Showing papers by "Technological Educational Institute of Western Macedonia published in 2013"
TL;DR: Production of carotenoids from algae has many advantages compared to other sources; for example, their production is cheap, easy and environmentally friendly; their extraction is easier, with higher yields, and there is no lack of raw materials or limited seasonal variation.
Abstract: Carotenoids are isoprenoid molecules which are synthesised de novo by photosynthetic plants, fungi and algae and are responsible for the orange, yellow and some red colours of various fruits and vegetables. Carotenoids are lipophilic compounds, some of which act as provitamins A. These compounds can be divided into xanthophylls and carotenes. Many macroalgae and microalgae are rich in carotenoids, where these compounds aid in the absorption of sunlight. Industrially, these carotenoids are used as food pigments (in dairy products, beverages, etc.), as feed additives, in cosmetics and in pharmaceuticals, especially nowadays when there is an increasing demand by consumers for natural products. Production of carotenoids from algae has many advantages compared to other sources; for example, their production is cheap, easy and environmentally friendly; their extraction is easier, with higher yields, and there is no lack of raw materials or limited seasonal variation. Recently, there has been considerable interest in dietary carotenoids with respect to their antioxidant properties and their ability to reduce the incidence of some chronic diseases where free radicals are involved. Possibly, carotenoids protect cells from oxidative stress by quenching singlet oxygen damage with various mechanisms. Therefore, carotenoids derived from algae could be a leading natural resource in the research for potential functional ingredients.
259 citations
TL;DR: Exposure assessment scenarios were developed for ages 1, 3, 5, 7 and 12 and their respective estimated weights and daily milk consumption and under the worst-case scenario all milk types presented a Hazard Index (HI) less than one.
90 citations
TL;DR: Results show that quality expectations comply with intention to buy pork, in many aspects, however, several differences have been identified.
66 citations
TL;DR: In this article, the authors compared the level of perceived service quality offered by various Greek banks and found that significant differences were found between the Greek banks regarding the perceived quality of their banking services.
Abstract: In today's turbulent economic environment service quality is an invaluable asset that banks should manage in order to survive and gain a competitive advantage. The present study assessed and compared the level of perceived service quality offered by various Greek banks. Significant differences were found between the Greek banks regarding the perceived quality of their banking services. Moreover, this study examined the highly debated link between service quality and service loyalty. The findings of the present study indicate that the convenience-proximity of the bank impacts significantly on the loyalty of bank customers.
37 citations
TL;DR: The model of open governance enables citizens to contribute toward how decisions are taken and accordingly democratize rulemaking as discussed by the authors, which increases citizens' ability to exercise control over the elected political representatives.
Abstract: The Internet and its innovative communicative codes stand at the center of a discussion regarding a new, more participatory, direct, and “strong” democracy. The widespread use of the Internet and its applications has profound implications on several facets of political life, such as the procedure of rulemaking. In modern, “large-scale” democracies, the complexity and plurality of political interests seem to be under-represented in official parliamentary procedures. The model of open governance enables citizens to contribute toward how decisions are taken and accordingly democratize rulemaking. At the same time, it increases citizens' ability to exercise control over the elected political representatives. One recent implementation of the idea of an open (e-)government in Greece is the Web site http://www.opengov.gr that was launched by the newly elected government of the Socialist party (PASOK) in October 2009. In this Web site, draft laws per ministry are uploaded, and citizens can upload their c...
21 citations
TL;DR: In this paper, the authors compared the use of the Thornthwaite and the Turc equations for the analysis of the water balance in an environmentally sensitive area, and the results obtained by the application of Turc method in the same area.
Abstract: The aim of this study was the assessment of the utilization of two methods, i.e. the Thornthwaite and the Turc equations, for the analysis of the water balance in an environmentally sensitive area. The hydrologic balance of a basin consisting in two lakes (Zazari and Cheimaditida) in northern Greece, and covering an area of 228 km2 has been estimated. The Thornthwaite method was applied in the study area, for the calculation of the evapotranspiration factor and was compared to the results obtained by the application of the Turc method in the same area. For the development of these equations and the calculation of the evapotranspiration rates, monthly temperature and precipitation values collected from meteorological stations over a period of 30 years were used. The utilization of monthly average temperatures in the Thornthwaite equation resulted to an actual evapotranspiration rate of ET = 412.7 mm (80.23%) for p = 514.4 mm and a runoff rate of Q = 101.7 mm (19.77%). However, the Turc equation ga...
