Crude Oil Prices Effect on Enhanced Oil Recovery Projects


Enhanced or tertiary oil recovery methods (EOR) contribute significantly in increasing oil recovery factor up to 60%. Additional oil recovery values depend on the type of the applied EOR method (thermal methods that include steam injection, in situ combustion; chemical methods such as polymer, alkaline or surfactant injection and injection of hydrocarbon, carbon dioxide or other gaseous fluids). Implementation of complex EOR methods involves high capital and operational costs, longer period of investmentˋs payback period and more risk and uncertainty in comparison to the use of conventional primary and secondary recovery methods of oil reservoirs.
In general, oil prices have the largest impact on the EOR projects’ economic viability.
Crude oil price decline since June 2014 had large impact at the world energy market, as well as at the application of oil exploitation methods and their commercial viability. In this paper are presented considerations of oil price impact on the oil production by EOR methods.

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Low Cost Cup Electronic Anemometer


In all studies involving wind speed, such as meteorology, wind turbines and agriculture, require accurate speed information for decision making. There are several types of anemometers, with medium and high costs, such as Cup, hot wire and Pitot tubes, and the hot wire is more sensitive and expensive than others.The device developed in this work is the Cup anemometer, to be easy to build. The great advantage of this device is the low cost, with an approximate value of US$ 50.00, using simple materials and easy to find in commercial stores. The Reed Switch sensor is also another advantage as it does not require a sophisticated programming, as well as the open platform Arduino. The use of aerodynamic drag coefficients and the presented calculations resulted in values very close to a commercial anemometer with a good coefficient of determination(R^2 ). The present sensor was developed as part of the project of a meteorological station to monitor the micro-climate of the city of Catanduva-SP, Brazil.

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Analysis of Multiple Injection Impact on Fuel Supply Parameters


Fuel injection causes considerable oscillations of fuel pressure at the injector inlet. One of the reasons is hydraulic impact originating when closing the injector nozzle needle. Evidently, these oscillations influence the fuel supply process in case of multiple injections: the previous injections would influence on the following ones. The influence of the interval between the impulses of a double injection on the injection rate value of the second portion was investigated. The superposition of waves in case of multiple injection may result both in amplification and damping of oscillations process. It is shown that with multiple injection, the controllability of fuel supply deteriorates, therefore, either a special design study of the fuel system for multiple injection or the introduction of additional electronic correction of control pulses by the diesel control system is required. On the other hand, it is shown how multiple injection can produce a stepwise injection characteristic, which can serve as a means of reducing nitrogen oxides and noise. Applied research and experimental developments are carried out with financial support of the state represented by the Ministry of Education and Science of the Russian Federation under the Agreement № 14.580.21.0002 of 27.07.2015, the Unique Identifier PNIER: RFMEFI58015X0002

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Calculation of Losses in the Distribution Grid Based on Big Data


This paper represents an approach for calculation of losses in a distribution power grid from data which are normally collected by the grid operator. The proposed approach utilizes the least squares optimization method in order to calculate the coefficients needed for estimation of losses. The amount of data used in calculations is very large due to the fact that electrical energy injected in distribution grid is measured every fifteen minutes. Therefore, this approach is classified as the big data analysis. The used data set is available in the Serbian distribution grid operator’s report for the year 2017. Obtained results are fairly accurate and can be used for losses classification as well as future losses estimation.

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Wind Farm Multiobjective Optimization using Nested Extremum Seeking Controls


Wind farm optimization has been the focus of research in recent years. Most of the control algorithms available to maximize the energy capture or reduce structural loads are model based. A Model-based controller is designed for wind turbines in ideal condition of operation. In real world, the actual wind power is a function of factors such as wind shear, temperature and surface roughness of the blade. This reduces the effectiveness of a model-based controller. Extremum seeking controls is a real-time, model free optimization algorithm that can adapt to the changes in the design and environment. Previous studies have shown the effectiveness of the algorithm to only maximize the energy capture, without considering the increase of structural loads. This paper presents a novel multiobjective nested extremum seeking controls algorithm to maximize the energy production and minimize the structural loads. The results show 30% reduction of the damage equivalent loads of the main shaft, and 25% reduction of the tower while increasing ~1% power output of a wind farm compared to a baseline controller.

