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Manufacturers face increasing pressure from environmental regulations, but some are meeting the tougher standards by purchasing the ability to pollute. While that may sound…
Abstract
Manufacturers face increasing pressure from environmental regulations, but some are meeting the tougher standards by purchasing the ability to pollute. While that may sound devious, it is within the law. It's part of a plan that is significantly reducing air pollution.
“When my boss handed me the company's new mission statement,” my brother Mark said, “he made me promise not to laugh when I read it. But I did get a chuckle out if it.” Now, Mark…
Abstract
“When my boss handed me the company's new mission statement,” my brother Mark said, “he made me promise not to laugh when I read it. But I did get a chuckle out if it.” Now, Mark is an exemplary human in most ways, but he's pretty much Everyman Employee in his reaction to mission statements.
Amir A. Abdelsalam, Salwa H. El-Sabbagh, Wael S. Mohamed and Mohsen A. Khozami
This study aims to investigate the swelling behavior, mechanical and thermal properties of ternary rubber blend composites prepared by melt blending based on carbon black…
Abstract
Purpose
This study aims to investigate the swelling behavior, mechanical and thermal properties of ternary rubber blend composites prepared by melt blending based on carbon black (CB)-filled natural rubber (NR)/styrene-butadiene rubber (SBR)/nitrile butadiene rubber (NBR) blends, containing a variety of compatibilizers. Various compatibilizers, maleic acid anhydride (MAH), prepared emulsion and adhesion system (HRH) were used. A series of NR/SBR/NBR blends at a 30/30/40 blend ratio reinforced with 45 phr of CB were prepared using the master-batch method.
Design/methodology/approach
Thermal aging properties of the composites characterized by their aging coefficient and retention in tensile and elongation at break (E.B. %). Thermal degradation of ternary rubber blend composites based on melt blending has been studied using thermogravimetric analysis.
Findings
The swelling coefficient decreased with increased compatibilizer loading. Results also showed that the tensile strength and E.B. (%) decreased with aging over the entire aging period. Additionally, the addition of compatibilizers into the ternary rubber blend composite had slightly improved the thermal stability.
Research limitations/implications
Interactions between the different components of blends at the interfaces have a high impact on the interfacial properties of the rubber blend.
Practical implications
Compatibilizers significantly improve the properties of the resulting composites with the loading of investigated compatibilizers because of the uniform dispersion of CB in the rubber matrix.
Social implications
Using blends in the rubber industry led to the high-efficiency production of low-cost products.
Originality/value
The rubber blending has a significant positive effect on a wide range of applications such as structural applications, aerospace, military, packaging, tires and biomedical, so improving the compatibility of blends will make new materials suitable for new applications.
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Selma Harrington, Branka Dimitrijevic and Ashraf M. Salama
The purpose of this paper is to focus on Sarajevo, the capital of Bosnia and Herzegovina, giving a general overview of its urban context through five historical periods, as part…
Abstract
Purpose
The purpose of this paper is to focus on Sarajevo, the capital of Bosnia and Herzegovina, giving a general overview of its urban context through five historical periods, as part of a research study on its modernist architectural heritage.
Design/methodology/approach
Designed to mimic the theatrical process which unfolds through acts and intervals, the paper combines literary, architectural, journalistic and historical sources, to sketch the key periods which characterise the city’s urban morphology.
Findings
The sequence of acts and intervals points to the dramatic historic inter-change of continuities and ruptures, in which the ruptures have often been less studied and understood. This explains the frequent conceptualising of Sarajevo through East–West binary, which synthesises it as a provincial capital from Ottoman and later Habsburg rule, a regional centre within two Yugoslav states and a capital city of a young state of Bosnia and Herzegovina. This highlights the need to study the ruptures as clues to the flow of continuities, in which the care and after care for built environment provide a field of evidence and possibilities for diverse perspectives of examination.
Research limitations/implications
Corroborated by secondary sources, the paper examines the accounts of urban heritage destruction in the 1990s war, as recorded by a writer, an architect and a journalist, and outlines a pattern of unbroken inter-relations between urban and architectural space (tangible) and sense and identity of place (intangible).
Practical implications
This discourse is relevant to the current situation where the city of Sarajevo expands again, in the complexity of a post-conflict society.
Social implications
Challenged by the political divisions and the laissez-faire economy, the public mood and interest is under-represented and has many conflicting voices.
Originality/value
Inspired by Italo Calvino’s Invisible Cities and the accounts from the siege of Sarajevo in the 1990s, this conceptual paper contributes to the formulation of a cross-disciplinary discursive prism through which the fragments of the city and its periods come together or apart, adding, subtracting and changing layers of meaning of the physical space.
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Adel Attia, Lobna Khorshed, Samir Morsi and Elsayed Ashour
The purpose of this study was to investigate the polyacrylic polymer/Al2O3 as a new nanocomposite coating to protect brass and Al-bronze in 3.5% NaCl and the role of alumina…
Abstract
Purpose
The purpose of this study was to investigate the polyacrylic polymer/Al2O3 as a new nanocomposite coating to protect brass and Al-bronze in 3.5% NaCl and the role of alumina formulation on their protection efficiency
Design/methodology/approach
The corrosion efficiency of the nanocomposite coating (NCC) was evaluated by open circuit potential and electrochemical impedance spectroscopy (EIS).
