Template-directed olefin cross metathesis

[reaction: see text] A template containing two secondary dialkylammonium ion recognition sites for encirclement by olefin-bearing dibenzo[24]crown-8 derivatives has been used to promote olefin cross metatheses with ruthenium-alkylidene catalysts. For monoolefin monomers, the rates of metatheses and yields of the dimers are both amplified in the presence of the template. Likewise, for a diolefin monomer, the yield of the dimer is enhanced in the presence of the template under conditions where higher oligomers are not formed.     

Nuclear moments of neutron deficient iridium isotopes from laser spectroscopy

Laser spectroscopy measurements have been performed on neutron deficient iridium isotopes. The hyperfine structure and isotope shift of the optical Ir I transition 5d⁷6s^{2 4}F_9/2 → 5d⁷6s6p ⁶F_11/2 at 351.5 nm have been studied for the ^182–189Ir, and ^191,193Ir isotopes. The nuclear magnetic and quadrupole moments were obtained from the HFS measurements and the changes of the mean square charge radii from the IS measurements. A large mean square charge radius change between ¹⁸⁷Ir and ¹⁸⁶Ir and between and has been observed. This revised version was published online in August 2006 with corrections to the Cover Date.     

On the convergence of sequential minimization algorithms

This note gives a proof of convergence of a class of gradient-related minimization algorithms under slightly weaker conditions than were used in a recent paper (see Ref. 1) on the same subject.     

Film Violence and Verbal Aggression: A Naturalistic Study

Findings suggest that some results obtained in laboratory experiments can be generalized to apply to the viewing experience in real-life settings.     

Coherence transfer between collision partner molecules

Optical and/or microwave coherence transfer induced by molecular collisions is considered in a phenomenological manner. A particular attention is paid to coherence transfer between collision partner molecules and a time resolved experiment is proposed to detect such effects.     

Investigations on the luminescence of titanium-activated stannates and zirconates

The luminescence of several titanium-activated stannates and zirconates with spinel, perovskite, K₂NiF₄, pyrochlore, and fluorite structure is reported. For most compounds two emissions are observed, one blue and one yellow. Some compounds show only yellow emission and there is one compound with only blue emission. These results can be explained by one model, based on the occurrence of two different titanate centres, viz., a regular center and a defect center.     

Thermoanalytical investigations of some industrial wastes produced in steel works

The experiments involves three types of industrial wastes produced by iron works, which create serious hazards to the natural environment: (1) paint-shop sludge, (2) oil-polluted diatomite, and (3) oil-polluted scale. The choice of an appropriate and safe storage method should be based on extensive physicochemical examination.DTA, in combination with other data, allows characterization of the combustible properties of wastes. Thermoanalytical measurements were carried out in a dynamic air atmosphere. Enthalpy values were calculated from peak areas of DTA curves. Thermoanalytical data were compared with calorimetric results obtained with an oxygen bomb.

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Zusammenfassung Drei Arten industrieller Abtälle eines Stahlwerks, die schwere Umweltbelastungen darstellen, wurden untersucht: (1) Lackiererei-Schlamm, (2) ölhaltiger Diatomit, (3) ölhaltiger Kesselstein. Geeignete sichere Deponien setzen ausführliche physikalisch-chemische Untersuchungen voraus. DTA in Kombination mit anderen Untersuchungen erlaubt die Charakterisierung der Verbrennungseigenschaften der Abfälle. Die thermoanalytischen Untersuchungen erfolgten im Luftstrom, die Verbrennungswärmen wurden aus den DTA-peak-Flächen berechnet. Die Ergebnisse werden mit denen kalorimetrischer Messungen in einer Sauerstoffbombe verglichen.

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Entrapment of Metalloporphyrins Within an Electrodeposition Paint Layer as a Basis for Developing a Nitric Oxide Sensor

Ni tetra(4-N-methyl pyridyl)porphyrin was electrochemically entrapped within a polymer matrix formed by an anodic electrodeposition paint on the surface of Pt electrodes. Due to positive charges from the quaternised pyridinium side chains, the metalloporphyrin is soluble in water. By means of charge interactions between the positively charged metalloporphyrin and the negatively charged polymer backbone of the applied anodic electrodeposition paint, the entrapment of the metalloporphyrin in an insoluble polymer capsule prevents it from rapidly leaking off the electrode surface. The chemically modified electrodes obtained could be successfully applied to the sensitive determination of nitric oxide, and they displayed satisfactory stability for multiple nitric oxide measurements. The modified electrodes were employed for monitoring the decomposition of methylamine hexamethylene methylamine NONOate by continuous detection of the liberated nitric oxide.     

BCI Competition 2003--Data set Ia: combining gamma-band power with slow cortical potentials to improve single-trial classification of electroencephalographic signals

In one type of brain-computer interface (BCI), users self-modulate brain activity as detected by electroencephalography (EEG). To infer user intent, EEG signals are classified by algorithms which typically use only one of the several types of information available in these signals. One such BCI uses slow cortical potential (SCP) measures to classify single trials. We complemented these measures with estimates of high-frequency (gamma-band) activity, which has been associated with attentional and intentional states. Using a simple linear classifier, we obtained significantly greater classification accuracy using both types of information from the same recording epochs compared to using SCPs alone.