bluuebunny/crossref_metadata_2025 huggingface dataset:
Throughput maximisation in cognitive radio networks with residual bandwidth
Authors: Paul Anal , Banerjee Avik , Maity Santi P.
Published: February 2019

Recent progress in cognitive radio networks (CRNs) promises to meet device‐to‐device communication requirements for spectrum utilisation and power control to support billions of machines/devices to be connected worldwide. The architecture of the CRN must maintain a high data rate (throughput) at low power consumption, which requires both spectrum efficient and energy efficient system design. To this aim, the proposed work adopts a CRN model, which operates in an interweave mode that allows spectrum sensing followed by opportunistic secondary user (SU) data transmission over the unused bandwidth of the primary user (PU) in a non‐overlapping frame structure. Closed form expressions of the optimal spectrum sensing duration, bandwidth, and power allocation of each secondary node are obtained to maximise the sum throughput of the overall CRN while maintaining the constraints of sensing reliability of PU, individual SU transmission outage probability, permissible interference, and residual bandwidth. Numerical results highlight that the proposed scheme maximises the sum network throughput by and over the other existing techniques.
Design and experimental analysis of a wound brushless doubly Fed machine based on a rotor with the reluctance effect
Authors: Kan Chaohao , Ren Taian , Hu Yang
Published: February 2019

Brushless doubly fed machine BDFM) is a new type of motor that has bright prospect in industrial application, especially in the field of wind power generation. Here, a wound BDFM based on a rotor with the reluctance effect is proposed, it integrates the flexible connection method of wound rotor winding and the magnetic flux–oriented effect of the reluctance rotor, which restrains higher harmonic and has strong coupling ability. This paper introduces the structure of the new motor and elaborates the magnetic field modulation mechanism, then analyse the performance with the system's output power 6.4 kW using finite element method (FEM). To validate the FEM results, a 30 kW prototype is designed and manufactured. The prototype test verifies the correctness of the simulation results and also manifests the superiority of both steady‐state and dynamic performance of the motor.
Resilient wide‐area multi‐mode controller design based on Bat algorithm for power systems with renewable power generation and battery energy storage systems
Authors: Setiadi Herlambang , Mithulananthan N. , Shah Rakibuzzaman , Lee Kwang Y. , Krismanto Awan Uji
Published: February 2019

Modern power systems consist of power electronics devices, which are used in renewable energy (RE) conversion. However, these devices, associated controllers, and uncertainty in RE output could bring new challenges to power system stability, especially oscillatory stability. Hence, the integration of battery energy storage systems (BESSs) is being developed to minimise the uncertainty and variability in renewables. Furthermore, to tackle the complex dynamics and inertia‐less characteristics of wind and PV plants additional controllers such as power oscillation damping (POD) control and virtual inertia scheme are sought. However, the primary challenges associated with the wide‐area oscillation damping controller are signal transmission delay, loss of communication signal, data drops, and others. This paper proposes a bat algorithm (BA) based resilient wide‐area multi‐mode controller (MMC) for enhancing oscillatory stability margin with high penetration of renewable power generations (RPGs) and BESSs. The Java 500 kV Indonesian grid is used to evaluate the performance of the resilient wide‐area MMC. From the results, it is found that the proposed controller effectively damp the critical mode of oscillation in the system even under communication failure as well as certain damping controller failures.
System congestion criteria for interconnection of WPP through VSC‐HVDC
Authors: Rios Mario A. , Guama Edison G.
Published: February 2019

The growth of utilisation of wind power plants (WPP) in power systems placed at long distance of the transmission power system has shown that the best connecting alternatives are by means of high‐voltage direct current lines (HVDC) using voltage source converter (VSC) stations. Generally, the bus closest to the WPP and with the highest level of short circuit is selected as the best option to connect the VSC‐HVDC link, mainly due to economic criteria. This paper proposes a methodology to select the best connection point in the AC system, taking advantage of the potential increase of transmission capability due to the reactive power controlled at the VSC converter stations; measured as the increment of the loadability margin computed by means of PV curves. Nevertheless, a trade‐off between this benefit and the cost of overhead HVDC transmission line as consequence of the length differences among alternatives is required. This trade‐off is computed as the cost of the equivalent STATCOM required to get the same loadability margin. Thus, a technical‐economical comparison of connection alternatives allows the selection of the best option for connecting the VSC‐HVDC line. The methodology has been applied to connect a WPP of 500 MW to the NETS.
Online parameter determination based adaptive single‐phase reclosing scheme for wind‐powered outgoing lines with shunt reactors
Authors: Xie Chao , Li Fengting
Published: February 2019

