Showing papers by "Technological Educational Institute of Western Macedonia published in 2019"
TL;DR: In this paper, a comparative study of the performance of Ni/CaO-MgO-Al2O3 and Ni/Al 2O3 catalysts is reported.
131 citations
TL;DR: In this article, Ni/Al2O3 and Ni/La2O-Al 2O3 catalysts were investigated for the biogas reforming reaction using CH4/CO2 mixtures with minimal dilution.
108 citations
TL;DR: Results indicate that disaggregation performance is significantly improved when relying on harmonic current vectors in respect to the case with only current amplitudes, which makes the methodology potentially suitable for the new smart meters that are expected to be widely installed.
68 citations
TL;DR: In this article, the performance of Ni supported on ZrO2 and SiO2-ZrO 2 catalysts was compared for glycerol steam reforming (GSR) reaction for H2 production.
62 citations
TL;DR: In this paper, the effect of the positions of the phase change materials (PCMs) on thermal stratification characteristics at various flow rates (0.06, 0.18, 18.81, 19.34, and 0.54m3/h) and with increasing dimensionless time was investigated.
50 citations
TL;DR: In this paper, the energy, technical and environmental characteristics of residential buildings in Greece, as well as their potential for energy conservation, based on their actual energy consumption data are presented.
46 citations
TL;DR: In this paper, a series of Ce-Sm-xCu (x = 5, 7, and 10 at%) catalysts were prepared through coupling of microwave irradiation with a sol-gel method and were evaluated for the glycerol steam reforming reaction in the 400-750 °C temperature range.
Abstract: A series of Ce–Sm–xCu (x = 5, 7, and 10 at%) catalysts were prepared through coupling of microwave irradiation with a sol–gel method and were evaluated for the glycerol steam reforming reaction in the 400–750 °C temperature range. Some critical comparison with co-precipitation catalysts is also discussed. The catalysts were characterized using BET, Raman, XRD, NH3-TPD, CO2-TPD, H2-TPR, SEM, HAADF-STEM and XPS analyses, while the bonding environment and thermal stability of the catalyst precursor compounds were studied using FTIR and TGA/DSC. For all catalysts it was found that the Ce, Sm, and Cu cations are all homogeneously distributed in the cubic fluorite cell with interplanar spacings of 0.355 nm, 0.370 nm and 0.373 nm for the Ce–Sm–5Cu, Ce–Sm–7Cu and Ce–Sm–10Cu catalysts, respectively. The surface of the catalysts was found to be Ce- and Cu-poor and Sm-rich, with Ce4+, Ce3+, Sm3+, Cu2+ and Cu+ oxidation states identified. In the bulk, the oxygen vacancies were found to be dependent on the catalyst composition (Cu content). Among the catalysts studied, the Ce–Sm–5Cu one exhibits the highest selectivity for hydrogen (H2) with its SH2 ranging from 40% (400 °C) to 75% (750 °C). The Ce–Sm–5Cu catalyst also produces the highest amount of CO (97–71%) and the lowest amount of CO2 (3–28%) among all samples for the low reaction temperature range (400 °C 650 °C and reaches values of 7, 10 and 12 for the samples Ce–Sm–5Cu, Ce–Sm–7Cu, and Ce–Sm–10Cu, respectively. All the catalysts showed a glycerol conversion of 80% after 6 h time on stream, although a variety of coke species was found on their surfaces. A potential correlation between Cu content and coke deposition was attempted.
36 citations
TL;DR: This work considers explicit methods and construct a family of fifth‐order methods with three stages of the general case that use several evaluations of f and g per step that derive methods with frequency‐dependent coefficients following the approach of Simos and Vanden Berghe.
18 citations
01 May 2019
TL;DR: A thorough analysis is performed to evaluate the impact of the battery energy storage systems (BESSs) on the electrical behavior of the prosumers using real measurements acquired from three pilot case studies located at the region of Northen Greece.
Abstract: In this paper, a thorough analysis is performed to evaluate the impact of the battery energy storage systems (BESSs) on the electrical behavior of the prosumers. Its distinct feature is the use of real measurements acquired from three pilot case studies located at the region of Northen Greece. Two types of BESS technologies are examined, namely the lead-acid OPzV and the lithium-ion LiFePO4 batteries. The evaluation process is implemented using the most well-known indicators, i.e., the self-consumption and the self-sufficiency rates.
