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.

Improved Plant Yield Efficiency is Essential for Maize Rainfed Production

Abstract: Plant yield efficiency reflects the single-plant yield at low density that precludes interplant interference for resources. The role of plant yield efficiency in adaptation to water deficit was investigated in maize (Zea mays L.). Also investigated was whether yield of space-planted environments is transferable to densely seeded situations. Further, the correlation and genotype by environment (G × E) interaction of spaced and densely seeded plots were investigated. Thirty-one lines and 31 crosses among them were tested in three locations under dense stand and the ultra low density of 0.74 plants m–² as well as in normal and deficit irrigation treatments. The dense stand was 4.44 plants m–² in the water deficit regime and 6.67 plants m–² (lines) and 7.84 plants m–² (hybrids) in the normal water treatment. Hybrids of greater plant yield efficiency were less sensitive to water shortage. Among four hybrids yielding the same at normally irrigated dense stand (11.50 Mg ha–¹), yield loss due to water shortage was 46% for that of the lowest plant yield efficiency (645 g plant–¹) and 17% for that of the highest plant yield efficiency (880 g plant–¹). Correlations between hybrid plant yield efficiency and gas exchange water-use efficiency in dense stand were significant. The low density ensured G × E interaction in the quantitative aspect only and thus was of higher heritability, placing emphasis on parental yield per se. Plant yield efficiency is a key element of hybrid ability to withstand water shortage and cope with environmental heterogeneity.

Unemployment Effects of the Greek Crisis: A Regional Examination☆

Abstract: Greece faces a strong economic crisis as a consequence of the public debt problems and the economic adjustment program applied in the Greek economy. One of the main consequences has been the growth of the unemployment. Although studies examined the crisis’ consequences to the Greek economy, no study focused on the regional impact and particularly on the unemployment. Even thought the unemployment grew up considerably during the crisis period, this growth had a different impact within Greek regions; even within the same region, it affected on a different level the regions’ departments. This study examines the growth of the unemployment on a departmental basis and tries to connect it to the department's production specialization. The study examines the period just before and during the crisis period, 2005 to 2012. Results show that departments specialized on tourism and agriculture are less affected than other departments.

Investigation of the magnetic field response from eddy current inspection of defects

Abstract: Eddy current testing is one of the most widely used methods in non-destructive testing for the inspection of conductive materials. Numerical modelling of eddy current testing has emerged as an important approach alongside experimental studies. This paper investigates an application of numerical modelling and experimental study as a means of the quantitative non-destructive evaluation (QNDE) of defects in conductive samples. There are two methods of measuring eddy current response, more commonly by measuring the change in impedance of the eddy current probe coil, or as used in this work, by measuring the change in magnetic field directly using magnetic field sensors such as superconducting quantum interference devices, giant magneto resistance, or as in this case Hall sensors. Specifically, measurements made using an eddy current probe containing an excitation coil and a Hall sensor, experimentally obtained using an X–Y scanner table, are compared with a numerical (finite element method) model. The discrepancies between the experimental tests and the numerical models have been analysed and explained, which is an important factor in engineering applications of QNDE.

Combustion behaviour of different types of solid wastes and their blends with lignite

Abstract: The combustion characteristics of blends of lignite with various organic waste materials are evaluated in this study in order to assess their potential for energy recovery. Different types of municipal solid waste (i. e. paper, plastic, textile, organic), as well as sewage sludge and agri-residues (sunflower shells) samples were collected from the Western Macedonia region, northern Greece. Mixtures of each one of them with lignite in different proportions (30-50-70 wt.%) were prepared. Proximate analysis, calorific value determination, and thermogravimetry (TGA/ DTG) were performed. Thermal parameters such as ignition temperature, total weight loss, maximum rate of weight loss, peak and burnout temperatures and burnout time were determined from the TG/DTG profiles of the raw materials and their blends. The combined utilization of proximate analysis, calorific value determination and TG/DTG method proved to be an effective method for a preliminary assessment of the energetic potential of raw solid waste “combustible” materials and their blends with lignite. The analytical results revealed that most of the blends are promising for energy recovery. Regarding the raw wastes, sunflower shells were the most reactive. A non-synergistic effect was found for the blends. Organic and sewage sludge blends revealed the lowest combustibility, which is attributed to the high content of inorganic matter and the heterogeneity of these two types of wastes.

Long-term optimization case studies for combined heat and power system

Abstract: In the next years distributed poly-generation systems are expected to play an increasingly important role in the electricity infrastructure and market. The successful spread of small-scale generation either connected to the distribution network or on the customer side of the meter depends on diverse issues, such as the possibilities of technical implementation, resource availability, environmental aspects, and regulation and market conditions. The aim of this approach is to develop an economic and parametric analysis of a distributed generation system based on gas turbines able to satisfy the energy demand of a typical hotel complex. Here, the economic performance of six cases combining different designs and regimes of operation is shown. The software Turbomatch, the gas turbine performance code of Cranfield University, was used to simulate the off-design performance of the engines in different ambient and load conditions. A clear distinction between cases running at full load and following the load could be observed in the results. Full load regime can give a shorter return on the investment then following the load. In spite combined heat and power systems being currently not economically attractive, this scenario may change in future due to environmental regulations and unavailability of low price fuel for large centralized power stations. Combined heat and power has a significant potential although it requires favorable legislative and fair energy market conditions to successfully increase its share in the power generation market.