Search results for "Step"

Refractometric sensor based on whispering-gallery modes of thin capillarie.

2009

Whispering-gallery modes resonances of submicron wall thickness capillaries exhibit very large wavelength shifts as a function of the refractive index of the medium that fills the inside. The sensitivity to refractive index changes is larger than in other optical microcavities as microspheres, microdisks and microrings. The outer surface where total internal reflection takes place remains always in air, enabling the measure of refractive index values higher than the refractive index of the capillary material. The fabrication of capillaries with submicron wall thickness has required the development of a specific technique. A refractometer with a response higher than 390 nm per refractive ind…

Air Traffic, Boarding and Scaling Exponents

2014

The air traffic is a very important part of the global transportation network. In distinction from vehicular traffic, the boarding of an airplane is a significant part of the whole transportation process. Here we study an airplane boarding model, introduced in 2012 by Frette and Hemmer, with the aim to determine precisely the asymptotic power–law scaling behavior of the mean boarding time 〈t b 〉 and other related quantities for large number of passengers N. Our analysis is based on an exact enumeration for small system sizes N ≤ 14 and Monte Carlo simulation data for very large system sizes up to \(N = 2^{16} = 65,536\). It shows that the asymptotic power–law scaling 〈t b 〉 ∝ N α holds with…

A facile chemoenzymatic approach: one-step syntheses of monoterpenoid indole alkaloids.

2010

Facile chemoenzymatic syntheses of cytotoxic monoterpenoid indole alkaloids with novel skeletons and multiple chiral centers are described. Synthesis of these alkaloids was achieved by a simple one-step reaction using strictosidine and 12-aza-strictosidine as the key intermediates. Strictosidines were prepared by coupling of secologanin with tryptamine and 7-aza-tryptamine, respectively, using the immobilized recombinant Rauvolfia strictosidine synthase. A detailed stereochemical analysis is presented herein. The results provide an opportunity for a chemoenzymatic approach that leads to an increased diversification of complex alkaloids with improved structures and activities.

Predictive Study of Heat Transfer to an Incompressible Fluid Past a Downstream-Facing Step in Turbulent Flow

1988

Magmatism Along Lateral Slab Edges: Insights From the Diamante-Enotrio-Ovidio Volcanic-Intrusive Complex (Southern Tyrrhenian Sea)

2019

Volcanic‐intrusive complexes often formed along lateral slab edges as a consequence of subduction‐induced mantle flow. We investigate this process in the southern Tyrrhenian Sea by integrating multibeam bathymetry, seismic‐reflection data, regional magnetic anomalies data, and seismological data. The interpretation of the data highlights the presence of magmatic intrusions that locally reach the seafloor forming volcanic edifices. Chimneys, lava flows, and laccoliths are observed beneath and surrounding the volcanoes. The emplacement and cooling of the magma occurred during the Brunhes Chron. The volcanoes are not active even if the hydrothermal activity occurs. The volcanic‐intrusive compl…

Shear bond strength of one-step self-etch adhesives to dentin: Evaluation of NaOCl pretreatment

2018

Background The aim of this study was to evaluate the influence of dentin pretreatment with NaOCl on shear bond strength of four one-step self-etch adhesives with different pH values. Material and methods Bovine permanent incisors were used. Four one-step self-etch adhesives were tested: Adper™ Easy Bond, Futurabond NR, G-aenial Bond, Clearfil S3 Bond. One two-step self-etch adhesive (Clearfil SE Bond) was used as control. Group 1- no pretreatment; group 2- pretratment with 5,25 % NaOCl; group 3- pretreatment with 37 % H3PO4 etching and 5,25 % NaOCl. A hybrid composite resin was inserted into the dentin surface. The specimens were tested in a universal testing machine. The examiners evaluate…

Adaptive Tracking Control of Nonlinear Time-Varying Systems with Unknown Control Coefficients and Unknown Time-Varying Parameters

2019

This paper investigates the tracking control of a class of strict-feedback uncertain nonlinear systems in the presence of unknown signs of control coefficients and unknown time-varying parameters as well as unknown disturbances. A robust adaptive controller and a new decoupled backstepping approach to stability analysis are developed by constructing a new compensation scheme. By introducing a Nussbaum function and a new type of hyperbolic tangent function, the effects of unknown time-varying parameters and unknown control coefficients are effectively compensated. By using the decoupled backstepping technique, it is proved that under the proposed control, all closed-loop states are uniform u…

Pimeydestä päivänvaloon : 2000-luvun alun vampyyri - kasvissyöjä, rakastaja ja tappaja

2011

Tutkin sivututkielmassani millainen 2000-luvun alun vampyyri on ja millainen sen suhde on aiempaan vampyyrikirjallisuuteen ja vampyyriperinteeseen. Tutkielman motivaatio ja tärkeys nousevat omasta kiinnostuksesta vampyyrikirjallisuuteen sekä vampyyrin ja yliluonnollisuuden kulttuurisesta ajankohtaisuudesta. Tutkielma perustuu Charlaine Harrisin Dead until dark, Stephenie Meyerin Twilight ja J. R. Wardin Dark lover romaanien tarkkaan lukemiseen ja esiin nousevien piirteiden yhdistämiseen ja vertailuun. Vertailen nykyvampyyria vampyyrikirjallisuuden lähtökohtiin eli goottilaiseen romaaniin, gotiikkaan ja kauhukirjallisuuteen sekä vampyyrikirjallisuuden omaan historiaan intertekstuaalisuuden j…

Simple method for measuring bilayer system optical parameters

2012

A simple method for measuring bilayer system refractive indexes and thicknesses in the low absorbing part of spectra is demonstrated. The method is based on application of Savitzky - Golay smoothing filters and interference fringe separation in the reflected or transmitted spectra of the bilayer system. The refractive indexes and thicknesses are extracted from the wavelengths corresponding to extreme points in the spectrum. Due to the fact that wavelength difference of extreme points in the analyzed spectrum is defined by the product of both, the layer thickness and refractive index, one must generate an appropriate initial guess of these parameters. For refractive index approximation two d…

Varietal and geographic classification of french red wines in terms of major acids

1989

Concentrations of acids other than malic and lactic appeared to be related more to area of production than to grape variety. These variables (2- hydroxyglutaric, butyric and isovaleric acid concentrations) were attributed to differences in the technological process used for vinification in the various areas. Shikimic and galacturonic acids were helpful for classifying and discriminating wine varieties. Principal component analysis characterised Cabernet Franc, Grenache and Carignan wines well by their acid content but failed to discriminate Merlot from Cabernet Sauvignon and Cinsault. Stepwise discriminant analysis allowed a clear separation of all wines according to the different varieties…