Categoria: Excen

Comparative and quantitative analysis of white light-emitting diodes and other lamps used for home illumination.

Posted GabiruLeave a commentPosted in Artigo, Edson da Costa Bortoni, Excen

We compared the photometric and radiometric quantities in the visible, ultraviolet, and infrared spectra of white light-emitting diodes (LEDs), incandescent light bulbs and a compact fluorescent lamp used for home illumination. The color-rendering index and efficiency-related quantities were also used as auxiliary tools in this comparison. LEDs have a better performance in all aspects except […]

Life cycle assessment (LCA) for biofuels in Brazilian conditions: A meta-analysis.

Posted GabiruLeave a commentPosted in Artigo, Excen, Luiz Horta Nogueira

The key objective of this study is to evaluate and compare the main environmental life cycle impacts and energy balance of ethanol from sugarcane and biodiesel from soybean and palm oil, in the Brazilian conditions. The methodological tool used was the Life Cycle Assessment (LCA), in Well-To-Tank (WTT) perspective. A process based on cradle-to-gate attribution […]

Parameter Determination of Asynchronous Machines From Manufacturer Data Sheet.

Posted GabiruLeave a commentPosted in Artigo, Edson da Costa Bortoni, Excen

This paper presents a methodology for obtaining the parameters of the equivalent circuit for an induction motor from the information on the nameplate and manufacturer catalog data sheet. The proposed method is straight and noniterative. The variation in rotor parameters for deep bars or double squirrel-cage rotors is modeled and presented as a function of […]

Novos Rumos para a Infraestrutura: Eficiência, Inovação e Desenvolvimento.

Posted GabiruLeave a commentPosted in Afonso Henriques Moreira Santos, Excen, Livro

A presente obra, Novos Rumos para a Infraestrutura: Eficiência, Inovação e Desenvolvimento, traz, em formato inovador, no qual especialistas de diferentes áreas do conhecimento se juntam para analisar o contexto atual da infraestrutura nacional, uma visão geral e técnica do assunto. Não se limitam, porém, ao diagnóstico. Buscam propor soluções, desvendar problemas enraizados e também […]

The rationality of biofuels.

Posted GabiruLeave a commentPosted in Artigo, Excen, Luiz Horta Nogueira

In an editorial of a recent issue of a known academic journal, Prof. Hartmut Michel affirmed that “…the production of biofuels constitutes an extremely inefficient land use… We should not grow plants for biofuel production.”, after comparing the area occupied with plants for bioenergy production with the one required for photovoltaic cells to supply the […]

A Model to Extract Wind Influence From Outdoor IR Thermal Inspections.

Posted GabiruLeave a commentPosted in Artigo, Edson da Costa Bortoni, Excen

A model proposal to determine the influence of wind over temperature measurements when conducting outdoor infrared (IR) themographic inspections is addressed in this paper. A wind velocity-dependent temperature reduction factor is developed and applied in order to estimate the target temperature in the absence of wind, which is considered as the worst case. The model […]

Biofuels in Brazil: Evolution, achievements and perspectives on food security.

Posted GabiruLeave a commentPosted in Artigo, Excen, Luiz Horta Nogueira

Liquid biofuels, as ethanol and biodiesel, supply 25% of the road transport fuel consumed in Brazil. Ethanol blending has been mandatory since 1931, pure ethanol has been used since 1975, and nowadays flex-fuel cars are widely used. In 2008, ethanol production reached 28 Mm³, but recently, government efforts to reduce gasoline prices have reduced the […]

Evaluation of the Efficiency Energy of Wood Stove from Irati Brazilian City.

Posted GabiruLeave a commentPosted in Artigo, Excen, Luiz Horta Nogueira

This study aimed to evaluate the energy efficiency, thermal power and amount of volatiles released (CO2, CO and SO2) by three models of wood-metallic cookstoves into single-family residences in the city of Irati / PR, Brazil. All cookstoves had a low average energy efficiency from 2.9% ± 0.3 (stove 1), 2.6% ± 0.5 (stove 2) […]

Trends in global warming and human health impacts related to Brazilian sugarcane ethanol production considering black carbon emissions.

Posted GabiruLeave a commentPosted in Artigo, Excen, Luiz Horta Nogueira

Sugarcane produced in Brazil has several environmental advantages. However, burning residues, which leads to GHG and black carbon (BC) emissions, has been used to facilitate manual harvest. BC emissions have a net warming effect and cause health problems. Mechanized harvest without burning is gradually replacing manually harvested burned sugarcane. Global warming potential (GWP) and human […]

An assessment of energy benefits of efficient household air-conditioners in Brazil.

Posted GabiruLeave a commentPosted in Artigo, Excen, Jamil Haddad, Luiz Horta Nogueira

Increasing efficiency of electrical equipment is essential to national energy rationality, enabling energy consumption reduction and postponing inversion in distribution, transmission and generation, as well as mitigating environmental impacts associated with such activities. Considering such purposes, two actions have been promoted in Brazil: (a) minimum energy performance standards (MEPS) have been required for some appliances […]