Search results for "Energy engineering"
showing 10 items of 1099 documents
Contributions Regarding the Reduction of Production Costs for Brewing by Recovering and Reusing the Carbon Dioxide
2014
Abstract Nowadays in every field the main aim is to produce corresponding quality products at competitive prices for buyers. In addition to the multiple possibilities to reduce the brewing production cost, one of the most significant ways is to reduce the production cost by recovering the carbon dioxide (CO2) resulting from the fermentation of beer, taking into account the fact that the CO2 thus resulting is completely natural. This scientific paper presents a certain strategy based on costs, strategy which relies on the experience of the authors, on the economic impact of CO2 recovery resulting from the fermentation of beer and which reflects itself in the production cost and implicitly in…
Backward solution of PV nodes in radial distribution networks
2009
In this paper an iterative backward methodology to solve radial distribution networks with fixed voltage (PV) nodes and with constant power loads or mixed loads (with at least one component with constant power) is proposed. The method developed, although deriving conceptually from the backward/forward (b/f) methodology, presents only the backward phase in which all the network variables are evaluated. In themethods developed up until nowfor the solution of such systems, PV nodes are taken into account at the end of each iteration by evaluating, based on the known quantities of the network, the unknowns associated with PV nodes. In the methodology developed here the unknowns relevant to PV n…
Ben Ambridge y Elena V. M. Lieven: Child language acquisition: Contrasting theoretical approaches
2013
Traditional analytic approaches establish a strong connection between discourse markers (DMs) and a number of prosodic cues regularly associated to them (esp...
Assessment of Gamma Dose Rate at Mine Waste Dump
2013
Abstract Exploitation of coal deposits in Upper Silesia is associated with production of large quantities of waste deposited at dumps. The tested samples from five dumps showed different radioactivity from each other. Radioactivity measurements made it possible to analyze the degree of risk with the factors specified by UNSCEAR such as radium equivalent activity Raeq, internal Ein and external Eex occupancy factor. There is a raised level of radiation in dumps as compared with outside dump areas. In the study area, however, there is no risk associated with elevated levels of radiation in relation to standards established by the Council of Ministers of the ionizing radiation dose limits.
Evidence for H2S gas as an intermediate species in the reaction mechanism of trapping hydrogen by cobalt disulfide
2011
Cobalt sulfide prepared by aqueous precipitation using Na2S and a Co(II) salt is known to trap hydrogen at room temperature and low pressure. The importance of oxidation of the primary CoS precipitate with atmospheric oxygen with respect to its efficiency as a hydrogen absorber is demonstrated. This stage of oxidation produces a mixture of two solid phases: a partially crystallized cobalt hydroxide Co(OH)2 and an amorphous cobalt sulfide CoS2 with a Co(OH)2/CoS2 molar ratio of 1 as predicted by thermodynamics. This biphasic product is probably the basic cobalt sulfide CoSOH considered in older and even more recent work. This product traps molecular hydrogen with a H2/Co molar ratio of 0.5 w…
Exergy recovery during LNG regasification: Electric energy production – Part one
2009
Abstract In liquefied natural gas (LNG) regasification facilities, for exergy recovery during regasification, an option could be the production of electric energy recovering the energy available as cold. In a previous paper, the authors propose an innovative process which uses a cryogenic stream of LNG during regasification as a cold source in an improved combined heat and power (CHP) plant. Considering the LNG regasification projects in progress all over the World, an appropriate design option could be based on a modular unit having a mean regasification capacity of 2 × 109 standard cubic meters/year. This paper deals with the results of feasibility studies, developed by the authors at DRE…
The critical Swedes and the consensual Finns: Leading newspapers as watchdogs or lapdogs of nuclear waste repository licensing?
2020
Abstract The final disposal of spent nuclear fuel has long stirred up societal debate and controversy in most countries utilizing nuclear energy. Various discourses contextualising the issue affect both the general public and policy-making. Both Finland and Sweden are considered forerunners in implementing final disposal. In this paper we explore similarities and differences in media attention paid to final disposal in Finland and Sweden by focusing on two leading newspapers in each country during the time period of 2008–2015. A longitudinal comparative study suggests that there are clear national differences in the roles assumed by print media in the handling of the final disposal issue. I…
Characterization and pilot scale fluidized bed gasification of herbaceous biomass: A case study on alfalfa pellets
2015
Abstract Pilot-scale bubbling fluidized bed gasification tests of alfalfa pellets were performed at two different operational periods ranged on the basis of the two given equivalence ratio (ER) (the ratio between actual air and the stoichiometric air) namely as 0.25 and 0.30. During the test, the solid feeding rate was kept constant at 4.7 kg/h while the air input was varied and thus the ER. Increasing air from 4.16 to 4.99 N m3/h contributed to the evolution pattern of several parameters such as the rise in gas lower heating value (LHV) and gas yield, the average maximum of which were 4.2 MJ/N m3 and 1.5 N m3/kg respectively. Gas composition was mainly boosted by the concentration of CO, a…
Preferential CO oxidation over catalysts with well-defined inverse opal structure in microchannels
2008
Catalyst supports of CeO 2 /SiO 2 and Al 2 O 3 with three-dimensionally ordered macroporous structure were fabricated in microchannels by application of PMMA opals as templates. Pt-Rh supported on CeO 2 /SiO 2 showed high efficiency for CO removal in preferential CO oxidation in the presence of excess hydrogen. Pt-Rh supported on Al 2 O 3 with an inverse opal structure showed higher reactivity than that supported on wash-coated Al 2 O 3 layers in microchannel reactor.
Melt flow instability and vortex structures in Czochralski growth under steady magnetic fields
2002
Abstract The hydrodynamics of melt motion in the CZ-process of silicon single crystal growth in axial and axial–radial magnetic fields is studied using a physical model. The modeling liquid is eutectics InGaSn. Most attention is paid to the problem of flow stability. A multi-channel system gathering data is used to define the pattern and dynamics of velocity disturbances. Instant spatial distributions of the electric potential induced by motion in the melt are obtained. Temporal evolution of the instant distributions in vertical and horizontal planes of the working volume is under investigation.