As the only power output channel of wind farms, wind‐powered outgoing lines carry the risk of reclosing to faults as an applied single‐phase reclosing scheme recloses the outgoing line after a fixed time without distinguishing transient and permanent faults. Although various transient‐fault identification (TFI) methods were proposed for conventional power transmission lines with shunt reactors, they can be hardly utilised on wind‐powered outgoing lines with shunt reactors due to the influence of outgoing line complex working conditions and wind farms inconsistent output power. In this study, reactive power was calculated using the instantaneous power algorithm to obtain the equivalent reactance of the outgoing line faulty phase shunt reactor. Then, a TFI method for the outgoing lines with shunt reactors based on online parameter determination was proposed, a relevant adaptive single‐phase auto‐reclosing (ASPAR) scheme was established. Finally, the validity and feasibility of the proposed TFI method and ASPAR scheme were verified by conducting simulation experiments on the software PSCAD/EMTDC. The experiments confirmed that the proposed ASPAR scheme can achieve immunity to changes in fault location and transition resistance, and are therefore suitable for inconsistent output power of wind farms and complex working conditions of outgoing lines.
Optimised solution for hybrid TDOA/AOA‐based geolocation using Nelder‐Mead simplex method
Authors: Lee Kyunghyun , Lee Hyukwoo , You Kwanho
Published: February 2019

A hybrid geolocation model that combines advantages of time difference of arrival (TDOA) and angle of arrival (AOA) techniques is widely used to determine a mobile location. However, measurement noise in TDOA and AOA data restricts the estimation accuracy of a mobile location. Based on general geolocation equation using TDOA and AOA measurements, the authors derived a total noise‐enhanced localisation (TNEL) model here. Unlike the general geolocation equation, the proposed TNEL model overcomes the accuracy limit even when geolocation equation contains environmental error. Moreover, the objective function and constraint derived from TNEL model can yield optimal solution that is closer to the real location of an emitter. In order to increase localisation measurement accuracy, the authors applied Nelder‐Mead (NM) simplex algorithm‐based optimisation technique to minimise the estimation error of the TNEL model. Simulation results confirmed the performance of authors’ proposed geolocation method.
Target detection method based on polarisation‐space joint spectrum feature
Authors: Longfei Shi , Gang Cui , Jiazhi Ma
Published: February 2019

As of the large receiving gain from radar antenna and the little difference with targets in the time‐frequency‐spatial domain, the main‐lobe interference has become an important challenge to radar detection. In recent years, suppressing main‐lobe interference by using polarisation filtering has gained significant theoretical and practical progress. However, when there are multiple interference sources occurring in the radar main lobe, the performance of all existing methods is badly limited. With the idea of feature identification, a novel target detection method based on polarisation‐space joint spectrum characteristic is developed, which effectively utilises the polarisation scattering feature difference between the target returns and the interference signal, instead of trying to suppress interference energy as usual. This proposed method can effectively enhance the capability of radar target detection under the background of multi‐point source interference in main lobe. The simulation results show that the proposed method can detect the target in the background of the main‐lobe multi‐point source interference.
Least‐squares collocation modelling of regional ionospheric TEC for accelerating real‐time single‐frequency PPP convergence
Authors: Gong Yangzhao , Cai Changsheng , Dai Wujiao , Zhu Jianjun
Published: February 2019

Modelling of the regional ionospheric total electron content (TEC) is an important means for mitigating the ionospheric delay errors in the single‐frequency (SF) precise point positioning (PPP). Mostly, the existing regional ionospheric models (RIM) only takes the trend term of the ionospheric TEC variations into account and neglect their random variable part. As a result, the TEC's irregular variations cannot be well modelled. In this study, a regional ionospheric TEC model based on the least‐squares collocation (LSC) approach is proposed to account for both the trend and random parts. The predicted TEC from the LSC RIM is then employed in the real‐time (RT) SF PPP for speeding up convergence. Datasets collected in two different latitude regions are utilised to establish the LSC RIM with a comparison to the conventional polynomial model and the global ionosphere map (GIM)‐predicted products. The results show that the LSC model can remove ionospheric delay errors of at least 92%, which is larger than the polynomial model and GIM products. Further, the GPS RT SF PPP after introducing the predicted TEC from the LSC RIM can significantly reduce the convergence time by at least 48%, 58%, and 5% in the east, north, and up directions.
Energy conversion and efficiency in turboshaft engines
Authors: Dobromirescu Cristian , Vilag Valeriu
Published: February 2019

This paper discusses the methods of energy conversion in a turboshaft engine. Those methods cover the thermodynamic cycle and the engine performances, the possible energy sources and their impact on environment as well as the optimal solutions for maximum efficiency in regards to turbine design and application. The paper also analyzes the constructive solutions that limit the efficiency and performances of turboshaft engines. For the purpose of this paper a gas-turbine design task is performed on an existing engine to appreciate the methods presented. In the final part of this paper it is concluded that in order to design an engine it is necessary to balance the thermodynamic aspects, for maximum efficiency, and the constructive elements, so that the engine can be manufactured.
Comparing the energy efficiency of exterior shading by metal slats and mesh screens in an early phase design exercise for an office building in Bucharest
Authors: Udrea Ioana , Popa Romeo
Published: February 2019

