scholarly journals The water vapour self- and water–nitrogen continuum absorption in the 1000 and 2500 cm −1 atmospheric windows

2012 ◽  
Vol 370 (1968) ◽  
pp. 2578-2589 ◽  
Author(s):  
Yu. I. Baranov ◽  
W. J. Lafferty
Keyword(s):  
Experimental Data ◽  
Water Vapour ◽  
Continuum Model ◽  
Pure Water ◽  
Laboratory Data ◽  
The Other ◽  
Continuum Absorption ◽  
Infrared Spectrometer ◽  
Atmospheric Windows ◽  
The Continuum

The pure water vapour and water–nitrogen continuum absorption in the 1000 and 2500 cm −1 atmospheric windows has been studied using a 2 m base-length White-type multi-pass cell coupled with a BOMEM DA3-002 Fourier transform infrared spectrometer. The measurements were carried out at the National Institute of Standards and Technology (NIST, Gaithersburg, MD) over the course of several years (2004, 2006–2007, 2009). New data on the H 2 O:N 2 continuum in the 1000 cm −1 window are presented and summarized along with the other experimental results and the continuum model. The experimental data reported on the water vapour continuum in these atmospheric windows basically agree with the most reliable laboratory data from the other sources. The MT_CKD (MlawerTobinCloughKneizysDavies) continuum model significantly departs from the experimental data in both windows. The deviation observed includes the continuum magnitude, spectral behaviour and temperature dependence. In the 2500 cm −1 region, the model does not allow for the nitrogen fundamental collision-induced absorption (CIA) band intensity enhancement caused by H 2 O:N 2 collisions and underestimates the actual absorption by over two orders of magnitude. The water vapour continuum interpretation as a typical CIA spectrum is reviewed and discussed.

scholarly journals Development and recent evaluation of the MT_CKD model of continuum absorption

2012 ◽  
Vol 370 (1968) ◽  
pp. 2520-2556 ◽  
Author(s):  
Eli J. Mlawer ◽  
Vivienne H. Payne ◽  
Jean-Luc Moncet ◽  
Jennifer S. Delamere ◽  
Matthew J. Alvarado ◽  
...  
Keyword(s):  
Water Vapour ◽  
Line Shape ◽  
Mathematical Formulation ◽  
Field Measurements ◽  
Continuum Absorption ◽  
Semi Empirical ◽  
Vapour Molecule ◽  
Primary Agent ◽  
The Continuum

Water vapour continuum absorption is an important contributor to the Earth's radiative cooling and energy balance. Here, we describe the development and status of the MT_CKD (MlawerTobinCloughKneizysDavies) water vapour continuum absorption model. The perspective adopted in developing the MT_CKD model has been to constrain the model so that it is consistent with quality analyses of spectral atmospheric and laboratory measurements of the foreign and self continuum. For field measurements, only cases for which the characterization of the atmospheric state has been highly scrutinized have been used. Continuum coefficients in spectral regions that have not been subject to compelling analyses are determined by a mathematical formulation of the spectral shape associated with each water vapour monomer line. This formulation, which is based on continuum values in spectral regions in which the coefficients are well constrained by measurements, is applied consistently to all water vapour monomer lines from the microwave to the visible. The results are summed-up (separately for the foreign and self) to obtain continuum coefficients from 0 to 20 000 cm −1 . For each water vapour line, the MT_CKD line shape formulation consists of two components: exponentially decaying far wings of the line plus a contribution from a water vapour molecule undergoing a weak interaction with a second molecule. In the MT_CKD model, the first component is the primary agent for the continuum between water vapour bands, while the second component is responsible for the majority of the continuum within water vapour bands. The MT_CKD model should be regarded as a semi-empirical model with strong constraints provided by the known physics. Keeping the MT_CKD continuum consistent with current observational studies necessitates periodic updates to the water vapour continuum coefficients. In addition to providing details on the MT_CKD line shape formulation, we describe the most recent update to the model, MT_CKD_2.5, which is based on an analysis of satellite- and ground-based observations from 2385 to 2600 cm −1 (approx. 4 μm).

