Direct-fitting approach to the analysis of high-resolution optical spectra: Monte Carlo and experimental studies of OH A(0)→X(0) spectra

2001 ◽  
Vol 114 (8) ◽  
pp. 3465-3475 ◽  
Author(s):  
Joel Tellinghuisen
Keyword(s):  
Monte Carlo ◽  
High Resolution ◽  
Experimental Studies ◽  
Optical Spectra

Porous Aluminophosphates as Adsorbents for the Separation of CO2/CH4 and CH4/N2 Mixtures – a Monte Carlo Simulation Study

2018 ◽  
Author(s):  
Michael Fischer
Keyword(s):  
Monte Carlo ◽  
Landfill Gas ◽  
Experimental Studies ◽  
Chem Phys ◽  
Monte Carlo Simulation Study ◽  
Mixture Adsorption ◽  
Vacuum Swing Adsorption ◽  
Separation Of Co2 ◽  
Pressure Swing ◽  
Gcmc Simulations

<div>Aluminophosphates with zeolite-like topologies (AlPOs) have received considerable attention as potential adsorbents for use in the separation of methane-containing gas mixtures. Such separations, especially the removal of carbon dioxide and nitrogen from methane, are of great technological relevance in the context of the “upgrade” of natural gas, landfill gas, and biogas. While more than 50 zeolite frameworks have been synthesised in aluminophosphate composition or as heteroatom substituted AlPO derivatives, only a few of them have been characterised experimentally with regard to their adsorption and separation behaviour. In order to predict the potential of a variety of AlPO frameworks for applications in CO<sub>2</sub>/CH<sub>4</sub> and CH<sub>4</sub>/N<sub>2</sub> separations, atomistic grand-canonical Monte Carlo (GCMC) simulations were performed for 53 different structures. Building on previous work, which studied CO<sub>2</sub>/N<sub>2</sub> mixture adsorption in AlPOs (M. Fischer, <i>Phys. Chem. Chem. Phys.</i>, 2017, <b>19</b>, 22801–22812), force field parameters for methane adsorption in AlPOs were validated through a comparison to available experimental adsorption data. Afterwards, CO<sub>2</sub>/CH<sub>4</sub> and CH<sub>4</sub>/N<sub>2</sub> mixture isotherms were computed for all 53 frameworks for room temperature and total pressures up to 1000 kPa (10 bar), allowing the prediction of selectivities and working capacities for conditions that are relevant for pressure swing adsorption (PSA) and vacuum swing adsorption (VSA). For CO<sub>2</sub>/CH<sub>4 </sub>mixtures, the <b>GIS</b>, <b>SIV</b>, and <b>ATT</b> frameworks were found to have the highest selectivities and CO<sub>2 </sub>working capacities under VSA conditions, whereas several frameworks, among them <b>AFY</b>, <b>KFI</b>, <b>AEI</b>, and <b>LTA</b>, show higher working capacities under PSA conditions. For CH<sub>4</sub>/N<sub>2</sub> mixtures, all frameworks are moderately selective for methane over nitrogen, with <b>ATV</b> exhibiting a significantly higher selectivity than all other frameworks. While some of the most promising topologies are either not available in pure-AlPO<sub>4</sub> composition or collapse upon calcination, others can be synthesised and activated, rendering them interesting candidates for future experimental studies. In addition to predictions of mixture adsorption isotherms, further simulations were performed for four selected systems in order to investigate the microscopic origins of the macroscopic adsorption behaviour, <i>e.g. </i>with regard to the very high CH<sub>4</sub>/N<sub>2</sub> selectivity of <b>ATV</b> and the loading-dependent evolution of the heat of CO<sub>2</sub> adsorption and CO<sub>2</sub>/CH<sub>4</sub> selectivity of <b>AEI</b> and GME.</div>

Laser interstitial thermotherapy (LITT) monitoring using high-resolution digital mammography: theory and experimental studies

2002 ◽  
Vol 47 (16) ◽  
pp. 2987-2999 ◽  
Author(s):  
Ahmed M Minhaj ◽  
Fabrice Manns ◽  
Peter J Milne ◽  
David B Denham ◽  
Nelson Salas Jr ◽  
...  
Keyword(s):  
High Resolution ◽  
Digital Mammography ◽  
Experimental Studies ◽  
Interstitial Thermotherapy

scholarly journals Photoionization Cross-Sections of Carbon-Like N+ Near the K-Edge (390–440 eV)

