Search results for "STEAM"
showing 10 items of 125 documents
Sensitivity Analysis of the MASLWR Helical Coil Steam Generator Using TRACE
2011
Accurate simulation of transient system behavior of a nuclear power plant is the goal of systems code calculations, and the evaluation of a code's calculation accuracy is accomplished by assessment and validation against appropriate system data. These system data may be developed either from a running system prototype or from a scaled model test facility, and characterize the thermal hydraulic phenomena during both steady state and transient conditions. The identification and characterization of the relevant thermal hydraulic phenomena, and the assessment and validation of thermal hydraulic systems codes, has been the objective of multiple international research programs. The validation and…
Citrus cybrid leaf essential oil
2000
The essential oil from the leaves of a Citrus cybrid plant, obtained by somatic hybridization between ‘Valencia’ sweet orange (Citrus sinensis L. Osbeck), embryogenic parent, and ‘Femminello’ lemon (C. limon L. Burm f.), leaf parent, has been studied by steam distillation and GC–MS analysis and compared with the correspondent oils from the parent plants. Although the overall composition of the cybrid essential oil appears much closer to that of ‘Femminello’, the relatively higher percentage of β-caryophyllene, as well as the qualitative and quantitative modifications of the esteric fraction, are characteristic of the new hybrid. Since cybrid cells possess the nuclear genome of the mesophyll…
Technological change and wage premiums: historical evidence from linked employer-employee data
2013
Abstract This study analyses the impacts of a technological change (the steam engine) on wage premiums. Using historical employer–employee panel data, we found that steam technology had both new skill-demanding and skill-replacing aspects. The former manifested itself as an increase in the demand for high-skilled engineers, the latter in a decline in the demand for intermediate-skilled, able-bodied seamen and an increase in the demand for unskilled engine room operators. Our panel data analysis, which controls for unobserved heterogeneity, implies that high-skilled labourers in abstract tasks and unskilled labourers in manual tasks improved their wage positions relative to intermediate-skil…
Redox regulation of enzymatic activity and proteolytic susceptibility of ribulose-1,5-bisphosphate carboxylase/oxygenase fromEuglena gracilis.
1992
The activity of ribulose-1,5-bisphosphate carboxylase/oxygenase fromEuglena gracilis decays steadily when exposed to agents that induce oxidative modification of cysteine residues (Cu(2+), benzofuroxan, disulfides, arsenite, oxidized ascorbate). Inactivation takes place with a concomitant loss of cysteine sulfhydryl groups and dimerization of large subunits of the enzyme. 40% activity loss induced by the vicinal thiol-reagent arsenite is caused by modification of a few neighbor residues while the almost complete inactivation achieved with disulfides is due to extensive oxidation leading to formation of mixed disulfides with critical cysteines of the protein. In most cases oxidative inactiva…
Thermal damage of the inner vein wall during endovenous laser treatment: key role of energy absorption by intravascular blood.
2002
background. Despite the clinical efficacy of endovenous laser treatment (EVLT), its mode of action is incompletely understood. objective. To evaluate the role of intravascular blood for the effective transfer of thermal damage to the vein wall through absorption of laser energy. methods. Laser energy (15 J/pulse, 940 nm) was endovenously administered to explanted greater saphenous vein (GSV) segments filled with blood (n = 5) or normal saline (n = 5) in addition to GSVs under in vivo conditions immediately prior to stripping. Histopathology was performed on serial sections to examine specific patterns of damage. Furthermore, in vitro generation of steam bubbles by different diode lasers (81…
Composition of the essenthial oil of Petagnaea gussonei (Sprengel) Rauschert, a relict species from Sicily (Southern Italy).
2008
The essential oil from leaves, stems and roots of Petagnaea gussonei (Sprengel) Rauschert ( = Petagnia saniculifolia Guss.), endemic to the Nebrodi Mountains (Sicily, Italy), has been analysed by the gas chromatography–mass spectrometry (GC–MS) system on two fused-silica capillary columns of different polarities. A total of 94 components were identified. Quantitative and qualitative differences were found among the analysed parts. The principal compounds from the leaves oil were found to be (w/w%) germacrene D (19.9%), γ-muurolene (7.96%) and caryophyllene oxide (6.85%), while in the oil from stems hexadecanoic acid (23.40%), germacrene D (18.50%) and (Z,Z)-9,12-octadecadienoic acid (13.20%…
Zero Emissions and Bio-refineries for Natural Fibres, Biomaterials and Energy: Genesis of Concepts. Review
2015
Depletion of world recourses, increasing pollution, and climate change make us to shift from linear economy to system economy—an economy of technologies integrated to reach a system of non-polluting zero emissions production. Transition to renewable resources requires replacing the present crude oil refinery by biomass refinery. Along with conventional biomass refinery technologies bioengineering and nano-technologies become significant players in systems designed as clusters of integrated bio-refinery technologies. The authors consider a number of case studies of biomass conversion into value-added chemicals and sources of energy, the steam explosion auto-hydrolysis (SEA) in particular. Re…
Aroma behaviour during steam cooking within a potato starch-based model matrix.
2012
To help understand the organoleptic qualities of steam cooked foods, the kinetics of aroma release during cooking in a potato starch based model matrix was studied. Behaviour of components having a major impact in potato flavour were studied using solid phase micro extraction-gas chromatography (SPME-GC). Evolution of microstructure of potato starch model-matrix during steam cooking process was analyzed using environmental scanning electron microscopy (ESEM). Both aroma compounds that are naturally present in starch matrix and those that were added were analyzed. Both the aroma compounds naturally presented and those added had different behaviour depending on their physico-chemical properti…
Grapefruit essential oils inhibit quorum sensing of Pseudomonas aeruginosa.
2019
Citrus essential oils are used in food to confer flavor and aromas. The citrus essential oils have been granted as GRAS and could be used as antimicrobial additives to control bacterial quorum sensing from potential food bacterial pathogens. The chemical composition and inhibitory activity of Citrus paradisi (grapefruit) essential oils obtained by cold-pressed method (EOP) and cold-pressed method followed by steam distillation, against Pseudomonas aeruginosa were determined . The GC-MS analyses of the oil indicated the amount of the essential oil components was highest with D-limonene in both cases. However, the extraction method modified the chemical composition. EOP had higher amount of …
Study of the synergistic interaction between nickel, gold and molybdenum in novel modified NiO/GDC cermets, possible anode materials for CH4 fueled S…
2013
Abstract The present study concerns the structural and physicochemical characterization of novel Au–Mo–NiO/GDC cermets, alongside with measurements of their carbon tolerance. This is an investigation on whether commercially available NiO/GDC powder that is modified with Au and/or Mo can yield possible electrocatalysts as anodes for CH4 fueled SOFCs. Specifically, the performed preparation methods of deposition-precipitation and deposition-coprecipitation permitted the modification of a commercial electrocatalyst and lead to cermets that exhibit different reaction kinetics for the catalytic dissociation of CH4 and different performance for CH4 steam reforming. The most interesting structural…