18 citations
TL;DR: The conclusion is that the Balance Scorecard method (BSC) can be applied as a performance measurement to an industry in Greece.
Abstract: The aim of this paper is to deal with the analysis of the concept of Balance Scorecard and performance measurement in a Tourism company using the case study method. This paper analyze the theoretical and practical approach of strategic Balance scorecard tool, analyzing the advantages and disadvantages, areas that can be applied and the procedures followed in hierarchical order when applied to an industry. The conclusion is that the Balance Scorecard method (BSC) can be applied as a performance measurement to an industry in Greece.
16 citations
TL;DR: In this paper, supercritical carbon dioxide (scCO2) has also been used as a medium of clay dispersion in the polymer matrix providing a solvent-free fabrication route for nanocomposites.
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.
16 citations
01 Jan 2013
TL;DR: In this article, the authors examined the willingness of 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 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.
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
16 citations
TL;DR: The analysis of gilded gold, black and red pigments from the Byzantine icon of Panagia from the church of Agioi Anargyroi Gymnasiou in Kastoria, northern Greece is the aim of.
Abstract: The investigation of gilded gold, black and red pigments from the Byzantine icon of Panagia from the church of Agioi Anargyroi Gymnasiou in Kastoria, northern Greece is the aim of this study. Small fragments, having a gold leaf finish, were detached from the icon and were analyzed by Environmental Scanning Electron Microscopy coupled to Energy Dispersive System (ESEM-EDS) and Raman microscopy. The chemical (EDS) composition of the gilding material revealed a high gold content alloy (Au 81.34 wt%) with trace amounts of silver (Ag 1.66 wt%), copper (Cu 0.62 wt%) and iron (Fe 0.58 wt%). The Raman spectrum of the gold leaf showed characteristic bands at 236, 369, and 468 cm−1. The red pigment on the surface comprises of Hg, S, and minor amounts of Pb and is attributed to the minerals cinnabar (HgS) and minium (Pb3O4). The black pigment has high carbon content, attributed to organic material (black carbon). The micro-Raman spectroscopy provided a more detailed determination of the composition of the red and bl...
13 citations
Journal Article•
TL;DR: It is made clear that the presence of dioxins and persistent organic pollutants in human milk is not an indication for avoiding breastfeeding, and the beneficial effect of breastfeeding as the optimal food source for newborn babies should not be disregarded.
Abstract: Publications produced over the past 20 years regarding the concentration of xenobiotics in human and dietary milk were evaluated, focusing primarily on persistent organic pollutants (e.g. polychlorinated biphenyls, flame retardants), pesticides (e.g organochlorine) and mycotoxins. In general, countries of low industrialization rate present low levels of dietary milk contamination with dioxins compared to those with high rate of industrialization. According to published data, the most common persistent organic pollutants detected in breast and dietary milk are dichlorodiphenyltrichloroethane compounds, hexachlorocyclohexane, and hexachlorobenzene. Even though the potential risks of persistent organic pollutants in human milk have been acknowledged, the beneficial effect of breastfeeding as the optimal food source for newborn babies should not be disregarded. Especially when sharing information with the general public, it should be made clear that the presence of dioxins and persistent organic pollutants in human milk is not an indication for avoiding breastfeeding. The implications of xenobiotics in human and dietary milk is a matter of growing importance and warrants future work given its important health effects.
TL;DR: In this article, an empirical research was carried out in order to explore the role of an Environmental Center in distant areas, and the research showed that the operation of Environmental Education Centres influences the students and the local communities, especially when the centre operates in peripheral and disadvantaged areas.