12 citations
TL;DR: Interannual and monthly variations of herbage production and nutritive value regarding grazing ruminants' needs and welfare were evaluated in three grasslands located at different altitudes in northern Greece during 2015–2016.
Abstract: . Interannual and monthly variations of herbage production and nutritive value
regarding grazing ruminants' needs and welfare were evaluated in three
grasslands (semi-mountainous, mountainous and sub-alpine) located at
different altitudes (480–900, 901–1500 and 1501–2334 m,
respectively) in northern Greece during 2015–2016. Herbage biomass was
collected from 30 experimental cages (10 per grassland), weighed, dried at
65 ∘ C, milled and analyzed for crude protein (CP), neutral detergent fiber (NDF), acid
detergent fiber (ADF), lignin, calcium (Ca) and phosphorus (P) content
and in vitro dry matter digestibility (IVDMD). The sub-alpine grassland was the most
productive (1031 and 1231 kg DM ha −1 ) with the
highest mean annual herbage CP content (93 and 87 g kg −1
dry matter; DM) for 2015 and 2016, respectively. CP content was sufficient to meet small
ruminants' and beef cattle maintenance requirements until April and May in
the semi-mountainous and mountainous grasslands, respectively, while it
could cover the above requirements in the sub-alpine grassland until June and
August, respectively. The herbage Ca concentration was higher than the
grazing ruminants' needs, while the phosphorus concentration was
insufficient. Protein and phosphorus supplementation should be provided to
animals to cover their maintenance requirements during the whole period and
to reach high levels of welfare. Even though grazing is considered as a
welfare-friendly procedure, it is uncertain whether all the welfare
principals are satisfied in extensive production systems due to variations
of forage availability and nutritive value as well as the lack of
infrastructure in grasslands.
11 citations
10 Jun 2019
TL;DR: In this paper, a simple and accurate thermal model based on ISO 52016-1:2017 is proposed for the calculation of both heating and cooling energy needs in residential properties, which can be used in any type of building as well.
Abstract: The total energy consumption of the buildings’ sector has been increasing steadily over the last decades, increasing the energy-related carbon dioxide emissions. By the transformation of buildings into nearly or net zero energy ones (nZEBs), they will likely play a pivotal role in the smart grid context, being able to both produce and consume energy on-site and even acting as small nanogrids. In order to achieve that, a move towards smart and more energy efficient buildings with increased energy autonomy is mandatory for the existing and new properties. In this direction, the project "Enhancing storage integration in buildings with Photovoltaics" of "INTERREG Balkan Mediterranean 2014-2020" aims at both modelling and validating methods of optimal energy management in buildings equipped with Photovoltaics (PV) and storage systems. In this paper, a simple and accurate thermal model based on ISO 52016-1:2017 is proposed for the calculation of both heating and cooling energy needs in residential properties. The model has been tested in residential buildings in various European locations, but can be used in any type of building as well. From the comparison of the model with other simulation tools, it is concluded that slight deviations occur due to differences in climate data, the operative temperature, as well as the different approaches of ventilation and shading effects.
TL;DR: Ovine milk had better nutritional value in comparison to caprine milk that had an enriched terpene profile than ovine milk and β-Caryophyllene was detected in the majority of the examined ovine and caprine Milk samples suggesting that its presence could be used as a potential biomarker of grass feeding.
TL;DR: The aim of this paper is to examine the effectiveness of sample selection schemes in combination with different classifiers for constructing reliable default prediction models.
Abstract: Credit risk assessment is a very challenging and important problem in the domain of financial risk management. The development of reliable credit rating/scoring models is of paramount importance in this area. There are different algorithms and approaches for constructing such models to classify credit applicants (firms or individuals) into risk classes. Reliable sample selection is crucial for this task. The aim of this paper is to examine the effectiveness of sample selection schemes in combination with different classifiers for constructing reliable default prediction models. We consider different algorithms to select representative cases and handle class imbalances. Empirical results are reported for a dataset of Greek companies from the commercial sector.
TL;DR: The paper proposes both terminological and computational adjustments and differentiated approaches for the models and their indices, in order to ameliorate their capabilities and to exploit their peculiarities for the developmental patterns.
