphalt Concrete ◽  
Concrete Slab ◽  
Testing Temperature ◽  
Environmental Condition ◽  
Ageing Processes ◽  
Before And After ◽  
Short And Long Term ◽  
Asphalt Content

The fatigue life of asphalt concrete is often related to environmental condition, loading condition, ageing, material composition and  properties. This work investigates the influence of short and long term ageing of laboratory beam specimens, asphalt content, and testing temperature on fatigue life of asphalt concrete wearing course. Slab samples of (30 x 40x 6) cm have been prepared, beam specimens of (40x 5x 6) cm were cut from the asphalt concrete slab samples. Beam specimens were tested for fatigue life under the influence of three levels of micro strain (250, 400, and [3]750) at (5, 20, and 30) °C before and after practicing long-term aging. It was observed that the fatigue life decreases by (85 and 97) %, (87.5 and 97.4) %, (71.4 and 95.2) % after increasing the applied microstrain from (250 to 400 and 750) μƐ for control mixture and for mixtures subjected to short-and long-term ageing processes respectively. The fatigue life increases by (142.8 and 257.1) %, (34.4 and 57.8) % and (10 and 30) % when the asphalt content increases from (4.4 to 4.9 and 5.4) % for specimens practicing the applied microstrain of (250, 400 and 750) μƐ respectively. It was concluded that the fatigue life increases by a range of (two to fifteen) folds when the testing temperature increases from (5 to 20 and 30)°C respectively.

scholarly journals Improving The Performance of Asphalt Concrete Mixtures With Polymer Asphalt in Submerged Floods

2021 ◽  
Vol 2 (02) ◽  
pp. 62-69
Author(s):  
Yanuar Setiawan ◽  
Erlina Yanuarini ◽  
Nunung Martina ◽  
Muhammad Fathur Rouf Hasan ◽  
Rinawati Rinawati
Keyword(s):  
Asphalt Concrete ◽  
Asphalt Pavement ◽  
Water Immersion ◽  
The Road ◽  
Concrete Mixtures ◽  
Asphalt Content ◽  
The Difference ◽  
The Stability

The road conditions which is always submerged can reduce the performance of the asphalt pavement. This research was conducted to obtain the characteristics of polymer asphalt concrete against flooding. Marshall testing was carried out on conventional and polymer asphalt concrete with optimum asphalt content treated with water immersion in variations of 0 days, 0.5 days, 1 day, 2 days, and 4 days. The results show polymer asphalt can improve the durability of asphalt concrete which is submerged in floodwater. This is indicated by the difference in the stability value of 113% in the variation of immersion for 4 days.

The IMO Initial Strategy for the Reduction of GHGs from International Shipping: A Commentary

2019 ◽  
Vol 34 (3) ◽  
pp. 482-512
Author(s):  
Aldo Chircop
Keyword(s):  
International Standards ◽  
Shipping Industry ◽  
Short Term ◽  
International Convention ◽  
International Shipping ◽  
The Road ◽  
Initial Strategy ◽  
On The Road

AbstractIn 2018 the IMO adopted the initial Strategy for the international shipping industry’s reduction of global greenhouse gas emissions towards achieving the goal set in the 2015 Paris Agreement. At this time the Strategy is no more than a preliminary structure to frame the measures that will need to be adopted for the short, medium and long terms. In the short term (2018–2023) a first suite of measures will be adopted, and the initial Strategy will be revised and adopted as changed in 2023 with proposed measures for the medium term (2023–2030) and long term (2030–2050 and beyond). New international standards, tools and best practices will be needed to supplement the existing energy efficiency management rules in the International Convention on the Prevention of Pollution from Ships, 1973/78. This article discusses the Strategy and the role of the IMO in leading the shipping industry on the road to decarbonization.

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 Antioxidant Characteristic from Waste Cooking Oil in Modified Asphalt Binder

2016 ◽  
Vol 700 ◽  
pp. 197-206 ◽  
Author(s):  
Wan Nur Aifa Wan Azahar ◽  
Mastura Bujang ◽  
Ramadhansyah Putra Jaya ◽  
Mohd Rosli Hainin ◽  
Norzita Ngadi ◽  
...  
Keyword(s):  
Aging Process ◽  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Waste Cooking Oil ◽  
Short Term ◽  
Aging Rate ◽  
Modified Asphalt ◽  
Cooking Oil ◽  
Modified Asphalt Binder

