scholarly journals Bitumen and Bitumen Modification: A Review on Latest Advances

2019 ◽  
Vol 9 (4) ◽  
pp. 742 ◽  
Author(s):  
Michele Porto ◽  
Paolino Caputo ◽  
Valeria Loise ◽  
Shahin Eskandarsefat ◽  
Bagdat Teltayev ◽  
...  

This synthesis explores the state-of-the-knowledge and state-of-the-practice regarding the latest updates on polymer-modified bitumens (PmBs). The information in this study was gathered from a thorough review of the latest papers in the literatures related to modified bituminous materials, technologies, and advances. For this purpose, the paper is presented in two principle sections. In the first part, the bitumen itself is investigated in terms of chemical structure and microstructural systems. In the second part, the paper focuses on bitumen modification from different aspects for assessing the effectiveness of the introduced additives and polymers for enhancing the engineering properties of bitumen in both paving and industrial applications. In conclusion, the knowledge obtained in this study has revealed the importance of the chemical composition of base bitumen for its modification. It can be declared that while some polymers/additives can improve one or some aspects of neat bitumen properties, they can lead to compatibility problems in storage and production. In this respect, several studies showed the effectiveness of waxes for improving the compatibility of polymers with bitumen in addition to some benefits regarding warm mix asphalt (WMA) production.

2021 ◽  
pp. 125753
Author(s):  
Abhishek Singhal ◽  
Maria Goossens ◽  
Davide Fantozzi ◽  
Antti Raiko ◽  
Jukka Konttinen ◽  
...  

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Ahmed Salah Mahmoud Ahmed Shehata ◽  
Mohamed Rafik El-Halaby ◽  
Ahmed Mohamed Saafan

Abstract Objectives to make a reliable correlation between the chemical composition of the urinary calculi and its Hounsfield unit on CT scan, upon which we can depend on it for prediction of the type of the urinary calculi. The prediction of the chemical structure of the stone would help us to reach a more efficient therapeutic and prophylactic plan. Methods A retrospective study was performed by interpretation of the preoperative CT scans for patients who were presented by urinary stones. Identification of the chemical structure of the calculi was implemented using Fourier Transform Infrared Spectroscopy (FT-IR spectroscopy). The laboratory report revealed multiple types of stones either of pure or mixed composition. Afterwards, a comparison was done between Hounsfield units of the stones and the chemical structure. Results The chemical structure of the urinary stones revealed four pure types of stones (Uric acid, Calcium Oxalate, Struvite and Cystine) and two types of mixed stones (mixed calcium oxalate+ Uric, and mixed calcium oxalate+ calcium phosphate). Uric acid stone had a mean Hounsfield Unit (HU) density of428 ± 81, which was quite less than the other stones, followed by struvite stones with density ranging about 714 ± 38. Mixed calcium oxalate stones could be differentiated from other types of stones like uric acid, pure calcium oxalate and struvite stones by the Hounsfield unit of Computed Tomography (the mean Hounsfield Unit was 886 ± 139 and 1427 ± 152 for mixed calcium oxalate + uric stone and mixed calcium oxalate + calcium phosphate stones respectively). Moreover, pure calcium oxalate stones were easily differentiated from all other stones using the mean Hounsfield density as it was 1158 ± 83. It was challenging only when it was compared to cystine stones, as they were quiet similar to HU value (997 ± 14). The variation of Hounsfield values among the previously mentioned stones, was statistically significant (p < 0.001). Conclusion The study proved that the Hounsfield Unit of CT scanning is a convenient measure to predict the chemical structure of urinary calculi.


Sensors ◽  
2020 ◽  
Vol 20 (5) ◽  
pp. 1459 ◽  
Author(s):  
Tamás Czimmermann ◽  
Gastone Ciuti ◽  
Mario Milazzo ◽  
Marcello Chiurazzi ◽  
Stefano Roccella ◽  
...  

This paper reviews automated visual-based defect detection approaches applicable to various materials, such as metals, ceramics and textiles. In the first part of the paper, we present a general taxonomy of the different defects that fall in two classes: visible (e.g., scratches, shape error, etc.) and palpable (e.g., crack, bump, etc.) defects. Then, we describe artificial visual processing techniques that are aimed at understanding of the captured scenery in a mathematical/logical way. We continue with a survey of textural defect detection based on statistical, structural and other approaches. Finally, we report the state of the art for approaching the detection and classification of defects through supervised and non-supervised classifiers and deep learning.


2019 ◽  
Vol 20 (7) ◽  
pp. 707 ◽  
Author(s):  
Michal Malík ◽  
Jiří Primas ◽  
Michal Kotek ◽  
Darina Jašíková ◽  
Václav Kopecký

The mixing of two immiscible phases is a process commonly seen in many industrial applications. Whether it is desirable (e.g. mixing of ingredients in chemical or food industry) or undesirable (e.g. sediments or contaminants in water purification) process, it has to be taken into consideration and a detailed description would be beneficial to any end product. This paper deals with a method for observing the volume ratio of two immiscible phases from the state of total separation to the state of a homogenous mixture using industrial Electrical Impedance Tomography (EIT) system ITS p2+. This paper also shows a great advantage in combining the EIT measuring method with a theoretically derived formula. It is used to calculate the concentration of a non-conductive phase in the final mixture using the initial and final conductivity values. The authors were also able to show a possibility to successfully use the formula in situations, where the initial conditions for it are not fully met.


