Etching of Laminates with Hydrogen Peroxide in Sulphuric Acid Solution

Three types of nuclear reaction have been applied to study chromium conversion coatings on zinc electroplate. The 1005keV resonance in the ⁵²Crlp, Y)⁵³Mn reaction has been used to determine the depth versus concentration profile of chromium in the coatings, while the ¹⁵O(d,α) ¹⁴N reaction has been used to profile oxygen content, or particle induced elastic forward scattering of protons (proton recoil) was used to determine the hydrogen profile in the samples. The results suggest that the newly introduced trivalent type treatments produce coatings containing comparable water/hydroxide contents to the establishedhexavalent type treatments.     

New statistical method for detection and quantification ofrespiratory sinus arrhythmia

A statistical method with the advantages of 1) enabling graphical representation of within-respiratory cycle heart rate variations, 2) detecting the presence of respiratory sinus arrhythmia (RSA) in a moving window, and 3) providing breath-by-breath RSA amplitude and phase obtained from the fitting of a sinusoid to the instantaneous relative heart rate is presented.     

cis-Diaminedichloroplatinum(II) Complexes Reversibly Linked into the Main Chain of Water-Soluble Polyamides

As a follow-up study to previous work involving the platination of polyamide carriers through metal chelation by side group-incorporated ethylenediamine ligands, the present investigation is concerned with the synthesis of platinum-containing polymers in which the metal-coordinating ethylenediamine segments are components of the main chain. Two chloro groups in cis geometry are attached to each Pt atom as additional ligands, complementing a square-planar cis-diaminedichloroplatinum(II) complex system. The water-soluble polymeric carriers are synthesized by Michael-type addition polymerization, interfacial polymerization, and high-temperature solution polycondensation techniques and are crudely fractionated by stepwise aqueous dialysis, ultimately in tubing with a molecular mass cutoff of 25,000. Carrier platination is brought about by treatment with tetrachloroplatinate(II) anion in aqueous solution, care being taken to exercise strict control of reaction variables and workup conditions in an effort to restrict platination to the given ligands and avoid metal aquation or hydroxylation. The platinum conjugates, with Pt contents ranging from about 11 to 23% by mass, are completely soluble in aqueous media when freshly prepared, although long-term storage at room temperature in the solid state is conducive to gradual loss of solubility. The conjugates are of interest as carcinostatic agents.     

Heterogeneous functionalizing of polysulfone membranes

In recent years efforts have been increased to work with more intelligent membranes which render more than normal filtration properties. Thus, membranes have been prepared using chemically modified polymers or have been furnished with additives in order to increase their selectivity and/or special sorbing capabilities. In this paper, methods are described how commercially available polysulfone membranes can be functionalized by chemical reactions without disintegrating their mechanical properties. For this purpose, Sulfonation, chloromethylation, aminomethylation, and lithiation reactions were applied. A broad spectrum for further conversions modified membranes is opened by these chemical reactions which allow an individual fitting of the membranes with special substitutes. The chemical reactions and the analytical procedures are also described.     

Ozonation of Cycloalkenes Dissolved in Ethanol

The ozonation of cyclooctene and cyclododecene in ethanol was studied at 278 K in a stirred reactor with a flat gas/liquid interface. The parallel reactions with ethanol in the gas and the liquid phase had to be accounted for. At high cyclooctene concentrations, ozone transfer into the liquid phase was enhanced by up to a factor of E = 325. Due to the high ozone solubility and the high enhancement factors, up to half of the mass transfer resistance was on the gas-side. The reaction rate constant k₂ is more than threefold higher for cyclooctene as compared to cyclododecene.     

A real-time robotic model of human reference resolution using visual constraints

Evidence from recent psycholinguistic experiments suggests that humans resolve reference incrementally in the presence of constraining visual context. In this paper, we present and evaluate a computational model of human reference resolution that directly builds a semantic interpretation of an utterance without the need for a separate syntactic analysis phase, which typically involves the construction of parse trees. The model is implemented on a robot using real audio and video inputs, (thus it operates in real time), and is distributed over several computers, which run in parallel. Results from experiments with the model confirm the viability of the algorithm to process semantic interpretations, in particular reference incrementally, as demonstrated to be employed by humans.     

Auflösungsverhalten von Dolomit in Stahlwerksschlacken sowie Grenzen der Löslichkeit und Folgen für den Feuerfestverschleiß

Das Auflösungsverhalten von gebranntem Dolomit wurde durch Schmelzversuche ermittelt, bei denen stahlwerksähnliche Schlakken mit einem Dolomittiegel reagierten. Die Auflösung des Tiegelmaterials in der Schlacke wurde dabei sowohl unter dem Aspekt des Schlackenbildners Dolomit als auch aus der Sicht MgO-haltigen Feuerfestmaterials ausgewertet. Es konnte verfolgt werden, wie die beiden unverbunden nebeneinander vorliegenden Hauptkomponenten des Dolomitkalks, CaO und MgO, entsprechend ihren jeweils treibenden Kräften, den Abständen zur Sättigung, unterschiedlich schnell in Lösung gehen. Trotz bevorzugter Auflösung des CaO erreicht das MgO wegen eines geringeren Abstandes zur Sättigung eher die Löslichkeitsgrenze, unterstützt durch den Effekt, daß bereits gelöstes CaO die MgO-Sättigungsgehalte erniedrigt, während umgekehrt MgO die CaO-Löslichkeit zunächst durch Zurückdrängen der Dicalciumsilikat-Ausscheidung (?C₂S-Nase”) deutlich, dann an der eigentlichen Kalksättigung noch leicht erhöht. Die Auflösung kommt durch eine rasche Sättigung an MgO zwar nicht völlig zum Stillstand, wird aber stark verlangsamt, so daß die metallurgisch wichtige Kalksättigung bei alleinigem Einsatz von Dolomitkalk als Schlackenbildner nicht erreicht werden kann. Darüberhinaus wird die Schlacke infolge der Übersättigung an MgO heterogen und viskos. Die Auflösung von magnesitischem Feuerfestmaterial konnte simuliert werden, indem nur das Verhalten der MgO-Komponente des Dolomits zu Beginn des Versuchs betrachtet wurde. Die verschleißmindernde Wirkung von MgO-Vorgaben zur angreifenden Schlacke wurde nachgewiesen. Ferner konnten durch Annahme einer diffusionsgesteuerten Auflösung in der ersten Phase des Versuchs Stoffübergangskoeffizienten des CaO und des MgO gewonnen werden.