Atoms ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 27
Author(s):  
Jean-Paul Mosnier ◽  
Eugene T. Kennedy ◽  
Jean-Marc Bizau ◽  
Denis Cubaynes ◽  
Ségolène Guilbaud ◽  
...  
Keyword(s):  
High Resolution ◽  
Cross Section ◽  
Cross Sections ◽  
Experimental Studies ◽  
Photoionization Cross Section ◽  
Theoretical Work ◽  
Rydberg Series ◽  
R Matrix ◽  
Resonance Strengths ◽  
Nitrogen Ion

High-resolution K-shell photoionization cross-sections for the C-like atomic nitrogen ion (N+) are reported in the 398 eV (31.15 Å) to 450 eV (27.55 Å) energy (wavelength) range. The results were obtained from absolute ion-yield measurements using the SOLEIL synchrotron radiation facility for spectral bandpasses of 65 meV or 250 meV. In the photon energy region 398–403 eV, 1s⟶2p autoionizing resonance states dominated the cross section spectrum. Analyses of the experimental profiles yielded resonance strengths and Auger widths. In the 415–440 eV photon region 1s⟶(1s2s22p2 4P)np and 1s⟶(1s2s22p2 2P)np resonances forming well-developed Rydberg series up n=7 and n=8 , respectively, were identified in both the single and double ionization spectra. Theoretical photoionization cross-section calculations, performed using the R-matrix plus pseudo-states (RMPS) method and the multiconfiguration Dirac-Fock (MCDF) approach were bench marked against these high-resolution experimental results. Comparison of the state-of-the-art theoretical work with the experimental studies allowed the identification of new resonance features. Resonance strengths, energies and Auger widths (where available) are compared quantitatively with the theoretical values. Contributions from excited metastable states of the N+ ions were carefully considered throughout.

scholarly journals Exploring the robustness of Keplerian signals to the removal of active and telluric features

2020 ◽  
Vol 500 (1) ◽  
pp. 548-557
Author(s):  
M Lisogorskyi ◽  
H R A Jones ◽  
F Feng ◽  
R P Butler ◽  
S Vogt
Keyword(s):  
Monte Carlo ◽  
High Resolution ◽  
Monte Carlo Simulations ◽  
Large Amplitude ◽  
Absorption Cell ◽  
Stellar Rotation ◽  
Long Period ◽  
Active Line ◽  
Low Amplitude ◽  
Rotation Signal

ABSTRACT We examine the influence of activity- and telluric-induced radial velocity (RV) signals on high-resolution spectra taken with an iodine absorption cell. We exclude 2-$\mathring{\rm A}$ spectral chunks containing active and telluric lines based on the well-characterized K1V star α Centauri B and illustrate the method on Epsilon Eridani – an active K2V star with a long-period, low-amplitude planetary signal. After removal of the activity- and telluric-sensitive parts of the spectrum from the RV calculation, the significance of the planetary signal is increased and the stellar rotation signal disappears. In order to assess the robustness of the procedure, we perform Monte Carlo simulations based on removing random chunks of the spectrum. Simulations confirm that the removal of lines impacted by activity and tellurics provides a method for checking the robustness of a given Keplerian signal. We also test the approach on HD 40979, which is an active F8V star with a large-amplitude planetary signal. Our Monte Carlo simulations reveal that the significance of the Keplerian signal in the F star is much more sensitive to wavelength. Unlike the K star, the removal of active lines from the F star greatly reduces the RV precision. In this case, our removal of a K star active line from an F star does not a provide a simple useful diagnostic because it has far less RV information and heavily relies on the strong active lines.

scholarly journals 92 Years of the Ising Model: A High Resolution Monte Carlo Study

2018 ◽  
Vol 1012 ◽  
pp. 012002 ◽  
Author(s):  
Jiahao Xu ◽  
Alan M. Ferrenberg ◽  
David P. Landau
Keyword(s):  
Monte Carlo ◽  
Ising Model ◽  
High Resolution ◽  
Monte Carlo Study