19 Sep 2013
TL;DR: This paper provides an overview of the advances on web mining in the domain of education by categorizing research on the field using the web-mining taxonomy: web content, web usage and web structure mining.
Abstract: This paper provides an overview of the advances on web mining in the domain of education by categorizing research on the field using the web-mining taxonomy: web content, web usage and web structure mining. Previous reviews focused on data mining methods applied to data derived from educational software applications (web based or not) and institutional administrative systems as well as from data gathered in typical classroom environments. The overview focuses on knowledge acquired from web based educational environments and the open web. More specifically it addresses: a) applications that dynamically update their content by extracting relevant educational information from the open web in order to meet user specific needs, b) applications that extract knowledge from usage data coming from educational web-based environments, and, c) applications that obtain knowledge coming from structure data such as links or social network connections that exist in e-learning applications and the open web.
TL;DR: The numerical integration of Hamiltonian systems with oscillatory or periodic solution is considered and a trigonometrically fitted symplectic fourth algebraic order method is constructed.
TL;DR: Together techniques were employed, such as environmental scanning electron microscopy coupled with an energy dispersive system, μ Raman spectroscopy, X-ray diffraction, and cathodoluminescence for the determination of morphological, microstructural, and compositional characteristics of gallbladder stones surgically removed from patients dwelling in northern Greece.
Abstract: The present study aims to characterize gallbladder stones surgically removed from patients dwelling in northern Greece. Combined techniques were employed, such as environmental scanning electron microscopy coupled with an energy dispersive system, μ Raman spectroscopy, X-ray diffraction, and cathodoluminescence for the determination of morphological, microstructural, and compositional (chemical and mineralogical) characteristics. Four characteristic gallstones were determined: a black pigment, consisting of aragonite and bilirubin; a mixed stone, composed of calcite, oxalates, and phosphates; a cholesterol-rich stone; and a large stone, consisting of uric acid. The importance of using such mineralogical complementary techniques is emphasized in this work. It should be noted that this is the first published analytical characterization of gallbladder stones from northern Greece.
Proceedings Article•
15 Oct 2013
17 Oct 2013
TL;DR: In this article, a modified trigonometrically fitted symplectic Runge Kutta Nystrom method based on the forth order five stages method of Calvo and Sanz-Serna is presented.
Abstract: In this work we construct a modified trigonometrically fitted symplectic Runge Kutta Nystrom method based on the forth order five stages method of Calvo and Sanz-Serna. We apply the new method on the numerical integration of the two-body problem.
TL;DR: In this paper, the Free (or Open) Boundary Condition (FBC, OBC) was extended to viscoelastic fluids governed by explicit differential constitutive equations.
Abstract: The Free (or Open) Boundary Condition (FBC, OBC) was proposed by Papanastasiou et al. (A New Outflow Boundary Condition, Int. J. Numer. Meth. Fluids, 1992; 14:587–608) to handle truncated domains with synthetic boundaries where the outflow conditions are unknown. In the present work, implementation of the FBC has been extended to viscoelastic fluids governed by explicit differential constitutive equations. As such we consider here the Criminale-Ericksen-Filbey (CEF) model, which also reduces to the Second-Order Fluid (SOF) for constant material parameters. The Finite Element Method (FEM) is used to provide numerical results in simple Poiseuille flow where analytical solutions exist for checking purposes. Then previous numerical results are checked against Newtonian highly non-isothermal flows in a 4:1 contraction. Finally, the FBC is used with the CEF fluid with data corresponding to a Boger fluid of constant material properties. Particular emphasis is based on a non-zero second normal-stress difference, which seems responsible for earlier loss of convergence. The results with the FBC are in excellent agreement with those obtained from long domains, due to the highly convective nature of viscoelastic flows, for which the FBC seems most appropriate. The FBC formulation for fixed-point (Picard-type) iterations is given in some detail, and the differences with the Newton–Raphson formulation are highlighted regarding some computational aspects.
19 Sep 2013
TL;DR: A formal design framework is described that it allows for correct-by-construction complex circuit generation from high-level program models with arbitrary data and control flow and the functionality of the generated finite-state-machines and datapaths is formally equivalent to that of the source programs.