Abstract: Input-Output literature can be characterized as complicated and chaotic. The complications concern the nomenclature of concepts for the derived indices from the multipliers’ models, their mathematical expressions and computable applications. The terminologies’ inconsistencies often end up to a deviation between the description for these indices and their actual computation, or/and to a misunderstanding as for their usefulness and outcomes. The aim of the paper is to help the readers to face the weaknesses in the literature. In this way, the paper provide an overview with a critical look to the constructed multipliers’ matrices and their derived indicators from the I-O models, and elaborate the causes for the scrutinized confusions. The paper proposes both terminological and computational adjustments and differentiated approaches for the models and their indices, in order to ameliorate their capabilities and to exploit their peculiarities for the developmental patterns. Alternative interpretative ways and applicable expansions are suggested.
27 Feb 2019
TL;DR: Synchronous-asynchronous tele-education platform (SATEP) is a software application for educational purposes, with a lot of parametrising (configuration) features written entirely from scratch, a platform that can be adjusted to the needs of each lesson.
Abstract: Synchronous-asynchronous tele-education platform (SATEP) is a software application for educational purposes, with a lot of parametrising (configuration) features written entirely from scratch. It aims at the training and examination of computer skills, a platform that can be adjusted to the needs of each lesson. In the application the trainer and the administrator can define the number of the lectures and upload files for each one of them. Furthermore, he can insert, modify and delete questions which are used for evaluation tests but also for the trainees' examinations. The trainee can read/download the files of each lesson and also test his knowledge on what he has studied through a series of questions/tests. A chat module where registered users as well as system administrator can discuss and solve questions is also developed.
TL;DR: In this paper, the authors examined the relationship between crude oil prices, one of the major inputs, of economic activity and environmental degradation as reflected in the volume of carbon emissions, and validated that climate change mitigation policies are effective in the long run, though this is not the case in the short run.
Abstract: The present study examines the relationship between crude oil prices, one of the major inputs, of economic activity and environmental degradation as reflected in the volume of carbon emissions. The nonlinear autoregressive distributed lag cointegration approach was employed to study the intertemporal causal crude oil prices–carbon emissions relationship. Our findings confirm long-run asymmetry in both directions of the relationship studied. In the short run, asymmetric effects are confirmed running only from carbon emissions to the crude oil prices. Furthermore, it is validated that the climate change mitigation policies are effective in the long run, though this is not the case in the short run. The quantification of this relationship outlines the key role of crude oil prices to sustainable economic growth conditional to environmental policies in global terms.
TL;DR: Findings suggest no population structure and high levels of gene flow, a common feature observed in marine bivalves with long pelagic larval phases.
Abstract: The horse mussel Modiolus barbatus is a marine benthic bivalve, distributed mainly in the Mediterranean basin, that constitutes a fishery product of high economic importance and a promising candidate for aquaculture. The current study provides the first insights regarding the genetic profile of M. barbatus populations from the eastern Mediterranean, by analysis of a partial segment of the mitochondrial COI gene in individuals collected from five sampling localities within the Aegean Sea. To the best of our knowledge, the derived haplotypes represent the first DNA barcodes of M. barbatus from the entire Mediterranean region. Maximum likelihood phylogenetic analysis revealed that M. barbatus from the North Sea and M. barbatus from the eastern Mediterranean may not belong to the same species and as a consequence, there might be three species of the genus Modiolus in Europe. On the other hand, eastern Mediterranean M. barbatus haplotypes were found to be more closely related to the Asian-Pacific Modiolus species. All geographic populations analysed displayed high levels of genetic diversity, in terms of haplotype and nucleotide diversity and a considerable number of unique alleles. Divergence among populations was found at generally low levels, corresponding with the majority of pairwise Fst values not being significant. These findings suggest no population structure and high levels of gene flow, a common feature observed in marine bivalves with long pelagic larval phases.
TL;DR: In this article, the performance evaluation of the meteorological component of The Air Pollution Model (TAPM), a nestable prognostic model, in predicting meteorological variables in urban areas, for both its surface layer and atmospheric boundary layer (ABL) turbulence parameterizations.
