Search results for "periodic table"

Computational modeling of isotropic electron paramagnetic resonance spectra of doublet state main group radicals

2007

The combined use of theoretical and mathematical methods in the analysis of electron paramagnetic resonance data has greatly increased the ability to interpret even the most complex spectra reported for doublet state inorganic main group radicals. This personal account summarizes the theoretical basis of such an approach and provides an in-depth discussion of some recent illustrative examples of the utilization of this methodology in practical applications. The emphasis is on displaying the enormous potential embodied within the approach. peerReviewed

Semiempirical correlation between the optical band gap of oxides and hydroxides and the electronegativity of their constituents

2000

AbstractOn the basis of new experimental results a previous proposed correlation between the optical band gap of oxides and the difference of electronegativity of their constituents is extended to mixed crystalline and amorphous TiO2-Fe2O3 (d,d-metal oxides) as well as to amorphous passive films grown on Al-Ta, Al-Ti, Al-Nb and Al-W alloys (sp,d-metal oxides). Moreover in analogy with previous results on anhydrous oxides, a correlation is proposed between the optical band gap of hydroxides and the electronegativities of their constituents after substituting the electronegativity of hydroxilic group to that of the oxygen. Like in the case of anhydrous oxides, two different interpolation line…

ChemInform Abstract: Mixed Group 14-Group 14 Bonds. Part 5. Six Perphenylated Propane Analogues Ph3M-M′Ph2-M′′Ph3 (M, M′, M′′: Si/Ge): Electronegativ…

2010

Environmental and biological factors influencing trace elemental and microstructural properties of Arctica islandica shells

2018

Long-term and high-resolution environmental proxy data are crucial to contextualize current climate change. The extremely long-lived bivalve, Arctica islandica, , is one of the most widely used paleoclimate archives of the northern Atlantic because of its fine temporal resolution. However, the interpretation of environmental histories from microstructures and elemental impurities of A. islandica, shells is still a challenge. Vital effects (metabolic rate, ontogenetic age, and growth rate) can modify the way in which physiochemical changes of the ambient environment are recorded by the shells. To quantify the degree to which microstructural properties and element incorporation into A. island…

BIOALGA reactor: preliminary studies for heavy metals removal

2002

Abstract Microalgae have a high affinity for polyvalent metals, for that reason they could be used to reduce the concentration of heavy metals present in water and wastewater. In the present work an evaluation of a rotary biofilm reactor for algae immobilization (BIOALGA) with the subject of heavy metal removal was investigated. The BIOALGA reactor consisted of a pilot scale model that was operated with synthetic wastewater with an initial concentration of 3000 μg/l of cobalt ion. Scenedesmus obliquus was immobilized in the reactor, which was operated in batch mode for a period of 20 days. The rotary velocity used, 2 rpm, was constant during the experiment. A maximum removal of cobalt ion o…

Homopolymerization of styrenic monomers and their copolymerization with ethylene using group 4 non‐metallocene catalysts

2020

Homopolymerization of styrenic monomers (St, p ‐Me‐St, p ‐t Bu‐St, p ‐t BuO‐St) and their copolymerization with ethylene, with the use of [( t Bu2O2NN′)ZrCl]2(μ‐O) (1 ) and ( t Bu2O2NN′)TiCl2 (2 ), where t Bu2O2NN′ = Me2N(CH2)2N(CH2‐2‐O−‐3,5‐t Bu2‐C6H2)2, is explored in the presence of MMAO and (i Bu)3Al/Ph3CB(C6F5)4. The ethylene/styrenic monomers copolymerization with 1 /MMAO produces exclusively copolymers with high activity and good comonomer incorporation whereas the other catalytic systems yield mixtures of copolymers and homopolymers. The use of p ‐alkyl styrene derivatives instead of styrene raises the catalytic activity, comonomer incorporation and molecular weights of the copolyme…

Achievement of Interlaboratory Uniformity — A Summary of Work Carried out by the EDNAP Group

1992

This paper describes a collaborative exercise intended to demonstrate whether uniformity of DNA profiles results could be achieved between different European laboratories. It was shown that this goal would be obtained provided that a common protocol was followed (specifically the use of a common electrophoretic buffer is the most important parameter).

Periodic volcanic degassing behavior: The Mount Etna example

2013

[1] In contrast to the seismic and infrasonic energy released from quiescent and erupting volcanoes, which have long been known to manifest episodes of highly periodic behavior, the spectral properties of volcanic gas flux time series remain poorly constrained, due to a previous lack of hightemporal resolution gas-sensing techniques. Here we report on SO2 flux measurements, performed on Mount Etna with a novel UV imaging technique of unprecedented sampling frequency (0.5Hz), which reveal, for the first time, a rapid periodic structure in degassing from this target. These gas flux modulations have considerable temporal variability in their characteristics and involve two period bands: 40–250…

1986

Microsatellite-based species identification method for Drosophila virilis group species

2007

Species of the D. virilis group are widely used in evolutionary research, but the individuals of different species are difficult to distinguish from each other morphologically. We constructed a fast and easy microsatellite-based identification method for the species of the group occurring sympatrically in northern Europe. The neighbor joining tree based on 14 microsatellite loci also gave a good resolution of the species divergence pattern in the whole group.