Search results for "scot"

New occurrence of the family Hipponicharionidae (Bradoriida, Arthropoda), in the lower and middle Cambrian of the Cadenas Ibéricas, Spain

2004

The bradoriids Hipponicharion aff, hispanicum and Wimanicharion aff. matthewi are reported from the lower and middle Cambrian strata of the Cadenas Ibericas, Spain. The genus Hipponicharion seems to be restricted to the Acadobaltic Province. Wimanicharion has been recorded from Sweden and Canada (Nova Scotia). The new discovery of Wimanicharion in Spain indicates its similar palaeobiogeographical distribution to Hipponicharion.

Liquid Crystalline Ordering and Charge Transport in Semiconducting Materials

2009

Organic semiconducting materials offer the advantage of solution processability into flexible films. In most cases, their drawback is based on their low charge carrier mobility, which is directly related to the packing of the molecules both on local (amorphous versus crystalline) and on macroscopic (grain boundaries) length scales. Liquid crystalline ordering offers the possibility of circumventing this problem. An advanced concept comprises: i) the application of materials with different liquid crystalline phases, ii) the orientation of a low viscosity high temperature phase, and, iii) the transfer of the macroscopic orientation during cooling to a highly ordered (at best, crystalline-like…

Introduction. L'Écosse de Charles Nodier, un Eldorado romantique

2013

International audience

3,5-Dialkoxy Substituted Triphenyl-tristriazolotriazines: Fluorescent Discotic Liquid Crystals

2015

Tristriazolotriazines with a threefold 3,5-dialkoxyphenyl substitution were prepared from the corresponding phenyltetrazoles and cyanuric chloride. These star-shaped compounds are discotic liquid crystals that form broad and stable thermotropic mesophases. The thermal behaviour was studied by DSC and polarizing optical microscopy. An increasing length of the side chains reduces the phase transition temperatures, this effect is more pronounced for the crystalline to mesophase transition than for the clearing temperature. XRD on an oriented sample revealed a hexagonal columnar structure for the mesophase. All TTTs emit a strong fluorescence in the UV-violet region.

Sound absorption prediction of linear damped acoustic resonators using a lightweight hybrid model

2019

International audience; A lightweight numerical method is developed to predict the sound absorption coefficient of resonators whose cross-section dimensions are significantly larger compared to the viscous and thermal boundary layer’s thicknesses. This method is based on the boundary layer theory and on the perturbations theory. According to the perturbations theory, in acoustical domains with large dimensions, the fluid viscosity and thermal conductivity only affect the boundary layers. The model proposed in this article combines the lossless Helmholtz wave equation derived from a perfect fluid hypothesis, with viscosity and thermal conductivity values of a real fluid to compute the sound …

Volatile Oil Content of Scots Pine Needles (Pinus sylvestris L.)

2016

Abstract This study focused on how the concentration of volatile oils in Scots Pine needles varied in relation to the age of the trees, the age of the needles and their location within the canopy. Study material were pine needles from 15-, 44- and 89-year-old pine stands. The mean content of oils increased with the age of trees. The averaged oil content in needles was: 0.46% in the 15-year-old stand, 0.55% in the 44-year-old and 0.61% in the 89-year-old stands. The mean content of volatile oils decreased with the age of the needles. 1-year-old needles contained the highest concentration of volatile oils (0.56%), and the 3-year-old needles contained the least (0.48%). In 15-year-old stands t…

1992

The synthesis of a new type of combined polymers containing both disc- and rod-like mesogens is reported. The polyesters, having a triphenylene derivative as a discotic mesogen in the side group and azobenzene or biphenyl derivatives as rod-like mesogens in the main chain were characterized by polarizing microscopy, differential scanning calorimetry, and X-ray scattering studies. The homopolymer 7 is highly crystalline, while the copolymer 8 is amorphous, both, however, do not form liquid-crystalline phases.

Characterization of pre-treatments on wood chips prior to delignification by near infrared spectroscopy

2017

A near infrared (NIR) spectroscopy-based method for predicting yields and lignin contents of differently pre-treated silver/white birch (Betula pendula/B. pubescens) and Scots pine (Pinus sylvestris) chips was developed. The approach was to create multivariate calibration models from the NIR data by the partial least squares (PLS) method. Both parameters are important factors when adjusting adequate conditions for pre-treatments either with hot-water (HW) as such and slightly acidified HW (collectively referred to as autohydrolysis) or dilute alkaline aqueous solutions prior to alkaline pulping. Pre-treatment conditions were varied with respect to temperature (130 °C and 150 °C) and treatme…

ChemInform Abstract: Monolayers and Langmuir-Blodgett Multilayers of Discotic Liquid Crystals?

1990

The field of monolayer and multilayer films of discotic LCs is at its very beginning. The scope and limitations of this preparation method have not yet been explored, and little is known about the structures obtainable. However, the potential access to extraordinary, ordered thin films is fascinating, and will stimulate research in the future.

Transient reduction of the ocular perfusion pressure and the oscillatory potentials of the ERG

2005

Abstract Purpose. To evaluate the changes of the Oscillatory Potentials (OPs) of Electroretinogram (ERG) caused by short-term hypertension in human subjects, and their relationship with ocular perfusion pressure (OPP). Methods. Suction cup technique in 12 normal volunteers with OPs simultaneously recording. Results. Scotopic and photopic OPs were altered during OPP drop. Scotopic OPs showed more sensitiveness, with higher reduction (from 21% to 47%), when compared to the basal value, than in photopic recordings (from 14% to 34%). In both conditions, the relationship between OPP and OPs presented a steady amplitude before the trough after the +30 step, and rapid recovery after OPP normalisat…