An early phase design exercise for shading a South facade of an office building in Bucharest is presented here. The problem to solve is deciding in a simple and quick way (not using the complicated BSDF approach), based strictly on energy-efficiency considerations, between two options in principle: the first, exterior screens, is much cheaper and the send is unmovable horizontal aluminium slats. The tool used to produce the necessary result quantities by building energy simulation is COMFEN 4.1. The conclusion is positive: if aesthetic reasons are ignored, in Bucharest and very likely many other Romanian cities having a quite similar climate, screens can be at least equally effective in saving energy by South facade shading. As they allow a flexible shading strategy (removing them during some months of the heating season), the energy-efficiency realized by having them on throughout the year can be increased further.
Experimental investigation of an Air Source Heat Pump
Authors: Tălpigă Mugurel Florin , Iordache Florin , Mandric Eugen
Published: February 2019

An experimental investigation were driven to catch all working parameters of an Air Source Heat Pump such as temperature differences between refrigerant working states and evaporator respectively condenser environment temperatures. Heat Pump compressor were monitored to know inlet and outlet refrigerant temperatures to build working diagram of the heat pump in heating configuration. At condenser, a plate heat exchanger is used to discharge the energy from refrigerant to water, liquid used in secondary circuit. Heat exchanger temperatures of refrigerant and water were monitored to drive the working diagram of the heat exchanger equipment. Current consumption of Heat Pump were registered together with heat exchanger secondary circuit temperature differences and his water flow to estimate Seasonal Performance Factor during experiment.
Numerical simulation of the natural, forced and mixed convection in a tunnel with a flat track of sinusoidal shape and a roof opening
Authors: Drame Oumar , Mbow Cheikh , Bode Florin , Dia Samba , Thiam Omar Ngor
Published: February 2019

In this work, we studied the mixed convection of the airflow in a tunnel open at both ends. The tunnel has a sinusoidal trace and the horizontal ceiling is provided with an opening in the center. The tunnel floor is uniformly heated. Although of interest for many industrial applications, the configuration of this study has been studied very little from an academic point of view. Coupled equations of Naiver-Stokes and energy are solved numerically by the finite volume method with the Boussinesq hypothesis. We analyzed the effect of the parameters that characterize heat transfer, and the flow structure. Several situations have been considered by varying the Richardson number (1.3610-3≤Ri≤2.17.104) for a Prandtl number Pr = 0.71.
Experimental combustion chamber simulation at transient regimes
Authors: Gherman Bogdan , Mălăel Ion , Florean Florin , Porumbel Ionuţ
Published: February 2019

The transient regimes in a combustion chamber has to be as short as possible because flame front position and thickness can destroy the combustion chamber in couple seconds. The simulation of such a regime has to be performed unsteady. An experimental combustion chamber it is simulated at two unsteady regimes to see the flame front structure and comparison it is made with the experimental data to validate the results. For this analysis Ansys CFX was used and the turbulent model was DES while the combustion model was Eddy Dissipation. The two cases show different flame front structures while the boundary conditions for the two regimes are very similar.
Numerical analysis of the thermal comfort in a church building
Authors: Ţurcanu Florin Emilian , Verdeş Marina , Ciocan Vasilică , Burlacu Andrei , Luciu Răzvan Silviu , Bălan Marius Costel , Şosoi Gavril
Published: February 2019

Based on the monitoring campaigns, we have evaluated the indoor microclimate in a church. Most church buildings are characterised by low thermal comfort due primarily to their architecture, heating huge volume of air. The CFD tools was used for thermal comfort evaluation in case of the existing heating system during the winter season. The simulation model was validated with experimental data and it was used for thermal and air velocity profiles in the occupancy zone of churchgoers. The aim of the paper is the study the feasibility of maintaining the heritage values of the churches while achieving the significant improvement of the thermal comfort.
Study of air bubble dynamics in an air column using CFD
Authors: Boncescu Corina , Robescu Lăcrămioara Diana
Published: February 2019

The energy used for biological process in a wastewater treatment plant depends on aeration equipment and hydraulic parameters in aeration tank. Gas bubbles flow into bioreactor determines an extra turbulence into the mixture. This paper presents the results obtained using the volume of fluid (VOF) mathematical model to determine the velocities generated by bubbles into an upward flow air-water mixture in a column of water. Also, it was identified vertexes center in the ascending air bubbles movement and the number and the diameter of the bubbles were determined. The theoretical results were compared to experimental and theoretical data from the literature and it was found a good correlation.
Local exhaust ventilation solutions for an industrial hall – Part 1 CFD analysis of the local exhaust systems
Authors: Chitaru George-Mădălin , Sandu Mihnea , Croitoru Cristiana Verona , Bode Florin
Published: February 2019