Findings
The protection efficiency was more in the case of Al-bronze even for the same formulation of alumina NCC indicated the Cu substrate contribution. The Cu oxides in alloys and Al2O3 from the NCC and Al-bronze were responsible for this protection.
Originality/value
All the techniques supported each other, the presence of alumina was responsible for the corrosion protection efficiency.
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Eva Nezbedova, Frantisek Krcma, Zdenek Majer and Pavel Hutar
Polymeric particulate composites with thermoplastics, especially polypropylene (PP) matrix with mineral fillers, are of great practical importance due to their simple possibility…
Abstract
Purpose
Polymeric particulate composites with thermoplastics, especially polypropylene (PP) matrix with mineral fillers, are of great practical importance due to their simple possibility of modifying mechanical properties and reducing the price/volume ratio of the resulting material. Both filler properties and interface properties have a great effect on the mechanical properties, primarily on stiffness and toughness, of the resulting composite material. Good final dispersion of the filler particles also plays a very important role. To reach the best adhesion and distribution of the particles, various procedures are carried out for activation of the particles. Therefore, the purpose of this paper is to investigate and discuss the effect of using plasma as a tool for treating commercially available CaCO3 nanoparticles in PP matrix.
Design/methodology/approach
The effect of the composite structure on its mechanical properties was studied from an experimental as well as a theoretical point of view. For an experimental study, four PP matrix were chosen. For use as filler, the commercially available precipitated surface-treated calcium carbonate was chosen. The composites were prepared with 5, 10, and 15 wt% of fillers. The sequence of expositions of plasma was chosen to verify the optimal treatment duration. The filler particles were characterized by several structure analytical methods. The composite mechanical properties were characterized by tensile, bending, impact, and creep tests. The deformation behavior of the three-phase composite with homogeneously distributed coated particles was numerically simulated on a microscopic scale.
Findings
The main conclusions of this work can be summarized as follows: with the use of plasma to the precipitated calcium carbonate, composites with well-dispersed particles can be prepared; the surface modification using plasma is done mainly by grafting –OH groups onto the particles’ surface; a synergetic effect of modifier enhancing the performance was observed; performance modifier increases the resistance against viscoelastic strain; and the size of the particles and their volume content generally lead to increase in the macro modulus of the composite.
Originality/value
Plasma, as a tool for treating the inorganic fillers, enables to destroy the agglomerates in composite, which is the basic way on how to optimally utilize the synergetic effect of composite with PP matrix.
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This paper examines the dynamic causal relationship between education and economic growth in South Africa using annual time-series data from 1986 to 2017. The study attempts to…
Abstract
Purpose
This paper examines the dynamic causal relationship between education and economic growth in South Africa using annual time-series data from 1986 to 2017. The study attempts to answer one critical question: Does education, which is one of the priority sectors in South Africa, drive economic growth?
Design/methodology/approach
The study uses the ARDL bounds testing approach and ECM-based Granger causality model to examine this linkage. The study also uses three proxies to measure the level of education. In addition, the study uses two variables: investment and labour, as intermittent variables between the various proxies of education and economic growth, thereby creating a system of multivariate Granger-causality models.
Findings
The study finds that the causal relationship between education and economic growth in South Africa is dependent on the variable used to measure the level of education. In addition, the causality tends to change over time. Overall, the study finds the causal flow from economic growth to education to supersede the causal flow from education to economic growth.
Originality/value
Unlike some previous studies, the current study uses three proxies of education in South Africa and two intermittent variables in a multivariate setting. To our knowledge, this may be the first study of its kind to examine in detail the dynamic causal relationship between education and economic growth in South Africa – using the ARDL bounds testing approach and a multivariate Granger causality model.
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Rou Li, Changqing Miao, Mingfen Nie and Yichun Wang
This paper aims to investigate the equivalent relationship of accelerated corrosion and compilation method of environmental spectrum of corroded steel wires.
Abstract
Purpose
This paper aims to investigate the equivalent relationship of accelerated corrosion and compilation method of environmental spectrum of corroded steel wires.
Design/methodology/approach
Based on Faraday’s law and the principle of equivalent corrosion damage, the method for compiling the equivalent environmental spectrum of accelerated corrosion was established. The equivalent conversion relationship of steel wire under different temperature and pH conditions and the relationship between corrosion factors and corrosion rate through the electrochemical tests were proposed.
Findings
The high temperature had a greater impact on the equivalent conversion coefficient than the low temperature. When the temperature increased from 15°C to 60°C, the equivalent conversion coefficient increased by about 3–6 times. The weak acid had a greater impact on equivalent conversion coefficient compared with strong acid. The effect of temperature on the equivalent conversion coefficient was much greater than that of pH value.
Originality/value
The compilation method of corrosion environment spectrum of bridge operation and the calculation method of corrosion depth proposed in this paper were reasonable, and the corrosion depth and service life of cable components could be predicted.