Abstract: This paper provides the performance evaluation of the meteorological component of The Air Pollution Model (TAPM), a nestable prognostic model, in predicting meteorological variables in urban areas, for both its surface layer and atmospheric boundary layer (ABL) turbulence parameterizations. The model was modified by incorporating four urban land surface types, replacing the existing single urban surface. Control runs were carried out over the wider area of Kozani, an urban area in NW Greece. The model was evaluated for both surface and ABL meteorological variables by using measurements of near-surface and vertical profiles of wind and temperature. The data were collected by using monitoring surface stations in selected sites as well as an acoustic sounder (SOnic Detection And Ranging (SODAR), up to 300 m above ground) and a radiometer profiler (up to 600 m above ground). The results showed the model demonstrated good performance in predicting the near-surface meteorology in the Kozani region for both a winter and a summer month. In the ABL, the comparison showed that the model’s forecasts generally performed well with respect to the thermal structure (temperature profiles and ABL height) but overestimated wind speed at the heights of comparison (mostly below 200 m) up to 3–4 ms−1.
11 Mar 2019
TL;DR: The proposed conceptual product design concept is dealing with in-store displays that are inspired from nature forms that can lead to further opportunities for research and marketing success of the retail industry.
Abstract: Nature is a great laboratory where many experiments are taking place every moment. Especially, nature-based design is perhaps the oldest methodology of design with examples from all over the fields of applied sciences. From the conceptual side, product design uses a different approach in nature-based methodology. The proposed conceptual product design concept is dealing with in-store displays that are inspired from nature forms. Those nature-based design ideas can lead to further opportunities for research and marketing success of the retail industry. A number of illustrative case studies of in-store displays are presented in this paper.
01 Jan 2019
TL;DR: In this article, a discussion of the recent trends in credit provision, and an outline of the regulatory framework is presented, and the main elements of credit risk modeling are identified, namely the estimation of the probability of default, loss given default, and exposure at default.
Abstract: Credit is a fundamental tool for financial transactions in the private and public sector, providing the liquidity needed for all forms of economic activity for consumers and corporate activities. This chapter sets the basis for understanding the concepts and aspects of credit risk management and the current practices in this field. The discussion starts with a presentation of the recent trends in credit provision, and an outline of the regulatory framework. Then, some fundamental factors that create uncertainties are outlined, and the main elements of credit risk modeling are identified, namely the estimation of the probability of default, loss given default, and exposure at default. The requirements set by the Basel Capital Accords regarding these elements are discussed and different modeling schemes are outlined, including judgmental approaches, data-driven empirical models, and financial models. The chapter closes with some financial measures for assessing the loan profitability, such as risk-adjusted return on capital.
TL;DR: A model named sustainability push & pull is presented, which is focused on the cultivation of sustainable behaviour to the citizens, which was based on a framework which was built according to the direct communication between users and designers.
Abstract: The concept of the sustainable development which is defined in terms of the triple bottom line (economic, environmental and social) is becoming increasingly important. Until now, however, the social aspects have been under-investigated in comparison to environmental and economic aspects. From the product design point of view there is an emergency for development tools and methodologies that are directly linked with the social pillar of sustainability. The research has as main target to discover the future role of designers and engineers to address sustainability as well as emerging priorities from societal to environmental challenges. Furthermore, the present paper presents a model named sustainability push & pull, which is focused on the cultivation of sustainable behaviour to the citizens. The key issue is the users/citizens participation during the product design process, playing an active role to the product development. The whole work was based on a framework which was built according to the direct communication between users and designers. Focused on this target, two new design for X methodologies a) Design for Promoting Sustainable Principles through user education and b) Design for Green Usability developed following the guidelines of the proposed User Assessment Tool. The research garnered responses from 72 participants who answered detailed questions during the whole design process. Data analysis was accomplished according to the data analysis process proposed by Miles and Huberman. The positive view to the whole process made clear that the used methodologies are friendly and very interesting for both the users/citizens and designers. The results from both the questionnaires and interviews show that it is also very educating while the proportions of knowledge about sustainability were grown up.
21 May 2019
TL;DR: The methodology applies on performed measurements of typical Low Voltage residential installations considering harmonic order currents as the input features for both the training and disaggregation scheme supports the hypothesis that the identification performance is enhanced when higher harmonic currents are included in the NILM methodology.
