نتایج جستجو برای: bitumen

تعداد نتایج: 1875  

2017
Sabrina B Sholts Kevin Smith Cecilia Wallin Trifa M Ahmed Sebastian K T S Wärmländer

BACKGROUND Polycyclic aromatic hydrocarbons (PAHs) are the main toxic compounds in natural bitumen, a fossil material used by modern and ancient societies around the world. The adverse health effects of PAHs on modern humans are well established, but their health impacts on past populations are unclear. It has previously been suggested that a prehistoric health decline among the native people l...

Fereidoon Moghadas Nejad Mohammad Reza Allahgholi Ghasri Sholeh Kazemifard Sima Habibi

The fuel resistance property plays an important role in asphalts, but available standards for determining this characteristic are presently lacking. In the present work, a number of polymer modified bitumen with styrene-butadiene-styrene (SBS) polymer (4, 5, 6% SBS) and SBS/ sulfur modified bitumen with various percentages of sulfur (1.65, 3, 3.5% based on polymer content) were prepared. Each s...

2012
Roland I. Hall Brent B. Wolfe Johan A. Wiklund Thomas W. D. Edwards Andrea J. Farwell D. George Dixon

BACKGROUND The extent to which Alberta oil sands mining and upgrading operations have enhanced delivery of bitumen-derived contaminants via the Athabasca River and atmosphere to the Peace-Athabasca Delta (200 km to the north) is a pivotal question that has generated national and international concern. Accounts of rare health disorders in residents of Fort Chipewyan and deformed fish in downstre...

2009
Mohamed Abdel Raouf

Most bituminous adhesives or binders that are used for pavement materials are derived mainly from fossil fuels. Due to the availability of large quantities of biorenewable sources such as triglyceride oils, proteins, starch, and other carbohydrates from different organic sources, there are virtuous technical and economic prospects in utilizing them to produce bio-binders. Recently, through the ...

2012
T SUBRAMANI

The development of transportation plays an important role in the development of nation. With flexible pavements being widely used in India, steps must be taken to increase the life of the bituminous pavements. Flexible pavements are often plagued with problems of cracking and rutting due to repeated traffic loads. Hence one needs to address these problems in order to improve the performance of ...

2014
Hassan Al-Haj Ibrahim Ali Abdullah

Syrian petroleum coke, produced by a delayed coking unit, is characterized by a high percentage of fines which tends to reduce its commercial value. Blending coke fines using appropriate binders, such as bitumen and polyacrylic acid, can lead, however, to an improved coke that is similar in structure, appearance and other properties to better-quality coke lumps. In this work, samples of Syrian ...

Journal: :The Annals of occupational hygiene 2000
P Bonnet S Binet H Brandt A J Kriech M Lafontaine H Nunge Y Morele P de Groot H Wissel M Castegnaro

Bitumen fumes emitted during road paving or roofing contain polycyclic aromatic hydrocarbons (PAHs). Experimental studies have been previously performed to test the carcinogenic potency of bitumen fumes. Some of them have been criticised either on the grounds that the fume condensates were not representative of fumes to which humans are exposed or because the fumes were never characterised in t...

2005
M. H. ALAWI M. I. RAJAB

Neural Networks technology provides several reliant analysis in many science and technology applications. In particular neural network is often applied to the development of statistical models for intrinsically non-linear systems, since neural networks behave better in complex conditions. In this research, applications of neural networks in determination of optimum bitumen content, Marshall Sta...

2011
Sebastian K.T.S. Wärmländer Sabrina B. Sholts Jon M. Erlandson Thor Gjerdrum Roger Westerholm

BACKGROUND The negative health effects of polycyclic aromatic hydrocarbons (PAHs) are well established for modern human populations but have so far not been studied in prehistoric contexts. PAHs are the main component of fossil bitumen, a naturally occurring material used by past societies such as the Chumash Indians in California as an adhesive, as a waterproofing agent, and for medicinal purp...

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