scholarly journals Chemical and Rheological Evaluation of Aged Lignin-Modified Bitumen

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4176 ◽  
Author(s):  
Yi Zhang ◽  
Xueyan Liu ◽  
Panos Apostolidis ◽  
Wolfgang Gard ◽  
Martin van de Ven ◽  
...  
Keyword(s):  
Environmental Benefits ◽  
Asphalt Pavements ◽  
Environmental Scanning ◽  
Physical Interaction ◽  
Test Results ◽  
Modified Bitumen ◽  
Oxidative Aging ◽  
Anti Oxidant ◽  
Rheological Effect

As bitumen oxidizes, material stiffening and embrittlement occur, and bitumen eventually cracks. The use of anti-oxidants, such as lignin, could be used to delay oxidative aging and to extend the lifetime of asphalt pavements. In this study, the chemical and rheological effect of lignin on bitumen was evaluated by using a single dosage organsolv lignin (10 wt.% dosage). A pressure aging vessel (PAV) was used to simulate the long-term aging process after performing the standard short-term aging procedure, and the lignin-modified bituminous binders were characterized by an environmental scanning electron microscope (ESEM), Fourier-transform infrared (FTIR) spectroscopy, and a dynamic shear rheometer (DSR). From the ESEM results, the uniform microstructure was observed, indicating that the addition of lignin did not affect the worm structure of bitumen. Based on the FTIR test results, lignin-modified bitumen showed that a lower number of carbonyl and sulfoxide compounds were generated after aging than for neat bitumen. Based on the linear amplitude sweep (LAS) results, the addition of lignin slightly reduced the fatigue life of bitumen. From the frequency sweep results, it showed that lignin in bitumen acts as a modifier since the physical interaction between lignin and bitumen predominantly affects the material rheology. Overall, lignin could be a promising anti-oxidant due to its economic and environmental benefits.

The Utilization of Rice Husks Powder as an Antioxidant in Asphalt Binder

2014 ◽  
Vol 567 ◽  
pp. 539-544 ◽  
Author(s):  
Mohammed Hadi Nahi ◽  
Ibrahim B. Kamaruddin ◽  
Napiah Madzlan
Keyword(s):  
Thermal Stresses ◽  
Asphalt Binder ◽  
Fine Powder ◽  
Age Hardening ◽  
Asphalt Pavements ◽  
Rice Husks ◽  
Antioxidant Additive ◽  
Oxidative Aging ◽  
Point Test

Aging is one of the main contributors for asphalt failure. Oxidation aging is the main cause of long-term deterioration in asphalt pavements as a pavement ages, oxidation stiffens a pavement, making it more susceptible to failure from load and thermal stresses. Slowing a pavement’s oxidative aging would maintain its elastic properties and delay aging problems. There is no performance enhancer in widespread use, acting as an antioxidant that slows the oxidative aging of asphalt binder. The main objective of this research is to investigate the feasibility of using biomass powder derived from rice husks as an antioxidant additive to control the asphalt age hardening. The waste of rice husks was dried at 40°C for 9–11 days. The dried materials was grounded, and sieved to get fine powder. To evaluate the performance of the antioxidant, samples have to be aged according to SUPERPAVE standards (RTFOT and PAV) and physical, chemical, and rheological properties have to be analyzed. The preliminary results of penetration test softening point test shows that adding 4% of rice husks’ powder to 80/100 binder didn’t change the grade of the binder.

Influence Analysis of Performance on Sasobit Warm Mix Asphalt with Salinity

2014 ◽  
Vol 490-491 ◽  
pp. 138-141
Author(s):  
Kun Wang ◽  
Jing Ya Chen ◽  
Xiang Qu
Keyword(s):  
Low Temperature ◽  
Environmental Benefits ◽  
Fatigue Performance ◽  
Test Results ◽  
Temperature Performance ◽  
Cracking Performance ◽  
Low Temperature Cracking ◽  
Short And Long Term ◽  
Analysis Of Performance