1985 ◽  
Vol 7 ◽  
pp. 185-190 ◽  
Author(s):  
R.S. Schemenauer ◽  
P.W. Summers ◽  
H.A. Wiebe ◽  
K.G. Anlauf

The physical and chemical structure of the snowpack near North Bay, Ontario was examined during the winter of 1984. precipitation chemistry measurements were also made. A marked areal uniformity was noted in the layered structure of the snowpack and in the vertical variation of the chemical composition. In late January, pH values of the snowpack varied from ∼4.1 at the surface to ∼4.8 near the ground. After rain and a major thaw in February the pH was near 4.8 throughout. Nitrate concentrations exceeded those of sulfate in the snowpack. The molar concentration ratio of / was typically 0.5. Samples of precipitation from six sites had pH values ranging from 3.4 to 5.2. to equivalent ratios were <1 in snow and near 1 or >1 in rain. The chemical composition of the precipitation was closely related to the airmass trajectory. Southerly trajectories yielded the lowest pH values and highest pollutant concentrations. The one-month period from 20 January to 21 February had a deposition of 0.2 g m−2 and a deposition of 0.35 g m−2. For , this deposition would be about one-twelfth the expected annual deposition and for about one-fifth.


2019 ◽  
Vol 15 (S357) ◽  
pp. 119-122
Author(s):  
S. Charpinet ◽  
P. Brassard ◽  
N. Giammichele ◽  
Gilles Fontaine

AbstractGiammichele et al. (2018) proposed a full determination, largely independent of evolution calculations, of the chemical composition and stratification inside the hot pulsating DB white dwarf KIC 08626021. However, Timmes et al. (2018) pointed out that neglecting the effects of neutrino cooling, such as in the static models used in Giammichele et al. study, could impact significantly the derived seismic solution and compromise conclusions drawn upon it. Here we present a reanalysis of KIC 08626021, using improved static models which now incorporate more realistic luminosity profiles that reflect the still significant energy losses induced by neutrino emission mechanisms in hot DB white dwarfs. We show that this effect has only a limited impact on the derived seismic model properties and, more importantly, that all the conclusions brought by Giammichele et al. (2018) remain entirely valid.


2020 ◽  
Vol 12 (5) ◽  
pp. 1187-1215 ◽  
Author(s):  
Pallavi Kumari ◽  
Visakh V.S. Pillai ◽  
Antonio Benedetto

Abstract Ionic liquids (ILs) are a relatively new class of organic electrolytes composed of an organic cation and either an organic or inorganic anion, whose melting temperature falls around room-temperature. In the last 20 years, the toxicity of ILs towards cells and micro-organisms has been heavily investigated with the main aim to assess the risks associated with their potential use in (industrial) applications, and to develop strategies to design greener ILs. Toxicity, however, is synonym with affinity, and this has stimulated, in turn, a series of biophysical and chemical-physical investigations as well as few biochemical studies focused on the mechanisms of action (MoAs) of ILs, key step in the development of applications in bio-nanomedicine and bio-nanotechnology. This review has the intent to present an overview of the state of the art of the MoAs of ILs, which have been the focus of a limited number of studies but still sufficient enough to provide a first glimpse on the subject. The overall picture that emerges is quite intriguing and shows that ILs interact with cells in a variety of different mechanisms, including alteration of lipid distribution and cell membrane viscoelasticity, disruption of cell and nuclear membranes, mitochondrial permeabilization and dysfunction, generation of reactive oxygen species, chloroplast damage (in plants), alteration of transmembrane and cytoplasmatic proteins/enzyme functions, alteration of signaling pathways, and DNA fragmentation. Together with our earlier review work on the biophysics and chemical-physics of IL-cell membrane interactions (Biophys. Rev. 9:309, 2017), we hope that the present review, focused instead on the biochemical aspects, will stimulate a series of new investigations and discoveries in the still new and interdisciplinary field of “ILs, biomolecules, and cells.”


2019 ◽  
Vol 81 (4) ◽  
Author(s):  
Gatot Rusbintardjo ◽  
Sitti Salmah Abdul Wahab ◽  
Faridah Hanim Khairuddin ◽  
Ahmad Nazrul Hakimi Ibrahim ◽  
Nur Izzi Md Yusoff ◽  
...  

Pavement failure phenomena is normally caused by low quality of mixture materials, especially bitumen. The modification of bitumen is one of the alternatives to improve the performance of the material. Therefore, this study was conducted to investigate the performance of a polymer-modified binder (PG-76) with the addition of different percentages of Reduce Heat-Warm Mix Asphalt (RH-WMA) at 1, 2, 3, 4 and 5 % (by-weight of binder). Several testings such as penetration, softening point and ductility tests were conducted to determine the physical properties of PG-76 and RH-WMA modified binders. The molecular structures of the materials were analysed using Fourier transform infrared spectroscopy (FTIR) test while the contact angle test was conducted to investigate the type of binder’s surface. In addition, an optical microscopy test was carried out to determine the morphological properties of the modified binders. Results show that the PG-76’s hardness decreases with the increasing of RH-WMA percentage, but the ductility values are still within the specification. The FTIR test shows an increase of RH-WMA percentage does not provide a significant reaction of the binder and the original properties of the materials remain. The morphology test shows that all percentage of RH-WMA selected are well dispersed in bitumen PG-76. Based on the contact angle results, all the PG-76 and RH-WMA modified binders fall into hydrophobic category.


2020 ◽  
Vol 299 ◽  
pp. 938-942
Author(s):  
Leonid Moiseevich Gurevich ◽  
Dmitri Pronichev ◽  
Aleksey Serov

The structure and chemical composition of the surface layers of aluminum 6000-series alloys after crystallization and homogenization annealing at 580 °C were investigated. It is shown that the state of the surface significantly depends on the presence of impurities in the coolant of the crystallizer, which deteriorate the continuity of the oxide film, which leads to the formation of light color of individual parts of the ingot surface.


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