Industrial hygiene is an important aspect of any workplace environment, especially for the industrial domain. A previous study has shown that high ammonia levels were present in a wastewater treatment facility in Romania. The initial ventilation strategy was not efficient in maintaining pollutant concentrations within standard safety limits. An optimization of the initial ventilation system was realized, but CFD results and on-site measurements have shown that high local concentrations were still present. Two local exhaust methods have been proposed and analysed in order to improve the quality of the air inside the hall. A CFD approach has been used for the preliminary design process. The results indicate that both local exhaust solutions offer great improvements over the general dilution-based system, but only one can be applied.
Experimental and numerical investigation on the convective thermal plume around the head of the standing and lying hu-man body
Authors: Tăcutu Laurenţiu , Năstase Ilinca , Bode Florin , Croitoru Cristiana Verona , Dogeanu Angel , Sandu Mihnea
Published: February 2019

This paper presents a study for two thermal plumes generated by two humanoid thermal manikins, one standing and one lying down. The research was approached from a numerical and experimental perspective. The numerical model represents an operating room (OR) with two surgeons, a patient and a unidirectional air flow (UAF) diffuser. The experimental study was made in a climatic chamber, having a similar air distribution system, using particle image velocimetry (PIV) and infrared thermography (IR) measurements. The purpose of the study was to characterize the thermal plumes of the two manikins by numerical and experimental studies. The results obtained from these different approaches were compared with each other and with the ones from the literature in order to validate our numerical models.
Hybrid solar-biomass system for district heating
Authors: Ilie Adrian , Vişa Ion
Published: February 2019

The energy used in the built-up environment represents at least 40% of the total energy consumed, out of which, at least 60% is required for heating, cooling and domestic hot water (DHW). Within the European Union, more than 6,000 communities (i.e. over 9%) use district heating systems, the majority of which use the conversion of fossil fuels as a source of energy. This aspect, which is corroborated by the directives of the EU legislation on the use of renewable energy sources and energy performance, imposes the development of new solutions through which the existing district heating systems may be adapted to use renewable energy sources. The solar-thermal systems that are used on a large (district) scale are becoming more and more efficient from the point of view of their feasibility; however, it is almost impossible to create systems that should satisfy the thermal energy demand throughout the four seasons of the year. The hybrid solar-biomass system is becoming the applicable solution for the majority of the communities that have from this potential, since it can secure independence from the point of view of the use of thermal energy. This paper presents the design stages for the implementation of the hybrid solar-biomass systems with a view to identifying the optimal solutions for systems to be integrated into an existing district heating system. A case study (Taberei District in Odorheiu Secuiesc City), which provides a detailed description of the feasible technical solutions, is presented.
Stereo MicroPIV measurements in an irrigation nozzle
Authors: Ergin F. Gökhan , Tomas Séverine , Pătraşcu Claudiu
Published: February 2019

Irrigation nozzles often feature small serpentine-shaped channels to avoid clogging. Reduced clogging improves the lifetime of the irrigation nozzle, which reduces plastic waste and thereby reduces the impact on the environment. Clogging in micro channels is often suppressed in the presence of three- dimensional (3D) flow structures called vortices. In micro scales the initiation of such 3D microstructures is normally suppressed because of the low Reynolds number inherent to micro scale flows. Passive, zig-zag shaped irrigation nozzles have the potential to induce three- dimensional rotating flow structures around sharp corners, which enhance 3D flows in the channel and thereby reduce clogging. The aim of this study is to identify and characterize such vortices using a Stereoscopic MicroPIV system.
Increasing the energy conversion efficiency for shrouded hydrokinetic turbines using experimental analysis on a scale model
Authors: Chihaia Rareş-Andrei , El-Leathey Lucia-Andreea , Cîrciumaru Gabriela , Tănase Nicolae
Published: February 2019

The objective of the paper is to study the influence of certain shroud types suitable for horizontal axis hydrokinetic turbines using experimental testing in order to increase the energy conversion efficiency. The scale model of the shrouded hydrokinetic turbine is tested on a dedicated experimental bench for axial hydraulic turbine models. Two types of shrouds were tested in order to be compared: convergent shroud and divergent shroud. The rotor and shroud were made using 3D printer technology and were tested at a water velocity of 0.9 m/s on the closed-circuit testing bench. The testing facility allows the determination of the power extracted for each shroud at five distinct positions. Thus, the rotor can be moved within the shroud from inlet to outlet in order to establish the proper operating position. The mechanical power is measured using a torque transducer and an electromagnetic particle brake. The testing results will be analysed based on the variation of power curves obtained for different shroud types and operating positions. The optimum design and the best operating position will be recommended by comparing the testing result with the data collected from the bare turbine using the same rotor placed directly in free flow.
About the conception and design of anaerobic digesters in zootehnical farms
Authors: Erbaşu Ruxandra , Ţăpuşi Daniela
Published: February 2019

