Quantitative Study of Geometrical Scaling in Deep Inelastic Scattering at HERA

We propose a method to assess the quality of geometrical scaling in Deep Inelastic Scattering and apply it to the combined HERA data on $\gamma^{\ast}p$ cross-section. Using two different approaches based on Bjorken $x$ binning and binning in $\gamma^{\ast}p$ scattering energy $W$, we show that geometrical scaling in variable $\tau\sim Q^{2} x^{\lambda}$ works well up to Bjorken $x$'s 0.1. The corresponding value of exponent $\lambda$ is 0.32 -- 0.34.Comment: 18 pages, 11 figures, version accepted in JHEP, new discussion of experimental error

Quantitative Study of Different Forms of Geometrical Scaling in Deep Inelastic Scattering at HERA

We use recently proposed method of ratios to assess the quality of geometrical scaling in deep inelastic scattering for different forms of the saturation scale. We consider original form of geometrical scaling (motivated by the Balitski-Kovchegov (BK) equation with fixed coupling) studied in more detail in our previous paper, and four new hypotheses: phenomenologically motivated case with $Q^2$ dependent exponent $\lambda$ that governs small $x$ dependence of the saturation scale, two versions of scaling (running coupling 1 and 2) that follow from the BK equation with running coupling, and diffusive scaling suggested by the QCD evolution equation beyond mean field approximation. It turns out that more sophisticated scenarios: running coupling scaling and diffusive scaling are disfavored by the combined HERA data on $e^+p$ deep inelastic structure function $F_2$.Comment: 13 pages, 6 figure

CFD modeling of a high enthalpy geothermal context

The promising development of highly energetic geothermal resources could considerably enhance geothermal power production worldwide. The first attempt at tapping supercritical/heated fluids was made by the Iceland Deep Drilling project (IDDP), but unfortunately a magma layer at a depth of 2,100m was encountered, and the drilling was abandoned. Yet, this drilling operation failure generated new opportunities for assessing the potential power generation close to shallow magmatic intrusions. Detailed numerical methods are required to assess the heat transfer and fluid thermodynamics at wellbore and reservoir scale at near supercritical conditions to provide production scenarios and forecasts as accurate as possible. A primary steady-state study of reservoir and wellbore heat extraction from a geothermal well near a magmatic chamber has been performed with Computational Fluid Dynamics (CFD) techniques. Using simplified geological assumptions based on the IDDP-1 well description, a 2D axisymmetric single phase flow model was developed and its results were compared to those obtained with a full 3D CFD model. The simulated output power simulations reached 25 MW at 350°C and a wellhead pressure of 140 bars. Methodology and results from this study show that CFD techniques can be successfully used to assess geothermal energy outputs for unconventional geothermal wells and can provide details of a vapor superheated flow structure at wellbore-reservoir scale

Thermal analysis of 8.5 MVA disk-type power transformer cooled by biodegradable ester oil working in ONAN mode by using advanced EMAG–CFD–CFD coupling

Power transformers are the first devices used to transfer the electrical energy produced in power plants to the grid to supply the industrial and individual receivers with electricity. The heat generation in windings and core, being an effect of the power losses, is usually dissipated in large units by using mineral oils, which are harmful to the environment. Nowadays, the industry and global society seek environmentally-friendly alternatives. One of the most promising substitute for their high biodegradability, safety in operation, and favourable thermo-physical properties are natural ester oils. For this reason, a numerical study of 8.5 MVA disk-type power transformer cooled using conventional mineral oil and a commercially used rapeseed ester oil is presented in this paper. Moreover, due to different thermal behaviour of the considered oils, the comparison was made for the unit working in different seasons of hot and moderate climate zones (Argentina and Poland). In the numerical approach, electromagnetic (EMAG) and computational fluid dynamics (CFD) models were used for a detailed study of the selected device. In particular, a novel and very efficient EMAG–CFD–CFD coupling procedure was developed to assess the cooling of the large power transformer. Such a coupled computational procedure allowed for the detailed investigation of the power loss, oil flow characteristics, and temperatures with a satisfying computational effort. The results showed that the average windings temperatures are higher by 2–9 K when the ester oil is used, dependent on the ambient conditions. The hotspot temperature in the low voltage windings increased by up to 9 K and up to 18 K in the high voltage windings using ester oil. According to the results, the oil duct construction requires modification in the high voltage region for transformers cooled using mineral oil in cold climate conditions.Fil: Stebel, Michal. Silesian University Of Technology; PoloniaFil: Kubiczek, Krzysztof. Silesian University Of Technology; PoloniaFil: Rios Rodriguez, Gustavo Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; ArgentinaFil: Palacz, Michal. Silesian University Of Technology; PoloniaFil: Garelli, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; ArgentinaFil: Melka, Bartlomiej. Silesian University Of Technology; PoloniaFil: Haida, Michal. Silesian University Of Technology; PoloniaFil: Bodys, Jakub. Silesian University Of Technology; PoloniaFil: Nowak, Andrzej J.. Silesian University Of Technology; PoloniaFil: Lasek, Pawel. Silesian University Of Technology; PoloniaFil: Stepien, Mariusz. Silesian University Of Technology; PoloniaFil: Pessolani, Francisco. Tadeo Czerweny S.a.; ArgentinaFil: Amadei, Mauro. Tadeo Czerweny S.a.; ArgentinaFil: Granata, Daniel. Tadeo Czerweny S.a.; ArgentinaFil: Storti, Mario Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; ArgentinaFil: Smolka, Jacek. Silesian University Of Technology; Poloni