Abstract: This paper examines the application of machine learning techniques in NILM methodologies based on the first three odd harmonic order current vectors as the only attributes of the appliances. Proper formulation of the measured current waveform of appliances' combinations is also presented. We apply our methodology on performed measurements of typical Low Voltage residential installations considering harmonic order currents as the input features for both the training and disaggregation scheme. Our results support the hypothesis that the identification performance is enhanced when higher harmonic currents are included in the NILM methodology.
23 Apr 2019
TL;DR: The potential of efficiently utilizing the stored energy of Battery Energy Storage Systems (BESSs) in order to face the increased load demand by the penetration of EVs in LV Distribution Networks (DNs), with the presence of PVs is examined.
Abstract: The penetration of Electric Vehicles (EVs) is rapidly increasing at the Low Voltage (LV) level, thus increasing the electrification rate of transport. Moreover, Photovoltaic (PV) systems at the LV level have been constantly increasing as well. Buildings with PVs on their roof and EVs as the main transport means may well become the norm the following years, considering additionally that all new buildings in the EU should be Nearly Zero Energy Buildings (NZEBs). Such NZEBs should cover the majority of their low energy demand by Renewable Energy Sources, and PV technology is the main candidate to achieve that. Both these facts pose considerable challenges on the LV networks. In this context, this paper examines the potential of efficiently utilizing the stored energy of Battery Energy Storage Systems (BESSs) in order to face the increased load demand by the penetration of EVs in LV Distribution Networks (DNs), with the presence of PVs. A Particle Swarm Optimization (PSO) algorithm is developed in order to perform optimal charging schedule for the EVs under the aim of optimizing the DN voltage profile. The analysis is performed on a real LV DN with real load data and the results indicate that under proper charging schedule both the voltage profile and the energy losses of the DN could be improved.
01 Jan 2019
TL;DR: The Metadata-Aware Analytic Network Process (MANP) algorithm is proposed in order to weigh the user preferences for each monument type, and the Trapezoidal Fuzzy Topsis for Heritage Route Selection (TFT-HRS) algorithm ranks the candidate heritage routes.
Abstract: Virtual tours using drones enhance the experience the users perceive from a place with cultural interest. Drones equipped with 360o cameras perform real-time video streaming of the cultural sites. ...
TL;DR: Differences in social media usage of MEPs were found to be explained by variables such as parliamentarians’ gender, Euro-party affiliation, and country of origin, and the results suggest that the social media popularity of MEP’s can be predicted by the European region from which political actors originate, the ideology of their Euro- party affiliation and the type of committee to which MEPs are assigned.
Abstract: The present study examines the usage of social media (i.e. Facebook and Twitter) by Members of the European Parliament (MEPs) of the 8th and 7th legislative term. Specifically, it examines the differences in social media usage between MEPs of the current legislature (2014–2019) and MEPs of the preceding period (2009–2014). Moreover, it tests the impact of several predictors on MEPs’ social media adoption and popularity, as measured by the number of social media supporters. Differences in social media usage of MEPs were found to be explained by variables such as parliamentarians’ gender, Euro-party affiliation, and country of origin. Further, the results suggest that the social media popularity of MEPs can be predicted by the European region from which political actors originate, the ideology of their Euro-party affiliation, and the type of committee to which MEPs are assigned. In addition, the study sheds light on how the two platforms (Facebook and Twitter) differ in regard to the factors that impact MEPs’ social media popularity.
TL;DR: The comparison of the models showed clearly that adopting genetic algorithm (GA) equals to the improvement of the efficiency of the network performance.
Abstract: In the present study, Artificial Neural Network (ANN) approaches were adopted for the prediction of thrust force (Fz) and torque (Mz) during drilling of St60 workpiece, according to importa...
28 May 2019
TL;DR: In this paper, a comparative assessment of thermal and battery storage in the context of nearly zero energy buildings (NZEBs) is presented, in terms of the self-consumption rate and the net present value.
Abstract: In order to determine the most suitable storage system for buildings with photovoltaics (PVs), a holistic analysis of the energy consumption is often required. In that sense, this paper provides a comparative assessment of thermal and battery storage in the context of nearly zero energy buildings (NZEBs). A NZEB with a PV, heat pump and a radiant floor has been considered for this purpose. The comparison is conducted in terms of the self-consumption rate and the net present value. In addition, a control strategy that maximizes the buildings self-consumption has been developed for the NZEB with thermal storage. For the NZEB with a battery, a common rule-based strategy has been employed. The results indicate that for smaller capacities, the thermal storage is better at improving self-consumption. Moreover, under a pure self-consumption scheme, battery storage becomes economically viable if investment costs are lower than 200 EUR/kWh.