Anaerobic sludge fermentation is one of the main technological steps for treating the wastewater resulting from urban consumption in the food industry. Anaerobic fermentation ensures the sludge mineralization treatment and the fermentation gas (biogas) resulting from the process can be used for the production of thermal or electric energy. The fermentation process can take place in closed reinforced concrete tanks (digesters) having different structural forms: cylinder, tapering, ovoid depending on the type of fermentation: mesophilic or thermophilic and on the performance of sludge mixing and homogenization equipment. Fermentation tanks with a capacity of 1000-4000 m3 were designed in Romania so far, the most important being those of Bucharest wastewater treatment plant made of prestressed reinforced concrete having an ovoid shape. The present paper aims at presenting the issues related to designing the fermentation tanks of the water waste plants from urban consumption in the food industry and zoo-technical farms in a new concept in which the main fermentation tank is coupled with the fermenter for the fermentation gas storage. Consequently, hereinafter structural and functional requirements for this kind of structures are presented, together with design principles and methods that must be applied in order to fulfil the performance exigencies related to strength, stability, tightness and durability.
Biomass conversion into valuable products within the integrated management of bio-resources
Authors: Ionescu Gabriela , Bulmău Cora
Published: February 2019

The present research proposes two scenarios for the biomass conversion into valuable products within the integrated management of bio-resources. The scenarios have been developed considering: the biomass availability, material and by-products characteristics and the comprehensive combination of the primary technologies used for the conversion of the biomass mixtures into energy. In scenario 1 the biomass waste valorisation is made via integrated pyrolysis and combustion treatment, while in scenario 2 the biomass conversion in done considering the integration of the pyrolysis, gasification and combustion treatments into the conversion chain. The results revealed that all analysed scenarios purposed are self-independent from the energetic point of view.
GIS use of Land Use/Land Cover layers and historical data for water losses indices
Authors: Aldea Alexandru , Aldea Mihaela , Perju Sorin
Published: February 2019

The population growth and/or its use and development of the land is a continuous preoccupation of the decision factors regarding the water supply system in general and the development of the potable water distribution networks in particular. This issue is even more critical especially in the areas of big cities and important urban growing. As the urbanization of land outgrows the existing water supply systems, one of the possible solutions is to expand the water distribution network in order to cover this urban growth. The present paper analyses further the possibilities to define and use certain indices of urban development together with water loss indices in order to determine trends or issues related with the provision of water supply services and connectivity.
Comparison of urban residential storm water runoff quality in Bucharest, Romania with international data
Authors: Rădulescu Dan , Racoviţeanu Gabriel , Swamikannu Xavier
Published: February 2019

Diffuse pollution is a major source of contaminants to surface waters in urban areas. Land use activities and the degree of imperviousness have a strong influence on the pollutant loadings and the pattern and distribution of the pollutograph. Uncontrolled discharges of contaminated urban storm water runoff contribute to impairments of water quality in receiving waters. In this study, grab samples of storm water runoff were collected from a small high-density residential catchment area in Bucharest. The pollutant concentrations were analysed for several water quality physical and chemical parameters including pH, conductivity, oil and grease, nutrients, pathogen indicator bacteria and some heavy metals. The storm events were monitored through grab sampling. The sample results for this representative residential catchment area in Bucharest were then compared with data reported from other regions of the world. The analysis demonstrates that the characteristics of the urban runoff quality from residential areas in Bucharest were comparable with data obtained from other areas in the world.
The use of the ash of thermal power plants for the production of efficient porous insulation
Authors: Pavlenko Anatoliy , Koshlak Hanna , Slowak Anna Maria
Published: February 2019

The article presents the results of research related to the use of ash from thermal power plants for the production of porous heat insulating materials. Using the method of differential - thermal analysis, the optimal values of the composition of the raw mix and the thermal regimes of the formation of the porous structure were found. It is shown that it is possible to obtain a new ash-based binder and thus replace up to 70% of cement in the production of thermal insulationthe properties of the new material are similar to the properties of foam concrete.
Directions of development of rural areas in Poland (sustainable agriculture, organic agriculture)
Authors: Wójcik-Leń Justyna
Published: February 2019

