Elaboration and study of the thermo-mechanical properties of an aligned cnt - polypropylene nanocomposite by twin-screw mixer

This study presents first the fabrication of a nanocomposite material based on Multi-Walled Carbon Nanotubes, and on a thermoplastic polymer matrix. First, a twin-screw mixer had been employed for preparing polypropylene nanocomposites loaded at 0.1, 1, 2, and 5wt% of MWCNT. Second, a characterization of rheological behavior for polypropylene as well as polypropylene/multi-walled carbon nanotube mixtures, at three temperatures (180, 200, and 220 °C,) has been carried out using cone and plate rheometer. Then, its thermomechanical properties have been studied. The work demonstrates how the addition of functionalized CNTs to a polypropylene will allow it to act as thermal conductor rather than as insulator

RETRACTED : Positional finite element solutions for laminated composites

This article has been retracted at the request of the Editors-in-Chief, according to the Publication Ethics Policy and Publication Malpractice Statement. Please see: http://revue.ummto.dz/index.php/JMES/about/editorialPolicies#custom-2Reason : This paper duplicated parts of a master's thesis that had already appeared in the digital library of São Paulo University (Brazil) in May 2015, DOI:10.11606/D.18.2015.tde-27052015-171842.One of the conditions of submission of a paper for publication is that authors declare explicitly that they have written entirely original works, and should ensure that the sources of any ideas and/or words in the manuscript that are not their own have been properly attributed through appropriate citations and/or quotes. Plagiarism constitutes unethical publishing behaviour and is unacceptable. Any attempt of plagiarism should be followed by the rejection of the submitted manuscript.As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and we apologize to readers of the journal that this was not detected during the submission process.This note is published, 12 April 202

Migration, Unemployment and Net Benefits of Inbound Tourism in a Developing Country

International tourism is increasingly viewed as one of the best opportunities for a sustainable economic and social development of developing countries. There is also an increasing concern from public policy makers as to whether mass tourism coastal resorts can play a catalytic role in the overall economic development and improve the real income of their community. In this paper, we present a general equilibrium model which explicitly takes into consideration specific features of some developing countries (e.g. coastal tourism, dual labour market, unemployment, migrations, competition between agriculture and tourism for land) to analyse the ways by which an inbound tourism boom affects this kind of country, in particular its real income. We define the conditions under which an inbound tourism boom makes developing countries residents worse off.Economic impacts, General equilibrium model, Inbound tourism, Migration, Unemployment, Developing countries

Experimental analysis and numerical simulation of sintered micro-fluidic

This paper investigates the use of numerical simulations to describe solid state diffusion of a sintering stage during a Powder Hot Embossing (PHE) process for micro-fluidic components. Finite element analysis based on a thermo-elasto-viscoplastic model was established to describe the densification process of a PHE stainless steel porous component during sintering. The corresponding parameters such as the bulk viscosity, shearing viscosity and sintering stress are identified from dilatometer experimental data. The numerical analyses, which were performed on a 3D micro-structured component, allowed comparison between the numerical predictions and experimental results of during a sintering stage. This comparison demonstrates that the FE simulation results are in better agreement with the experimental results at high temperatures

RETRACTED : Composite parameters analysis with boundary element method

This article has been retracted at the request of the Editors-in-Chief, according to the Publication Ethics Policy and Publication Malpractice Statement.Please see: http://revue.ummto.dz/index.php/JMES/about/editorialPolicies#custom-2 This note is published, 26 June 202

RETRACTED : Influence parameters analysis in the gear helix correction

This article has been retracted at the request of the Editors-in-Chief, according to the Publication Ethics Policy and Publication Malpractice Statement.Please see : http://revue.ummto.dz/index.php/JMES/about/editorialPolicies#custom-2 This note is published, 25 June 202

RETRACTED : Influence parameters analysis in the gear helix correction

This article has been retracted at the request of the Editors-in-Chief, according to the Publication Ethics Policy and Publication Malpractice Statement.Please see : http://revue.ummto.dz/index.php/JMES/about/editorialPolicies#custom-2 This note is published, 25 June 202

Physical modelling of amorphous thermoplastic polymer and numerical simulation of micro hot embossing process

