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排序方式: 共有1738条查询结果,搜索用时 15 毫秒
171.
Angel Uruea Monica Aleman Emanuele Cornagliotti Aashish Sharma Michael Haslinger Loic Tous Richard Russell Joachim John Filip Duerinckx Jozef Szlufcik 《Progress in Photovoltaics: Research and Applications》2016,24(8):1149-1156
We report on the progress of imec's n‐type passivated emitter, rear totally diffused rear junction silicon solar cells. Selective laser doping has been introduced in the flow, allowing the implementation of a shallow diffused front surface field and a reduction of the recombination current in the contact area. Simplifications have been implemented towards a more industrial annealing sequence, by replacing expensive forming gas annealing steps with a belt furnace annealing. By applying these improvements, together with an advanced texturing process and emitter passivation by atomic layer deposition of Al2O3, 22.5% efficient cells (three busbars) have been realized on commercial 156 · 156 mm2 Czochralski‐Si. This result has been independently confirmed by ISE CalLab. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
172.
Monica Anese Lara Manzocco Enrico Maltini 《European Food Research and Technology》2005,221(3-4):434-438
The mechanisms of volatile release from soluble coffee powders with different roasting degrees were studied. The presence of volatiles in the headspace during coffee humidification was analyzed by gas chromatography. Small amounts of volatiles were observed at low water activities (aw), independently from the roasting degree; as the aw increased headspace volatiles rose and then decreased as the moisture further increased. The changes in aw and volatiles went along with the changes of coffee structure from a free-flowing powder to a sticky viscous fluid. The mechanism of volatiles release was controlled by both kinetic and thermodynamic factors. The former prevailed at low aw in glassy systems; while the latter became important at high aw when, due to increased mobility, equilibrium conditions were approached. Modified state diagrams were used to predict the critical temperature and aw at which structural collapse and volatile release occurred. As far as equilibrium condition was achieved, coffee volatiles were partially re-adsorbed in the liquid phase. 相似文献
173.
Zicarelli F Calabrò S Cutrignelli MI Infascelli F Tudisco R Bovera F Piccolo V 《Journal of the science of food and agriculture》2011,91(7):1213-1221
BACKGROUND: The aim of this trial was to evaluate the replacement of rumen fluid with faeces as inoculum in studying the in vitro fermentation characteristics of diets for ruminants using the in vitro gas production technique. Six iso‐protein diets with different forage/concentrate ratios were incubated with rumen fluid (RI) or faeces (FI) collected from sheep. RESULTS: Most of the fermentation parameters were influenced by diet and inoculum (P < 0.01). With both inocula, organic matter degradability (dOM), cumulative gas production (OMCV) and maximum fermentation rate (Rmax) increased as the amount of concentrate in the diet increased. Rmax was lower with FI vs RI (P < 0.01); dOM was higher with FI vs RI and the diet × inoculum interaction was significant. As expected, with both inocula, Rmax increased as the neutral detergent fibre content of the diet decreased. Significant correlations were obtained using both inocula between OMCV/dOM and gas/volatile fatty acid (VFA), while the correlation VFA/dOM was significant only with FI. The microbial biomass yield calculated by stoichiometric analysis for all diets was higher with FI vs RI. With FI the organic matter used for microbial growth showed an overall decreasing trend as the amount of concentrate in the diet increased. CONCLUSION: The results indicate that both faeces and rumen fluid from sheep have the potential to be used as inoculum for the in vitro gas production technique. Copyright © 2011 Society of Chemical Industry 相似文献
174.