The development of rural areas is determined primarily by the natural environment. Abiotic factors such as soil, water and ambient temperature are very significant for agriculture. At the same time, the development of rural areas is conditioned by demographic aspects, structure of settlement, and professional activity of the local people. The main objective of rural land management is improving the spatial structure and the working and living conditions of the rural population in close relation to environmental protection and development of such grounds. In Poland, agricultural development directions include sustainable and organic agriculture. These forms of agriculture are developing intensively with regard to a large need for maintaining high crop yield and at the same time reducing the environmental burden. The production of high quality food is significant, while the highest possible biological equilibrium in the natural environment should be maintained at the same time. This article aims to indicate that the above-mentioned directions of development of rural areas are very important for Poland and they generate many advantages for the natural environment. In addition, a useful procedure in improving the spatial structure is land consolidation process carried out in rural areas. Its main objective is improving the configuration of land giving it an optimum shape. This process has a positive impact on agriculture and the community living in such areas.
The hierarchization of needs related to land consolidation and exchange in rural areas in the villages of district Leżajsk
Authors: Wójcik-Leń Justyna , Leń Przemysław
Published: February 2019

Rural areas in Poland are characterized by differentiated spatial structure. The spatial structure of rural areas can be improved through the consolidation and exchange of land (Art.1, Act of 26 March 1982 on consolidation and exchange of land) aiming to create more favourable management conditions in agriculture and forestry by improving the territorial structure of farms, forests and forestland, reasonable configuration of land, aligning the limits of real properties with the system of water irrigation facilities, roads and terrain. In connection with such a requirement for the consolidation and exchange of land, a hierarchy of needs and their urgency must be established. Such an approach makes it possible to secure funds for liquidating the spatial structure of agricultural land according to the urgency ranking. The studies were carried out in the rural areas of the Leżajsk poviat.
The analysis of the spatial layout of land in relation to less favoured areas (LFA) in the Milejów comune, Łęczna district
Authors: Stręk Żanna , Wójcik-Leń Justyna
Published: February 2019

Rural land in Poland accounts for more than 90% of the area of the country and plays a very significant role. It is inhabited by 38.1% of the population. Unfortunately, these people are largely unemployed. The present status of the agricultural production space is a result of many centuries of human activity closely connected with social and economic, legal and political conditions. The spatial arrangement of land in the rural areas of central, southern, south eastern and eastern Poland, developed by historical processes, is characterized by the frequent occurrence of individual plot patchworks. An incorrect configuration of land owned by farmers considerably affects the profitability and effectiveness of agricultural production. The accession of Poland to the European Union offered many options for development to our country and in particular to the Polish countryside. Reconstruction of the defective spatial structure in Poland is one of the priorities of the EU’s agricultural policy. Numerous development programmes (SOP, RDP) are used for financing land consolidation and exchange works which are one of the basic tools for transforming ownership and structural relations in rural areas. With regard to the fact that agricultural land in Poland is greatly differentiated, particular attention should be paid to less favoured areas (LFA). It seems obvious that farmers in LFA are not able to generate the same earnings from crops as those generated by farmers in favoured areas. For the purposes of this publication, detailed surveys were carried out in the Milejów commune, Łęczna district, Lublin voivodship. Five villages in that commune were classified as less favoured areas. The analyses showed that Milejów is one of two communes in the Łęczna district with the smallest average area of plot owned by individual farmers. Based on the analysis of the structure of ownership and use, fragmentation and distribution of plots, as well as identification of less favoured areas, an alternative land development model was proposed, along with the reconstruction of the existing arrangement of land through comprehensive consolidation and exchange of land.
Evaluation of the impact of selected environmental aspects on the shaping of the land market on the example of the Wieliczka commune
Authors: Hanus Paweł , Jasińska Elżbieta
Published: February 2019

The land market is usually influenced by many factors, but the key to some of them is decisive when buying a property. These are both physical features of the property, such as the area, shape or class of the land as well as external factors related to the popularity of the area or the availability of communication. The group of factors that decide about the purchase is certainly the vulnerability of land to natural phenomena related to mass movements. They belong to factors that have a very negative impact on the price of real estate, limiting the possibility of its use, and above all buildings. In a situation where data on mass movements are available in a given area, these data directly affect the provisions of the study of conditions and directions of spatial development of the commune and, as a consequence, also local plans. The article analyzes the impact of landslide areas on property prices. The research was carried out in the municipality of Wieliczka where in 2008 a comprehensive assessment of mass movements was carried out, defining their character and making their classification.
Influence of variability in the amount of inflow wastewater pollution concentration in small sewer system (case study)
Authors: Kurek Karolina , Bugajski Piotr , Operacz Agnieszka , Śliz Paulina , Jóźwiakowski Krzysztof
Published: February 2019

