Technological Educational Institute of Western Macedonia

About: Technological Educational Institute of Western Macedonia is a based out in . It is known for research contribution in the topics: Symplectic geometry & Numerical integration. The organization has 291 authors who have published 522 publications receiving 7682 citations. The organization is also known as: TEI of West Macedonia & TEI of Western Macedonia.

Foaming of PCL/clay nanocomposites with supercritical CO2 mixtures: The effect of nanocomposite fabrication route on the clay dispersion and the final porous structure

Abstract: Supercritical fluids have been established as alternative foaming agents in various polymers as well as nanocomposite systems. Most recently, supercritical carbon dioxide (scCO2) has also been used in some studies as a medium of clay dispersion in the polymer matrix providing a solvent-free fabrication route for nanocomposites. In this work, this latter route was followed for the development of porous poly(ɿ-caprolactone) (PCL)/clay nanocomposites after pressure quench. Similarly, PCL/clay nanocomposites were also prepared using the solvent casting and melt blending methods and were then processed with scCO2 with the batch foaming technique (isothermal pressure quench) to produce their porous counterparts. Poor clay dispersion and non-uniform porous structures were observed when pure CO2 was used as a dispersion medium for nanocomposite preparation and as a blowing agent, respectively. On the contrary, polymer intercalation and more uniform cell structures were produced when CO2⿿ethanol mixtures were used as blowing agents.

Porous composite structures derived from multiphase polymer blends

Abstract: Porous biopolymer structures have attracted a lot of attention in the recent years because of their potential applications in tissue engineering. In this work, porous structures of poly(lactic-co-glycolic acid) (PLGA) reinforced with organically modified montmorillonite (Cl15A) were fabricated. A ternary, co-continuous blend consisting of PLGA/PS/Cl15A (PS: Polystyrene) was prepared by melt extrusion. Then, a porous PLGA composite was created by the sacrificial extraction of the PS phase. The morphological characterization revealed the creation of a well-formed 3D porous network consisting of Cl15A-reinforced PLGA. Quantitative results obtained from the scanning electron microscopy (SEM) micrographs of the fabricated porous structures show that small variations in the clay loading affect the geometrical characteristics (% porosity and pores average diameter) of these porous structures. The results suggest that these porous PLGA/clay structures may be promising candidates for mechanically strong scaffolds in tissue engineering applications, but this remains upon testing. POLYM. ENG. SCI., 55:1856–1863, 2015. © 2014 Society of Plastics Engineers

Local Cooperation: A Dynamic Force for Endogenous Rural Development

Abstract: The main objective of this study is to indicate that many times rural development is achievable endogenously through local forces It is believed that a direct relationship exists between local cooperation and local forces in rural communities, allowing them to become a mechanism for endogenous development The examination of local cooperation as a mechanism for endogenous development is important and thus, after a review of theoretical works related to local cooperation and endogenous development, the study presents an analysis derived from a case study, performed in a typical peripheral rural area in northwest Greece Especially, after the recent spectacular shift of the global financial status, the existence of a local cooperation framework attracts the interest of the analysts as it can shed new light on endogenous development and on modeling and understanding better the long-term behavior of rural residents Thus, this study examines the willingness of the local society to accept and support a local factor such as an investment proposal of the local union of agricultural cooperatives, by revealing the foremost reasons thereof Both descriptive statistics and multivariate analysis were employed Two-step cluster analysis was used to explore the different levels of local factor’s adoption and a binomial logit model was estimated to determine the relation between social characteristics and willingness to adopt endogenous development

A practical approach to resource - constrained project scheduling

Abstract: In this paper a solution approach is discussed for managing projects with resource constraints. For this purpose a heuristic method is developed based on traditional CPM scheduling calculations and leveling algorithms. The method can be applied using normal scheduling software such as P3 and MS project, and as such, it is of value to practitioners. An illustrative example is also presented herein to exemplify the concepts. The problem solved has importance and direct application to the management of a wide variety of project-structured efforts with prevailing resource constraints.

Characterization of natural resin materials using water adsorption and various advanced techniques

Abstract: A physicochemical characterization of natural raw resin material was evaluated and reported. The studied material is a natural resin, a natural product from pinus halepensis trees which is collected from the forests of Chalkidiki region of North Greece. The plurality of this product combined with its special property of removing water from commercial liquid fuels commands the detailed physicochemical characterization of this material. In particular, various techniques, such as water adsorption at 22 °C, thermogravimetric analysis, differential scanning calorimetry, Fourier transform infrared spectroscopy and X-ray diffraction, were used in order to evaluate the structural and surface properties of the material. The water adsorption isotherm was also measured and fitted using the Guggenheim, Anderson and De Boer model in order to correlate the water activity characteristics. In addition, the kinetics of the adsorption was also fitted with good accuracy using the exponential Chapman model. Furthermore, as the results show, the natural resin presents good thermal characteristics. Finally, the studied material presents efficient water adsorption properties, up to 246.8 mmol/g, and it can be proposed as a promising dehydration material.