Sasobit warm mix drainage asphalt pavement has become increasingly popular due to its environmental benefits and comfortable using effect. However, test results show that its low-temperature and anti-fatigue performance have a certain degree of reduced. To improve the performance of asphalt four different doses (1%, 3%, 5% and 7%) of salt are added to the Sasobit asphalt. Laboratory tests were used to simulate short and long term aging asphalt in the process of construction and using pavement. A series of binder tests including bending beam rheometer (BBR), dynamic shear rheometer (DSR) and Brookfield viscosity tests were conducted. Results show an increase of rutting performance for warm mix binders with Sasobit while asphalt with salt has similar high temperature performance to original asphalt. Unlike Sasobit which has a decrease of cracking performance for asphalt at low-temperature, salinity can greatly improve the Low-temperature performance. And the low-temperature cracking performance and anti-fatigue performance presents a tendency of climbing up first and then declining with the increase of salinity. The figure of viscosity-temperature curve shows that the optimum of salinity is 5%.Further more, asphalt with Sasobit and salt can gain better performance and same mixing and compaction effect in lower 20°C than hot mix asphalt without it.

Effect of Hydrated Lime on Long-Term Oxidative Aging Characteristics of Asphalt

2002 ◽  
Vol 1810 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Shin-Che Huang ◽  
J. Claine Petersen ◽  
Raymond Robertson ◽  
Jan F. Branthaver
Keyword(s):  
Phase Angle ◽  
Fatigue Cracking ◽  
Hydrated Lime ◽  
Age Hardening ◽  
Asphalt Binders ◽  
Asphalt Pavements ◽  
Initial Stiffness ◽  
Oxidative Aging ◽  
Useful Lifetime

An experiment involving neat asphalts AAD-1, ABD, and their mixtures with two different grades of hydrated lime was conducted to investigate the effect of lime on the long-term aging characteristics of asphalt binders. Rheological properties of unaged and aged asphalt-lime mixtures were measured with a dynamic shear rheometer at 25°C (77°F) and 60°C (140°F). The addition of hydrated lime to one asphalt (AAD-1) effectively reduced oxidative age hardening. In addition, the phase angle reached the same value as aging time reached after approximately 800 h at 60°C in the pressure-aging vessel for AAD-1 and its mixtures with lime. After 800 h of aging, the phase angle was greater for the limetreated asphalt than for the untreated asphalt, and it continued to decrease at a slower rate. This result indicates that the addition of lime to this asphalt increases the initial stiffness of the binder, but, more importantly, it preserves elasticity during long-term oxidative aging. Thus, for this asphalt, at a level of oxidation typical of pavements, limetreated and untreated asphalts arrived at the same viscosity with time, but the lime-treated asphalt had better viscous flow properties than the untreated asphalt. It could then be predicted that the aged, lime-treated asphalt would be more resistant to fatigue cracking. The other asphalt tested (ABD) did not exhibit substantial effects of lime on the rate of oxidative age hardening. This highly compatible, low-asphaltene asphalt is not typical of most paving asphalts. Because hydrated lime has been shown to reduce oxidative age hardening both in the laboratory and during the first few years in the pavement, adding hydrated lime should extend the useful lifetime of most asphalt pavements.

Parents' long-term adjustment to the genetic test results of minors at risk for Long QT Syndrome

2004 ◽  
Author(s):  
K. S. W. H. Hendriks ◽  
F. J. M. Grosfeld ◽  
A. A. M. Wilde ◽  
J. van den Bout ◽  
I. M. van Langen ◽  
...  
Keyword(s):  
At Risk ◽  
Long Qt Syndrome ◽  
Genetic Test ◽  
Test Results ◽  
Long Qt ◽  
Genetic Test Results ◽  
Qt Syndrome

The Implementation Of Make A-Match Model In Social Science Learning To Improve Student Learning Outcomes In Class IV SDN 115 Manado

2019 ◽  
Vol Volume 2 Nomor 2 ◽  
Keyword(s):  
Social Science ◽  
Learning Outcomes ◽  
Teaching And Learning ◽  
Science Learning ◽  
Design Activity ◽  
Test Results ◽  
Match Model ◽  
Fourth Grade Students ◽  
Improve Student Learning

