Low-Temperature Mobility of Thionine in a Faujasite Cage

1994 ◽  
Vol 366 ◽  
Author(s):  
F. W. Deeg ◽  
M. Ehrl ◽  
C. Bräuchle
Keyword(s):  
Low Temperature ◽  
Pore Structure ◽  
Zeolite Y ◽  
Three Dimensional ◽  
Molecular Size ◽  
Energy Difference ◽  
Temperature Dependent ◽  
Host Interaction ◽  
The Relationship

ABSTRACTWe have used low-temperature optical spectroscopy to characterize the guest/host interaction of thiazine and oxazine dyes encapsulated in the three-dimensional pore structure of faujasite cages. The system thionine in dehydrated zeolite-Y exhibits a thermal and optical equilibrium between two spectroscopically distinguishable species. Temperature-dependent measurements allow the determination of the energy difference and barrier between these two forms as 170 cm−1 and 120 cm−1, respectively. The two forms are associated with two different locations/conformations of the chromophore within the faujasite pore structure. The degree of freedom responsible for the interconversion of the two forms is extremely sensitive to the relationship between molecular size and form of the void.

Calculation of Shell Element Failure Based on the State of Stress Inside of a Neck

2015 ◽  
Author(s):  
R. C. Dragt ◽  
J. Kraus ◽  
C. L. Walters
Keyword(s):  
Three Dimensional ◽  
Shell Element ◽  
Offshore Structures ◽  
Shell Elements ◽  
Thin Walled Structures ◽  
Coulomb Failure ◽  
Correct Determination ◽  
Element Failure ◽  
The Relationship

Simulation of failure in thin-walled structures is critical for the correct determination of crash performance of ships and offshore structures. Typically, shell elements are used, but these elements are not able to adequately capture local failure, especially inside of a neck. This paper addresses these gaps by adapting the Bridgman (1952) model of a neck inside of a plate by making it three-dimensional and offering an estimate of the relationship between state parameters of a shell element and the geometry inside of a neck. Finally, recommendations are also made about how to interface this information with the Modified Mohr-Coulomb failure locus to create a practical algorithm for assessing failure in shell elements.

scholarly journals Temperature-Dependent Broadening of the Ultraviolet Photoelectron Spectrum of Au(110)

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5969
Author(s):  
Tomonari Nishida ◽  
Ikuo Kinoshita ◽  
Juntaro Ishii
Keyword(s):  
Fourier Transform ◽  
Temperature Dependence ◽  
Photoelectron Spectroscopy ◽  
Photoelectron Spectrum ◽  
Thermodynamic Temperature ◽  
Temperature Dependent ◽  
Photoelectron Emission ◽  
The Fourier Transform ◽  
The Relationship

To determine the thermodynamic temperature of a solid surface from the electron energy distribution measured by photoelectron spectroscopy, it is necessary to accurately evaluate the energy broadening of the photoelectron spectrum and investigate its temperature dependence. Broadening functions in the photoelectron spectrum of Au(110)’s surface near the Fermi level were estimated successfully using the relationship between the Fourier transform and the convolution integral. The Fourier transform could simultaneously reduce the noise of the spectrum when the broadening function was derived. The derived function was in the form of a Gaussian, whose width depended on the thermodynamic temperature of the sample and became broader at higher temperatures. The results contribute to improve accuracy of the determination of thermodynamic temperature from the photoelectron spectrum and provide useful information on the temperature dependence of electron scattering in photoelectron emission processes.

The Temperature Dependence of Band Maxima Molar Absorptivities of the Carbon-Bromine Stretching Modes in n-Butyl Bromide in the Liquid Phase

1987 ◽  
Vol 41 (5) ◽  
pp. 807-809 ◽  
Author(s):  
J. E. Katon ◽  
Stanislaus R. Lobo ◽  
J. C. Simpson
Keyword(s):  
Mathematical Model ◽  
Infrared Spectroscopy ◽  
Liquid Phase ◽  
Temperature Dependence ◽  
Energy Difference ◽  
Temperature Dependent ◽  
Butyl Bromide ◽  
Absorption Bands ◽  
A Value

In the determination of energy differences of conformers in the fluid states by infrared spectroscopy it is nearly always assumed that the ratio of the molar absorptivities at the band maxima of two separate absorption bands is independent of temperature. This assumption has been tested by fitting the data obtained from n-butyl bromide to a mathematical model which can be iterated to convergence on a value of the energy difference between the trans and gauche isomers. The data utilized are the C-Br stretching modes of the two conformers at about 655 and 567 cm−1, respectively. It is shown that the assumption of temperature independence of the ratios of the molar absorptivities at the peak maxima is a good one, although both values are individually temperature dependent.

