Hydrogen production through dry reforming of biogas using a porous electrochemical cell: Effects of a cobalt catalyst in the electrode and mixing of air with biogas

This paper reports the performance of porous Gd-doped ceria (GDC) electrochemical cells with Co metal in both electrodes (cell No. 1) and with Ni metal in the cathode and Co metal in the anode (cell No. 2) for CO₂ decomposition, CH₄ decomposition, and the dry reforming reaction of a biogas with CO₂ gas (CH₄ + CO₂ → 2H₂ + 2CO) or with O₂ gas in air (3CH₄ +?1.875CO₂ +?1.314O₂ → 6H₂ +?4.875CO +?0.7515O₂). GDC cell No. 1 produced H₂ gas at formation rates of 0.055 and 0.33?mL-H₂/(min?m²-electrode) per 1?mL-supplied gas/(min?m²-electrode) at 600?°C and 800?°C, respectively, by the reforming of the biogas with CO₂ gas. Similarly, cell No. 2 produced H₂ gas at formation rates of 0.40?mL-H₂/(min?m²) per 1?mL-supplied gas/(min?m²) at 800?°C from a mixture of biogas and CO₂ gas. The dry reforming of a real biogas with CO₂ or O₂ gas at 800?°C proceeded thermodynamically over the Co or Ni metal catalyst in the cathode of the porous GDC cell. Faraday's law controlled the dry reforming rate of the biogas at 600?°C in cell No. 2. This paper also clarifies the influence of carbon deposition, which originates from CH₄ pyrolysis (CH₄ → C + 2H₂) and disproportionation of CO gas (2CO → C + CO₂), on the cell performance during dry reforming. The dry reforming of a biogas with O₂ molecules from air exhibits high durability because of the oxidation of the deposited carbon by supplied air.     

Low-loss athermal silica-based lattice-form interleave filter with silicone-filled grooves

We describe a low-loss athermal silica-based interleave filter with a lattice-form structure. We athermalize the filter by using a silicone-filled groove formed in each delay line and we employ a low-loss design to reduce the accumulated groove excess loss in the multiple delay lines. By using these designs, we obtained a very low groove excess loss of 0.4 dB and achieved satisfactory temperature insensitivity and optical characteristics with this filter.     

Extremely low-loss 1.5%-/spl Delta/ 32-channel athermal arrayed-waveguide grating multi/demultiplexer

A silica-based 1.5%-/spl Delta/ 100 GHz-spacing 32-channel athermal arrayed-waveguide grating (AWG) with compact size and extremely low insertion loss is described. By reducing the fibre coupling loss and the excess loss in a silicone-filled groove, an insertion loss of 1.3 dB was achieved with this athermal AWG.     

Effectiveness of spatial representation in the formation of network communities: experimental study on community organizer

In this paper, we present and discuss Community Organizer, a system designed to support network communities. The main characteristic of Community Organizer is the use of spatial representations for the relationships among community members including the communications exchanged among these members. These spatial representations reflect the degree of closeness of interests and concerns among the members, and are intended to provide users with clues on how to form network communities. In order to investigate the effectiveness of the proposed spatial representations, we conducted experiments with two different versions of the software. One version offered meaningful spatial representations while the other version did not. The subjects who used the former software version felt a greater sense of ‘community’, enjoyed using the software more, and actively used it longer than the subjects using the latter software version (control condition). These results indicated that the proposed spatial representations are effective in supporting network community formation.     

Rapid and comprehensive indicator for evaluation of performance of treatment processes and of river waters.

Naturally occurring UV active compounds, commonly present in almost all source waters, can be rapidly monitored by their ultraviolet absorbance at 260 nm (E260). Herein, the extent of correlation between the E260 and the removal efficiency of the hazardous contaminants, endocrine disrupters and dioxins, were investigated using various treatment and river source waters. The detection of various types of hazardous contaminants using sophisticated analytical methods, such as high resolution gas chromatography (HRGC)/high resolution mass spectrometry (HRMS) and high performance liquid chromatography (HPLC)/inductively coupled plasma (ICP)/mass spectrometry (MS), as well as various short-term bioassays, can require hours or even days for results to be obtained. The removal of the E260 correlated well with those of individual contaminants, such as endocrine disruptor chemicals and dioxins, with the various treatment processes employed. In the plots of the endocrine disrupters against the DOC/E260, a correlation was found with the endocrine activity of the Korean/Japanese river waters employed in this study.     