scholarly journals Discrete versus homogenized continuum modeling in finite deformation bias extension test of bi-pantographic fabrics

2020 ◽  
Author(s):  
E. Barchiesi ◽  
J. Harsch ◽  
G. Ganzosch ◽  
S. R. Eugster
Keyword(s):  
Experimental Data ◽  
Discrete Model ◽  
Continuum Model ◽  
Raw Material ◽  
Image Correlation ◽  
Generalized Coordinates ◽  
Bias Extension ◽  
Constitutive Parameters ◽  
Pantographic Fabrics ◽  
The Continuum

Abstract A 2D-continuum model describing finite deformations in plane of discrete bi-pantographic fabrics has been recently obtained by applying an asymptotic procedure based on a set of local generalized coordinates. Rectangular bi-pantographic prototypes were additively manufactured by selective laser sintering using polyamide as raw material. Displacement-controlled bias extension tests were performed on such specimens for total elastic deformations up to ca. 25%. Experimental force measurements, complemented by discrete displacement measurements obtained by local digital image correlation, were used to fit the continuum model. In the present paper, a global and minimal set of generalized coordinates, alternative to the one used for the homogenization, is introduced for the discrete model. The mechanical constitutive parameters appearing in the discrete model are then found by means of collected experimental data. Finally, a comparison between experiments, the discrete and the continuum model is presented. It is concluded that (a) the discrete model and the experimental data are in excellent agreement, and that (b) the continuum retains the relevant phenomenology of the discrete system even for a rather low number of cells.

scholarly journals Mechanical interactions between adjacent airways in the lung

2014 ◽  
Vol 116 (6) ◽  
pp. 628-634 ◽  
Author(s):  
Baoshun Ma ◽  
Jason H. T. Bates
Keyword(s):  
Computational Model ◽  
Continuum Model ◽  
Network Models ◽  
The Other ◽  
Two Dimensional ◽  
Elastic Continuum ◽  
Spring Network Model ◽  
Triangular Network ◽  
One Airway ◽  
The Continuum

The forces of mechanical interdependence between the airways and the parenchyma in the lung are powerful modulators of airways responsiveness. Little is known, however, about the extent to which adjacent airways affect each other's ability to narrow due to distortional forces generated within the intervening parenchyma. We developed a two-dimensional computational model of two airways embedded in parenchyma. The parenchyma itself was modeled in three ways: 1) as a network of hexagonally arranged springs, 2) as a network of triangularly arranged springs, and 3) as an elastic continuum. In all cases, we determined how the narrowing of one airway was affected when the other airway was relaxed vs. when it narrowed to the same extent as the first airway. For the continuum and triangular network models, interactions between airways were negligible unless the airways lay within about two relaxed diameters of each other, but even at this distance the interactions were small. By contrast, the hexagonal spring network model predicted that airway-airway interactions mediated by the parenchyma can be substantial for any degree of airway separation at intermediate values of airway contraction forces. Evidence to date suggests that the parenchyma may be better represented by the continuum model, which suggests that the parenchyma does not mediate significant interactions between narrowing airways.

scholarly journals The water vapour self-continuum absorption in the infrared atmospheric windows: new laser measurements near 3.3 and 2.0 µm

2018 ◽  
Vol 11 (4) ◽  
pp. 2159-2171 ◽  
Author(s):  
Loic Lechevallier ◽  
Semen Vasilchenko ◽  
Roberto Grilli ◽  
Didier Mondelain ◽  
Daniele Romanini ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Water Vapour ◽  
Cross Sections ◽  
Optical Feedback ◽  
Molecular Spectroscopy ◽  
The Self ◽  
Continuum Absorption ◽  
Laser Measurements ◽  
Enhanced Absorption ◽  
Atmospheric Windows