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Application of Multi-criteria Decision-making Methods in Energy Research – a Review


Multi-criteria decision making (MCDM) has been widely employed in different research domains that typically involve complex decision-making problems. Energy planning is one of the most challenging contemporary development domain. Building on previous studies, the objective of this paper is to review some characteristics of recent application of MCDM in energy research. 132 articles from the Scopus database, for period 2017-2018 were analyzed in respect to ten criteria. Besides the rising trend in application of MCDM it is shown that 1) the most used method is AHP, 2) the traditional form dominates, 3) MCDM are primarily used in evaluation studies, focusing on combined energy sources or solar energy, 4) hybrid approaches are employed more than individual methods, 5) most of the MCDM methods are applied in its original form, 6) the most researched spatial level is national, 7) top-ranked journal is Energy, and 8) most articles come from China.

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Contribution of Renewable Energy Sources to Overall National Energy Security Policy


Energy is necessary for the functioning of every society. Although the development implies increasing energy efficiency, due to the increase in the number of inhabitants, introduction of various new technologies and development of automated industry, there is significant increase in energy needs. The lack of energy is therefore a threat to the security of every country. The use of renewable energy sources increases country energy independence. In this paper, the importance of application of renewable energy sources in Serbia in the context of its energy security policy has been considered.

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Potential of Climate Change Mitigation Associated with the Utilization of Solar Thermal Energy in the Ice Cream Industry


The negative environmental impact associated with the generation of thermal energy in the Brazilian industrial sector has become an increasing concern due to its contribution to global warming. The implementation of solar thermal energy, through flat collectors, has been studied to minimize negative environmental impacts. This can reduce atmospheric emissions associated with the installation and generation of thermal energy for use in industrial processes. The pasteurization process of ice cream was analysed herein, using the Life Cycle Assessment (LCA) methodology. SimaPro software v.8.5.0.0 was utilized, with the EcoInvent database. The environmental impact assessment method chosen was IPCC 2013 GWP 100y, which expresses the environmental impact in terms of kg CO2-eq (carbon footprint). An ice cream factory located in João Pessoa (Northeast Brazil) was selected to represent the case study: the existing system (LPG burner) was compared with a solar thermal energy system. The carbon footprint of the existing system was 2172 kg CO2-eq/year while the impact of the solar system (flat collectors) was only 117.9 kg CO2-eq/year, demonstrating a reduction of 2054 kg CO2- eq/year (-95%). These results highlight the introduction of solar thermal energy as an environmentally viable alternative.

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Exergetic Pinch Evaluation of a Steam Power Plant Heat Exchanger Network


In this paper, a steam power plant’s heat exchanger network (HEN) is analyzed, using the pinch, exergy, and combined pinch and exergy methodologies, in order to evaluate its performance under design and operational conditions. The pinch analysis show that, under current operational conditions, the minimum hot utility requirement was 539,491kW at a temperature of 549°C, which is 30,618kW (6.02%) more than the design minimum hot utility requirement (508873.7kW), and the optimum minimum temperature difference between hot and cold streams ( ΔT min ) in the HEN is 12°C. Results from standard exergy analysis showed that heaters 5, 2 and deaerator performance improved while the other components experienced decrease in exergetic efficiencies. Though the boiler had the highest avoidable and inevitable exergy losses 〖(ĖL〗_AVO and 〖Ėx〗_INE) respectively, Heater 3 showed the most potential for performance improvement with (158.04%). Followed by Heater 6 (54.7%), the deaerator (15.15%), the condenser (13.55%), and Heater 1 (12.62%) when we consider 〖ĖL〗_AVO/〖Ėx〗_INE . A combined pinch and exergy analysis (CPEA) gave similar outcomes, and showed further that changes in cold stream properties majorly led to performance declines observed. For improved plant performance, the exergy losses identified in the HEN should be reduce beginning from the cold streams.

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Improved Algorithm for FEM Analysis of MTL Problems


This paper deals with improvement of time integration scheme for transient finite element method (FEM) analysis. FEM is applied to the system of hyperbolic differential equations i.e. system of multi-conductor transmission line (MTL) equations. Spatial integration of system of hyperbolic differential equations is usually done by the weighted residual method. Improvement of accuracy was obtained by using Heun’s method. Numerical solutions obtained using Heun’s method and using the generalized trapezoidal rule for different values of a time integration parameter ϑ are compared to analytical solution. It has been shown that Heun’s method yields the results with much higher accuracy comparing to results obtained by generalized trapezoidal rule (ϑ-method) with the approximately equal computational time.

