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1 – 10 of 52R. Aghababazadeh, A.R. Mirhabibi, F. Moztarzadeh and Z. Salehpour
In this paper, the synthesis and the application of chromic oxide as a high temperature pigment have been reported. To synthesise chromic oxide, solid‐state reaction using sulphur…
Abstract
In this paper, the synthesis and the application of chromic oxide as a high temperature pigment have been reported. To synthesise chromic oxide, solid‐state reaction using sulphur and sodium chromate tetrahydrate was undertaken. Morphology of the pigment synthesised was investigated by scanning electron microscopy. Formation of the chromic oxide was observed at 888°C in an oxidising atmosphere. Thorough washing of the resultant pigment played a vital role in the aggregation of the pigment particles, as demonstrated by a particle size characteristics.
F. Moztarzadeh, S. Boghozian and F. Halek
Pigments are fine solid particles which when exposed to light they emit different colours, depending on the nature of substances they are composed of.
A.R. Mirhabibi, F. Moztarzadeh, A. Aghajani Bazazi, M. Solati, A. Maghsoudipour and M.H. Sarrafi
Long afterglow Sr2MgSi2O7 (SMS) phosphor was prepared by Douby's methods at high temperature and reductive atmosphere. The excitation and emission spectra of this phosphor showed…
Abstract
Long afterglow Sr2MgSi2O7 (SMS) phosphor was prepared by Douby's methods at high temperature and reductive atmosphere. The excitation and emission spectra of this phosphor showed that both had broad bands and that the main emission peak at 469 nm was due to 4f‐5d transitions of Eu+2 and implied that the luminescence centres Eu+2 occupied the Sr+2 sites in the Sr2MgSi2O7 host. The phosphor doped only with Eu ions did not demonstrate the long afterglow phenomenon, but when co‐doped with Dy+3 ions in the SMS matrix, significant long afterglow was observed.
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Mahendra Uttam Gaikwad, A. Krishnamoorthy and Vijaykumar S. Jatti
Electrical discharge machining (EDM) of hard materials like NiTi 60 alloys is important as it finds application in different sectors of engineering such as automobile, aircraft…
Abstract
Purpose
Electrical discharge machining (EDM) of hard materials like NiTi 60 alloys is important as it finds application in different sectors of engineering such as automobile, aircraft, biomedical, oil industries, etc.
Design/methodology/approach
The first target of this investigation is to determine the effect of process parameters such as current, voltage, pulse on time and pulse off time on the material removal rate (MRR), surface roughness (SR) and white layer formation (WLT) for NiTi 60 smart material alloy. The secondary aim is to identify the presence of surface integrity parameters such as cracks, WLT, microvoids, globules and debris formation by using the scanning electron microscopy technique and with the use of ImageJ software for die sink EDM machining of NiTi 60 alloy.
Findings
The results reveal that current is significant for MRR, voltage and current influence SR, and for WLT, voltage is a significant factor. The experimentation study also shows the generation of oxide and carbide layers on the machined surface, which were evident with the use of the X-ray diffraction technique. The presence of these oxide and carbide layers causes to form WLT on the machined surface and thereby increases the hardness of the machined surface.
Originality/value
Hardness test was performed with Vickers hardness tester, which gives evidence for the increase in hardness of machined surface due to the generation of WLT.
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A.R. Mirhabibi, M. Rabiee, R. Aghababazadeh, F. Moztarzadeh and S. Hesaraki
ZnS:Cu phosphors were prepared by co‐precipitating Cu along with ZnS using H2S and thiourea. Phosphors giving luminescence at around 530 nm were prepared. The difference in the…
Abstract
ZnS:Cu phosphors were prepared by co‐precipitating Cu along with ZnS using H2S and thiourea. Phosphors giving luminescence at around 530 nm were prepared. The difference in the characteristic properties among the samples prepared appeared to be due to the formation of nanoparticles during the preparation of the samples by different methods.
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Róberson de Oliveira, João Leitão and Helena Alves
Corporate governance (CG), initially associated with private organizations, has been adopted by higher education institutions (HEIs). These are being managed more as firms in this…
Abstract
Corporate governance (CG), initially associated with private organizations, has been adopted by higher education institutions (HEIs). These are being managed more as firms in this post-standardization phase, in which the commercialization of higher education, competition and selective choice, finite resources and sustainable development (SD) have become major requirements for accountability and action. Principles of CG can collaborate and guide the process of making universities sustainable. The chapter analyses the effects of CG on the creation of a culture of sustainability in universities. In doing so, it analyzes the websites of public HEIs in EU-15 countries for a set of social responsibility indicators and investigates the impact and practices of two young Portuguese universities regarding United Nation’s Sustainable Development Goals. The results point out that CG and SD principles tend to guide the strategy of most public HEIs in the EU-15, confirming that they have made a commitment to good governance and sustainability.
