scholarly journals Advanced Characterization of Bituminous Binders: Comparing Industrial and Paving-Grade Bituminous Binders

2021 ◽  
Vol 23 (1) ◽  
pp. 45
Author(s):  
S. Eskandarsefat ◽  
P. Caputo ◽  
C. Oliviero Rossi ◽  
R. Vaiana ◽  
C. Sangiorgi

This paper deals with the fundamental differences between industrial and paving-grade bituminous binders. The paper is presented in two main sections: 1) a review of the materials’ colloidal structure and the required properties for the industrial and paving applications; 2) a wide range of experimental tests with which the bituminous binders were studied and compared. In this research, a 160/220 industrial bitumen was studied and compared to a paving-grade bitumen with the same penetration and with a lower penetration, 70/100 one. The research consisted of physical, chemical, thermal, microstructural, and rheological analysis to provide a comprehensive understanding of these bituminous binders of diverse applications. Overall, the comparison of the tests’ results indicated that while the asphaltene content and its characteristics have a great influence on the bitumen’s properties, it is not the only fundamental factor. During the study of the chemical structures via Atomic Force Microscopy (AFM), it was found that the Peri phase (attributed to the resins) also plays an important role, defining the bitumen’s physical visco-elastic properties. In fact, from a microstructural point of view using AFM a significant difference was notified between the industrial bitumen and the paving-grade ones. These differences allow the paving-grade bitumens to be more elastic and ductile compared to the industrial bitumen.

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1234 ◽  
Author(s):  
Henri Vahabi ◽  
Hadi Rastin ◽  
Elnaz Movahedifar ◽  
Karina Antoun ◽  
Nicolas Brosse ◽  
...  

Sustainable polymers are emerging fast and have received much more attention in recent years compared to petro-sourced polymers. However, they inherently have low-quality properties, such as poor mechanical properties, and inadequate performance, such as high flammability. In general, two methods have been considered to tackle such drawbacks: (i) reinforcement of sustainable polymers with additives; and (ii) modification of chemical structure by architectural manipulation so as to modify polymers for advanced applications. Development and management of bio-based polyurethanes with flame-retardant properties have been at the core of attention in recent years. Bio-based polyurethanes are currently prepared from renewable, bio-based sources such as vegetable oils. They are used in a wide range of applications including coatings and foams. However, they are highly flammable, and their further development is dependent on their flame retardancy. The aim of the present review is to investigate recent advances in the development of flame-retardant bio-based polyurethanes. Chemical structures of bio-based flame-retardant polyurethanes have been studied and explained from the point of view of flame retardancy. Moreover, various strategies for improving the flame retardancy of bio-based polyurethanes as well as reactive and additive flame-retardant solutions are discussed.


2020 ◽  
pp. 43-50
Author(s):  
Yauheniya N. Saukova

It is shown that the issues of metrological traceability for extended self-luminous objects with a wide range of brightness have not yet been resolved, since the rank scales of embedded systems are used for processing digital images. For such scales, there is no “fixed” unit, which does not allow you to get reliable results and ensure the unity of measurements. An experiment is described to evaluate the accuracy of determining the intensity (coordinates) of the color of self-luminous objects. In terms of repeatability and intermediate precision compared to the reference measurement method, the color and chromaticity coordinates of self-luminous objects (reference samples) were determined by their multiple digital registration using technical vision systems. The possibilities of the developed methodology for colorimetric studies in hardware and software environments from the point of view of constructing a multidimensional conditional scale are determined.


2020 ◽  
Vol 7 (2) ◽  
pp. 34-41
Author(s):  
VLADIMIR NIKONOV ◽  
◽  
ANTON ZOBOV ◽  

The construction and selection of a suitable bijective function, that is, substitution, is now becoming an important applied task, particularly for building block encryption systems. Many articles have suggested using different approaches to determining the quality of substitution, but most of them are highly computationally complex. The solution of this problem will significantly expand the range of methods for constructing and analyzing scheme in information protection systems. The purpose of research is to find easily measurable characteristics of substitutions, allowing to evaluate their quality, and also measures of the proximity of a particular substitutions to a random one, or its distance from it. For this purpose, several characteristics were proposed in this work: difference and polynomial, and their mathematical expectation was found, as well as variance for the difference characteristic. This allows us to make a conclusion about its quality by comparing the result of calculating the characteristic for a particular substitution with the calculated mathematical expectation. From a computational point of view, the thesises of the article are of exceptional interest due to the simplicity of the algorithm for quantifying the quality of bijective function substitutions. By its nature, the operation of calculating the difference characteristic carries out a simple summation of integer terms in a fixed and small range. Such an operation, both in the modern and in the prospective element base, is embedded in the logic of a wide range of functional elements, especially when implementing computational actions in the optical range, or on other carriers related to the field of nanotechnology.