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Application of Pre-treatment for Enchancing Biogas Production from Plant-based Agricultural Waste


Agricultural waste is a suitable renewable source for the production of biogas, which can be converted into different forms of energy. Chemical pre-treatment can make anaerobic digestion faster and increase biogas yields. In this study, a mechanical and alkaline combination of pre-treatment is used. The aim of study is to compare the biogas yield with and without pre-treatment, as well as to develop a device which can be used as a system for chemical pre-treatment. Results show that a combination of the granulation of raw materials and alkaline treatment is an effective pre-treatment for increasing biogas yield.

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Analysis of an Indirect Evaporative Air Cooler


Performance of a counter-flow indirect evaporative air cooling device is analysed numerically. The device characteristic dimensions, inlet air temperature and humidity as well as inlet air velocity are investigated for the assessment of the thermal performance with the aim to determine the most influential design parameters. Additionally, design guidelines for central european climatic conditions are given.

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District Heating Final Users Energy Efficiency Improvements – Goals and Challenges in Republic of Serbia


Households in Serbia spend around 35% of the total final energy. This is the greatest potential for energy, economic and environment improvements. The apartment buildings, which cover 60% of total dwellings, are mostly in the lowest energy efficiency class. Transparent calculation of the heat energy price, based on the measured consumption, accompanied with founding a fund for energy efficiency improvement with significant human recourses and a budget is crucial for the energy efficiency improvement, heating costs reduction and increase in customers’ satisfaction. Another possibility is application of an obligatory scheme of energy efficiency, according to Article 7 of the Directive 2012/27/EU, according to which distributors and retail energy sales companies are obliged to achieve end-users energy savings. It means the obligation of the heat suppliers to provide a financial and technical support for energy efficiency improvement in buildings.

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Li-ion battery-packs modeling based on joint time-frequency analysis for vehicle applications


In this paper a modeling procedure based on joint time-frequency analysis is presented. In this way, the parameters of the electrical circuit include the different time constants that affect the transient response of the battery-packs. The model has been experimentally validated by means of a hardware-in-the-loop (HIL) simulation. Simulations results show that the model presents consistent accuracy to reproduce the voltage response of the battery-pack at different driving cycles.

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Circuit Breaker Replacement Strategy Based on the Substation Risk Assessment


Using statistical data of 427 circuit breakers gathered in past 10 years, Weibull probability distribution of contact resistance for breakers on both overhead and underground feeders is determined. Substations reliability is calculated using minimal path and minimal cuts method. With this methodology influence of CB’s condition on substations reliability can be observed by using real field data. In this paper influence of CB removal on substations reliability is presented, together with cost justification of such investment. Example of calculation will be shown on 35/10kV substation.

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Benchmarking of Heat Energy Consumption in Public Buildings in the City of Kragujevac


Final energy consumption in buildings has the highest share in final energy consumption on a global level. Heat has the highest share in final energy consumption in European buildings. Also, public buildings consume more final energy than residential buildings in general. Specific heat consumption is an important parameter that indicates the state of energy efficiency of the building sector. In this paper, specific heat consumption of public buildings in the city of Kragujevac is analyzed. Part of the data collected for the Energy Efficiency Program for the City of Kragujevac is presented and compared with similar results from other countries and cities. Authors conclude that specific heat consumption in municipal buildings of Kragujevac is relatively high compared to other countries and that its values also vary depending on building purpose and building built year.

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Quality Management of Sugarcane focused on Efficient Bioelectricity, Ethanol and Sugar Production


The main objective of this work is to present a proposal to manage sugarcane requirements in sugarcane growers’ relations with their suppliers and customers, focusing on meeting the requirements of the product in order to produce ethanol efficiently as alternative energy source. To meet this objective, an empirical research of multiple cases was performed in the main agents of the sugarcane production chain in order to investigate the use of practices of the elements of supply chain quality management theory related to relationship with suppliers and clients. The field study showed that, in most cases, the relationship of both upstream and downstream growers is not of partnership, where there is a lack of actions that promote compliance with sugarcane quality requirements, such as actions to preserve product quality and incentives that promote quality as quality audits. The proposal is limited to a model that meets the requirements of sugarcane focusing on supplier-client integration. The proposal presents solutions to the existing gaps in sugarcane growers’ relations with their suppliers and customers. This can corroborate towards the attendance and improvement of sugarcane quality, resulting in more efficiency in the production of the sugar, ethanol and electricity by milling plants.

