Visualizing Agents for Esters of Higher Fatty Acids in TLC

JPC – Journal of Planar Chromatography – Modern TLC - Eighteen new agents have been used for visualizing eight esters of higher fatty acids after chromatography on silica gel, on a...     

Learning in innovation networks: Some simulation experiments

According to the organizational learning literature, the greatest competitive advantage a firm has is its ability to learn. In this paper, a framework for modeling learning competence in firms is presented to improve the understanding of managing innovation. Firms with different knowledge stocks attempt to improve their economic performance by engaging in radical or incremental innovation activities and through partnerships and networking with other firms. In trying to vary and/or to stabilize their knowledge stocks by organizational learning, they attempt to adapt to environmental requirements while the market strongly selects on the results. The simulation experiments show the impact of different learning activities, underlining the importance of innovation and learning.     

Use of Structural Descriptors to Predict the RM Values of m- and p-Alkoxyphenols in RP TLC

JPC – Journal of Planar Chromatography – Modern TLC - Selected meta- and para-alkoxyphenols have been separated by RP TLC on cellulose impregnated with ethyl oleate, with ethanol-water,...     

High resolution neutron scattering study of low-energy magnetic excitations in Nd2-xCexCuO4

The low-energy magnetic excitations (?ω ≤ 2 meV) of polycrystalline samples of Nd_2-xCe_xCuO₄ with x = 0, 0.1 and 0.15 have been measured with high resolution inelastic neutron scattering using time-of-flight technique at temperatures below 0.3 K. All observed scattering originates from transitions within the ground state doublet of Nd³⁺. For Nd₂CuO₄ the response is inelastic, and shows at least three different modes, of which one is almost dispersionless. For x = 0.1 the excitation spectrum shifts towards lower energies, but the main features of the undoped compound are still visible, whereas for x = 0.15 the response is mainly quasi-elastic but remains localised in Q-space around the first magnetic Bragg point (0.5 0.5 1). A comparison with data obtained on a triple-axis-spectrometer on single crystals with x = 0.0 and x = 0.15 reveals that the response of the doped sample in the [0 0 1] direction is still inelastic.     

A high-precision segmented Paul trap with minimized micromotion for an optical multiple-ion clock

We present a new setup to sympathetically cool ¹¹⁵In⁺ ions with ¹⁷²Yb⁺ for optical clock spectroscopy. A first prototype ion trap made of glass-reinforced thermoset laminates was built, based on a design that minimizes axial micromotion and offers full control of the ion dynamics in all three dimensions. We detail the trap manufacturing process and the characterization of micromotion in this trap. A calibration of the photon-correlation spectroscopy technique demonstrates a resolution of 1.1 nm in motional amplitude of our measurements. With this method, we demonstrate a sensitivity to systematic clock shifts due to excess micromotion of $|(\Updelta\nu/\nu)_{\rm mm}|=7.7\times10^{-20}$ along the direction of the spectroscopy laser beam. Owing to our on-board filter electronics on the ion trap chips, no rf phase shifts could be resolved at this level. We measured rf fields over a range of 400 μm along the ion trap axis and demonstrated a region of 70 μm where an optical frequency standard with a fractional inaccuracy of ≤1 × 10^?18 due to micromotion can be operated.     

Photothermal measurements in determination of the thermal diffusivity of SiC

In this work a measuring method for determination of the thermal diffusivity of SiC substrates commonly used in electronic industry is proposed. Such substrates are (300 900) μm thick plates, The method bases on generation of temperature field disturbance in the sample by modulated light beam. Fitting of theoretical curves to the ratio of signals measured in two experimental geometries as a function of modulation frequency allows determination of the thermal diffusivity and optical absorption of the sample. Optical absorption is also measured independently using typical spectrometer. Results obtained for a few SiC substrates confirm usability of proposed method for investigation of such samples. Determined thermal diffusivities of polycrystalline samples are of the order of (0.2 0.5) cm² s ^{- 1}. The thermal diffusivities of single crystals are considerably higher and reach (1.3 1.5) cm² s^-1.     

Investigation of Homologous Series of Fatty Acids by TLC. Part I. Comparison of Separations of Fatty Acids on RP-18 Plates With and Without a Concentrating Zone

JPC – Journal of Planar Chromatography – Modern TLC - Fatty acids from pentanoic acid to tricosanoic acid have been separated on RP-18 plates with and without a concentrating zone....     

Restudy of the Ground Vibrational State of Hydrazine Using the Generalized IAM-like Treatment for the Amino-Wagging Tunneling Motion

The amino-wagging tunneling process in hydrazine was treated using the generalized IAM-like method developed by Hougen and Coudert, and Hamiltonian matrix elements were derived for each symmetry species in the combined group-theoretical and IAM-like treatment. Ground state microwave absorption transition data of hydrazine were least squares analyzed again in this treatment to determine axis switching angles for the amino-wagging tunneling process. Copyright 2001 Academic Press.     

Agency and structure: a social simulation of knowledge-intensive industries

Modern knowledge-intensive economies are complex social systems where intertwining factors are responsible for the shaping of emerging industries: the self-organising interaction patterns and strategies of the individual actors (an agency-oriented pattern) and the institutional frameworks of different innovation systems (a structure-oriented pattern). In this paper, we examine the relative primacy of the two patterns in the development of innovation networks, and find that both are important. In order to investigate the relative significance of strategic decision making by innovation network actors and the roles played by national institutional settings, we use an agent-based model of knowledge-intensive innovation networks, SKIN. We experiment with the simulation of different actor strategies and different access conditions to capital in order to study the resulting effects on innovation performance and size of the industry. Our analysis suggests that actors are able to compensate for structural limitations through strategic collaborations. The implications for public policy are outlined.