Impact of public subsidies on farms’ technical efficiency in New Member States before and after EU accession

This paper presents some results of a two-year (2006-2007) research project supported by the French Ministry of Research’s funding program ECONET. One of the project’s objectives was to investigate the determinants of farm technical efficiency in New Member States before and after accession to the European Union, and in particular the role of public subsidies on this performance variable. Four countries were considered: Hungary, the Czech Republic and Slovenia, who acceded to the EU in 2004, and Romania, whose accession was in 2007. The study found that subsidies had a negative impact on farm technical efficiency in Hungary over the period 2001-2005, in the Czech dairy corporate sector over the period 2000-2004, in Slovenia over the period 1994-2003, and in the Romanian crop sector in 2005.technical efficiency, farms, subsidies, Hungary, Czech Republic, Slovenia, Romania, Farm Management,

Considerations on the expertise of pumping plants from irrigation systems

The paper presented a series of concepts on the technical expertise of irrigation pumping stations. Sprinkling irrigation screens in operation show significant wear and aging phenomena. Any project for the rehabilitation and upgrading of a pumping station is based on technical expertise. It critically analyses the design, construction and operation of structural components and installations serving a pumping station. The technical expertise consists of four components: 1 - Critical analysis of the data on the achievement of the objective; 2 - field research and research on the behaviour of the objective during the exploitation period; 3 - complementary studies and research to define the response situations of the objective to the action of internal and external factors; 4 - the conclusions of the expertise and the directions of rehabilitation and modernization. The expertise for a sprinkler irrigation plot equipped with a pumping and pressure plant (considered a case study) highlighted the complexity of the rehabilitation and modernization process. The rehabilitation process must be carried out in successive stages and by using modern equipment and technologies

Considerations on rehabilitation of monophilar pumping stations of the irrigation sprinkler plots

The paper presents an analysis of the directions of rehabilitation of the single-line pumping stations from aspersion irrigation plots. The single-line pumping station consists of one or two pumping units supplied from a canal. Each pumping unit supplies a distribution pipeline equipped with irrigation hydrants. The rehabilitation and modernization has been differentiated on the structural and functional components: foundations, hydromechanical technological line, power supply system, monitoring and automation system. The case study was prepared for an irrigation plot located in the Moldavian area (Plot 7, Doniceasa Falciu, Vaslui County). The irrigation plot has 1222 ha and is equipped with 15 single-line pumping stations. The pumps type is 6 NDS and has the parameters: flow rate 241 - 345 m3 /h, pressure 6.5 - 7.5 bar and power 75 - 110 kW. The paper presents two options for the rehabilitation of the pumping stations: a - equipping with horizontal pumps; b - equipping with vertical pump

On the electrostatic inertia in microgrids with inverter-based generation only—an analysis on dynamic stability

Storage4Grid project grant agreement No. 731155 RESERVE project grant agreement No. 727481 KIOS CoE grant agreement No. 739551.Microgrids are about to change the architecture and the operation principles of the future power systems towards smartness and resiliency. Power electronics technologies are key enablers for novel solutions. In this paper we analyze the benefits of a “microgrid by design” architecture (MDA), using a solid-state transformer (SST) as a low-voltage grid-former and inverter-based generation only. In this context, the microgrid stability is maintained with the help of “electrostatic energy inertia” that can be provided by the capacitor connected to the DC busbar behind the SST inverter topology. This happens in a natural way, alike the mechanical inertia in power systems with synchronous machines, however without depending on frequency and without the need of a rotational inertia. This type of microgrid always operates (both fully connected to the main grid or in islanding mode) with all the necessary mechanisms needed to maintain the microgrid stable—no matter of the perturbations in the upstream of the point of common coupling (PCC). In the case of microgrids with inverter-based generation only (including the energy storage systems), there is no mechanical inertia and different stability mechanisms need to be applied compared to the stability principle of the classical power systems. Our proposed mechanism differentiates from the recently proposed stability assessments of microgrids based on virtual synchronous generators from the control theory perspective. This paper is a continuation of our previous work where the MDA was first introduced. The use-cases and scenarios are based on realistic and yet reasonable complexities, by coupling the disturbance magnitude with the voltage stability limit in power grids. The paper finds meaningful disturbances to test the electrostatic energy inertia at the boundaries of grid stability, as guidance to understand the range of voltage variation for extreme conditions. The results show that in microgrids with inverter-based generation only and passive loads (RLC type) the operation is no longer frequency dependent. The energy of the DC busbar capacitor as electrostatic energy inertia of the MDA has a role similar to that of the rotational machines in classical grids in terms of maintaining dynamic stability, however impacting two different types of stability.publishe

Hard Alloys with High Content of WC and TiC—Deposited by Arc Spraying Process

Obtained by different spraying technologies: in atmospheric plasma spray, High Velocity Oxygen Fuel (HVOF) or laser cladding, the layers of hard alloys with a high content of WC and TiC find their industrial applications due to their high hardness and resistance to wear. Recognized as being a process associated with welding, the arc spraying process is a method applied industrially both in obtaining new surfaces and for reconditioning worn ones. This chapter presents the technology for obtaining ultra-hard layers based on WC and TiC - by the arc spraying process, using a classic spray device equipped with a conical nozzle system and tubular wire additional material containing ultra-hard compounds (WC, TiC). To study both the quality of deposits and the influence of thermal spray process parameters on the properties of deposits with WC and TiC content, we approached various investigative techniques, such as optical scanning microscopy (SEM), X-ray diffraction, and determination of adhesion, porosity, Vickers micro-hardness and wear resistance

Facile synthesis and characterization of hydroxyapatite particles for high value nanocomposites and biomaterials

Lately Hydroxyapatite has gained a lot of research interest and intense focus due to its structural as well as compositional similarity to the components of human bone mineral. The conversion of calcium-rich precursors to hydroxyapatite could lead to the development of a new sustainable alternative with a valuable environmental and socio-economically impact. Still, current approaches faces lots of challenges in terms of synthesis parameters compatible to a reproducible route for calcium phosphates (hydroxyapatite included) synthesis. The optimization of Rathje synthesis route and characterization of biogenic derived calcium phosphates from dolomitic marble and Mytilus galloprovincialis seashells, constitutes the main goals of this study. The synthesized materials were characterized using FTIR, SEM coupled with EDS, and X-ray diffraction at all synthesis stages. Precursors were also subjected to thermal analysis and differential scanning calorimetry for thermal transformations investigations and dissociation temperature setting. This study suggests that acid quantity and magnetic stirring are the key-factors for Ca/P molar ratio adjustment, hence for the amount of naturally-derived hydroxyapatite. This research also contributes to the development of new strategies for further optimization of the conversion procedure and removal of residual components

Near-Earth Asteroids Data mining on Astronomical Databases: EuroNEAR experience

Program available at: http://www.imcce.fr/hosted_sites/naroo/program.htmlInternational audienceIn the framework of EuroNEAR network several databases around the world were datamined. The main scientifi c objective was the astrometry of Near-Earth Asteroids (NEAs) for both precovery and secure orbits of these objects. The article presents few aspects of data-mining and the developed procedures for accomplishing these objectives