Abstract: In this paper, a formal design framework is described that it allows for correct-by-construction complex circuit generation from high-level program models with arbitrary data and control flow. The formal nature of the program compilation allows for design flow iteration -- free design, rapid development times and bug-free product implementation. The discussed formal framework, translates program subroutines into hardware coprocessors. The translation process is implemented with formal compiler-compiler and logic programming techniques. Due to this the functionality of the generated finite-state-machines and datapaths is formally equivalent to that of the source programs. This is practically proven in this paper with verification of the designed systems at both the program code and at the produced circuit RTL simulations level. The presented design flow enables rapid prototyping and it allows for compression of the development time from months down to a few hours.
TL;DR: models of mathematical biology referred in the literature as Volterra-Lotka models of competing species defined by ordinary differential equations are considered for the construction of a model for analysing the mobile telecommunications sector in Greece and suggest that in the long-run only one company will remain in the market.
Abstract: Models of mathematical biology referred in the literature as Volterra-Lotka models of competing species defined by ordinary differential equations are considered in this paper for the construction of a model for analysing the mobile telecommunications sector in Greece. Market size data from the three mobile telecommunication companies that operate under licence of the Greek state for the period 1999-2011 are used. Parameter estimation is performed using non-linear least squares. The findings suggest that in the long-run only one company will remain in the market.
TL;DR: In this paper, the authors present a comparative study of the countries through the financial ratios that were analysed, in order to find the characteristics of each economy in comparison to the others.
Abstract: The aim of this paper is to present a comparative study of the countries through the financial ratios that were analysed. This study was carried out in order to find the characteristics of each economy in comparison to the others. It would be worthy to mention that the three economies that were put under comparative study, are not of the same dynamic. The United States of America and Great Britain show some common characteristics due to the positions of power that they possess in the allocation of the global economy. However, in the case of Greece the same dynamic with the other two countries doesn’t exist, a fact that is greatly imprinted in their in-between comparison.
01 Jan 2013
TL;DR: An alternative HLS toolset is presented that the author has developed and which is based on formal methods, thus it guarandees the correctness of the synthesized hardware and system.
Abstract: The current complexity of custom and embedded core or IP integrated electronics demand for a new generation of automated system design and development methods. High-Level Synthesis plays a critical part of such automated methods. However, existing HLS tools are not widely accepted by the engineering community for a number of practical reasons. This article is a practical perspective of such issues, and it analyses the reasons for this. Morever, the article is a useful introduction to the system engineer that wants to consider HLS as part of his everyday system design practice. An alternative HLS toolset is presented that the author has developed and which is based on formal methods, thus it guarandees the correctness of the synthesized hardware and system. The paper completes with conclussions and a number of suggestions about the future directions of HLS technology and what is actually needed by the engineering community.
01 Jan 2013
TL;DR: An overview of the available standards and technologies for multimedia content representation and retrieval is made and a prototype semantic P2P architecture is presented which delivers personalized audio information.
Abstract: Multimedia information has been increased in the recent years while new content delivery services enhanced with personalization functionalities are provided to users. Several standards are proposed for the representation and retrieval of multimedia content. This paper makes an overview of the available standards and technologies. Furthermore a prototype semantic P2P architecture is presented which delivers personalized audio information. The metadata which support personalization are separated in two categories: the metadata describing user preferences stored at each user and the resource adaptation metadata stored at the P2P network’s web services. The multimedia models MPEG-21 and MPEG-7 are used to describe metadata information and the Web Ontology Language (OWL) to produce and manipulate ontological descriptions. SPARQL is used for querying the OWL ontologies. The MPEG Query Format (MPQF) is also used, providing a well-known framework for applying queries to the metadata and to the ontologies.
01 Jan 2013
TL;DR: In this article, the authors quantified the contribution of five lignite power plants (LPPs) operating in Western Macedonia to the particulate pollution of this region, using PM10 concentrations measurements and simulations.
