Search results for "POWER"

Characterization and reactivity of charcoal from high temperature pyrolysis (800-1600°C)

2019

This study presents the effect of wood origin and heat treatment temperature on the CO2 reactivity, nanostructure and carbon chemistry of chars prepared at 800, 1200, and 1600 °C in slow pyrolysis reactors. The structure of charcoal was characterized by transmission electron microscopy, Raman spectroscopy, mercury intrusion porosimetry and N2 adsorption. The CO2 reactivity of char was investigated by thermogravimetric analysis. Results showed that spruce and oak chars have similar reactivity at all heat treatment temperatures. The oak char prepared at 1600 °C contained long and flat graphene layers and interplanar distance that is similar to graphite and thus, was more ordered t…

On the self-heating behavior of upgraded biochar pellets blended with pyrolysis oil: Effects of process parameters

2020

Abstract Biochar obtained from biomass pyrolysis is a promising carbon neutral material which can be used in substitution of fossil coal and coke in metallurgical applications. Biochar’s mechanical properties improve significantly without compromising reactivity, when upgraded by densification with pyrolysis oil and reheated. However, upgraded biochar pellets use in the industry is limited due to the risks associated with self-heating. This issue must be seriously considered for further industrial production of upgraded biochar pellets. Self-heating oven tests are generally time-consuming and limit the possibility of testing various potential solutions. The aim of this work was both to inve…

Precursor Polymers for the Carbon Coating of Au@ZnO Multipods for Application as Active Material in Lithium-Ion Batteries

2014

The synthesis of statistical and block copolymers based on polyacrylonitrile, as a source for carbonaceous materials, and thiol-containing repeating units as inorganic nanoparticle anchoring groups is reported. These polymers are used to coat Au@ZnO multipod heteroparticles with polymer brushes. IR spectroscopy and transmission electron microscopy prove the successful binding of the polymer onto the inorganic nanostructures. Thermogravimetric analysis is applied to compare the binding ability of the block and statistical copolymers. Subsequently, the polymer coating is transformed into a carbonaceous (partially graphitic) coating by pyrolysis. The obtained carbon coating is characterized by…

Experimental tests on Li-ceramic breeders for the helium cooled pebble bed (HCPB) blanket design

2003

The Helium Cooled Pebble Bed (HCPB) Test Blanket Module (TBM) to be tested in ITER (International Thermonuclear Experimental Reactor) Reactor foresees the utilization of Lithiate ceramics as Tritium breeder in form of pebble beds. Since 1998, ENEA has launched many experimental activities for the evaluation of the breeder thermomechanics and the interaction between the pebble beds and the prismatic steel containment walls. Main objectives of these activities are the measurement of the pebble bed effective thermal conductivity, the wall heat transfer coefficient, the pressure loads and deformations on the lateral walls and their dependency from the mechanical constraints. The paper presents …

Epistemic and didactic values of the demonstrative process in different cultures: a case study in Geometry with Chinese and Italian students

2011

Spin-valve current sensor for industrial applications

2003

This work presents an industrial application of a new spin-valve current sensor based on the giant magnetoresistance effect (GMR) and provides a comparison between this sensor and the typical sensor used in these applications, the hall sensor. Experimental results derived from the application of this two sensors in a power application (a bi-directional three-phase rectifier) are shown.

Implementation on NI-SOM sbRIO-9651 and Experimental Validation of Multi-Carrier PWM Techniques for Three-Phase Five Level Cascaded H-Bridge Inverter

2021

Multilevel Power Inverters (MPIs) represent a valid solution to improve the performances of energy production systems from renewable energy sources. Furthermore, the use of novel FPGA control systems allows simplifying the implementation of multicarrier PWM techniques for MPIs with computational benefits. This paper describes the implementation of several multicarrier PWM techniques on NI-SOM sbRIO-9651 for the control of a three-phase five-level cascaded H-bridge inverter. In detail, sbRIO-9651 is a control system in the field of Power Electronics and Drives (PED) programmable in the LabVIEW graphical programming environment. The paper is focused on modulation techniques implementation, te…

Teacher-Student Relations in Two Tibetan Buddhist Groups in Helsinki

2017

AbstractBased on sixteen interviews with members of two Tibetan Buddhist groups in Helsinki, Finland, this article investigates how the role of the guru, power imbalance and power abuse are perceived by the students. This qualitative study aims at understanding what shape the reverence to the Vajrayana teacher takes in the egalitarian environment of a European country, where Buddhism is a relatively new phenomenon. The interviews show that while teachers are not losing importance, ways of choosing and paying respect to them changes. They also reveal confusion in defining abuse, and emphasis on personal agency and teachers’ accountability for avoiding it.

The first experimental values for the stopping power of 89Y ions in carbon, nickel and gold

2009

Abstract The stopping power values of 89 Y ions in carbon, nickel and gold were measured with accuracy to better than 5% in the energy range from 0.03 to 8.2 MeV/u. The newly developed B-TOF method was used for the measurements. The results are compared with theoretical and semi-empirical predictions. For this ion/absorber combination no prior experimental data are available.

On the Effect of Slotted Blades on Savonius Wind Generator Performances by CFD Analysis

2012

In this paper a new bucket configuration for Savonius wind generator is proposed. With the aim to increase the effect of the overlap ratio RS on the wind turbine performances and to increase the amount of lift force able to produce torque and power, slotted blades are investigated by means of the Computational Fluid Dynamics analysis. The numerical analyses are performed by Comsol Multiphysics® and the results obtained for a Savonius wind turbine with overlap only are compared to numerical and experimental benchmarks. Parametric analyses are performed, for fixed overlap ratio, by varying the slot angle β and the results show that for low angle β the Savonius rotor exploits improved performa…