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Health Risk of Polycyclic Aromatic Hydrocarbons – PAHs in Primary School Environment in Serbia, Probabilistic Modeling Study


Polycyclic aromatic hydrocarbons (PAHs) are a group of organic compounds and many of them are toxic and carcinogenic environmental contaminants. They typically result from the incomplete combustion processes of organic materials. Exposure to PAHs emissions can create a number of adverse health effects. Children represent one of the most susceptible population groups with regard to potentially harmful effects. The main objectives of this paper are: first, experimental evaluation of concentrations of 16 priority PAHs in indoor and outdoor air in Serbian school, where residential heating and traffic are the only major PAH sources. The second objective is calculation of cancer risk of PAHs for children from total suspended particles (TSP) using suggested incremental lifetime cancer risk (ILCR) model based on Monte Carlo simulations. The obtained measured values as well as calculated numerical results showed, that although PAHs concentration values are lower than suggested limits, additional care should be taken in order to further decrease children cancer health risk of PAHs’ emissions.

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Energetic Potential of Microalgae from Swamps and Ponds of South Serbia


Algae offer solutions to many problems of our civilization. Biotechnological applications of algae has become a part of modern reality. As one of the many application possibilities, algae can be used as a renewable energy source. Algae can store energy in the form of oil which can be appropriate raw material for the biodiesel production. Microalgae are especially significant because of their high growth rate, high oil content and ability to grow in the unfavorable environment for agriculture. Also, the cultivation of microalgae can improve the reduction of carbon dioxide emissions. An overview of the existing studies of the possibility of using microalgae for the production of biodiesel and the results of experimental research with isolated microalgae strains from the South Serbia stagnant water are given in this paper.

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Online IFRA for Identification of Power Transformer Faults Based on Pulse Compression Method


The most accurate method, recommended for the energy transformers diagnostic, is the Frequency Response Analysis (FRA), in the form of two implementations, Impulse-Frequency Response Analysis (IFRA), and Sweep-Frequency Response Analysis (SFRA). Both implementations have their own advantages, as well as difficulties, when applied to a transformer without disconnecting them from the load. Till now, there is no clear consensus which of them is better. However, for the case of the IFRA method applied to distribution transformers, difficulties about signal injection on low voltage side can be easily overcome if the pulse compression method is used for generation of testing excitations. Using pulse compression method, other obstacles connected to high voltage application is avoided, and many signal processing advantages that exist in various system identification methods can be implemented. On that way on-line IFRA can be method of choice for preventive diagnostic of distribution transformers.

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Local DC Power Network


The energy sector is about to undergo a major transformation. In this paper, we discuss the best possible energy solution for a smart and green community. This paper focusses on the decentralized power generation, storage and distribution through photovoltaics and lithium batteries. It encompasses the need for local direct current (DC) power through the factors driving this change. The importance of local DC power in the surface transport sector is also established. Finally, we conclude with data bolstering our argument towards the paradigm shift in the power network.

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Carbon footprint associated with a cake factory


Consumers are progressively more interested in purchasing products that are associated with environmental preservation and social development. In the food sector, the search for healthy food products is increasing, which is confirmed by the success of products that have different eco-labels or certifications. This demonstrates that consumers care about the source of the label and the quality of information it contains, especially regarding changes related to food production and processing. The food we eat also has different climatic impacts, and the food carbon footprint comprises the amount of greenhouse gases that are emitted in the stages of cultivation, processing, packaging and transportation of food products. Thus, choosing one nutrient, or another, affects not only our health but also the environment. In this context, eco-labels emerge to help the consumer in the decision-making process, thus contributing to a sustainable food production system. The objective of this study is to calculate the carbon footprint associated with two cake flavors, English pound cake and carrot cake, using SimaPro software. For the production of these cakes, the ingredients and consumption of energy (electricity and butane gas for cooking) were accounted for, along with water consumption and transportation to sale points. The carbon footprint for one English pound cake was 0.91 kg CO2-eq (0,81×10-3 kg CO2-eq/kcal) and for a carrot cake, 1.52 kg CO2-eq (1,42×10-3 kg CO2-eq/kcal). It was observed that the eggs were responsible for the highest share in the emissions.