Preoperative determination of anatomic variations of the small saphenous vein for varicose vein surgery by three-dimensional computed tomography venography

2011 ◽  
Vol 27 (5) ◽  
pp. 235-241 ◽  
Author(s):  
S-Y Kim ◽  
E-A Park ◽  
Y-C Shin ◽  
S-I Min ◽  
W Lee ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Saphenous Vein ◽  
Varicose Vein ◽  
Preoperative Evaluation ◽  
Three Dimensional ◽  
Anatomical Variations ◽  
The Impact ◽  
The Relationship ◽  
Computed Tomography Venography

Objective To define the anatomical variations of small saphenous vein (SSV) for varicose vein (VV) surgery by three-dimensional computed tomography venography (3D-CTV) and to analyse the impact of this preoperative evaluation on surgical outcomes. Methods A total of 120 consecutive limbs with SSV insufficiency having undergone VV surgery from January 2005 until December 2007 were enrolled. The medical records and images were analysed retrospectively. Results The relationship between SSV and gastrocnemial vein (GNV) were categorized into two: (a) SSV and GNV drained to popliteal vein (PV) separately (100 limbs, 87%) and (b) SSV and GNV made common channel which drained to PV (15 limbs, 13%). Saphenopopliteal junction morphology was normal (75 limbs), severe tortuosity near PV (19 limbs), ampullary ectasia (4 limbs) and duplicated drainage to PV (2 limbs). No recurrence of VV was noted. Conclusions CTV can provide thorough preoperative anatomic information of the SSV variations and reduce the recurrence of VV.

scholarly journals Experimental determination of the temperature dependence of oxygen-isotope fractionation between water and chitinous head capsules of chironomid larvae

2021 ◽  
Author(s):  
Alex Lombino ◽  
Tim Atkinson ◽  
Stephen J. Brooks ◽  
Darren R. Gröcke ◽  
Jonathan Holmes ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Oxygen Isotope ◽  
Oxygen Isotopes ◽  
Isotope Fractionation ◽  
Temperature Dependent ◽  
Oxygen Isotope Fractionation ◽  
Chironomid Larvae ◽  
Increasing Temperature ◽  
The Relationship

AbstractOxygen-isotope values of invertebrate cuticle preserved in lake sediments have been used in palaeoenvironmental reconstructions, generally with the assumption that fractionation of oxygen isotopes between cuticle and water ($$\upalpha_{\text{cuticle}-\text{H}_{2}\text{O}}$$ α cuticle - H 2 O ) is independent of temperature. We cultured chironomid larvae in the laboratory with labelled oxygen-isotope water and across a range of closely controlled temperatures from 5 to 25 °C in order to test the hypothesis that fractionation of oxygen isotopes between chironomid head capsules and water ($$\upalpha_{\text{chironomid}-\text{H}_{2}\text{O}}$$ α chironomid - H 2 O ) is independent of temperature. Results indicate that the hypothesis can be rejected, and that $$\upalpha_{\text{chironomid}-\text{H}_{2}\text{O}}$$ α chironomid - H 2 O decreases with increasing temperature. The scatter in the data suggests that further experiments are needed to verify the relationship. However, these results indicate that temperature-dependence of $$\upalpha_{\text{chironomid}-\text{H}_{2}\text{O}}$$ α chironomid - H 2 O should be considered when chironomid δ18O is used as a paleoenvironmental proxy, especially in cases where data from chironomids are combined with oxygen-isotope values from other materials for which fractionation is temperature dependent, such as calcite, in order to derive reconstructions of past water temperature.

scholarly journals Limit loads for centrally cracked square plates under biaxial tension

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Marcin Graba
Keyword(s):  
Biaxial Tension ◽  
Three Dimensional ◽  
Limit Load ◽  
Plane Stress State ◽  
Load Factor ◽  
Specimen Thickness ◽  
Limit Loads ◽  
Biaxial Load ◽  
The Relationship

Abstract This paper is concerned with the determination of limit loads for centrally cracked square plates subjected to biaxial tension. It briefly discusses the concept of limit loads and some aspects of numerical modelling. It presents results of numerical calculations conducted for two-dimensional (plane strain state and plane stress state) and three-dimensional cases. It also considers the relationship between the limit load and the crack length, the specimen thickness, the yield strength and the biaxial load factor, defined for the purpose of this work. The paper includes approximation formulae to calculate the limit load.

scholarly journals Determination of surfaces in three-dimensional Minkowski and Euclidean spaces based on solutions of the Sinh-Laplace equation

2005 ◽  
Vol 2005 (9) ◽  
pp. 1393-1404 ◽  
Author(s):  
Paul Bracken
Keyword(s):  
Laplace Equation ◽  
Gaussian Curvature ◽  
Three Dimensional ◽  
Lax Pair ◽  
Constant Gaussian Curvature ◽  
Coordinate Vector ◽  
Particular Solution ◽  
Fundamental Equations ◽  
The Relationship

The relationship between solutions of the sinh-Laplace equation and the determination of various kinds of surfaces of constant Gaussian curvature, both positive and negative, will be investigated here. It is shown that when the metric is given in a particular set of coordinates, the Gaussian curvature is related to the sinh-Laplace equation in a direct way. The fundamental equations of surface theory are found to yield a type of geometrically based Lax pair for the system. Given a particular solution of the sinh-Laplace equation, this Lax can be integrated to determine the three fundamental vectors related to the surface. These are also used to determine the coordinate vector of the surface. Some specific examples of this procedure will be given.

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