The aim of study was the analyze of the impact of hydraulic load on the changes in the concentration of pollution indicators in raw sewage in years 2009-2014 in the small wastewater treatment plant. Qualitative analysis for raw sewage was included three parameters: total suspension solid, BOD and COD. The characteristics relation between the concentration of pollution indicators in raw sewage (depend variable) from the hydraulic load(independent variable) was presented by the Pearson linear correlation. In the 6 year study period were collected 32 samples of raw wastewater. Based on the result of linear regression analysis, showed that along with the increasing amount of wastewater in the sewer decrease the concentration of pollutions in raw wastewater. For total suspension solid, increase by 1 m3 of quantity of raw sewage inflowing to wastewater treatment plant, causes a decrease in the concentration of this indicator by 0,53 g·m-3. For the both organic indicators (BOD and COD), the was found that an increase of 1 m3 the amount of raw sewage inflowing to wastewater treatment plant, caused a decrease of 0,75 gO2·m-3 BOD value and 0,66 gO2·m-3 COD value in raw sewage.
Optimal Selection of Gear Ratio for Hybrid Electric Vehicles Using Modern Meta-Heuristics Search Algorithm
Authors: Kamboj Vikram Kumar , Saxena Sobhit , Sandhu Kamalpreet
Published: February 2019

Gear Train Design problem is most important design problem for machine tools manufacturers. Recent work on gear train improvement has been bound towards multi-shaft gear trains of the speed-change kind, where major focus is to maximize the range of operating speeds and to minimize the number of gears and spindles. In the proposed research, a hybrid meta-heuristic search algorithm is presented to design and optimize multi-spindle gear trains problem. The objective of the research is to optimize gear trains on the basis of minimum overall centre distance, minimum overall size, minimum gear volume, or other desirable criteria, such as maximum contact or overlap ratios. The proposed hybrid meta-heuristic search algorithm is inspired by canis lupus family of grey wolves and exploitation capability of existing grey wolf optimizer is further enhanced by pattern search algorithm, which is a derivative-free, direct search optimization algorithm suitable for non-differential, discontinuous search space and does not require gradient for numerical optimization problem and have good exploitation capability in local search space. The effectiveness of the proposed algorithm has been tested on various mechanical and civil design problem including gear train design problem, which includes four different gear and experimental results are compared with others recently reported heuristics and meta-heuristics search algorithm. It has been found that the proposed algorithm indorses its effectiveness in the field of nature inspired meta heuristics algorithms for engineering design problems for hybrid electric vehicles.
Extensive review on Supercapacitor cell voltage balancing
Authors: B.T. Prashant Singh , Phaneendra Babu Bobba , Suresh K.
Published: February 2019

This paper explains about the supercapacitor cell voltage balancing circuits by comparing different topologies with regard to parameters like cost, balancing time, weight of the components used and control of switches. The advantage of supercapacitor over battery made to overcome weight and faster responding source problems. In supercapacitor bank cell voltages differ from each other which effects the performance of the device. Passive circuits consume power from cell for balancing but active circuits consume power from source. Many topologies are considered in this paper for different ratings and with different components. Balancing circuit is selected based upon total number of components in the balancing circuit, many components make circuit less reliable, complex and also increase the cost for balancing.
DSTATCOM with Improved LMS based IRP theory
Authors: Suresh D. , Sravanthi G. , Chander R.
Published: February 2019

In this paper, grid connected DSTATCOM with three phase three wire has been proposed for harmonics elimination, reactive power compensation and active power injection into the grid. An improved instantaneous reactive power theory based on the least mean square is computed. The least mean square (LMS) algorithm is combined with instantaneous reactive power theory (IRPT) to improve its dynamics performance and eliminates the use of low pass filter requirement for computation of reference current. The harmonics component of the active power is estimated from LMS algorithm generated load harmonics currents. The performance characteristic of DSTATCOM is estimated with control scheme using computer simulation. The technique is based on the instantaneous transformation of instantaneous signals and taking advantage of the subsequent calculation of power from supply side to the loads. The neural network based method to estimate the harmonic online, DSTATCOM can compensate the harmonics. The computer simulation is carried out with MATLAB Simulink power system block sets.
Power Savings with all SiC Inverter in Electric Traction applications
Authors: Chakravarthy B.K. , Sree Lakshmi G.
Published: February 2019

The advantage of Silicon Carbide (SiC) based devices are less thermal management requirements and smaller passive components which result in higher power density. SiC devices have higher blocking voltages, lower on-state resistance and switching losses and higher thermal conductivity and operating temperatures. SiC devices can operate at higher voltages, higher frequencies and higher junction temperatures than comparable Si devices, which results in significant reduction in weight and size of the power converter and increase in system efficiency.
A rubust fractional order PID controller for MIMO power systems
Authors: Shashidhar Vasampalli , Padhan Dola Gobinda
Published: February 2019

This paper proposes a novel fractional order PID control scheme for Multi Input and Multi Output (MIMO) power systems. This control scheme utilizes Cuckoo Search algorithm to tune the fractional PID controller to guarantee better closed loop performance in the transmission or distribution networks. Cuckoo Search optimization algorithm is proposed to optimize gain values of the fractional PID controller. The effectiveness of the proposed control strategy has been assessed by simulations in MATLAB/Simulink platform. The robustness of the proposed controller has been validated by varying the plant parameters.
Variable Switch Regenerative Braking Technique for PM BLDC Motor Driven Electric Two-wheeler
Authors: Dubey Manish Kumar , Bobba Phaneendra Babu
Published: February 2019