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Performance Improvement of AC Adjustable Speed Drives During Voltage Sag Events


This paper analyses voltage sag effects on adjustable speed drives (ASDs) performance reduction with vector controlled induction motors (IMs). The ability of ASDs to maintain desired speed and/or torque responses during voltage reduction is of partial importance for some industrial ASDs. Improvement of motor control software is superior solution in relation to hardware modifications, primarily from the aspect of price, and also in terms of simple upgrade of existing electrical drives. Flux weakening with appropriate drive selection is efficient solution to overcome the most common voltage sag events. In this paper, theoretical explanation is supported with experimental tests of industrial and laboratory drives.

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The influence of nonlinear background on the quality of electricity


This paper discusses the load in the power distribution network, three-phase of the power supply where the transformer coupling via YgYg powered nonlinear load for a set of personal computers (PC). The load is balanced at each stage. The aim is partly to show through the analysis of higher harmonic loads personal computer, coupling transformer YgYg.
The tool will be used software tool MATLAB.

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PV based Automated Irrigation Management in Remote Onshore Area in India


Photovoltaic (PV) based irrigation is one of the most promising application of renewable energy for agronomy. This paper presents an PV based automated irrigation management system and its implementation for a remote onshore area in India. In this work, the effects of parameters such as solar irradiation, soil moisture, selection of pump, etc. has been studied. The plant is also capable of storing excess generated PV as a backup for retrieval during lean periods. An economic analysis is also performed using HOMER software. Suitable simulations and experimental implementation on a laboratory prototype validates the proposed study.

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Comparing Multilayer Perceptron and Multiple Regression models for Predicting Energy Use in the Balkans


Global demographic and economic changes have a critical impact on the total energy consumption, which is why demographic and economic parameters have to be taken into account when making predictions about the energy consumption. This research is based on the application of a multiple linear regression model and a neural network model, in particular multilayer perceptron, for predicting the energy consumption. Data from five Balkan countries has been considered in the analysis for the period 1995-2014. Gross domestic product, total number of population, and CO2 emission were taken as predictor variables, while the energy consumption was used as the dependent variable. The analyses showed that CO2 emissions have the highest impact on the energy consumption, followed by the gross domestic product, while the population number has the lowest impact. The results from both analyses are then used for making predictions on the same data, after which the obtained values were compared with the real values. It was observed that the multilayer perceptron model predicts better the energy consumption than the regression model.

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Reducing Smart Microgrid Dependency on the Main Grid using Electric Vehicles and Decentralized Control Systems


This paper proposes a new control system to reduce the power flow at the integration point of DC smart microgrids (SMGs) equipped with non-dispatchable renewable energy resources. The control system is fully decentralized, and it is based on the cooperative control, which requires the minimal communication infrastructure. In the proposed method, plug-in electric vehicles are utilized as distributed energy storage systems to mitigate the power-flow fluctuation. The PEVs start charging in excess of generation, and discharge in generation shortage. The proposed method decreases the dependency of SMGs on the main grid. It also improves the overall power quality in the bulk power systems by minimizing the integration point power-flow fluctuations. The proposed control system is evaluated using Matlab/Simulink. According to the simulation results, the performance of the proposed method is assessed, and its pros and cons are discussed.

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The Effect of Solar Radiation on the Ampacity of an Underground Cable with XLPE Insulation


The main purpose of this paper is to quantify the thermal effect of solar radiation on the ampacity of a low voltage underground cable with cross-linked polyethylene (XLPE) insulation. The quantification was performed for different laying depths of the cable, different colors of the upper surface of the pavement above the cable, different dimensions of the cable bedding, various load currents, various solar irradiances and different periods of the year. Simulation results were obtained using the finite element method in COMSOL and were compared with the corresponding experimental data. It was found that the ampacity of the XLPE-cable installed at a standard depth of 0.7 m can be increased up to 25.6 % in summer and up to 10.2 % in winter compared to the corresponding base cases.

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Comparative Analysis of Operating Parameters of Medium-Speed Diesel, Gas Diesel and Gas Engines


Conversion of medium-speed engines to operate on natural gas is a pressing issue because gas is cheaper than oil and combustion of gas in the cylinders of IC engines decreases emissions of pollutants and CO2. Using gas as fuel for medium-speed engines is especially reasonable because they consume a lot of fuel during their life cycle. Two main methods of conversion of diesel engines were examined: gas engines operating on a lean mixture and gas diesel engines. Comparative analysis of parameters of diesel, gas diesel and gas versions of a medium-speed locomotive engine was carried out using a simulation model developed in MADI calibrated by the results of experimental research of a high-speed diesel and gas diesel engines and medium-speed diesel engine, as well as calculations using a multi-zone model. Transfer from diesel cycle to gas and gas diesel cycles resulted in considerable decrease of fuel consumption and emissions of particles, NOx and CO2. Medium-speed gas engine was found to be most suitable for electric energy generation and gas diesel engine – for transport application such as locomotive engine.

