Search results for "Capillary Action"

Gas chromatography of homologous esters

1984

Abstract The gas chromatographic retention behaviour of the propanoyl and monochloropropanoyl esters of saturated C3C5 branched-chain and unsaturated C3C6 alcohols on SE-30 and OV-351 capillary columns at several temperatures is reported. Retention index increments at 80 and 120°C show the effect of branching in the alkyl chain and also the effect of unsaturation and of its position in the chain with chlorination at the two possible positions in the acyl chain. The various incremental effects are discussed and compared with the behaviour of the corresponding n-alkyl esters.

Chromatography with dense gases

1992

A capillary restrictor for supercritical fluid chromatography (SFC) with CO2 was made by using a micro torch and fine emery cloths or grinding blocks. This restrictor could be drawn out either directly from the end of the analytical capillary column, or from a short piece of any capillary, which was then connected to the analytical column by standard techniques. It was found that the base current of a flame ionisation detector (FID) depends strongly on the position of the capillary end with respect to the FID flame tip and on the CO2 grade, of course. Best results have been achieved at around 5 to 7 mm distance between the restrictor and the flame tip ends, and using SFC grade CO2.

Improved method for quantitative analysis of vitamin K1i and vitamin K1 2,3-epoxide in human plasma by electron-capture gas-liquid capillary chromato…

1984

Numerical modelling of the electrochemical behaviour of 316 stainless steel based upon static and dynamic experimental microcapillary-based technique…

2008

objective of this work was to determine the parameters that affect the mass transport and the distribution of species in microcapillaries close to the specimen surface. Local experiments were carried out under static and flow conditions on type 316L stainless steel in 1.7 M NaCl, pH = 3, by means of the electrochemical microcell and the scanning droplet cell technique. The polarisation behaviour of pure iron (used as a model system) in an aqueous environment was calculated adopting a finite element approach and was compared to the experimental results. The corrosion system consists of three parallel electrochemical reactions: the oxygen reduction reaction (ORR), the hydrogen evolution react…

Effect of the surrounding aeration on microcapillary electrochemical cell experiments

2008

In the microelectrochemical capillary cell technique a silicone rubber gasket is used to avoid any electrolyte leakage between the pulled glass capillary and the working electrode (the metallic tested material). In this study, it is demonstrated that the oxygen reduction reaction (ORR) is strongly affected by the use of the silicone rubber. Experiments under a surrounding argon gas shielding of the pulled capillary in contact with the metallic surface have been performed showing a large effect on the ORR. Considering the high permeation rate of oxygen through silicone, the decrease of the reaction rate observed experimentally was validated by FEM modelling assuming that the air/silicone/wat…

Water capillary absorption in porous media in different wettability conditions studied by Quantitative MRI and X-ray CT

2007

X-ray computed tomography (CT) and magnetic resonance imaging (MRI) have been successfully applied to study both the capillary properties of several samples of Lecce stone and the performances of treatments used for protection and conservation of historical stone artifacts. The presence of water inside the sample may be visualized by both MRI and X-ray CT. For the treated samples, the different dynamics of water absorption gives indirectly the efficacy of the polymer in the rock.

Tunable source of infrared pulses in gas-filled hollow core capillary

2020

International audience; We report a tunable source that generates pulses in the infrared from an optical parametric amplification in a gas-filled hollow core capillary based on four-wave mixing process, in which the phase matching strongly depends on the gas pressure and the pump. In our case, we have generated pulses from 1 to 1.6 m in the sub-µJ level together with a parametric amplification in the visible.

Stretch-induced Intussuceptive and Sprouting Angiogenesis in the Chick Chorioallantoic Membrane

2014

Vascular systems grow and remodel in response to not only metabolic needs, but also mechanical influences as well. Here, we investigated the influence of tissue-level mechanical forces on the patterning and structure of the chick chorioallantoic membrane (CAM) microcirculation. A dipole stretch field was applied to the CAM using custom computer-controlled servomotors. The topography of the stretch field was mapped using finite element models. After 3 days of stretch, Sholl analysis of the CAM demonstrated a 7-fold increase in conducting vessel intersections within the stretch field (p 0.05). In contrast, corrosion casting and SEM of the stretch field capillary meshwork demonstrated intense …

Photobiomodulation Therapy in the Management of Burning Mouth Syndrome: Morphological Variations in the Capillary Bed

2020

Burning mouth syndrome (BMS) is an idiopathic condition that manifests itself primarily with the onset of a burning sensation. The aim of this research was to perform photobiomodulation therapy (PBM) using a diode laser on the oral mucosa of BMS patients, followed by an objective evaluation of the morphological changes in the vascular bed underlying the mucosa using polarized light videocapillaroscopy. A group of 40 patients were included in the study. The patients were randomly divided into two groups (using simple randomization) as follows: 20 patients were assigned to the laser group and 20 patients were assigned to the placebo group. Each patient of the laser group received eight irradi…

Optimization of CASA-Mot Analysis of Donkey Sperm : optimum Frame Rate and Values of Kinematic Variables for Different Counting Chamber and Fields

2020

In order to optimize the donkey sperm motility analysis by the CASA (Computer Assisted Sperm Analysis)-Mot system, twelve ejaculates were collected from six jackasses. Capillary loaded chamber (CLC), ISAS&reg