The effect of the manufacturing method on the characteristics of apple juice

Summary Apple juices, obtained by straight pressing, pulp enzyming or liquefaction and clarification by the conventional process using bentonite, gelatin, and silicasol or by ultrafiltration, were analysed for sugar and acid content, colour, polyphenol content, ultrafiltration fluxes and polysaccharide content and composition. The amount and composition of the high-M _r polysaccharide fractions found indicate the importance of the juice processing method and enzyme preparation chosen. Polysaccharides solubilized from the cell walls were found to contain galacturonic acid and arabinose as the major constituent sugars. Ultrafiltration enabled the removal of high-M _R polymers but neutral arabinans were still found to be present in ultrafiltered juice.

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Der Einfluß der Herstellungsmethode auf Merkmale des Apfelsaftes

Zusammenfassung In verschiedenen Apfelsäften, die durch direkte Pressung, enzymatische Pulpbehandlung oder Verflüssigung und auf konventionelle Weise mittels Bentonit, Gelatine und Silicasol oder durch Ultrafiltration geklärt wurden, wurden der Zucker- und Säuregehalt, die Farbe, der Polyphenolgehalt, die Ultrafiltrations-Durchflußgeschwindigkeit und der Gehalt und die Zusammensetzung der Polysaccharide bestimmt. Die Menge und Zusammensetzung der gefundenen hochmolekularen Polysaccharid-Fraktionen zeigen deutlich die Bedeutung der Herstellungsmethode und der verwendeten Enzympräparate. Galakturonsäure und Arabinose waren die Hauptbestandteile der aus den Zellwänden gelösten Polysaccharide. Die Ultrafiltration ermöglichte die Abtrennung von hochmolekularen Polymeren; jedoch wurden auch in ultrafiltrierten Säften noch neutrale Arabinane nachgewiesen.

     

Perceived depth and the feeling of presence in 3DTV

The present study investigates the subjective feeling of presence elicited by 3DTV and its relationship to perceived depth and image content. Subjective methods of assessing presence that have been used or proposed to date do not provide a measure of temporal variation. To overcome this limitation, we have applied the continuous assessment methodology (ITU-R, BT 500-7) to the assessment of presence, perceived depth and naturalness of depth.

Twelve observers continuously rated their instantaneous perception of presence, depth and naturalness of depth when viewing stereoscopic footage. The results indicate that subjective presence ratings are subject to considerable temporal variation depending on the image content and camera techniques used. The correlations between the different attributes suggest that an increase in depth may lead to an enhanced sense of presence, provided depth is perceived as natural.

A qualitative analysis of the data in relation to the image content provides evidence for the hypothesis that the extent of sensory information available to an observer is a determinant of presence, as proposed by T.B. Sheridan, Musings on telepresence and virtual presence, Presence: Teleoperators and Virtual Environments 1 (1992) 120-125.     

The determination of the absolute bioavailability for drug substances with long elimination half-lives (with PC-programs for the method of truncated areas).

A survey is given of the methods for the determination of the absolute bioavailability for drug substances with long elimination half-lives. All methods depend on the assumption of linear pharmacokinetics. Emphasis is laid on Urso and Aarons' regression method of truncated areas-under-the-curve (AUC) to obtain estimates of the absolute bioavailability, F, and the absorption rate constant, ka, without obeying the otherwise general rule of following blood or plasma levels for at least three times the terminal half-life. It is shown by simulation when the linear and when the logarithmic trapezoidal rule is to be used for the calculation of the AUC. Two PC-programs for the regression method of truncated areas are presented: one program (SIMF&KA.EXE) simulates, based on tentative pharmacokinetic parameters, whether a blood sampling scheme, together with the precision of the analytical assay, is adequate to obtain accurate and precise estimates of F and ka; the method is insensitive to large variations in the tentative value of the elimination half-life. The other program (ESTF&KA.EXE) provides estimates of F and ka, with standard deviations of the estimates, from empirical data.     

Prediction of NOx Emissions from a Transiently Operating Diesel Engine Using an Artificial Neural Network

For an adequate control of the reductant flow in selective catalytic reduction of NO_x in diesel exhaust, a tool has to be available to accurately and quickly predict the engine's NO_x emission. For these purposes, elaborate computer models and expensive NO_x analyzers are not feasible. The application of a neural network is proposed instead. Measurements were performed on a transient operating diesel engine. One part of the data was used to train the network for NO_x emission prediction, the other part was used to test. The average absolute deviation between the predicted and measured NO_x emission is 6.7 %. The reductant buffering capacity of the deNOx catalyst will diminish the effect of the deviation on the overall NO_x removal efficiency. The high accuracy of the neural network predictions, combined with the short computation times (0.2 ms/data point), makes the neural network a very promising tool in automotive NO_x control.     