There is a tendency in the education field today to return to the idea that children will learn better if the environment is created naturally. Learning will be more meaningful if children "experience" themselves what they are learning, not 'knowing' it. Target-oriented learning of material mastery proves to be successful in short-term 'remembering' competitions, but fails to equip children to solve problems in long-term life. The problems that would to be studied in this study are: (a) how is the improvement of Social Science learning outcomes by applying the Make A-Match Model to it? (b) how does the Make A-Match Model apply towards the learning motivation? The objectives of this study are: (a) want to know the improvement in Social Science learning achievement after the implemetation of the Make A-Match Model. (b) want to know the effect of Make A-Match Model towards students’ motivation of the subject after it is applied. This research is used two rounds of action research. In each round consists of four stages, namely: design, activity and observation, reflection and revision. The target of this research is the fourth grade students of Mongodow. The data obtained in the form of formative test results, observation sheets of teaching and learning activities. From the results of analysts obtained student achievement has increased from cycle I to cycle II namely, cycle I (65%), cycle II (83%). The conclusion of this research is the Make A-Match Model of Social Science learning could positively influence the motivation of learning of central students, and this learning model could be used as an alternative to Social Science learning.

Long Term Field Test Results of Experimental EPDM and PUF Roofing

1990 ◽  
Author(s):  
David M. Bailey ◽  
Stuart D. Foltz ◽  
Myer J. Rosenfield
Keyword(s):  
Field Test ◽  
Test Results ◽  
Term Field

scholarly journals Multi-Criteria Selection of Additives in Porous Asphalt Mixtures Using Mechanical, Hydraulic, Economic, and Environmental Indicators

2021 ◽  
Vol 13 (4) ◽  
pp. 2146
Author(s):  
Anik Gupta ◽  
Carlos J. Slebi-Acevedo ◽  
Esther Lizasoain-Arteaga ◽  
Jorge Rodriguez-Hernandez ◽  
Daniel Castro-Fresno
Keyword(s):  
Cellulose Fiber ◽  
Environmental Indicators ◽  
Asphalt Mixtures ◽  
Environmental Benefits ◽  
Modified Bitumen ◽  
Porous Asphalt ◽  
Different Types ◽  
Product Assessment ◽  
Polymer Modified Bitumen ◽  
Selection Of

Porous asphalt (PA) mixtures are more environmentally friendly but have lower durability than dense-graded mixtures. Additives can be incorporated into PA mixtures to enhance their mechanical strength; however, they may compromise the hydraulic characteristics, increase the total cost of pavement, and negatively affect the environment. In this paper, PA mixtures were produced with 5 different types of additives including 4 fibers and 1 filler. Their performances were compared with the reference mixtures containing virgin bitumen and polymer-modified bitumen. The performance of all mixes was assessed using: mechanical, hydraulic, economic, and environmental indicators. Then, the Delphi method was applied to compute the relative weights for the parameters in multi-criteria decision-making methods. Evaluation based on distance from average solution (EDAS), technique for order of the preference by similarity to ideal solution (TOPSIS), and weighted aggregated sum product assessment (WASPAS) were employed to rank the additives. According to the results obtained, aramid pulp displayed comparable and, for some parameters such as abrasion resistance, even better performance than polymer-modified bitumen, whereas cellulose fiber demonstrated the best performance regarding sustainability, due to economic and environmental benefits.

scholarly journals Oral melatonin as a new tool for neuroprotection in preterm newborns: study protocol for a randomized controlled trial

Trials ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Francesca Garofoli ◽  
Stefania Longo ◽  
Camilla Pisoni ◽  
Patrizia Accorsi ◽  
Micol Angelini ◽  
...  
Keyword(s):  
Preterm Birth ◽  
Preterm Infants ◽  
Neurodevelopmental Outcome ◽  
Lipid Peroxidation Product ◽  
Cerebral Magnetic Resonance Imaging ◽  
Neurodevelopmental Impairment ◽  
Anti Oxidant ◽  
Preterm Newborns