Aging process especially in asphalt binder material can occur throughout the life cycle of asphalt pavement starting from mixing, placement and during the service life. During this process, the more stiffer and brittle of asphalt binder is produced due to age hardening and gives an indication of initial factor of deterioration in asphalt pavement. A number of noteworthy researchers have focused on oil based modification to produce modified asphalt binder by using Waste Cooking Oil (WCO), due to the presence of natural antioxidant properties possessed in WCO. Antioxidant has played the role as an oxidative inhibition and has the potential to minimize the aging rate to occur. The aging process is conducted by separating between short term and long term aging where short term oxidative aging of binders was simulated using rolling thin film oven (RTFO) while long term aging was performed using pressure aging vessel (PAV). The laboratory evaluation was carried out to investigate the relationship between the qualities of WCO that affect the availability of antioxidant amount towards the susceptibility of aging rate by conducting Dynamic Shear Rheometer (DSR). The result from rheological studies demonstrated that the lowest Aging Index (AI) is presented as 2.14, 2.18 and 1.79 for replacement by using WCO in December sample at concentration of 3%, 4% and 5% for short term aging while AI at 3% = 5.17 and 5% = 7.22 for long term aging. Therefore, the high quality of oil represented by WCO in December sample has indicated the high availability of antioxidant content that can minimize the aging susceptibility in the asphalt binder modified by WCO.

Long-Term Oven-Aging Effects on Fatigue and Initial Stiffness of Asphalt Concrete

1997 ◽  
Vol 1590 (1) ◽  
pp. 89-98 ◽  
Author(s):  
John Harvey ◽  
Bor-Wen Tsai
Keyword(s):  
Fatigue Life ◽  
Asphalt Concrete ◽  
Void Content ◽  
Aging Effects ◽  
Initial Stiffness ◽  
Asphalt Content ◽  
Flexural Beam ◽  
Air Void ◽  
Air Void Content

An investigation of the effects of long-term oven aging (LTOA) on initial stiffness and fatigue of asphalt concrete was made using two typical California asphalts, known to have different aging characteristics, in mixes with one aggregate. Asphalt content, air-voids content, and days of LTOA were varied independently. Stiffness and fatigue were evaluated using the controlled-strain flexural beam test developed by the Strategic Highway Research Program Project A-003A. The results indicated that both mixes exhibited an increase in initial stiffness with LTOA periods of up to six days. The sensitivity of beam fatigue life to LTOA depended on the asphalt. Beams containing Valley asphalt had virtually no change in fatigue life due to LTOA, whereas beams with Coastal asphalt showed some sensitivity to LTOA. For both asphalts, the average reduction in fatigue life from 6 days of LTOA was less than that caused by a 3 percent increase in air-void content or a 1 percent decrease in asphalt content. Simulations of thick and thin pavement structures were performed to reconcile the effects of LTOA, asphalt content, and air-void content on mix fatigue life and stiffness by evaluating their combined effects on predicted pavement fatigue life. The simulations indicated that aging, as induced by LTOA, increased fatigue life for all cases except one.

scholarly journals Association between ambient temperature and cognitive function in a community-dwelling elderly population: a repeated measurement study

BMJ Open ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. e049160
Author(s):  
Yuan-Ting C Lo ◽  
Wei-Peng Su ◽  
Shu-Hsuan Mei ◽  
Yann-Yuh Jou ◽  
Han-Bin Huang
Keyword(s):  
Older Adults ◽  
Cognitive Impairment ◽  
Cognitive Function ◽  
Ambient Temperature ◽  
Air Temperature ◽  
Community Dwelling ◽  
Secondary Outcome ◽  
Short Term ◽  
Temperature Exposure

ObjectivesEvidence on the associations between short-term and long-term air temperature exposure and cognitive function in older adults, particularly those in Asia, is limited. We explored the relationships of short-term and long-term air temperature exposure with cognitive function in Taiwanese older adults through a repeated measures survey.Design and settingWe used data the ongoing Taiwan Longitudinal Study on Aging, a multiple-wave nationwide survey.ParticipantsWe identified 1956, 1700, 1248 and 876 older adults in 1996, 1999, 2003 and 2007, respectively.Primary and secondary outcome measuresParticipants’ cognitive function assessment was based on the Short Portable Mental Status Questionnaire. We calculated the temperature moving average (TMA) for temperature exposure windows between 1993 and 2007 using data from air quality monitoring stations, depending on the administrative zone of each participant’s residence. Generalised linear mixed models were used to examine the effects of short-term and long-term temperature changes on cognitive function.ResultsShort-term and long-term temperature exposure was significantly and positively associated with moderate-to-severe cognitive impairment, with the greatest increase in ORs found for 3-year TMAs (OR 1.247; 95% CI 1.107 to 1.404). The higher the quintiles of temperature exposure were, the higher were the ORs. The strongest association found was in long-term TMA exposure (OR 3.674; 95% CI 2.103 to 6.417) after covariates were controlled for.ConclusionsThe risk of mild cognitive impairment increased with ambient temperature in community-dwelling older adults in Taiwan.

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