A test for fuzzy exponentiality based on Kullback-Leibler information

2021 ◽  
pp. 1-8
Author(s):  
Lingtao Kong
Keyword(s):  
Biological Sciences ◽  
Monte Carlo ◽  
Goodness Of Fit ◽  
Experimental Studies ◽  
Real Data ◽  
Test Statistics ◽  
Test Statistic ◽  
Goodness Of Fit Test ◽  
Higher Power ◽  
Leibler Information

The exponential distribution has been widely used in engineering, social and biological sciences. In this paper, we propose a new goodness-of-fit test for fuzzy exponentiality using α-pessimistic value. The test statistics is established based on Kullback-Leibler information. By using Monte Carlo method, we obtain the empirical critical points of the test statistic at four different significant levels. To evaluate the performance of the proposed test, we compare it with four commonly used tests through some simulations. Experimental studies show that the proposed test has higher power than other tests in most cases. In particular, for the uniform and linear failure rate alternatives, our method has the best performance. A real data example is investigated to show the application of our test.

scholarly journals 5.18. Molecular gas in the poststarburst galaxy NGC7331

1998 ◽  
Vol 184 ◽  
pp. 247-248
Author(s):  
T. Tosaki ◽  
Y. Shioya
Keyword(s):  
High Resolution ◽  
Spiral Galaxy ◽  
Stellar Populations ◽  
Optical Spectra ◽  
Molecular Gas ◽  
Early Type ◽  
Origin And Evolution ◽  
Co Observations

To understand the origin and evolution of starburst activity, we must study the full evolution of starburst; i.e., pre-, on-going, and post-starburst phases. It seems reasonable to suppose the numerous A-type stars indicate past starburst and they show strong Balmer absorption. NGC7331, nearby early-type spiral galaxy, is one of the poststarburst galaxies which show strong Balmer absorption. The optical spectra of NGC7331 were dominated by component of intermediate-age (5 × 109 years) stellar populations (Ohyama & Taniguchi 1996). We present the result of the high resolution CO observations of NGC7331 using Nobeyama Milimeter Array.

scholarly journals Application of Enhanced Sampling Monte Carlo Methods for High-Resolution Protein-Protein Docking in Rosetta

PLoS ONE ◽  
2015 ◽  
Vol 10 (6) ◽  
pp. e0125941 ◽  
Author(s):  
Zhe Zhang ◽  
Christina E. M. Schindler ◽  
Oliver F. Lange ◽  
Martin Zacharias
Keyword(s):  
Monte Carlo ◽  
High Resolution ◽  
Monte Carlo Methods ◽  
Protein Docking ◽  
Enhanced Sampling

scholarly journals A low-cost, human-like, high-resolution, tactile sensor based on optical fibers and an image sensor

2018 ◽  
Vol 15 (4) ◽  
pp. 172988141878363 ◽  
Author(s):  
Utku Büyükşahin ◽  
Ahmet Kırlı
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Fiber Optic ◽  
Low Cost ◽  
Experimental Studies ◽  
Main Idea ◽  
Tactile Sensor ◽  
Image Sensor ◽  
Sensor Design ◽  
Tactile Sensors

Tactile sensors are commonly a coordinated group of receptors forming a matrix array meant to measure force or pressure similar to the human skin. Optic-based tactile sensors are flexible, sensitive, and fast; however, the human fingertip’s spatial resolution, which can be regarded as the desired spatial resolution, still could not be reached because of their bulky nature. This article proposes a novel and patented optic-based tactile sensor design, in which fiber optic cables are used to increase the number of sensory receptors per square centimeter. The proposed human-like high-resolution tactile sensor design is based on simple optics and image processing techniques, and it enables high spatial resolution and easy data acquisition at low cost. This design proposes using the change in the intesity of the light occured due to the deformation on contact/measurement surface. The main idea is using fiber optic cables as the afferents of the human physiology which can have 9 µm diameters for both delivering and receiving light beams. The variation of the light intensity enters sequent mathematical models as the input, then, the displacement, the force, and the pressure data are evaluated as the outputs. A prototype tactile sensor is manufactured with 1-mm spatial and 0.61-kPa pressure measurement resolution with 0–15.6 N/cm2 at 30 Hz sampling frequency. Experimental studies with different scenarios are conducted to demonstrate how this state-of-the-art design worked and to evaluate its performance. The overall accuracy of the first prototype, based on different scenarios, is calculated as 93%. This performance is regarded as promising for further developments and applications such as grasp control or haptics.

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