Inhibitoren der Korrosion 6 (1) Vergleich der Schutzwerte einiger phosphor-, schwefel- und arsen-organischer Verbindungen gegenüber Eisenproben unterschiedlicher spezifischer Oberfläche

Corrosion inhibitors 6: Comparison of the protective values of some phosphorus, sulfur and arsenium organic compounds with respect to iron specimens of various specific surfaces Iron wire and carbonyl iron powder differ with respect to (1) composition (carbonyl iron powder is purer than iron wire 2) specific surface (0.5 grs of carbonyl iron powder have 23 times the surface of the iron wire of 3 mrs length used so far). The protective values of some representative phosphorus, sulfur and arsenium organic compounds are different with the two test materials; as a general rule they are lower at lower inhibitor concentrations with carbonyl iron than with iron wire. Exceptions are the biphosphonium salts tested. The protective action on iron is ascribed to a secundary inhibition. The molar concentrations required to obtain 50, 80 and 9O% protection are reported for 31 inhibitors with reference to 0.5 grs carbonyl iron in 250 ml HC1.     

Characterisation of carrageenan and whey protein gels using NMR PGSTE diffusion experiments

NMR PGSTE diffusion experiments are used to characterise the gelling behaviour of carrageenan mixtures and whey protein mixtures. The structure of developing networks can be observed as a function of the composition of the mixture (concentration of hydrocolloids, sugars and salts), the measuring temperature, and the protein denaturation, depending on the denaturation temperature and duration. Besides the fundamental aspects of these preliminary studies, these data are helpful for modelling processes sufficiently precisely for industrial production, to guarantee specific properties concerning the flow-, gelling- and syneresis/storage-behaviour and the texture and sensorial behaviour of food products, and to realise a process and quality control of thermal protein denaturation and hydrocolloid gelling processes. Therefore, further quantitative correlations between macroscopic quantities and the available NMR parameters must be established to trigger industrial applications of NMR diffusion experiments.     

Manipulative treatment of carpal tunnel syndrome: biomechanical and osteopathic intervention to increase the length of the transverse carpal ligament

To quantify the amount of transverse carpal ligament (TCL) elongation in response to osteopathic manipulation or sustained load bearing (or both), a study involving seven cadaver limbs was conducted. Distances from the trapezium to the hamate (distance A) and from the scaphoid to the pisiform (distance B) were measured in five mounted cadaver limbs during and after the limbs bore the weight (2 newtons [N] to 4 N) for 2 several-hour periods. A several-hour period occurred between the weight bearing to assess recoil. Distances A and B were measured before and after the limbs were manipulated, according to previously described techniques, as well as with a new maneuver, termed the "guywire" technique. Two dissected limbs also were subjected to further weight bearing, this time increased to 8 N. Greater weight loads produced greater lengthening of the TCL, and recoil after removal of weight loads was slower than recoil after manipulation. Manipulation was more effective than weight loading for increasing distance A (distal canal), but weight loading generally was more effective than manipulation for increasing distance B (proximal canal). The guywire manipulation combined with direct transverse extension appeared to have the greatest impact on lengthening the TCL distally. These results show promise for the effective use of manipulation and load bearing for TCL elongation and nonsurgical relief of pressure on the median nerve in patients with carpal tunnel syndrome.     

An all-round sweep algorithm for 2-dimensional nearest-neighbor problems

We present a simple, efficient, robust plane-sweep algorithm that solves 2-dimensional nearest-neighbor problems in asymptotically optimal timeO(n logn). A foolproof implementation guarantees an exact result at the cost of using triple-precision integer arithmetic at some key steps.     

Uncertainty-aware guided volume segmentation

Although direct volume rendering is established as a powerful tool for the visualization of volumetric data, efficient and reliable feature detection is still an open topic. Usually, a tradeoff between fast but imprecise classification schemes and accurate but time-consuming segmentation techniques has to be made. Furthermore, the issue of uncertainty introduced with the feature detection process is completely neglected by the majority of existing approaches.In this paper we propose a guided probabilistic volume segmentation approach that focuses on the minimization of uncertainty. In an iterative process, our system continuously assesses uncertainty of a random walker-based segmentation in order to detect regions with high ambiguity, to which the user's attention is directed to support the correction of potential misclassifications. This reduces the risk of critical segmentation errors and ensures that information about the segmentation's reliability is conveyed to the user in a dependable way. In order to improve the efficiency of the segmentation process, our technique does not only take into account the volume data to be segmented, but also enables the user to incorporate classification information. An interactive workflow has been achieved by implementing the presented system on the GPU using the OpenCL API. Our results obtained for several medical data sets of different modalities, including brain MRI and abdominal CT, demonstrate the reliability and efficiency of our approach.     

