Do human factors experts accept the ISO 9241 Part 10—Dialogue Principle—standard?

This paper presents the results of an international questionnaire survey that was developed to analyse how the potential addressees of the ISO 9241 part 10 standard—human factor (HF) experts engaged in the design, evaluation, purchase, and application of software systems—accept the first committee draft of this standard. It reports how HF experts from nine countries evaluated the First Committee Draft of ISO 9241 Part 10. Inquiries were made about whether the standard provides a framework for the design and evaluation of dialogue systems, or whether the subject of the standard is mature enough to be published as an international recommendation. Results indicate a widespread approval among 90 HF experts of the form and content of ISO 9241 Part 10.     

Temperature Dependence of Energy Degradation in Organic Liquid Scintillators

Under high energy excitation, organic molecules are generally excited to electronic states above the first excited state. Since, at not too high solute concentrations, energy transfer in organic liquid scintillators occurs via the first excited electronic state, the efficiency of degradation to this state affects the overall light output. Experimental results for a number of systems, at temperatures from 20°C to 24°C are reported. It was found that the efficiency of degradation to the first excited state generally decreases with increasing temperature, with some variation among the solvents tested. It was found that; the greater the efficiency of degradation to the first excited state at 20°C, the less this efficiency varies with temperature.     

A short proof of the Oslo algorithm

A short proof of the Oslo algorithm is presented that uses a simple comparison of coefficients     

A free boundary value problem for water invading an unsaturated medium

We discuss a mathematical model arising in the filtration of a fluid through a porous medium. The model leads to a free boundary value problem whose governing equation depends on the retention function. A numerical approximation by means of finite elements is used to obtain an existence and uniqueness theorem along with an error estimate for a linear retention function.     

Nine years of research and development on advanced water electrolysis. A review of the research programme of the Commission of the European Communities

The development of advanced water electrolysis was one of the main tasks of the R & D programme on hydrogen funded, within its main R & D programme on Energy, by the Commission of the European Communities. Most of the work has been concentrated on the development of alkaline water electrolysis, as this process appears particularly promising. (Water electrolysis based on ‘acidic’ solid polymer electrolytes, developed during the last 10 years, seems to be a potentially attractive alternative technology, at least for electrolysers of smaller scale (up to 100kW). Even at this size, however, there is not yet evidence of any overall economic advantage over advanced alkaline cells.) The results of 9 years of R & D in this field are critically examined, by reviewing the improvements achieved on the components of the electrolytic cell as well as the overall modification of the cell design. The anode, cathode and diaphragm have been the components investigated, but also the constituent materials, the nature of the electrolyte and its operating conditions have been dealt with. Three main lines of advanced electrolyser development were identified in the course of these investigations. The corresponding charcteristics are:

1. low temperature (70°C to 90°C), low current density (i=0.1–0.3 A cm^?2);
2. moderate temperature (<120°C), high current density (i up to 1 A cm^?2), medium pressure (5–10 bars);
3. medium temperature (120–160°C), high current density (i=1–2 A cm^?2), moderately high pressure (30 bars).

In cell design, very compact cell units have been devised, in which a ‘zero gap’ configuration (anode and cathode are placed directly on the diaphragm) is generally adopted, resulting in very low internal cell resistance (about 0.2 Ω cm²). Potential energy savings of 20 to 30% can be anticipated for the advanced electrolysis. In addition to this work on advanced alkaline water electrolysis, some limited research efforts on high temperature (>1100 K) water vapour electrolysis have been made and are reported. The latter work has been concentrated on the production of thin-layer doped zirconia solid electrolytes (d=50μm), potentially leading to high performance cells. The economic implications of high-temperature vapour electrolysis, however, cannot be judged at the present status of development.     

Influence of Batch Moisture on Melting Behavior of Glass

Melting behavior in the system sand-potash-dolomite was found to depend strongly on the amount of H₂O added to the batch, which was varied from 0.5 to 9.0 wt%. This dependence holds primarily for the formation and dissolution of K₂Ca(CO₃)₂, but other compounds are also influenced, e.g., α-K₂MgSi₃O₈, CaMgSiO₄, Ca₂MgSi₂O₇, andCaSiO₃.