Abstract: Quantifying the contribution of individual sources to air pollution in one area is the first essential step in managing air quality in this region. The area of Western Macedonia is a very complex in terms of air quality management problem because of large and complex pollution sources operating in the region. The emissions from five lignite power plants (LPP) operating in this region, the corresponding opencast lignite mining, as well as the urban activities in the industrial axis, is a complex problem to quantify the contribution of these sources in a spatial and temporal scale in the region. This paper attempts to quantify the contribution of LPP to the particulate pollution of this region, using PM10 concentrations measurements and simulations. Specifically were used: (a) suspended particulate PM10 concentration measurements for a 4 years period (2007–2010) at various locations in the region and (b) simulations of atmospheric dispersion.
01 Jan 2013
TL;DR: In this article, a particulate air pollution episode of relatively long duration was recorded in the industrial basin of Western Macedonia, Greece, during November of 2009, and a case study of the meteorological aspects of this episode is presented in this paper, based on the combined utilization of PM10 concentration measurements, surface and lower atmosphere parameters and simulations.
Abstract: A particulate air pollution episode of relatively long duration was recorded in the industrial basin of Western Macedonia, Greece, during November of 2009. A case study of the meteorological aspects of this episode is presented in this paper, based on the combined utilization of PM10 concentration measurements, surface and lower atmosphere parameters and simulations. An Omega blocking pattern which gradually transformed to a high-over-low pattern prevailed over central and southern Europe during the episode’s period. The absence of significant convection in the middle and lower troposphere combined with a weak horizontal wind field near the surface and the reduced mixing height, resulted in the pollutants’ trapping and the increased PM10 concentrations. The change of the synoptic setting marked the end of the episode.
01 Jan 2013
TL;DR: This work surveys and reviews past research in the area of formal methods for high-level and system synthesis and a prototype HLS compiler tool that has been developed by the author is presented here which uses compiler-generators, RDF rules and logic programming in combination with XML validation interfaces for the internal state of the compiler.
Abstract: The extreme complexity of today’s embedded systems and portable computing machines has motivated research in the area of high-level and system synthesis (HLS). HLS is the process of modeling the behavior of the system in a high, algorithmic level using a regular imperative programming language such as C or ADA, and automatically transforming this behavioral model into hardware implementations. If the HLS transformations that are applied on the source code are formal, then the generated system implementation is correct-by-construction. The HLS tasks include scheduling of operations, allocation and binding to library resources, and techniques for these tasks are explained here. This work surveys and reviews past research in the area of formal methods for high-level and system synthesis. Since this area of research has been active for almost three decades, first the early HLS attempts are reviewed and then the more mature toolsets and HLS algorithms are analyzed. A prototype HLS compiler tool that has been developed by the author is presented here which uses compiler-generators, RDF rules and logic programming in combination with XML validation interfaces for the internal state of the compiler. All these make the compilation process formal. The embedded scheduler PARCS and the formal compilation of the system are tested with a number of benchmarks and real-world applications.
01 Jan 2013
TL;DR: Formal and intelligent HLS techniques are presented in this contribution, thus the generated implementation is correct-by-construction and the whole transformation from source code to implementation, formal.
Abstract: The advancing complexity of contemporary microelectronics has motivated research in high-level and system synthesis (HLS). Formal and intelligent HLS techniques are presented in this contribution, thus the generated implementation is correct-by-construction. These intelligent techniques include RDF (Resource Description Framework) and logic relations, along with automatic implementation options and they are employed for the transformations of a hardware compiler. The proposed toolset utilizes compiler-generators, RDF rules and logic programming in combination with XML validation of the internal state of the compiler. These intelligent and formal techniques make the whole transformation from source code to implementation, formal. The HLS tool is enhanced with the Parallel, Abstract Resource – Constrained Scheduler, which aggressively optimizes the initial state schedules, into maximally parallelized ones. A number of custom options are applied by the user of this toolset, in order to automatically compile selected testcases from real-world applications which prove the usability of the embedded scheduler and the formal compilation of the intelligent HLS compiler.