Electron microscope studies of InxGav1−xAs/GaAs/Si grown by metalorganic chemical vapor deposition

The microstructure of In_xGa_1−xAs/GaAs (5 nm/5 nm, x < 0 to 1.0), as grown by a metalorganic chemical vapor deposition two-step growth technique on Si(100) at 450‡C, and subsequently annealed at 750‡C, is investigated using plan-view and cross-sectional transmission electron microscopy. The variations in resultant island morphology and strain as a function of the In content were examined through the comparison of the misfit dislocation arrays and moirés observed. The results are discussed in relation to the ways in which the island relaxation process changes for high In content.     

Gene regulation of trkB and trkC in the chick retina by light/darkness exposure

The trk gene family members; the neurotrophic receptors for neurotrophins, are implicated in the survival and the differentiation of neurons. The roles of these protooncogenes have been argued in the pathological conditions and in the specific developmental stage when the programmed cell death occurs to neurons. Here we studied a physiological role of the trk family members in the retina through observations of their gene regulation by light/darkness exposure. Northern blot analysis and immunohistochemistry demonstrate that trkB and trkC are up-regulated by light exposure and down-regulated by darkness in the rod/cone layer, the outer nuclear layer, and the ganglion cell layer. This physiological regulation suggests that these trk family members play a protective role from the damaging effect of light exposure in the retinal neurons.     

Temperature Dependence of Thermal Reflection Behavior of Al2O3–TiO2 Multilayer Thermal Energy Window Coating

An Al₂O₃–TiO₂ multilayer-coated sapphire thermal energy window coating has been fabricated using an ultra-high-speed vacuum sputtering method. Thermal reflection spectra of the coated material in the wavelength range from 1.43 to 3.33 μm are measured in ambient air at temperatures of 298, 773, and 1173 K. The result shows that the light reflectance of ∼70% is achieved using a layered structure and this performance continues up to 1173 K. Thermal reflection energy of the coated material at T =1173 K is estimated to be about three times higher than that of uncoated sapphire, suggesting the potential of this coating to control thermal radiation energy.     

Adsorption of trypsin onto poly(2-hydroxyethyl methacrylate)/polystyrene composite microspheres and its enzymatic activity

Poly(2-hydroxyethyl methacrylate)/polystyrene (PHEMA/PS) composite microspheres were produced by emulsifier-free seeded emulsion polymerization for styrene in the presence of PHEMA seed particles. Effects of the surface characteristics of the PHEMA/PS composite microspheres on the adsorption immobilization of trypsin and on its enzymatic activity were discussed. Above 5 mol% of HEMA content, trypsin molecules adsorbed had high activity, 65–100% of the activity of free trypsin. The excellence of the composite microspheres as a carrier for trypsin seems to be closely related with the surface heterogeneity consisting of both hydrophilic and hydrophobic parts.     

Studying high impact fix-inducing changes

As software systems continue to play an important role in our daily lives, their quality is of paramount importance. Therefore, a plethora of prior research has focused on predicting components of software that are defect-prone. One aspect of this research focuses on predicting software changes that are fix-inducing. Although the prior research on fix-inducing changes has many advantages in terms of highly accurate results, it has one main drawback: It gives the same level of impact to all fix-inducing changes. We argue that treating all fix-inducing changes the same is not ideal, since a small typo in a change is easier to address by a developer than a thread synchronization issue. Therefore, in this paper, we study high impact fix-inducing changes (HIFCs). Since the impact of a change can be measured in different ways, we first propose a measure of impact of the fix-inducing changes, which takes into account the implementation work that needs to be done by developers in later (fixing) changes. Our measure of impact for a fix-inducing change uses the amount of churn, the number of files and the number of subsystems modified by developers during an associated fix of the fix-inducing change. We perform our study using six large open source projects to build specialized models that identify HIFCs, determine the best indicators of HIFCs and examine the benefits of prioritizing HIFCs. Using change factors, we are able to predict 56 % to 77 % of HIFCs with an average false alarm (misclassification) rate of 16 %. We find that the lines of code added, the number of developers who worked on a change, and the number of prior modifications on the files modified during a change are the best indicators of HIFCs. Lastly, we observe that a specialized model for HIFCs can provide inspection effort savings of 4 % over the state-of-the-art models. We believe our results would help practitioners prioritize their efforts towards the most impactful fix-inducing changes and save inspection effort.