Development of the natural working fluid‐based refrigeration system for domestic scale freeze‐dryer

In this work, the analysis of the refrigeration system designed for the FrostX 10 freeze‐dryer is presented. The main goal of this study was to experimentally investigate the reference R452a freeze‐dryer and prepare recommendations for a machine based on the R290 refrigeration unit. In order to guarantee the temperature requirements and efficient operation of that unit, the analysis of suitable natural refrigerants was performed. Consequently, propane (R290) was selected. In addition, a number of modifications were introduced for the prototype system. System analysis showed that the replacement of the refrigerant in the existing system improves the system energy efficiency by approximately 18%. During the experimental campaign of the basic refrigeration unit, an unstable operation of the evaporator was found. The concept of a new cooling system for a prototype device was presented. The configuration and type of heat exchanger to maximise the performance of the ice trap of the freeze‐dryer were proposed.Development of the natural working fluid‐based refrigeration system for domestic scale freeze‐dryeracceptedVersio

Neural Network Classification of SDR Signal Modulation

Part 3: Images, Visualization, ClassificationInternational audienceWith the rising popularity of Software Defined Radios (SDR), there is a strong demand for automatic detection of the modulation type and signal parameters. Automatic modulation classification is an approach to identify the modulation type and its parameters such as the carrier frequency or symbol rate. In electronic warfare, it enables real-time signal interception and processing. In civil applications, it can be used, e.g., by the amateur radio operators to automatically set the transceiver to the appropriate modulation and communication protocol. This paper presents a modulation classification driven by a neural network. A set of signal features are provided as an input of the neural network. The paper discusses the relevance of different signal features and its impact on the success rate of the neural network classification. The proposed approach is tested on both artificial and real samples captured by the SDR

Experimental study of a R290 variable geometry ejector

Ejectors are classified as fluid-dynamics controlled devices where the “component-scale” performances are imposed by the local-scale fluid dynamic phenomena. For this reason, ejector performances (measured by the pressure-entrainment ratio coordinate of the critical point) are determined by the connection of operation conditions, working fluid and geometrical parameters. Given such a connection, variable geometry ejector represents a promising solution to increase the flexibility of ejector-based systems. The present study aims to extend knowledge on variable geometry systems, evaluating the local and global performances of the R290 ejector equipped with a spindle. The prototype ejector was installed at the R290 vapour compression test rig adapted and modified for the required experimental campaign. The test campaign considered global parameter measurements, such as the pressure and the temperature at inlets and outlet ports together with the mass flow rates at both inlet nozzles, and the local pressure drop measurements inside the ejector. In addition, the experimental data were gathered for different spindle positions starting from fully open position the spindle position limited by the mass flow rate inside the test rig with the step of 1.0 mm

Development of the natural working fluid‐based refrigeration system for domestic scale freeze‐dryer

In this work, the analysis of the refrigeration system designed for the FrostX 10 freeze‐dryer is presented. The main goal of this study was to experimentally investigate the reference R452a freeze‐dryer and prepare recommendations for a machine based on the R290 refrigeration unit. In order to guarantee the temperature requirements and efficient operation of that unit, the analysis of suitable natural refrigerants was performed. Consequently, propane (R290) was selected. In addition, a number of modifications were introduced for the prototype system. System analysis showed that the replacement of the refrigerant in the existing system improves the system energy efficiency by approximately 18%. During the experimental campaign of the basic refrigeration unit, an unstable operation of the evaporator was found. The concept of a new cooling system for a prototype device was presented. The configuration and type of heat exchanger to maximise the performance of the ice trap of the freeze‐dryer were proposed