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Evgeny Morozov, Mikhail Novikov, Vyacheslav Bouznik and Gleb Yurkov
Active employment of additive manufacturing for scaffolds preparation requires the development of advanced methods which can accurately characterize the morphologic structure and…
Abstract
Purpose
Active employment of additive manufacturing for scaffolds preparation requires the development of advanced methods which can accurately characterize the morphologic structure and its changes during an interaction of the scaffolds with substrate and aqueous medium. This paper aims to use the method of nuclear magnetic resonance (NMR) imaging for preclinical characterization of 3D-printed scaffolds based on novel allyl chitosan biocompatible polymer matrices.
Design/methodology/approach
Biocompatible polymer scaffolds were fabricated via stereolithography method. Using NMR imaging the output quality control of the scaffolds was performed. Scaffolds stability, polymer matrix homogeneity, kinetic of swelling processes, water migration pathways within the 3D-printed parts, effect of post-print UV curing on overall scaffolds performance were studied in details.
Findings
NMR imaging visualization of water uptake and polymer swelling processes during the interaction of scaffolds with aqueous medium revealed the formation of the fronts within the polymer matrices those dynamics is governed by case I transport (Fickian diffusion) of the water into polymer network. No significant difference was observed in front propagation rates along the polymer layers and across the layers stack. After completing the swelling process, the polymer scaffolds retain their integrity and no internal defects were detected.
Research limitations/implications
NMR imaging revealed that post-print UV curing aimed to improve the overall performance of 3D-printed scaffolds might not provide a better quality of the finish product, as this procedure apparently yield strongly inhomogeneous distribution of polymer crosslink density which results in subsequent inhomogeneity of water ingress and swelling processes, accompanied by stress-related cracks formation inside the scaffolds.
Practical implications
This study introduces a method which can successfully complement the standard tests which now are widely used in either additive manufacturing or scaffolds engineering.
Social implications
This work can help to improve the overall performance of the polymer scaffolds used in tissue engineering.
Originality/value
The results of this study demonstrate feasibility of NMR imaging for preclinical characterization of 3D printed biocompatible polymer scaffolds. The results are believed to contribute to better understanding of the processes vital for improving the design of 3D-printed polymer scaffolds.
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Misagh Rahbari, Seyed Hossein Razavi Hajiagha, Mahdi Raeei Dehaghi, Mahmoud Moallem and Farshid Riahi Dorcheh
In this paper, multi-period location–inventory–routing problem (LIRP) considering different vehicles with various capacities has been investigated for the supply chain of red…
Abstract
Purpose
In this paper, multi-period location–inventory–routing problem (LIRP) considering different vehicles with various capacities has been investigated for the supply chain of red meat. The purpose of this paper is to reduce variable and fixed costs of transportation and production, holding costs of red meat, costs of meeting livestock needs and refrigerator rents.
Design/methodology/approach
The considered supply chain network includes five echelons. Demand considered for each customer is approximated as deterministic using historical data. The modeling is performed on a real case. The presented model is a linear mixed-integer programming model. The considered model is solved using general algebraic modeling system (GAMS) software for data set of the real case.
Findings
A real-world case is solved using the proposed method. The obtained results have shown a reduction of 4.20 per cent in final price of red meat. Also, it was observed that if the time periods changed from month to week, the final cost of meat per kilogram would increase by 43.26 per cent.
Originality/value
This paper presents a five-echelon LIRP for the meat supply chain in which vehicles are considered heterogeneous. To evaluate the capability of the presented model, a real case is solved in Iran and its results are compared with the real conditions of a firm, and the rate of improvement is presented. Finally, the impact of the changed time period on the results of the solution is examined.
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Eleonora Di Maria, Valentina De Marchi and Katharina Spraul
This paper aims to analyze the characteristics and performance of university–industry (U-I) collaboration for knowledge transfer in relation to environmental sustainability…
Abstract
Purpose
This paper aims to analyze the characteristics and performance of university–industry (U-I) collaboration for knowledge transfer in relation to environmental sustainability, considering for both parties of the collaborations.
Design/methodology/approach
The study is explorative in nature, based on an original data set of more than 350 U-I research and consultancy contracts signed by more than 70 professors specializing in environmental sustainability-related academic disciplines at the University of Padova (Italy) for the period 2008-2012. A mixed-method approach is adopted. Social network analysis and regressions are used to explore the impact of U-I on performance considering for characteristics of the firms, the professors and the collaboration. Interviews with key informants at University of Padova is used to complement and validate the emerging evidence.
Findings
Results suggest that U-I positively impacts the performance of firms, but not of professors. Indeed, the hypothesis that professors’ performance (measures in terms of academic publications) is positively associated with academic engagement is not supported. On the contrary, firms’ financial performance is positively associated with U-I collaboration focused on knowledge transfer for environmental innovation; the higher the contracts activated the better the economic performance.
Originality/value
While most previous research has focused either on the university or the firm side of U-I, this study looks at both sides and focuses specifically on engagement in green contracts. The analysis of the geographical scope of U-I collaborations contributes to the growing body of literature by outlining geography’s role in U-I collaborations related to sustainability.
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