Influential Characteristics of Enterprise Information System User Interfaces

ABSTRACT

End-user acceptance is considered as a significant factor influencing the success of enterprise information system (EIS) implementations and operations. This study conceptualizes three aspects of EIS user interfaces (UIs), namely information overload, control familiarity, and UI fit, and proposes a model to understand their effect on two major factors that are considered to influence the end-user acceptance of these systems: EIS end user’s performance expectancy and effort expectancy. We developed a theoretical model and multiitem scales for the proposed EIS UI characteristics and tested the model empirically with data from a survey performed with a sample 98 EIS end users. The results from our test provide evidence for the key role that EIS UI design plays in the end user’s performance and effort expectancy.     

Connecting the family with awareness systems

Awareness systems have attracted significant research interest for their potential to support interpersonal relationships. Investigations of awareness systems for the domestic environment have suggested that such systems can help individuals stay in touch with dear friends or family and provide affective benefits to their users. Our research provides empirical evidence to refine and substantiate such suggestions. We report our experience with designing and evaluating the ASTRA awareness system, for connecting households and mobile family members. We introduce the concept of connectedness and its measurement through the Affective Benefits and Costs of communication questionnaire (ABC-Q). We inform results that testify the benefits of sharing experiences at the moment they happen without interrupting potential receivers. Finally, we document the role that lightweight, picture-based communication can play in the range of communication media available.

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The form of augmented force-feedback fields and the efficiency and satisfaction in computer-aided pointing tasks

This study investigates operation efficiency and user satisfaction for spatial and temporal shapes of augmented force-feedback fields to be used with computer pointing devices in target acquisition tasks. In an experiment, three different force-field shapes at two different mean force levels were compared, with an electromechanical force-feedback trackball as control device and with efficiency and user satisfaction as dependent variables. Efficiency was measured by the time required to perform a certain task, and user satisfaction was measured through a subjective rating procedure. Satisfaction results indicate that to a rough approximation, participants can be grouped into those who prefer high and those who prefer low force levels. Members of the former group were most satisfied with force fields with a gradual start and an abrupt ending. This force-field shape also proved to be the most efficient for both groups. When all participants were considered as a single group, none of the effects was found to be statistically significant. A gender effect was also found; in both preference groups women achieved significantly shorter task completion times than men. Actual or potential applications of this research include enabling computer interaction for people prone to repetitive strain injuries and the increment of efficiency and satisfaction in human-computer interaction in general.     

Mann-Whitney/Wilcoxon's nonparametric cumulative probability distribution

It is demonstrated how complete nonparametric, cumulative probability distributions for Mann-Whitney/Wilcoxon's nonparametric, two-sample test can be constructed based on algorithms published earlier in this journal. These procedures provide cumulative probabilities for all possible rank sums in the nonparametric two-sample test. Separate programs for MS(PC)-DOS and Macintosh computers are offered.     

On the assessment of bioequivalence in a two-period cross-over design.

The results obtained with Meineke and De Mey's algorithm for posterior probability distributions in the nonparametric evaluation of two-period cross-over bioequivalence studies are critically discussed. Suggestions for improvement of their program NEWPARM are given. It is shown that this program in its present form cannot handle the results from bioequivalence studies in which more than 15 subjects participated. For larger study sizes, conversion to a more powerful programming language capable of handling large three-dimensional arrays, is mandatory. An alternative algorithm, allowing large sample sizes to be analysed nonparametrically without program conversion, is offered. A general bioequivalence program written by the author, into which this alternative algorithm is implemented, has been in use by a number of pharmaceutical companies and drug regulatory agencies since February 1990; its most recent update is Version 3.7 (BIOEQV37.EXE) of October 1990.     

Embodiment and telepresence: Toward a comprehensive theoretical framework

What explains the experience of “being there” in a simulated or mediated environment? In recent years, research has pointed to various technological and psychological factors deemed important in eliciting this so-called experience of telepresence, including interactivity, sensory-motor integration, media transparency, and distal attribution. However, few theories exist that can combine these findings in a coherent framework. In the present paper, we formulate such a theoretical framework. We will argue that the experience of telepresence is a consequence of the way in which we are embodied, and that it extends naturally from the same ability that allows us to adjust to a slippery surface, or to the weight of a hammer. The importance of embodiment in the understanding of telepresence has been stated before, but these works have not yet fully addressed what it means to be embodied. We argue that “having a human body” means having a specific morphology, a body schema, and a body image. Subsequently we describe how tools and technological artifacts may be incorporated at each of these levels of embodiment, and the implications thereof for the experience of telepresence.