Influence of manufacturing conditions on the conjugated linoleic acid content and the isomer composition in ripened French Emmental cheese

In a study of the evolution of conjugated linoleic acid (CLA) during cheese production, the influence of Emmental cheese processing on the CLA content and the CLA isomer composition was evaluated. The use of raw and thermised milk, changes of processing temperature and the effect of propionic acid bacteria (PAB) were investigated. The content of CLA in raw milk was 8.6 +/- 1.9 mg/g fat and in the ripened cheese at 70 d was 8.6 +/- 1.6 mg/g fat, under normal processing conditions. No changes in the CLA content and CLA isomer composition were observed during Emmental cheese manufacturing process. Changes in cooking and moulding temperatures did not influence the CLA content. CLA content of cheese made from microfiltered milk with two different Propionibacterium freudenreichii strains was very close to cheeses made without PAB. CLA levels seem to be stable in this type of dairy product under the conditions examined.     

The diurnal pattern of ileal dry matter and endogenous ileal nitrogen flows in the growing pig

The aim was to examine the diurnal pattern of endogenous nitrogen flow at the terminal ileum of the pig. Seven entire male pigs with a mean body weight of 58 kg had post‐valve T‐caecum (PVTC) cannulae surgically implanted for the collection of ileal digesta. The pigs were fed equal‐sized meals (10% of metabolic body weight, W^0.75, per day) twice daily at 08:00 and 17:00. The semi‐synthetic diet included enzyme‐hydrolysed casein (<5000 Da, 100 g kg^?1 diet) as the sole source of nitrogen (N). The diet also contained chromic oxide (6 g kg^?1) as an indigestible marker. The pigs received the diet for an 8 day period, and digesta were continuously collected for 24 h periods (commencing at 08:00) on the fifth and eighth days. Digesta were analysed for dry matter (DM) and chromium (Cr), and endogenous N was determined in the precipitate + retentate fraction of the digesta following centrifugation and ultrafiltration (10 000 Da molecular weight cut‐off). The concentration of Cr expressed on a digesta DM basis and the ratio of endogenous N to Cr in the digesta were relatively constant over the 24 h digesta collection periods, with no statistically significant (P > 0.05) differences found for the latter measure in the digesta collected between 12:00 and 08:00. The endogenous N flow through the terminal ileum is the net effect of the secretion and reabsorption of endogenous N that occurs throughout the digestive tract. The net result of the latter two processes in the small intestine of the pig leads to a relatively constant endogenous N flow over time post‐feeding. © 2002 Society of Chemical Industry     

Influence of oxides on friction during Cu CMP

In this work, we investigated the frictional behavior of copper CMP. Using a laboratory polishing set up, we polished Cu with designed polishing media. After that the copper surface and the fumed silica particles Cu were analyzed. The surface analysis techniques used are the field emission SEM, the field-emission high-resolution analytical TEM, x-ray spectroscopy, and XPS. We found evident difference in friction value using different polishing media. Discussions lead to three mechanisms during copper CMP. The nature of copper oxides has a profound influence on friction and might be directly related to defects. Argonne National Laboratory     

Competing destinations and intervening opportunities interaction models of inter-city telecommunication flows

This research makes use of a large sample of individual telephone calls between local exchanges (cities, towns, villages) within a U.S. region. The interlocational flows, measured in conversation seconds, are analyzed by estimating, in a simultaneous equation framework, spatial interaction models that account for (1) the role of the spatial structure, which reflects the competition and agglomeration effects that take place among the flow destinations, and (2) the role of the reverse flows, which reflect the process of information creation necessary to complete economic and social transactions. A particular focus is set on Fotheringham's competing destinations model and Stouffer's intervening opportunities model. The implications of the results are discussed and areas for further research are outlined. Received: 1 September 1998 / Accepted: 18 December 1998     

Triggered Seismicity in a Flooded Former Coal Mining Basin (Gardanne Area,France)

We studied the correlation between seismicity and the water table level in an abandoned coal mine (Bouches-du-Rhône, France), closed in 2003, where groundwater has been pumped out since 2010 to prevent underground flooding. Microseismicity was first felt by the population in 2010 and a strongly felt seismic swarm occurred in November 2012. The origin of the seismicity was therefore questioned, in relation to both the potential instability of old, shallow galleries that might generate damage at the surface and a local seismic hazard assessment. A temporary dense seismic network in the area allowed us to analyse the spatial distribution of the seismicity in detail. Most of the seismicity was clearly located under the mine workings, highlighting that an existing fault system crossing the mining operation was being hydraulically activated, in accordance with the known tectonic extension regime. Our analysis clearly shows a spatiotemporal relationship between seismic migration and the level of the mine aquifer between 2013 and 2017. Thus, seismicity will persist with oscillations of the mining aquifer, depending on the pumping capacities and effective rainfall. Continuous hydraulic and seismic monitoring is necessary to better understand these phenomena and assess the associated risks.

     

Temperature and performance variations along single chamber solid oxide fuel cells

The catalytic activity of single chamber solid oxide fuel cells (SC-SOFCs) with respect to hydrocarbon fuels induces a major overheating of the fuel cell, temperature variations along its length, and changes in the original fuel/air composition mainly over the anode component. This paper assesses the temperature gradients and the variations in performance along electrolyte-supported Ni-YSZ/YSZ/LSM cells fed with methane gas. The investigations are performed in a useful range of CH₄/O₂ ratios between 1.0 and 2.0, in which the furnace temperature and flow rate of methane–air mixtures are held constant at 700 °C and 450 sccm, respectively. Electrochemical impedance spectroscopy (EIS) is used to sense the temperature at the location where smaller size cathodes are positioned on the opposite side of a full-size anode. Due to temperature increases, cells always perform better when the small cathodes are located at the inlet as well as at a CH₄/O₂ ratio of 1.0. With an increase in ratio, the results show the presence of artefacts due to the use of an active LSM material for the combustion of methane, and open-type gas distribution plates for the single chamber reactor.     

稀释燃烧的火焰稳定性

采用实验研究的方法探讨了反应物预热温度与稀释率两个因素对稀释燃烧火焰稳定性的影响.实验以氮气稀释的甲烷-空气对冲扩散火焰为研究对象,确定了不同反应物预热温度与氧化剂稀释率(氧气体积分数)时火焰的熄火极限,结果表明,增大反应物预热温度拓宽了火焰稳定燃烧区域,而增加氧化剂稀释率(降低氧气体积分数)会降低稀释火焰的稳定性,二者对火焰稳定性的影响作用相反.为了进一步分析反应物预热温度与稀释率对火焰稳定性的影响程度,引入了估算的Damkohler数,分析表明,在实验研究范围内,反应物预热温度对火焰稳定性的影响比稀释率的影响显著,是火焰稳定性的主要影响因素.     

Direct oxidation route from metal to ceramic: Study on cobalt oxide

The study deals with the direct-oxidation kinetics of micronic-cobalt metal particles and its simulation for the complete transition from metal to ceramic. The simulation was also experimentally verified. All the three possible interfaces, Co/CoO, CoO/Co₃O₄ and Co₃O₄/O₂ (air), have been taken into consideration for the simulation. The complete oxidation kinetics has been investigated from the thermogravimetric studies under isothermal conditions in the temperatures 973–1173 K. A quantitative interpretation based on the diffusion of Co or oxygen ions through the grown oxide layer has been proposed. The activation energy for the oxidation kinetics calculated from the Arrhenius law was 161 ± 20 kJ mol⁻¹.     

A novel business model for aggregating the values of electricity storage

Electricity storage is considered as a valuable source of flexibility with applications covering the whole electricity value chain. Most of the existing evaluation methods for electricity storage are conceived for one specific use of the storage, which often leads to the conclusion that the investment on storage does not pay off. However, the value of storage cannot be properly estimated without taking into account the possibility of aggregating the services that storage can offer to different actors. This paper proposes a new business model that allows aggregating multiple revenue streams of electricity storage in a systematic way. The model consists in coordinating a series of auctions in which the right to utilize the storage unit is auctioned upon different time horizons. In the mean time, non-conflicting usage of storage by the actors in these different auctions is ensured. The functioning of the model is demonstrated by a case study. The results show that a storage unit can achieve higher return on investment in the manner proposed in the business model.