High-spin alkali trimers on helium nanodroplets: spectral separation and analysis

Electronic excitation spectra of homo- (K(3),Rb(3)) and heteronuclear (K(2)Rb,KRb(2)) alkali trimers in the high-spin quartet state have been investigated in a broad spectral range (10,600-17,400 cm(-1)). Ten new bands showing laser induced fluorescence (LIF) were measured. Due to the pickup statistics, overlapping spectra of all possible oligomers are present at once, complicating the unraveling and assignment of individual spectra. To circumvent the problem, two variations of beam depletion spectroscopy were employed in addition to the conventional analysis of the relation between signal and pickup pressure: A two-laser V-type double resonance scheme combining beam depletion with LIF, and a mass selective beam depletion scheme. In principle, these allow accurate separation of an arbitrary number of overlapping spectra. The benefits and drawbacks of each method are discussed. Assignment to electronic states is achieved by comparison with ab initio complete active space self-consistent field calculations of the excited electronic level structure of the molecules.     

Estimation of stability constants of copper(II) and nickel(II) chelates with dipeptides by using topological indices

The estimation of the overall stability constants β₁ of copper(II) and nickel(II) chelates with dipeptides was performed by using the model with the valence connectivity index of the 3rd order (³χ^v). It was done by dividing β₁ to its constituting constants K₁ and K_a, and subsequently by dividing the basic set into subsets or treating the chelate rings as separate units. Altogether 15 copper(II) and eight nickel(II) chelates with dipeptides were investigated. Six models for the estimation of log K₁ and pK_a were checked, most of them by usage of indicator variables (for differentiation of copper(II) and nickel(II) complexes or subclasses of ligands). Estimates of log β₁ gave the range of rms values from 0.19 to 0.27. For the best model, errors of estimates were less than 0.34.     

A study on adjusted contact force laws for accelerated large scale discrete element simulations

The aim of this work is to systematically investigate the effect of the normal force law and the applied stiffness on the behavior of single particles and particle systems. A detailed review of the literature regarding altered stiffnesses and their use in force laws is provided. The effect on macroscopic simulation properties such as contact numbers, velocity profiles, discharge rates and quality of dispersion for different fractions of maximum overlap is studied in the case of a stirrer vessel and a rectan...     

Oxygen sensor nanoparticles for monitoring bacterial growth and characterization of dose–response functions in microfluidic screenings

Microchimica Acta - We are presenting a microfluidic droplet-based system for non-invasive, simultaneous optical monitoring of oxygen during bacterial cultivation in nL-sized droplets using...     

Biorefining: the role of endoglucanases in refining of cellulose fibers

Cellulose - With an annual production of more than 400 million tons, paper is the main product of the largest biorefinery process industrially implemented. Enzymes have been used for pulp refining...