1969 ◽  
Vol 62 (4_Suppla) ◽  
pp. S23-S35
Author(s):  
B.-A. Lamberg ◽  
O. P. Heinonen ◽  
K. Liewendahl ◽  
G. Kvist ◽  
M. Viherkoski ◽  
...  

ABSTRACT The distributions of 13 variables based on 10 laboratory tests measuring thyroid function were studied in euthyroid controls and in patients with toxic diffuse or toxic multinodular goitre. Density functions were fitted to the empirical data and the goodness of fit was evaluated by the use of the χ2-test. In a few instances there was a significant difference but the material available was in some respects too small to allow a very accurate estimation. The normal limits for each variable was defined by the 2.5 and 97.5 percentiles. It appears that in some instances these limits are too rigorous from the practical point of view. It is emphasized that the crossing point of the functions for euthyroid controls and hyperthyroid patients may be a better limit to use. In a preliminary analysis of the diagnostic efficiency the variables of total or free hormone concentration in the blood proved clearily superior to all other variables.


2019 ◽  
Author(s):  
Le Wang ◽  
Devon Jakob ◽  
Haomin Wang ◽  
Alexis Apostolos ◽  
Marcos M. Pires ◽  
...  

<div>Infrared chemical microscopy through mechanical probing of light-matter interactions by atomic force microscopy (AFM) bypasses the diffraction limit. One increasingly popular technique is photo-induced force microscopy (PiFM), which utilizes the mechanical heterodyne signal detection between cantilever mechanical resonant oscillations and the photo induced force from light-matter interaction. So far, photo induced force microscopy has been operated in only one heterodyne configuration. In this article, we generalize heterodyne configurations of photoinduced force microscopy by introducing two new schemes: harmonic heterodyne detection and sequential heterodyne detection. In harmonic heterodyne detection, the laser repetition rate matches integer fractions of the difference between the two mechanical resonant modes of the AFM cantilever. The high harmonic of the beating from the photothermal expansion mixes with the AFM cantilever oscillation to provide PiFM signal. In sequential heterodyne detection, the combination of the repetition rate of laser pulses and polarization modulation frequency matches the difference between two AFM mechanical modes, leading to detectable PiFM signals. These two generalized heterodyne configurations for photo induced force microscopy deliver new avenues for chemical imaging and broadband spectroscopy at ~10 nm spatial resolution. They are suitable for a wide range of heterogeneous materials across various disciplines: from structured polymer film, polaritonic boron nitride materials, to isolated bacterial peptidoglycan cell walls. The generalized heterodyne configurations introduce flexibility for the implementation of PiFM and related tapping mode AFM-IR, and provide possibilities for additional modulation channel in PiFM for targeted signal extraction with nanoscale spatial resolution.</div>


2019 ◽  
Author(s):  
Inc. OEAPS

"Academy Journal" is an international, peer-reviewed monthly journal. It is devoted to the publication of original scientific research articles dealing with various academic disciplines.Articles that may be of interest to a wide range of researchers are welcome, and not limited to those who work on specific research subjects."Academy Journal" has an open archive, according to which published articles are available immediately after publication, excluding embargoes.Expert reviewThere is one blind verification process in the journal. All articles will be initially evaluated by the editor for compliance with the journal. Manuscripts that are considered appropriate are then usually sent to at least two independent peer reviewers to assess the scientific quality of the article. The editor is responsible for the final decision on whether to accept or reject the article. The editor's decision is final.The main criterion used in assessing the manuscript submitted to the journal is: uniqueness or innovation in the work from the point of view of the methodology being developed and / or its application to a problem of particular importance in the public sector or service sector and / or the setting in which the efforts, for example, in the developing region of the world. That is, the very model / methodology, application and context of problems, at least one of them must be unique and important.Additional criteria considered in the consideration of the submitted document are its accuracy, organization / presentation (ie logical flow) and recording quality.