Abstract Background Prevention of neurodevelopmental impairment due to preterm birth is a major health challenge. Despite advanced obstetric and neonatal care, to date there are few neuroprotective molecules available. Melatonin has been shown to have anti-oxidant/anti-inflammatory effects and to reduce brain damage, mainly after hypoxic ischemic encephalopathy. The planned study will be the first aiming to evaluate the capacity of melatonin to mitigate brain impairment due to premature birth. Method In our planned prospective, multicenter, double-blind, randomized vs placebo study, we will recruit, within 96 h of birth, 60 preterm newborns with a gestational age ≤ 29 weeks + 6 days; these infants will be randomly allocated to oral melatonin, 3 mg/kg/day, or placebo for 15 days. After the administration period, we will measure plasma levels of malondialdehyde, a lipid peroxidation product considered an early biological marker of melatonin treatment efficacy (primary outcome). At term-equivalent age, we will evaluate neurological status (through cerebral ultrasound, cerebral magnetic resonance imaging, vision and hearing evaluations, clinical neurological assessment, and screening for retinopathy of prematurity) as well as the incidence of bronchodysplasia and sepsis. We will also monitor neurodevelopmental outcome during the first 24 months of corrected age (using the modified Fagan Test of Infant Intelligence at 4–6 months and standardized neurological and developmental assessments at 24 months). Discussion Preterm birth survivors often present long-term neurodevelopmental sequelae, such as motor, learning, social-behavioral, and communication problems. We aim to assess the role of melatonin as a neuroprotectant during the first weeks of extrauterine life, when preterm infants are unable to produce it spontaneously. This approach is based on the supposition that its anti-oxidant mechanism could be useful in preventing neurodevelopmental impairment. Considering the short- and long-term morbidities related to preterm birth, and the financial and social costs of the care of preterm infants, both at birth and over time, we suggest that melatonin administration could lead to considerable saving of resources. This would be the first study addressing the role of melatonin in very low birth weight preterm newborns, and it could provide a basis for further studies on melatonin as a neuroprotection strategy in this vulnerable population. Trial registration ClinicalTrials.gov NCT04235673. Prospectively registered on 22 January 2020.

Clinical features, treatment, and outcome of dogs with Coccidioides osteomyelitis

2022 ◽  
pp. 1-8
Author(s):  
Stephanie L. Shaver ◽  
Daniel S. Foy ◽  
Todd D. Carter
Keyword(s):  
Electronic Medical Records ◽  
Medical Records ◽  
Clinical Signs ◽  
Test Results ◽  
Serologic Test ◽  
Rapid Improvement ◽  
Radiographic Appearance ◽  
One Year ◽  
Positive Results

Abstract OBJECTIVE To describe signalment, clinical signs, serologic test results, treatment, and outcome of dogs with Coccidioides osteomyelitis (COM) and to compare those findings with findings for dogs with osteosarcoma (OSA). ANIMALS 14 dogs with COM and 16 dogs with OSA. PROCEDURES Data were retrospectively gathered from electronic medical records. RESULTS Dogs with COM were younger and weighed less than dogs with OSA. Six dogs with COM had appendicular lesions, 5 had axial lesions, and 3 had both appendicular and axial lesions; 9 had monostotic disease, and 5 had polyostotic disease. Axial lesions and nonadjacent polyostotic disease were more common in dogs with COM than in dogs with OSA, but radiographic appearance was not different between the 2 groups. Median IgG titer at diagnosis of COM was 1:48 and was significantly decreased after 6 and 12 months of treatment. Percentage of dogs with COM that had clinical signs was significantly decreased after 1, 3, 6, and 12 months of treatment. One year after initiation of treatment, 9 of 9 dogs were still receiving fluconazole and 8 of 9 dogs had positive results for serum IgG titer testing. CLINICAL RELEVANCE Dogs with COM typically had a rapid improvement in clinical signs after initiating treatment with fluconazole but required long-term antifungal treatment. Dogs with COM differed from dogs with OSA, but radiographic features had a great degree of overlap between groups, confounding the ability to make a diagnosis on the basis of diagnostic imaging alone.

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