Search results for "Magnitude"

On the Schwarzschild Effect in 3D Two‐Photon Laser Lithography

2019

International audience; The two‐photon Schwarzschild effect in photoresists suitable for 3D laser lithography is revisited. The study ranges over seven orders of magnitude in exposure time (from 1 µs to 10 s) and investigates a wide variety of different photoresist compositions. For short exposure times (“regime I”), the laser power at the polymerization threshold can scale with the inverse square root of the exposure time, as naively to be expected for two‐photon absorption. Substantial deviations occur, however, for low photoinitiator concentrations. For intermediate exposure times (“regime II”), a Schwarzschild‐type of behavior is found, as discussed previously. For very long exposure ti…

Pre-main-sequence stars older than 8 Myr in the Eagle nebula

2013

Root topology and allocation patterns of Atriplex patula supplied with different nutrient concentrations

2007

To test whether sub-optimal available nutrient concentrations would result in a more herringbone root branching pattern, in lower root diameters, and in greater resource allocation to root growth than to above-ground portions, seedlings of Atriplex patula were grown under optimal (full), intermediate (1/3 full), and low (1/6 full) nutrient treatments. No significant differences were found between the full and 1/3 nutrient treatments for any of the parameters tested. Root topologies did not show conclusive responses to nutrient availability, however roots treated with 1/6 nutrient concentration showed the tendency to grow in a more herringbone pattern. Total dry weights and shoot dry weights…

Honest mistake or perhaps not: The role of descriptive and injunctive norms on the magnitude of dishonesty

2021

Trivial acts of dishonesty are very prevalent in everyday life and have severe economic and societal consequences. The present study aims to examine the role of descriptive and injunctive norms in minor and major dishonesty under ambiguity. We devised a novel experimental design in which rule violations can be the result of honest mistakes or various dishonest processes. In this ambiguous context, we observed a high prevalence of minor rule violations at baseline. In two experiments, exposure to increased peer cheating (i.e., negative descriptive norms) promoted major rule violations, whereas the presence of explicit or subtle rule reminders (i.e., injunctive norms) marginally reduced minor…

Three-Dimensional Simulations of Solar Wind Preconditioning and the 23 July 2012 Interplanetary Coronal Mass Ejection

2020

Predicting the large-scale eruptions from the solar corona and their propagation through interplanetary space remains an outstanding challenge in solar- and helio-physics research. In this article, we describe three dimensional magnetohydrodynamic simulations of the inner heliosphere leading up to and including the extreme interplanetary coronal mass ejection (ICME) of 23 July 2012, developed using the code PLUTO. The simulations are driven using the output of coronal models for Carrington rotations 2125 and 2126 and, given the uncertainties in the initial conditions, are able to reproduce an event of comparable magnitude to the 23 July ICME, with similar velocity and density profiles at 1 …

Evaluation of yogurt and various beverages as carriers of lactic acid bacteria producing 2-branched (1,3)-β-D-glucan

2011

8 páginas, 2 figuras, 2 tablas -- PAGS nros. 3271-3278

Fluorescence and amplified spontaneous emission of glass forming compounds containing styryl-4H-pyran-4-ylidene fragment

2012

Potential of glassy films of newly synthesised low molecular weight organic molecules for light amplification and lasing applications has been investigated by analysing fluorescence, transient differential absorption and amplified spontaneous emission properties. These non-symmetric and symmetric molecules contain styryl-4H-pyran-4-ylidene fragment with three different electron acceptor groups: dicyanomethylene, barbituric acid, indene-1,3-dione. Fluorescence quantum yields of the investigated compounds in solutions are between 0.32 and 0.54, while they drop down by an order of magnitude in thin solid films. Incorporation of bulky side groups reduced excitonic interactions enabling manifest…

Polyelectrolytes:  Intrinsic Viscosities in the Absence and in the Presence of Salt

2008

Intrinsic viscosities were determined at 25 °C for 10 samples of narrowly distributed sodium polystyrene sulfonate (the molecular weights M ranging from 0.9 to 1000 kg/mol) in pure water and in aqueous solutions containing 0.9 wt % NaCl from the slope of ln ηrel versus polymer concentration. In the middle range of M, the [η] values are in the former case almost 2 orders of magnitude larger than in the latter case. In the absence of salt, the plot of log [η] as a function of log M exhibits a sigmoidal shape, which can be approximated within the interval 3 < M (in kg mol-1) < 30 by log[η] = −0.17 + 2.1 log M. In the presence of salt, the following relation holds true in the entire regime:  lo…

Precipitation chromatography. III. Optimization of the experimental conditions and determination of the polydispersity of fractions

1974

The influence of the solvent–nonsolvent gradient and the temperature gradient on the efficiency of the precipitation chromatography is investigated with radically and anionically prepared polystyrene samples. Only a combination of both gradients gives optimal effectiveness of the column. The separating power of the column was determined by using mixtures of well defined samples. From the elution curves of the mixtures the nonuniformity Ufr of fractions can be estimated. For fractions of anionically prepared polystyrenes Ufr is on the average 0.001; this value is of the same order of magnitude as the statistical error. These results show that with this chromatographic method it is possible t…

Enhanced thermoelectric performance of PEDOT with different counter-ions optimized by chemical reduction

2014

This work reports on the synthesis of the intrinsically conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) doped with several counter-ions, ClO4, PF6 and bis(trifluoromethylsulfonyl)imide (BTFMSI), by electro-polymerization and its thermoelectric properties. We show that, depending on the counter-ion size, the thermoelectric efficiency of PEDOT can be increased up to two orders of magnitude. A further chemical reduction with hydrazine optimizes the power factor (PF). By changing the counter-ions, we were able to increase the electrical conductivity (σ) of PEDOT by a factor of three, while the Seebeck coefficient remains at the same order of magnitude in the three polymers. The best…