Abstract. The amplitude, the temperature dependence, and the physical origin of the water vapour absorption continuum are a long-standing issue in molecular spectroscopy with direct impact in atmospheric and planetary sciences. In recent years, we have determined the self-continuum absorption of water vapour at different spectral points of the atmospheric windows at 4.0, 2.1, 1.6, and 1.25 µm, by highly sensitive cavity-enhanced laser techniques. These accurate experimental constraints have been used to adjust the last version (3.2) of the semi-empirical MT_CKD model (Mlawer-Tobin_Clough-Kneizys-Davies), which is widely incorporated in atmospheric radiative-transfer codes. In the present work, the self-continuum cross-sections, CS, are newly determined at 3.3 µm (3007 cm−1) and 2.0 µm (5000 cm−1) by optical-feedback-cavity enhanced absorption spectroscopy (OFCEAS) and cavity ring-down spectroscopy (CRDS), respectively. These new data allow extending the spectral coverage of the 4.0 and 2.1 µm windows, respectively, and testing the recently released 3.2 version of the MT_CKD continuum. By considering high temperature literature data together with our data, the temperature dependence of the self-continuum is also obtained.

scholarly journals Recent advances in measurement of the water vapour continuum in the far-infrared spectral region

2012 ◽  
Vol 370 (1968) ◽  
pp. 2637-2655 ◽  
Author(s):  
Paul D. Green ◽  
Stuart M. Newman ◽  
Ralph J. Beeby ◽  
Jonathan E. Murray ◽  
Juliet C. Pickering ◽  
...  
Keyword(s):  
Water Vapour ◽  
Spectral Band ◽  
Far Infrared ◽  
Ir Radiation ◽  
Continuum Absorption ◽  
Pure Rotation ◽  
Wide Range ◽  
Infrared Spectral ◽  
Research Aircraft ◽  
The Continuum

We present a new derivation of the foreign-broadened water vapour continuum in the far-infrared (far-IR) pure rotation band between 24 μm and 120 μm (85–420 cm −1 ) from field data collected in flight campaigns of the Continuum Absorption by Visible and IR radiation and Atmospheric Relevance (CAVIAR) project with Imperial College's Tropospheric Airborne Fourier Transform Spectrometer (TAFTS) far-IR spectro-radiometer instrument onboard the Facility for Airborne Atmospheric Measurement (FAAM) BAe-146 research aircraft; and compare this new derivation with those recently published in the literature in this spectral band. This new dataset validates the current Mlawer–Tobin-Clough–Kneizys–Davies (MT-CKD) 2.5 model parametrization above 300 cm −1 , but indicates the need to strengthen the parametrization below 300 cm −1 , by up to 50 per cent at 100 cm −1 . Data recorded at a number of flight altitudes have allowed measurements within a wide range of column water vapour environments, greatly increasing the sensitivity of this analysis to the continuum strength.

C. The Continuous Spectrum of Pulsating Variable Stars

1967 ◽  
Vol 28 ◽  
pp. 177-206
Author(s):  
J. B. Oke ◽  
C. A. Whitney
Keyword(s):  
Continuous Spectrum ◽  
Variable Stars ◽  
Velocity Fields ◽  
The Other ◽  
Line Spectrum ◽  
Direct Information ◽  
Thermodynamic Structure ◽  
Diagnostic Interpretation ◽  
Pulsating Variable Stars ◽  
The Continuum

Pecker:The topic to be considered today is the continuous spectrum of certain stars, whose variability we attribute to a pulsation of some part of their structure. Obviously, this continuous spectrum provides a test of the pulsation theory to the extent that the continuum is completely and accurately observed and that we can analyse it to infer the structure of the star producing it. The continuum is one of the two possible spectral observations; the other is the line spectrum. It is obvious that from studies of the continuum alone, we obtain no direct information on the velocity fields in the star. We obtain information only on the thermodynamic structure of the photospheric layers of these stars–the photospheric layers being defined as those from which the observed continuum directly arises. So the problems arising in a study of the continuum are of two general kinds: completeness of observation, and adequacy of diagnostic interpretation. I will make a few comments on these, then turn the meeting over to Oke and Whitney.