TL;DR: The DFQ appears to be an overall valid means of estimating the habitual intake of drinks in large-scale epidemiological surveys and supports the use of DFQ for assessing drinks consumption patterns and secular trends.
Abstract: AIM: Drinks can contribute to energy as well as micro‐ and macro‐nutrient intake. Drink‐specific, validated, quick and easy to administer questionnaires are needed to monitor secular trends in beverage consumption for different populations. The aim of the present cross‐sectional study was to develop and validate a drink‐specific questionnaire for the Greek population. METHODS: A 41‐item semi‐quantitative drinks frequency questionnaire (DFQ) was developed and validated against 7‐day weighed food records, among young Greek adults. Wilcoxon ranks tests, Kendall tau‐b correlations and Bland–Altman plot were used to compare the two methods. Fifty‐nine Greek University students (28 males, 31 females) completed both methods. RESULTS: No difference was observed in total drinks intake between the two methods. The Bland–Altman plot showed that the two methods are likely to agree concerning the total drinks intake. Wilcoxon's rank test showed no significant differences between the two methods, except for the ‘whiskey/vodka/gin’ intake (P 0.61) was observed for most DFQ items, including low‐fat and chocolate milk, hot chocolate, Greek/espresso coffee, commercial tea, packaged fruit juices, wine, alcohol‐free beer, light cola‐type drinks and water (tap/bottled/sparkling). ‘Low’ agreement (<0.30) was noted for filtered/instant/iced coffee, freshly squeezed orange juice and some alcoholic drinks (beer/whiskey/vodka/gin). CONCLUSIONS: The DFQ appears to be an overall valid means of estimating the habitual intake of drinks in large‐scale epidemiological surveys. The study supports the use of DFQ for assessing drinks consumption patterns and secular trends.
10 Jun 2019
TL;DR: In this article, a systematic comparison of the existing approaches for the calculation of the mutual impedance between overhead and underground insulated conductors is carried out, and results obtained using Pollaczek's complex integral formula, several approximate closed-form solutions proposed in the literature as well as the Finite Element Method.
Abstract: Significant harmonic voltage induction levels can be caused by distribution power lines, especially in distribution networks of North America. To investigate the harmonic voltage induction caused by overhead distribution lines to underground insulated conductors, it is critical to calculate accurately the mutual earth impedance between the conductors. In this paper, a systematic comparison of the existing approaches for the calculation of the mutual impedance between overhead and underground insulated conductors is carried out. Comparisons include results obtained using Pollaczek’s complex integral formula, several approximate closed-form solutions proposed in the literature as well as the Finite Element Method. The analysis focuses in the frequency range up to some hundreds of Hz, where most significant levels of harmonic currents in distribution networks can be observed.
TL;DR: This is the first case with a presentation mimicking an invasive tumor on contrast-enhanced MRI of a 43-year-old woman with a cavernous hemangioma of the breast, presenting only on MRI and evading mammographic and ultrasonographic imaging.
Abstract: Hemangiomas are vascular lesions, which are only rarely located in the breast. Larger breast hemangiomas may be detected by clinical examination, mammography, and breast ultrasound, whereas smaller lesions are usually incidental findings. We present a rare case of a 43-year-old woman with a cavernous hemangioma of the breast, presenting only on MRI and evading mammographic and ultrasonographic imaging. On breast MRI, a small lesion with irregular margins was detected in the right breast, and following gadolinium contrast medium administration, a type 3 curve, with rapid initial rise, followed by reduction in enhancement (washout) in the delayed phase was noted, raising suspicion for malignancy. The lesion could not be visualized on second-look targeted breast ultrasound and full-field digital mammography. A wide local excision was performed after 3 T MRI-guided hook wire localization and diagnosis of cavernous hemangioma was established histologically. Cavernous hemangioma is a rare breast lesion, with only few cases reported in the literature, and this is the first case with a presentation mimicking an invasive tumor on contrast-enhanced MRI.