An easy method for green and low-temperature (40°C) reduction of graphene oxide (GO) by increasing the antioxidant activity of green tea polyphenols (GTPs) in the presence of iron was developed. The ...reduction level (obtained by X-ray photoelectron spectroscopy) and electrical conductivity (obtained by current–voltage measurement) of the GO sheets reduced by GTPs in the presence of iron were comparable to those of hydrazine-reduced GO and much better than those of the GO reduced by only GTPs (in the absence of iron) at reduction temperatures of 40–80°C. Raman spectroscopy indicated that application of GTPs in the presence of iron, in contrast to hydrazine, resulted in better recovering of the sp2-hybridized structure of the sheets. The lasting water dispersion of the polyphenolic-reduced GO sheets in the presence of iron was assigned to π–π adsorption of Fe2+-polyphenol radicals on surface of the reduced sheets. A mechanism describing the role of iron in the reduction of the GO by epicatechin gallate and epigallocatechin gallate of green tea was also proposed.
The accurate prediction of the pavement temperature profile and history is critical for the calculation of the viscoelastic response of asphalt concrete pavements under traffic and thermal loadings. ...An accurate prediction is also essential in the estimation of the asphalt binder oxi-dative aging. A sound alternative approach is proposed to predict the pavement temperature profile with the finite control volume method in a fully implicit scheme. The model for the finite control volume method provides a fundamental and clear understanding of the heat energy balance, including the incoming and outgoing thermal energies, in addition to the dissipated heat in the system. Also, the variability in the materials’ thermal properties in a multilayered pavement structure can be remedied by assigning appropriate thermal properties to each control volume or cell. The fully implicit scheme improved the time efficiency of the calculation significantly. Moreover, enhancements were made by defining the accurate heat balance equations for the pavement surface and the bottom boundary conditions. With reliable meteorological data, solar radiation, and monthly variable pavement surface radiation properties, accurate prediction of the pavement temperature profile was made possible as validated by comparison with field measurements. Consequently, Windows-compatible software has been developed on the basis of the proposed model, which is capable of effectively predicting the pavement temperature profile and history.
Fuzzy filters in pseudo hoops Alavi, S.Z.; Borzooei, R.A.; Aaly Kologani, M.
Journal of intelligent & fuzzy systems,
01/2017, Letnik:
32, Številka:
3
Journal Article
Recenzirano
The aim of this paper is to introduce the notions of fuzzy filters, fuzzy (positive) implicative filters and fuzzy fantastic filters in pseudo hoops and investigate some of their properties. Some ...characterizations of fuzzy filters and fuzzy implicative filters are derived. The relation among these fuzzy filters are investigated and it is proved that any fuzzy fantastic and fuzzy positive implicative filter is a fuzzy implicative filter. Finally, we define a congruence relation by fuzzy filters on pseudo hoops and prove that if μ is a fuzzy normal implicative filter or fuzzy positive implicative filter, then A/μ is a Boolean algebra.
Folding theory applied to pseudo-hoops Borzooei, R. A.; Alavi, S. Z.; Kologani, M. Aaly ...
Journal of intelligent & fuzzy systems,
01/2020, Letnik:
39, Številka:
1
Journal Article
Recenzirano
In this paper, by considering the notion of pseudo-hoops, which introduced by Georgescu 10, we presented the concepts of n-fold filters in pseudo-hoop. Concerning ideas, we gave some related results. ...Also, we extended our definition to n-fold (positive) implicative and n-fold fantastic filters and investigated their properties and the relation among these n-fold filters. In particular, we proved that every n-fold fantastic and positive implicative filter is an n-fold implicative filter. Finally, we studied the quotient of these filters.