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Review of GIS application in energy research


Research in energy industry involves various types of tools and methods. The objective of this paper is to review the application of GIS in this field. The analysis includes 123 articles for the period 2014-2018. The articles were analysed according to following criteria: 1) research objective, 2) type of energy according to source, 3) methodological priority, 4) the tool/method applied, 5) methodological approach, 6) purpose of use, 7) innovation, 8) spatial level, 9) software used, 10) geographical distribution. Results shows an increase in the use of GIS in energy research from 2014 onwards, mostly in feasibility studies with a prominent focus on solar energy. In most cases, GIS is employed as a primary tool usually combined with multi-criteria decision making methods. In the term of purpose and innovation, analysis and application of existing tools dominate. The most used software is ArcGIS while a considerable number of articles comes from Italy.

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Range of Porosity in Typical Regenerators for an Appropriate Balance Between Heat Exchange and Pressure Drop


Heat transfer analysis in a rotary regenerator is performed. The matrix porosity of the exchanger directly influences the amount of heat transfer between the circulating gases in the equipment and the matrix plates. From the pre-established flow rate values in the regenerator, the total heat transfer and the pressure drop are calculated for different matrix porosity values. The heat transfer coefficient in the equipment and the friction factor are obtained from correlations. The total heat transfer is obtained using the Effectiveness-NTU method specific to rotary regenerators. A computer program is developed for the simulation of typical rotary regenerators. The results show that there is a range of matrix porosity values in which there is a good relationship between the total heat transfer and the pressure drop in the equipment.

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Thermal energy recovery in critical areas of hospitals


Hospitals are very energy-intensive due to their uninterrupted activity. High performance is required from heating, ventilation, and air conditioning (HVAC) systems to meet the cleaning requirements needed in critical areas of hospitals. This paper analyses available information about energy-saving and heat recovery techniques and equipment applied in high-performance HVAC systems in operating theatres. Discussion on the applicability of this equipment in critical areas of hospitals is presented. The heat recovery systems allow to reduce the energy consumption of the hospital, the value of the investment in equipment and the costs of exploitation maintaining the environmental conditions that favor the safety of the patient.

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Fuzzy Measurement Algorithm for Fault Detection in the Hydrogenerator


Fault detection involves the detection, location, and identification of faults. Three types of unbalances (mechanical, hydraulic and magnetic) can occur in hydrogenerators. There are two main reasons for the existence of magnetic unbalance: shorted turns in the windings of the rotor poles and geometric asymmetry of the air gap. In this study, the authors propose a novel fuzzy measurement algorithm for fault detection in the hydrogenerator. The proposed algorithm has been developed with aim to detect the presence and cause of the magnetic unbalance and vibrations of the hydrogenerator. The study is based on fuzzy theory and three measurement methods for measuring inner and outer magnetic fluxes and measuring mechanical vibrations. The fuzzy algorithm has to ensure, in situ and real time, magnetic and vibration monitoring and fault detection and as such it is suitable for implementation in on-line and real time monitoring systems. The main benefit of the proposed solution lies in the support for the optimal decision making regarding the predictive maintenance.

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Cloud-based SCADA Systems: Cyber Security Considerations and Future Challenges


In this paper, we first describe basic operation principles of SCADA system, and analyze migration strategies of such systems to public, private or hybrid cloud infrastructure. Further, special attention is dedicated to the cloud service selection as well as to the analysis of benefits and risks of cloud-based SCADA applications. Finally, we address security threats in cloud environment and present challenges in security provisioning regarding security solutions, risk management and test environment.

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Electrical Equipment’s Condition and Remaining Useful Life Assessment – a Review


Condition-based maintenance (CBM) is a preferable type of maintenance nowadays in power utilities. Assessment of equipment’s health condition and remaining useful life (RUL) is the main goal of CBM in order to allocate resources correctly and optimally, to make system more reliable and to reduce overall costs for the maintenance. There are a lot of methods and techniques used for condition and RUL assessment. This paper presents general approach for CBM and through the review of references presents three common techniques – ranking and scoring health index method, artificial neural network method and fuzzy logic method for evaluating electrical equipment’s condition. In the end, comparison of mentioned methods is briefly presented.

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