Micro hot embossing process is considered as one of the most promising micro replication processes for manufacturing of polymeric components, especially for the high aspect ratio components and large surface structural components. A large number of hot embossing experimental results have been published, the material modelling and processes simulation to improve the quality of micro replication by hot embossing process are still lacking. This paper consists to 3D modelling of micro hot embossing process with amorphous thermoplastic polymers, including the mechanical characterisation of polymers properties, identification of the viscoelastic behaviour law of the polymers, numerical simulation and experimental investigation of micro hot embossing process. Static compression creep tests have been carried out to investigate the selected polymers’ viscoelastic properties. The Generalized Maxwell model has been proposed to describe the relaxation modulus of the polymers and good agreement has been observed. The numerical simulation of the hot embossing process in 3D has been achieved by taking into account the viscoelastic behaviour of the polymers. The microfluidic devices with the thickness of 2 mm have been elaborated by hot embossing process. The hot embossing process has been carried out using horizontal injection/compression moulding equipment, especially developed for this study. A complete compression mould tool, equipped with the heating system, the cooling system, the ejection system and the vacuum system, has been designed and elaborated in our research. Polymer-based microfluidic devices have been successfully replicated by the hot embossing process using the compression system developed. Proper agreement between the numerical simulation and the experimental elaboration has been observed. It shows strong possibility for the development of the 3D numerical model to optimize the micro hot embossing process in the future

Andalusi Masters in Bejaia. Their role in activating historical knowledge during the 13th century

Durante el siglo XIII, la ciudad de Bujía atrajo un considerable número de andalusíes ligados directamente al conocimiento de la historia, que se establecieron en la ciudad de forma provisional o permanente. Los que permanecieron en la ciudad centraron su actividad en la enseñanza de una serie de obras históricas y crónicas a sus estudiantes, que procedían de la propia ciudad de Bujía y de fuera de ella. Al examinar los datos históricos dispersos en los libros, programas e índices de estos maestros, además de los libros de biografías, descubrimos la importancia de la actividad historiográfica de los andalusíes en Bujía, y arrojamos luz sobre los alumnos más destacados y los títulos de las obras que se enseñaban. Esto influirá en el desarrollo de la conciencia historiográfica de Bujía en el siglo XIII, ligada a la escuela de historia andalusí representada por los maestros más destacados, como Ibn Sarrāǧ al-Išbīlī, Ibn al-Abbār al-Balansī, y Abū ˁAbdallāh Muḥammad ibn Ṣāliḥ al-Kinānī al-ŠāṭibīThought the 7th century of Al-hegira / the 13th Century of Birth, the city of Bejaia had attracted a considerable number of Andalusian elements linked directly to historical knowledge, who settled in the city either in a temporary or in permanent manner. The latter had stressed their activities on teaching a set of works on History and Chronicles for a group of students’ campus (episodes). If we look on the historical data spread in the folders of books programs and lecturers’ indexes, alongside with the books of biographies studied therein, we shall discover the reality of the historical activity that the Andalousians’ Senate in Bejaia had practiced. A spotlight had been thrown on the brilliant pupils, whom had learned historical disciplines (modules), also the tittles of the literature news that were taught in their campuses. This will affect the general path in the progression of the historical consciousness in Bejaia of the 7th /13th Century, where we observe its relation with the Andalusian historical school seen by its famous lecturers in the city such as Ibn- Sarrāj Al-Ishbīlī, Ibn Al-Abbār Al-Balansī and Abū ˁAbdallāh Muḥammad b. Ṣāliḥ Al-Kinānī Al- Shāṭibī

Multiliteracies as a Landmark to Shape the 21st Century EFL Learners

Today's educators should be well-aware of the world of the 21st century; a world that is characterised by a constant technological advancement, a fierce economic competition, a diversified digital village at the end of a fingertip, and unforeseen pandemics and crises. Teachers need to develop innovative methods to allow their learners to successfully cope with the requirements of the 21st century. At present, students are digitally-oriented in need of skills and competencies that empower them to smoothly understand and critically engage in dialogue with the world they live and work in. A vivid incarnation of the  principles of  multiliteracy approach is the edited book entitled Films, Graphic Novels and Visuals: Developing Multiliteracies  in Foreign Language Education- An Interdisciplinary Approach by Daniela Elsner, Sissy Helff and  Britta Viebrock