Effects of α‐form or β‐form nuclei on polymorphic crystalline morphology of poly(butylene adipate)

The effects of α‐form and β‐form nuclei on polymorphic morphology of poly(butylene adipate) (PBA) upon recrystallization from the molten state up to various T_max values were examined by differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction (WAXD) and polarized light microscopy (PLM). In this study, PBA with complex melting and polymorphism behaviour was used as a model for examining different types and extents of residual nuclei. As the PBA initially containing the sole α‐crystal was brought to a molten state of various T_max, the extents of trace α‐form crystal nuclei varied and were dependent on T_max. Furthermore, it did not matter whether, initially, the PBA contained α‐ or β‐form crystals (or both) because only a single type of α‐nuclei could be left upon treatment to the molten liquid state at T_max. Therefore, only the α‐crystal in PBA had ‘memory capacity’ in the molten liquid state while the β‐crystal did not. This was so because the latter had been completely transformed into the solid state prior to being heated into a liquid. PBA crystallized before α‐nuclei could be packed into α‐crystal, regardless of the crystallization temperature (T_c). For recrystallization from molten PBA without any nuclei, the crystalline polymorphism was correspondingly influenced by T_c. Copyright © 2005 Society of Chemical Industry     

Mobile robot localization: integrating measurements from atime-of-flight laser

This paper presents an algorithm for environment mapping by integrating scans from a time-of-flight laser and odometer readings from a mobile robot. The range weighted Hough transform (RWHT) is used as a robust method to extract lines from the range data. The resulting peaks in the RWHT are used as feature coordinates when these lines/walls are used as landmarks during navigation. The associations between observations over the time sequence are made in a systematic way using a decision directed classifier. Natural geometrical landmarks are described in the robot frame together with a covariance matrix representing the spatial uncertainty. The map is thus built up incrementally as the robot moves. If the map is given in advance, the robot can find its location and navigate relative to this a priori given map. Experimental results are presented for a mobile robot with a scanning range measuring laser having 2-cm resolution. The algorithm was also used for an autonomous plastering robot on a construction site. The sensor fusion algorithm makes few erroneous associations     

Heparin effect on hydrolysis of fibrin clots in a bull and a man with varying fibrinolytic systems

Heparin was studied for its effect on the hydrolysis time of clots from desAA fibrin (FB), desAABB fibrin (F0) and fibrinogen (Fg) of a bull and a man by gly-or lys-plasminogen which is activated by the tissue activator. It is shown that heparin in the concentration to 4.6 M does not affect that hydrolysis time of clots from human and bovine Fg and human Fg by gly-plasminogen which is activated by the tissue activator. Heparin increases the hydrolysis time of clots from bovine Fg and F0 by gly-and lys-plasminogen, the tissue activator being present. It firstly increases (in concentrations below 0.5 (microM), and then decreases (in concentrations above 0.5 (microM) the hydrolysis time of clots from human FB, F0 and Fg and bovine FB and F0 by plasmin. In concentration 4.6 microM heparin increases the hydrolysis time of clots from human fibrinogen by fibrinolytic systems. Effect of heparin on fibrinolytic process from the viewpoint of affine interactions between the components of fibrin clots is discussed.     

PYY in developing murine islet cells: comparisons to development of islet hormones, NPY, and BrdU incorporation

Exhaustive characterizations of antisera to the structurally related peptides pancreatic polypeptide (PP), neuropeptide Y (NPY), and peptide YY (PYY) enabled us to establish the developmental pattern of these peptides in rat and mouse pancreas. PYY was the earliest detectable peptide and was present in all early appearing endocrine cell types. NPY appeared later and occurred exclusively in a subpopulation of insulin cells, whereas PP cells arose latest. At the earliest stage studied, all endocrine cells stored PYY. Most of these cells also contained glucagon. Subsequently, the endocrine cells comprised glucagon+PYY cells and glucagon+PYY+insulin cells. Later, cells storing either only insulin or insulin+PYY appeared. Quantitations of the relative numbers of these cell populations during development were consistent with a precursor role of triple-positive (insulin+glucagon+PYY) cells. Moreover, bromodeoxyuridine (BrdU) injections at E15.5 showed that a large percentage of triple-positive cells were in S-phase and therefore were actively dividing, whereas almost no pure insulin cells or insulin+PYY cells synthesized DNA at this time. These results suggest that PYY-positive endocrine cells may represent precursors for mature islet cells.     

A special-case surface voltage gradient formula [for substationdesign]

In the electrical design of a high-voltage substation, the designer needs a simple and reliable tool, preferably a closed-form formula, when calculating the surface voltage gradient of line segments within the substation since the surface voltage gradient is the governing parameter of the corona performance. This paper presents a derivation of a closed-form formula for calculation of the maximum surface voltage gradient of a special line configuration, namely a horizontal AC three-phase line configuration with bundle conductors consisting of three sub-conductors in a horizontal arrangement. The formula has been verified against exact calculations and was found to have an error less than 5% for all practical combinations of the conductor radius, the sub-conductor spacing, the phase distance, and the height above earth     

On the catalytic C-H activation of some silicon dioxide overlayers on thin metal film systems — An observation on the isokinetic effect

Kinetic data on the exchange reaction betwee hexane and deuterium have recently been reported by Maier and coworkers [1]. The reaction was catalysed by a series of platinum or rhodium systems, some of which had the property that the upper surface was shielded by a silica overlayer. The data are reinterpreted to indicate an isokinetic temperature of 580 K. This observation indicates that all the catalysts behave in a similar manner, which means that the exchange reaction does not require a free metal surface.     

Symbiosis of nurse and machine through fuzzy logic: improved specificity of a neonatal pulse oximeter alarm

This article describes the theoretical underpinnings that preceded the design of a new neonatal pulse oximeter alarm that differentiates true from false alarms based on an artificial intelligence theory called "fuzzy logic." The connection between the intuition and sense of advocacy gained through neonatal primary nursing and the application of fuzzy logic to solve the problem of false alarms--that is, the symbiosis between nurse and machine--are explained. Emphasis is placed throughout on the importance of involving nurses in the development of the technology for which they are responsible.