EMDialog: bringing information visualization into the museum

Digital information displays are becoming more common in public spaces such as museums, galleries, and libraries. However, the public nature of these locations requires special considerations concerning the design of information visualization in terms of visual representations and interaction techniques. We discuss the potential for, and challenges of, information visualization in the museum context based on our practical experience with EMDialog, an interactive information presentation that was part of the Emily Carr exhibition at the Glenbow Museum in Calgary. EMDialog visualizes the diverse and multi-faceted discourse about this Canadian artist with the goal to both inform and provoke discussion. It provides a visual exploration environment that offers interplay between two integrated visualizations, one for information access along temporal, and the other along contextual dimensions. We describe the results of an observational study we conducted at the museum that revealed the different ways visitors approached and interacted with EMDialog, as well as how they perceived this form of information presentation in the museum context. Our results include the need to present information in a manner sufficiently attractive to draw attention and the importance of rewarding passive observation as well as both short- and longer term information exploration.     

An Algorithm Adapted Autonomous Controlling Concept for a Parallel Single-Chip Digital Signal Processor

Recent sub- semiconductor technology supports the monolithic integration of multiprocessor systems. High wiring density and short on-chip memory access cycles motivate novel architecture concepts, outperforming conventional parallel systems. An efficient controlling strategy is a key to gain high performance from limited silicon resources. In this paper, a controlling concept for a monolithic Autonomous Single-Instruction/Multiple Data (ASIMD) processor is presented, which combines the high parallelism of an SIMD approach with the flexibility of standard DSP architectures. To demonstrate the performance gains of the concept, a digital video signal processor, the HiPAR-DSP has been implemented. It consists of an array of 4 or 16 datapaths, local memories for each datapath, a shared memory with concurrent data access in shape of a matrix and a central RISC controller. A three stage execution autonomy has been implemented, consisting of conditional instructions, conditional skip of instructions by the data paths and global evaluation of local conditions by the central controller. This allows efficient execution of data dependent medium- and high-level algorithms with very low controlling overhead. A performance of up to two arithmetic gigaoperations per second is achieved for algorithms with irregular data flow or control flow for the 100 MHz clocked processor with 16 data paths.     

In situ infrared ellipsometric study of stimuli-responsive mixed polyelectrolyte brushes

The switching behavior of stimuli-responsive mixed polymer brushes (d = 11 nm) was monitored for the first time in liquid phase in situ by infrared spectroscopic ellipsometry (IRSE). IRSE is presented as a new, sensitive in situ tool for online analysis of chemical changes in a thin complex film at the solid/liquid interface. Responsive behavior (protonation and deprotonation reaction) of the poly(acrylic acid)/poly(2-vinylpyridine) (PAA-mix-P2VP) brush was probed in aqueous solutions with pH ranging from pH 2 to pH 10. Structural and chemical changes in a thin polymer brush layer were identified from the analysis of infrared ellipsometric tanPsi spectra during the variation of pH. Systematic change in pH confirmed the reversible switching behavior of the PAA-mix-P2VP brush between three different states: swollen P2VP and compact PAA chains at pH 2, a compact "P2VP...PAA" complex at pH 6.5, and swollen PAA and compact P2VP chains at pH 10.     

Buoyancy influence on wrinkled premixed V-flames

Flame-flow interaction is crucial to the application of combustion. The flow field in which a flame is embedded depends on not only the coming flow but also the flame itself. Flame-generated flow will determine how the flame changes the flow field. Buoyancy is an instinctive feature of flames and will induce flow. To study how buoyancy influence flames will lead to better understanding on the mechanism of flame-flow interaction. CH₄-Air premixed V-flames of wrinkled flame fronts were studied in 1g₀ and μg experiments to observe buoyancy influence. In assistance to the experiments, the mechanism of buoyancy influence on V-flames was analyzed and the ratios of buoyancy force to corresponding dynamic force in the coming flow were estimated. The experiment was done in the Bremen Drop Tower and OHPLIF was used in both 1g₀ and μg to record the instantaneous flame fronts. The results show that buoyancy effect on the laminar flame differs form that on the turbulent flame. This suggests the existence of the buoyancy influence on flame wrinkling and the coupling between buoyancy and the coming flow. Another observation is that the laminar exhibited wrinkles in μg and this implies that μg is an ideal environment for the study of both buoyancy influence and other mechanisms generating flow in flames.