EELS white line intensities calculated for the 3d and 4d metals

1989 ◽  
Vol 47 ◽  
pp. 388-389
Author(s):  
C. C. Ahn ◽  
D. H. Pearson ◽  
P. Rez ◽  
B. Fultz
Keyword(s):  
Experimental Data ◽  
Line Intensity ◽  
Transition Probabilities ◽  
Initial Increase ◽  
White Line ◽  
Hartree Fock ◽  
Line Intensities ◽  
Integrated Intensity ◽  
X Ray Absorption ◽  
The Continuum

Previous experimental measurements of the total white line intensities from L2,3 energy loss spectra of 3d transition metals reported a linear dependence of the white line intensity on 3d occupancy. These results are inconsistent, however, with behavior inferred from relativistic one electron Dirac-Fock calculations, which show an initial increase followed by a decrease of total white line intensity across the 3d series. This inconsistency with experimental data is especially puzzling in light of work by Thole, et al., which successfully calculates x-ray absorption spectra of the lanthanide M4,5 white lines by employing a less rigorous Hartree-Fock calculation with relativistic corrections based on the work of Cowan. When restricted to transitions allowed by dipole selection rules, the calculated spectra of the lanthanide M4,5 white lines show a decreasing intensity as a function of Z that was consistent with the available experimental data.Here we report the results of Dirac-Fock calculations of the L2,3 white lines of the 3d and 4d elements, and compare the results to the experimental work of Pearson et al. In a previous study, similar calculations helped to account for the non-statistical behavior of L3/L2 ratios of the 3d metals. We assumed that all metals had a single 4s electron. Because these calculations provide absolute transition probabilities, to compare the calculated white line intensities to the experimental data, we normalized the calculated intensities to the intensity of the continuum above the L3 edges. The continuum intensity was obtained by Hartree-Slater calculations, and the normalization factor for the white line intensities was the integrated intensity in an energy window of fixed width and position above the L3 edge of each element.

The Continuum of Conscientiousness: The Antagonistic Interests among Obsessive and Antisocial Personalities

2014 ◽  
Vol 45 (2) ◽  
pp. 167-178 ◽  
Author(s):  
Steven C. Hertler
Keyword(s):  
Personality Disorder ◽  
Evolutionary Theory ◽  
Antisocial Personality Disorder ◽  
The Other ◽  
Antisocial Personality ◽  
Obsessive Compulsive ◽  
Demographic Differences ◽  
Other Hand ◽  
The Continuum

Abstract The five factor trait of conscientiousnessis a supertrait, denoting on one hand a pattern of excessive labor, rigidity, orderliness and compulsivity,and on the other hand a pattern of strict rectitude, scrupulosity, dutifulness and morality. In both respects the obsessive-compulsive personality is conscientious; indeed, it has been labeled a disorder of extreme conscientiousness (Widiger et al., 2009). Antisocial personality disorder, in the present paper, is described as occupying the opposite end of the conscientiousness continuum. The antisocial is impulsive rather than compulsive, illicit rather than licit, and furtive rather than forthright.After clinically comparing the obsessive and antisocial personalities, the present paper invokes evolutionary theory to explain their resultant behavioral, ideological, political and demographic differences.

On Commutation Properties of the Composition Relation of Convergent and Divergent Permutations (Part I)

2014 ◽  
Vol 58 (1) ◽  
pp. 13-22
Author(s):  
Roman Wituła ◽  
Edyta Hetmaniok ◽  
Damian Słota
Keyword(s):  
Finite Order ◽  
Convergent Series ◽  
The Other ◽  
Other Hand ◽  
The Family ◽  
Composition Relation ◽  
The Continuum

Abstract In the paper we present the selected properties of composition relation of the convergent and divergent permutations connected with commutation. We note that a permutation on ℕ is called the convergent permutation if for each convergent series ∑an of real terms, the p-rearranged series ∑ap(n) is also convergent. All the other permutations on ℕ are called the divergent permutations. We have proven, among others, that, for many permutations p on ℕ, the family of divergent permutations q on ℕ commuting with p possesses cardinality of the continuum. For example, the permutations p on ℕ having finite order possess this property. On the other hand, an example of a convergent permutation which commutes only with some convergent permutations is also presented.

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