The application of crumb rubber in the asphalt industry has demonstrated many advantages in pavement, yet the challenges associated with its application in pavement construction have limited its ...usage. In this study, Bio-Binder was used as an additive for crumb-rubber-modified (CRM) asphalt binder to enhance its rheological properties while improving workability and reducing segregation. The product produced by adding Bio-Binder to CRM binder is called Bio-Modified-Rubber (BMR) binder. Rheological studies showed a reduction in the mixing and compacting temperatures of BMR binder in comparison to CRM binder, which consequently leads to improvement in the workability and pumpability of the resulting asphalt mixture. The segregation which was quantified using a phase separation index, reduced from 58% in CRM binder to 33% in BMR binder. In addition, BMR binder showed better fatigue cracking resistance than both CRM and neat binders. Evaluating low-temperature properties of specimens conditioned at −12 °C for 12 h showed that BMR binder had improved low-temperature properties compared to CRM binder. In addition, mixture studies were conducted on the fine aggregate matrix (FAM). It was shown that low-temperature properties of FAM mixes made with BMR were significantly better than those of CRM mixtures.
As virgin pavement material sources become scarcer and costlier, the use of higher quantities of reclaimed asphalt pavement (RAP) in the production of new asphalt mixes becomes desirable. A major ...concern associated with the use of high percentages of RAP in new mixes is the interaction between age-hardened and new binders because the performance of the mix can be highly influenced by the properties of the composite binder. The objective of this study was to use asphalt binder testing and diffusion and aging theory to investigate the evolution of blending of virgin and RAP binders during asphalt mix production, storage, and placement. The rheological properties of a two-layer asphalt binder sample composed of virgin and simulated RAP binder and conditioned over time at different temperatures were measured with a dynamic shear rheometer. The conditioning process simulated the hot-mix asphalt (HMA) and warm-mix asphalt (WMA) time–temperature paths during mixing, storage, and placement. The diffusion and aging coefficients for the composite binder were estimated by comparing measured shear stiffness values with those predicted with a diffusion model and considering asphalt binder aging over time. The diffusion model was solved numerically with the finite control volume approach. On the basis of the preliminary laboratory test results, full blending of the age-hardened binder and the new binder was observed during HMA mixing and construction, while only partial blending was achieved during WMA production and construction. The blending of age-hardened and new binders could potentially be improved with the aid of warm-mix admixtures, rejuvenating agents, or both.
Arterial glycosaminoglycans are considered to be important in atherogenesis due to their ability to trap lipid inside the vessel wall and to influence cellular migration and proliferation. ...Atherosclerotic lesions have displayed an altered glycosaminoglycan content and distribution. Diabetes is a recognized risk factor for atherosclerosis, but no information is available on the arterial glycosaminoglycans in human diabetes. We examined glycosaminoglycans in normal and atherosclerotic intima of non-diabetic and Type 2 (non-insulin-dependent) diabetic patients. Intima was stripped from autopsy samples of thoracic aortas; normal and plaque areas were separated. Glycosaminoglycans were isolated by delipidation, proteolytic digestion, and precipitation and characterized by quantitation of total glycosaminoglycan and evaluation of glycosaminoglycan distribution by electrophoresis and densitometry. Results indicate a significant decrease in total glycosaminoglycan and significant changes in their distribution in atherosclerotic plaques: a relative decrease in heparan sulphate, a relative increase in dermatan sulphate and thus a decrease in the ratio of heparan sulphate to dermatan sulphate. A similar but less marked change in the ratio was found in normal intima of diabetic subjects, while in their plaques this change was more pronounced. This suggests that changes in arterial glycosaminoglycans (especially the ratio of heparan sulphate to dermatan sulphate) precede the development of lesions in diabetes and may be important in atherogenesis.
To evaluate hepatitis B serological markers in pregnant women from various geographical sites in Kenya.
A cross-sectional observational study of women attending antenatal clinics.
The Kenyatta ...National Hospital and eight hospitals from five provinces in Kenya.
All women in their third trimester of pregnancy attending the antenatal clinic over the period June 2001 to June 2002.
For each pregnant woman age and gestation were documented. Hepatitis serological markers were evaluated.
A total of 2241 pregnant women were enrolled. Among them 205 women (9.3%) were positive for HbsAg and from these 18 (8.8%) were found to have HbeAg. Protective antibodies (anti-HbsAg) were detected in 669 (30.2%) of the women. There were notable significant regional differences for HbsAg rates.
These results confirm the presence of high disease carrier rate and the corresponding previously reported low level of HbeAg suggesting questionable low rate of perinatal transmission but high rate of horizontal transmission.
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