In this paper PM BLDC motor driven electric two-wheeler is proposed. The operation of PMBLDC motor in all four quadrants along with various regenerative braking control strategies are simulated MATLAB/ SIMULINK. Three braking methods are proposed for electric vehicle application. Factors like recovered energy, braking time, maximum braking current are compared. Depending on the simulation results switching between different braking methods is proposed for efficient and reliable braking operation. Moreover, by using variable switch braking technique one can extract more braking energy.
Acoustic instrumentation for a bubble chamber towards dark matter searches
Authors: Reis M. , Felizardo M. , Fernandes A. C. , Kling A. , Morlat T. , Marques J.G.
Published: February 2019

Dark matter is one of the top unsolved mysteries in physics. Its existence is well-established although its nature remains unknown. Despite the progress made in the direct search effort, reflecting over 10 orders of magnitude in sensitivity since 1984, no true candidates to explain this phenomenon have appeared in searches covering a range from ~10 GeV to 1 TeV. This article reports on the development of a 1 kg freon bubble chamber prototype, including the chamber recompression system design and testing, initial acoustic detection of bubble formation, and initial neutron and alpha detector response studies. The prototype constructed was a transparent acrylic containment vessel, capable of withstanding recompression cycles to a pressure of 16 bar. The acoustic signal accompanying bubble formation was investigated using three different sensors: a low frequency microphone (Panasonic) with a flat response over 0.020-16 kHz, an ultrasound externallypolarized condenser microphone (AviSoft) with a flat response over 10-150 kHz, and an hydrophone (Reson) with a flat response over 5-170 kHz. Acoustic signatures of several induced events were successfully registered. The data acquisition digitizer used, to meet the range of the three microphones, was the NI PCI-6251 16-Bit, with at least 1.25 MSps for 1-Channel.
Ultra-low Noise EEG at LSBB: Effective Connectivity Analysis
Authors: Hamzei Nazanin , Steeves John , Kramer John (Kip) , Yedlin Matt , Dumont Guy A.
Published: February 2019

In this study, we further investigate electroencephalographic (EEG) data recorded during October 2014 in the ultra-shielded capsule at LSBB, with a focus on the study of task-specific Granger-causal effective connectivity pat-terns. In previous studies, we showed that noise-free EEG signals acquired in LSBB are suitable for analysis of activity patterns in high frequency bands, i.e. 30 Hz and above. We previously demonstrated that increases in task/rest gamma band (30-70 Hz) energy ratios during ankle and wrist movements are more prominent in the LSBB capsule than in an above-ground hospital environ-ment. The present study extends previous analyses by examining gamma-band connectivity, i.e. the functional patterns of interaction between 64 channels of EEG within the gamma band during motor tasks. We use parameters from a MultiVariate Auto-Regressive (MVAR) model to estimate effective connectivity in 10-second batches of EEG and report the average patterns across all batches in which subjects repetitively move their ankle/wrist. We report the gamma-band connectivity results in a reduced form as strength of hemispheric and inter-regional connections. The analysis reveals that for some subjects, significant channel-wise connections in the LSBB capsule outnumber those in the hospital, suggesting that patterns of gamma-band connectivity are better reflected in low-noise environments. This study again demonstrates the poten-tial of the ultra-shielded capsule and motivates further protocol enhancements and analysis methods for conducting future high-frequency EEG studies within LSBB.
Monitoring of groundwater redistribution in a karst aquifer using a superconducting gravimeter
Authors: Mouyen Maxime , Longuevergne Laurent , Chalikakis Konstantinos , Mazzilli Naomi , Ollivier Chloé , Rosat Séverine , Hinderer Jacques , Champollion Cédric
Published: February 2019

Geodetic tools monitor the earth’s deformation and gravity field. They are presently sensitive enough to record subtle changes triggered by hydrological processes, thus providing complementary data to standard hydrological measurements. Among these tools, superconducting gravimeter (SG) have proven useful to unravel groundwater redistribution, which significantly alter the gravity field. In the frame of the EquipEx MIGA (Matter wave-laser based Interferometer Gravitation Antenna) project, one SG (iOSG-24) was set up in July 2015 in the Low-noise Underground Laboratory (LSBB) at Rustrel, France, in a gallery located 500 m beneath the surface. In this work, we analyse the underground iOSG-24 gravity time series together with hydro-meteorological data and basic gravity modelling. We find that the gravimeter recorded the redistribution of water in the ground and that most of this redistribution occurs in the unsaturated zone located above the gravimeter. Nevertheless, residuals between our model and the gravity data suggest the occurrence of large lateral fluxes and rapid runoff not considered in our model. We discuss how the setting of a second SG, planned in July 2018, at the surface of the LSBB could help unravelling such hydrological processes.