Th e electricity generating effi ciency is the energy in the net electricity generated divided by the energy in the fuel used to generate that electricity on an all-in basis. Higher effi ciency means less coal consumed and reduced emissions per unit of electricity. Th e chemical energy in the fuel can be expressed as either its Lower Heating Value (LHV) or its Higher Heating Value (HHV) [5]. In...

A conceptual framework for crop production effi ciency was derived using thermodynamic effi ciency concept, in order to generate a tool for performance evaluation of agricultural systems and to quantify the interference of determining factors on this performance. In Thermodynamics, effi ciency is the ratio between the output and input of energy. To establish this relationship in agricultural sy...

data envelopment analysis (dea) is an eciency measurement tool for evaluation of similar decision making units (dmus). in dea, weights are assigned to inputs and outputs and the absolute eciency score is obtained by the ratio of weighted sum of outputs to weighted sum of inputs. in traditional dea models, this measure is also equivalent with relative eciency score which evaluates dmus in com...

Dielectric elastomer generators (DEGs) for harvesting electrical energy from mechanical work have been demonstrated but the energy densities achieved are still small compared with theoretical predictions. In this study, signifi cant improvements in energy density (560 J/kg with a power density of 280 W/ kg and an effi ciency of 27%) are achieved using equi-biaxial stretching, a mechanical loadi...

The ‘smarter’ approach to processing described in this paper is limited to the benefi ts of a more effi cient high pressure grinding roll (HPGR) circuit over a traditional semi-autogenous grinding (SAG) comminution circuit. The effi ciency challenge described concerns comminution circuit designs that are relatively risk averse and compliment current mainstream engineering practice. The HPGR eff...

Polymer:fullerene solar cells are demonstrated with power conversion effi ciencies over 7% with blends of PBDTTPD and PC 61 BM. These devices achieve open-circuit voltages ( V oc ) of 0.945 V and internal quantum effi ciencies of 88%, making them an ideal candidate for the large bandgap junction in tandem solar cells. V oc ’s above 1.0 V are obtained when the polymer is blended with multiadduct...

This paper fi rst discusses features of the Third Energy Package” of EU legislation regarding electricity transmission system operators (TSOs), which has been in place since 2009. The Package envisages three different types of TSO organization: full ownership unbundling (OU), independent system operator (ISO), and independent transmission operator (ITO). The question of economic effi ciency of ...

The role of the dairy cow is to help provide high-quality protein and other nutrients for humans. We must select and manage cows with the goal of reaching the greatest possible effi ciency for any given environment. We have increased effi ciency tremendously over the years, yet the variation in productive and reproductive effi ciency among animals is still quite large. In part this is because o...

Consumers, clinicians, and researchers lack an easy-to-use, reliable and cost effi cient way to accurately assess metabolic physical activity and energy expenditure, critical components of a variety of behavioral modifi cation programs, including diseaseand weight-management. BodyMedia has addressed this need by developing the SenseWear Pro2 Armband which utilizes a heat fl ux sensor, galvanic ...

Optical fi bressolar energy transmission and concentration provide a fl exible way of handling concentrated solar energy. Solar lighting with Fibre Optic Bundles (FOBs) can be considered a promising option for energy-effi cient green buildings. This study deals with the exergetic analysis and performance assessment of a system based on the idea of Transmission-Concentrated Solar Energy via Opti...