CNDO-CI-Berechnungen zum Einfluß der N-Acylierung auf das Absorptions-und Phosphoreszenzspektrum von Carbazol/ CNDO-CI Calculations of the Effect of N-Acylation on the Absorption and Phosphorescence Spectra of Carbazole

1975 ◽  
Vol 30 (12) ◽  
pp. 1700-1703 ◽  
Author(s):  
Maximilian Zander ◽  
Filip Fratev ◽  
Gottfried Olbrich ◽  
Oskar E. Polansky

Abstract The observed blue shift of the carbazole chromophore by N-acylation has been verified by CNDO-CI-calculations of fluorene, carbazole and N-formyl-carbazole. From the CNDO-CI results which are in excellent agreement with the experimental data, a detailed analysis of the spectra is derived.

1983 ◽  
Vol 105 (1) ◽  
pp. 29-33 ◽  
Author(s):  
A. M. Clausing

Cavity solar receivers are generally believed to have higher thermal efficiencies than external receivers due to reduced losses. A simple analytical model was presented by the author which indicated that the ability to heat the air inside the cavity often controls the convective loss from cavity receivers. Thus, if the receiver contains a large amount of inactive hot wall area, it can experience a large convective loss. Excellent experimental data from a variety of cavity configurations and orientations have recently become available. These data provided a means of testing and refining the analytical model. In this manuscript, a brief description of the refined model is presented. Emphasis is placed on using available experimental evidence to substantiate the hypothesized mechanisms and assumptions. Detailed comparisons are given between analytical predictions and experimental results. Excellent agreement is obtained, and the important mechanisms are more clearly delineated.


2021 ◽  
Author(s):  
Wassim Habchi ◽  
Philippe Vergne

Abstract The current work presents a quantitative approach for the prediction of minimum film thickness in elastohydrodynamic lubricated (EHL) circular contacts. In contrast to central film thickness, minimum film thickness can be hard to accurately measure, and it is usually poorly estimated by classical analytical film thickness formulae. For this, an advanced finite-element-based numerical model is used to quantify variations of the central-to-minimum film thickness ratio with operating conditions, under isothermal Newtonian pure-rolling conditions. An ensuing analytical expression is then derived and compared to classical film thickness formulae and to more recent similar expressions. The comparisons confirmed the inability of the former to predict the minimum film thickness, and the limitations of the latter, which tend to overestimate the ratio of central-to-minimum film thickness. The proposed approach is validated against numerical results as well as experimental data from the literature, revealing an excellent agreement with both. This framework can be used to predict minimum film thickness in circular elastohydrodynamic contacts from knowledge of central film thickness, which can be either accurately measured or rather well estimated using classical film thickness formulae.


2021 ◽  
Vol 81 (5) ◽  
Author(s):  
Mariana Frank ◽  
Levent Selbuz ◽  
Ismail Turan

AbstractWe study $$Z^{\prime }$$ Z ′ phenomenology at hadron colliders in an $$U(1)^{\prime }$$ U ( 1 ) ′ extended MSSM. We choose a $$U(1)^{\prime }$$ U ( 1 ) ′ model with a secluded sector, where the tension between the electroweak scale and developing a large enough mass for $$Z^{\prime }$$ Z ′ is resolved by incorporating three additional singlet superfields into the model. We perform a detailed analysis of the production, followed by decays, including into supersymmetric particles, of a $$Z^{\prime }$$ Z ′ boson with mass between 4 and 5.2 TeV, with particular emphasis on its possible discovery. We select three different scenarios consistent with the latest available experimental data and relic density constraints, and concentrate on final signals with $$2\ell +\not \! \! E_{T}$$ 2 ℓ + ⧸ E T , $$4\ell +\not \! \! E_{T}$$ 4 ℓ + ⧸ E T and $$6\ell +\not \! \! E_{T}$$ 6 ℓ + ⧸ E T . Including the SM background from processes with two, three or four vector bosons, we show the likelihood of observing a $$Z^\prime $$ Z ′ boson is not promising for the HL-LHC at 14 TeV. While at 27 and 100 TeV, the situation is more optimistic, and we devise specific benchmark scenarios which could be observed.


Author(s):  
Imtiyaz A. Najar ◽  
W. Bari

In this study, we have performed a detailed analysis of genuine pion correlations and fluctuations in terms of the normalized factorial comulant moments of second and third orders, [Formula: see text] and [Formula: see text], in case of [Formula: see text]O–AgBr interactions at [Formula: see text][Formula: see text]A and [Formula: see text][Formula: see text]A GeV/c. The experimental results are compared with the predictions of AMPT and UrQMD model simulated events. The UrQMD model reproduces the trends in experimental results but the strength of correlation is much smaller. However, the AMPT model does not also replicate all features of the experimental data. The genuine two-particle and three-particle correlations are found to become weaker with the increase in momentum of the projectile nucleus.


2018 ◽  
Vol 183 ◽  
pp. 01041
Author(s):  
Nicolas Jacques ◽  
Romain Barthélémy

A theoretical modelling is proposed to describe the shock response of foam materials. This model is based on micromechanical and energetic arguments, and takes into account the contribution of microscale inertia. Within this framework, an analytical expression of the Hugoniot stress-strain curve is proposed for elastic-plastic cellular materials. The predictions derived from the proposed model are in excellent agreement with experimental data for open-cell aluminium foams. The case of viscoplastic foams is also considered.


1982 ◽  
Vol 37 (2) ◽  
pp. 234-235 ◽  
Author(s):  
Rudy Susilo ◽  
Rolf Gmelin

Abstract The conformation of 1,2,4,5-tetrathian was determined by means of dynamic NMR spectroscopy. The barrier (ilG+) of the chair/twist equilibration is 14.5 kcal/mol and the chair form is more stable than the twist form in this molecule by 1.4 kcal/mol. These experimental data are in excellent agreement with force field calculations


2010 ◽  
Vol 25 (4) ◽  
pp. 746-753 ◽  
Author(s):  
Rui Dou ◽  
Brian Derby

The very high strengths that have been reported for nanoporous gold may be related to strain gradients within the deforming porous microstructure. We present a mechanism-based model for the strength of nanoporous foams that is derived from conventional models for the deformation of macroscopic foams and now includes the influence of strain gradients. This model predicts that the strength of the ligaments within the nanoporous gold is proportional to the ligament diameter raised to the power −0.5. We have used the model to analyze experimental data for the strength of nanoporous gold and find excellent agreement with published data.


2019 ◽  
Vol 19 (4) ◽  
pp. 186-192
Author(s):  
A. P. Demichkovskyi

The purpose of the study was to define informative indicators of technical and tactical actions of qualified rifle shooting athletes. Materials and methods. The study involved MSU (number of athletes n = 10), CMSU (number of athletes n = 9). To solve the tasks set, the following research methods were used: analysis and generalization of scientific and methodological literature, pedagogical observation. