Making the ordinary visible in microblogs

Microblogging is a “Mobile Web 2.0” service category that enables brief blog-like postings from mobile terminals and PCs to the World Wide Web. To shed light on microblogging as a communication genre, we report on multiple analyses of data from the first 10 months of a service called Jaiku. The main finding is that microblogging centers on selective, I-centered disclosure of current activities and experiences, making daily experiences visible for others. The high frequency of brief and mundane status updates, like “working,” may be a second-order effect resulting from posting becoming a routine executed to keep the audience interested. The results highlight the importance of reciprocal activity and feedback in users’ motivation to invest in this activity.     

Simplified probabilistic selectivity technique for earth fault detection in unearthed MV networks

A novel selectivity technique to identify the faulty feeder in unearthed Medium Voltage (MV) networks is introduced. The proposed technique is based on a simplified probabilistic method applied to transient features extracted from the residual currents only using the discrete wavelet transform (DWT). DWT will enhance the accuracy of localising fault events with different fault resistances and the probability will give the protection decision (detection/selectivity). The standard deviation of a window of the DWT detail coefficient is used to detect the fault and an adaptive threshold is used as input to the probability function to estimate the faulty feeder. A faulty unearthed 20 kV network is simulated by ATP/EMTP imitating practical fault cases such as arcing and tree leaning faults. The time-domain test cases provide evidence of the efficacy of the proposed technique.     

Multifunction spectrometer for optical inspection of red wine

The main goal of this study was to develop an apparatus that makes it possible to measure both, color, refractive index and light scattering (turbidity) of red wines using a single device only. Typically such measurement of red wine quality requires three different measurement devices. As an example of the efficiency of the present device we studied the change of the thermo-optical and time-dependent optical properties of red wine samples. Here we report on change of optical properties of two Merlot wine samples, which were obtained by opening authentic red wine bottles and preserving a set of samples both at room and refrigerator temperature for 26 days, respectively. The interesting feature with both red wine samples was that the light scattering, i.e. the turbidity of the samples, increased as a function of time due to oxidation process. It is suggested that the multifunction spectrophotometer can be applied for optical inspection of red and other wine products.     

Temperature rises in an OFAF transformer at OFAN cooling mode in service

In order to properly assess operating conditions of a 40 MVA, oil-forced air-forced (OFAF) transformer unit in service the permanent online monitoring system has been upgraded. Dissolved gas analysis laboratory measurements are also applied. The hot-spot temperature and the top-oil temperature responses predicted by two different thermal methods are compared to measured values.     

Growth and surface engineering of vertically-aligned low-wall-number carbon nanotubes

A novel catalyst of cobalt supported by single crystal MgO was prepared by atomic layer deposition and used for carbon nanotube growth. With CO as carbon source, vertically-aligned carbon nanotubes with predominant double-walled (82%) were produced at 700 °C. Similar carbon nanotube array with a majority of single-walled tubes (62%) was produced at 900 °C using methane as the carbon source. Due to their high flexibility compared with multi-walled carbon nanotubes, the low-wall-number carbon nanotube array could form a 3-dimensional honeycomb-like network when being spread with acetone.     

A chiral diamine bis-phenolate complex of dioxomolybdenum(VI)

A new dioxomolybdenum(VI) complex with a chiral tetradentate ligand is reported. The tripodal ligand containing two nitrogen atoms and two phenolic oxygen atoms was synthesized starting from a chiral diamine precursor. Further reaction with [MoO₂(acac)₂] yielded a monomeric molybdenum complex as a bright yellow solid. The structures of the molybdenum complex and the free diamine bis-phenol ligand were determined by X-ray diffraction.     

A homogeneous-heterogeneously catalysed reaction system in a loop reactor

Catalytic three-phase reactions including homogeneous liquid-phase steps were simulated in a loop reactor. The loop reactor consisted of a reaction vessel, an external loop as well as an ejector. The loop reactor was modelled using tanks-in-series or alternatively, axial dispersion models. Kinetics of the reductive alkylation of aromatic amines, which was determined from the experiments in a laboratory autoclave, was used for verifying the reactor model and for concentration profile simulations in the loop reactor.     

The role of acyl moiety in the formation and reactions of steryl ester hydroperoxides

‘Golden’ is the most cultivated apple group in Europe. In recent years, new mutants have emerged which improve both aspects of production and sensory attributes. In this work, emission of volatile compounds and the activity of lipoxygenase system–related enzymes in ‘Golden Reinders^®’ apples were analysed after 19 and 30 weeks under ultra low oxygen atmosphere (ULO) or under ULO plus different periods in cold air atmosphere and after remaining 1 and 7 days at 20 °C. This study examined modifications in the capacity for volatile ester production, specifically focusing on modification in lipoxygenase and hydroperoxide lyase activity. Volatile compound emission reached a maximum after 30 weeks of cold storage plus 7 days at 20 °C. Straight-chain esters were closely related to lipoxygenase activity in the flesh tissue, leading, suggesting that lipoxygenase enzyme plays an important role in the emission of straight-chain esters: the most characteristic volatile type associated with this apple variety.