Monica Sanden Marc H. G. Berntssen Gro-Ingunn Hemre 《European Food Research and Technology》2007,225(3-4):533-543
There is a continuing interest in the fate of DNA from genetically modified organisms (GMO) in the food chain including the
uptake of DNA by intestinal cells from dietary sources containing GM feed ingredients. The objective of this study was to
elucidate the uptake and persistence of foreign DNA in the intestinal tract of Atlantic salmon Salmo salar L. using in situ hybridization (ISH) that enables the intracellular localization of the DNA, and polymerase chain reaction
(PCR) to verify the ISH results qualitatively. Two salmon intestinal models were employed for the investigations; intestinal
tissues were sampled in two models namely (a) in vivo from salmon-fed diets containing 30% GM soybeans or 30% nonGM (nGM)
soybeans, and (b) ex vivo from intestinal sleeves incubated using different concentrations of PCR-amplified test DNAs (211
and 305 bp) designed from the 35S promoter/plant DNA junction of the RoundupReady soybean (RRS) genome. Additionally, for
the incubation study, the effect of a mucolytic agent dithiothreitol (DTT) and a permeability enhancer sodium deoxycholate
(SDA) on DNA uptake were investigated. Both treatments were found to enhance DNA uptake ex vivo. Dietary DNA and PCR-amplified
DNA could be visualized by ISH in the salmon intestine with more frequently observed signals in the ex vivo model compared
to the in vivo model. All results could be verified by PCR. Dietary DNA was localized in the cell vacuolar system and in lamina propria of the mid intestine. Thus, based on the investigated DNA fragment lengths, this study shows that foreign DNA, can be taken
up by Atlantic salmon intestinal tissue. 相似文献
175.
J. Antonio H. Carraro Monica Prezzi Rodrigo Salgado 《Canadian Metallurgical Quarterly》2009,135(9):1167-1178
This paper presents the results of a systematic laboratory investigation on the static behavior of silica sand containing various amounts of either plastic or nonplastic fines. Specimens were reconstituted using a new technique suitable for element testing of homogeneous specimens of sands containing fines deposited in water (e.g., alluvial deposits, hydraulic fills, tailings dams, and offshore deposits). The fabric of sands containing fines was examined using the environmental scanning electron microscope (ESEM). Static, monotonic, isotropically consolidated, drained triaxial compression tests were performed to evaluate the stress-strain-volumetric response of these soils. Piezoceramic bender element instrumentation was developed and integrated into a conventional triaxial apparatus; shear-wave velocity measurements were made to evaluate the small-strain stiffness of the sands tested at various states. The intrinsic parameters that characterize critical state, dilatancy, and small-strain stiffness of clean, silty, and clayey sands were determined. All aspects of the mechanical behavior investigated in this study (e.g., stress-strain-volumetric response, shear strength, and small-strain stiffness) are affected by both the amount and plasticity of the fines present in the sand. Microstructural evaluation using the ESEM highlighted the importance of soil fabric on the overall soil response. 相似文献
176.
LR Dekker H Rademaker JT Vermeulen T Opthof R Coronel JA Spaan MJ Janse 《Canadian Metallurgical Quarterly》1998,97(17):1724-1730
BACKGROUND: Patients with heart failure show a very high incidence of arrhythmias and sudden death that is often preceded by ischemia; however, data on electrophysiological changes during ischemia in failing myocardium are sparse. We studied electrical uncoupling during ischemia in normal and failing myocardium. METHODS AND RESULTS: Tissue resistance, intracellular Ca2+ concentration (Indo-1 fluorescence ratio), and mechanical activity were simultaneously determined in arterially perfused right ventricular papillary muscles from 11 normal and 15 failing rabbits. Heart failure was induced by combined volume and pressure overload. Before sustained ischemia, muscles were subjected to control perfusion (non-PC) or ischemic preconditioning (PC). The onset of uncoupling during ischemia was equal in non-PC normal (13.6+/-0.9 minutes of ischemia) and non-PC failing hearts (13.3+/-0.7 minutes of ischemia). PC postponed uncoupling in normal hearts by 10 minutes. In failing hearts, however, PC caused a large variability in the onset of uncoupling during ischemia (mean, 12.2+/-2.1; range, 5 to 22 minutes of ischemia). The duration of uncoupling process was prolonged in failing hearts (12.9+/-0.9 minutes) compared with normal hearts (7.8+/-0.4 minutes). The degree of heart failure and relative heart weight of the failing hearts significantly correlated with the earlier uncoupling after PC and the duration of uncoupling. In every experiment, the start of Ca2+ rise and contracture preceded uncoupling during ischemia. CONCLUSIONS: The duration of the process of ischemia-induced electrical uncoupling in failing hearts is prolonged compared with that in normal hearts. Ischemic PC has detrimental effects in severely failing papillary muscles because it advances the moment of irreversible ischemic damage. 相似文献
177.