Author(s):  
Stuart Friedman ◽  
Oskar Amster ◽  
Yongliang Yang ◽  
Fred Stanke

Abstract The use of Atomic Force Microscopy (AFM) electrical measurement modes is a critical tool for the study of semiconductor devices and process development. A relatively new electrical mode, scanning microwave impedance microscopy (sMIM), measures a material’s change in permittivity and conductivity at the scale of an AFM probe tip [1]. sMIM provides the real and imaginary impedance (Re(Z) and Im(Z)) of the probe-sample interface. By measuring the reflected microwave signal as a sample of interest is imaged with an AFM, we can in parallel capture the variations in permittivity and conductivity and, for doped semiconductors, variations in the depletion-layer geometry. An existing technique for characterizing doped semiconductors, scanning capacitance microscopy, modulates the tip-sample bias and detects the tip-sample capacitance with a lock-in amplifier. A previous study compares sMIM to SCM and highlights the additional capabilities of sMIM [2], including examples of nano-scale capacitance-voltage curves. In this paper we focus on the detailed mechanisms and capabilities of the nano-scale C-V curves and the ability to extract semiconductor properties from them. This study includes analytical and finite element modeling of tip bias dependent depletion-layer geometry and impedance. These are compared to experimental results on reference samples for both doped Si and GaN doped staircases to validate the systematic response of the sMIM-C (capacitive) channel to the doping concentration.


2020 ◽  
Vol 4 (1) ◽  
pp. 67-77
Author(s):  
Rohimah Ismail ◽  
Chong Mei Chan ◽  
Wan Muhammad Azly W. Zulkafli ◽  
Hasnah Zani ◽  
Zainab Mohd Shafie

                The evolution of information technology has exerted great influence on nursing education via new pedagogy of knowledge delivery without time and place restriction. Mobile technology revolutionises nursing education and clinical practice via empowering skills of critical thinking and clinical decision-making through learning. The aim of this study is to evaluate the effectiveness of using mobile messenger (Whatsapp) as an educational supporting tool among nursing students. The study design used is a Cluster Randomized Control Trail. Two nursing colleges were selected. Sample size was 93 participants, 48 from the Kuala Terengganu Nursing College Kuala Terengganu as the intervention group while the control group were recruited among 45 participants from UniSZA Nursing College. There is a significant difference in the level of knowledge between pre and posttest among intervention group (mean difference was -8.70 with a standard deviation 8.42, p-value< 0.001) and 93.8 percent of the respondents perceived the usefulness of using WhatsApp mobile messenger to enhance learning. This demonstrates that learning through mobile messenger (WhatsApp) enhances learning and is well received as a new method of learning by almost all students.   Keywords: Mobile learning, WhatsApp messenger, Social Interaction


Author(s):  
Georgiana Uță ◽  
Denisa Ștefania Manolescu ◽  
Speranța Avram

Background.: Currently, the pharmacological management in Alzheimer's disease is based on several chemical structures, represented by acetylcholinesterase and N-methyl-D-aspartate (NMDA) receptor ligands, with still unclear molecular mechanisms, but severe side effects. For this reason, a challenge for Alzheimer's disease treatment remains to identify new drugs with reduced side effects. Recently, the natural compounds, in particular certain chemical compounds identified in the essential oil of peppermint, sage, grapes, sea buckthorn, have increased interest as possible therapeutics. Objectives.: In this paper, we have summarized data from the recent literature, on several chemical compounds extracted from Salvia officinalis L., with therapeutic potential in Alzheimer's disease. Methods.: In addition to the wide range of experimental methods performed in vivo and in vitro, also we presented some in silico studies of medicinal compounds. Results. Through this mini-review, we present the latest information regarding the therapeutic characteristics of natural compounds isolated from Salvia officinalis L. in Alzheimer's disease. Conclusion.: Thus, based on the information presented, we can say that phytotherapy is a reliable therapeutic method in a neurodegenerative disease.


2018 ◽  
Vol 8 (2) ◽  
pp. 49-73
Author(s):  
Petr Adamec

The core issue of this paper is a quality in the lifelong learning. The aim of the contribution is to describe the area, level and dimensions of quality in a wide range of lifelong learning programs, respectively of further education, which are realized in the sense of § 60 and 60a of the Higher Education Act. The content of the paper also focuses on the theoretical and practical starting points of the quality phenomenon, both from the historical point of view and especially from the perspective of the current focus and concept of university policy in the European and Czech region. The paper also presents the results of a survey focusing on approaches to the quality assurance systems in the concept of components at selected public university.


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