Monica Lira-Cantu Amine ChafiqJeremy Faissat Irene Gonzalez-VallsYouhai Yu 《Solar Energy Materials & Solar Cells》2011,95(5):1362-1374
In this work, we study the effect of the transparent conducting oxide (TCO) and the polymer applied (MEH-PPV or P3HT) on the photovoltaic properties of TCO/TiO2/polymer/Ag bi-layer solar cells. The solar cells were analyzed under inert atmosphere conditions resembling an encapsulated or sealed device. We demonstrate that the substrate applied, ITO or FTO, modifies the crystalline structure of the TiO2: on an ITO substrate, TiO2 is present in its anatase phase, on an FTO, the rutile phase predominates. Devices fabricated on an FTO, where the rutile phase is present, show better stability under inert atmospheres than devices fabricated on an ITO, anatase phase. With respect to the polymer, devices based on MEH-PPV show higher Voc (as high as 1 V), while the application of P3HT results in lower Voc, but higher Jsc and longer device stability. These observations have been associated to (a), the crystalline structure of TiO2 and (b) to the form the polymer is bonded to the TiO2 surface. In-situ IPCE analyses of P3HT-based solar cells show a red shift on the peak corresponding to TiO2, which is not present on the MEH-PPV-based solar cells. The latter suggest that P3HT can be linked to the TiO2 though the S-end atom, which results in devices with lower Voc. All these observations are also valid for devices, where the bare TiO2 is replaced by an Nb-TiO2. The application of an Nb-TiO2 with rutile structure in these polymer/oxide solar cells is the reason for their higher stability under inert atmospheres. We conclude that the application of TiO2 in its rutile phase is beneficial for long-term stability devices. Moreover there is an interplay between low Voc and Jsc in devices applying P3HT, since power conversion efficiency can be partially canceled by their lower Voc in comparison with MEH-PPV. These findings are important for polymer/oxide solar cells, but also for organic solar cells, where a layer of semiconductor oxides are in direct contact with a polymer, like in an inverted or tandem organic solar cells. 相似文献
178.
This paper assesses the increase in demand and supply for forest biomass for heating in Norway in 2020. By then there is a political aim to double the national production of bioenergy from the level in 2008. The competitiveness of woody biomass in central and district heating is analyzed in a model selecting the least-cost heating technology and scale in municipalities given a set of constraints and under different fuels price scenarios. The supply of forest biomass from roundwood is estimated based on data of forest inventories combined with elasticities regarding price and standing volumes. The supply of biomass from harvesting residues is estimated in an engineering approach based on data from the national forest inventories and roundwood harvest. The results show how the production of bioenergy is affected by changes in energy prices and support schemes for bioenergy. One conclusion from the analyses is that the government target of 14 TWh more bioenergy by 2020 is not likely to be met by current technologies and policy incentives. The contribution of the analysis is the detailed presentation of the heat market potentials and technology choices combined with supply functions for both roundwood and harvesting residues. 相似文献
179.
Donato Maria Bernadette Milasi Monica Villanacci Antonio 《Networks and Spatial Economics》2022,22(2):327-359
Networks and Spatial Economics - We deal with the analysis of a general equilibrium model with restricted participation in financial markets and with numeraire assets. We consider an exchange... 相似文献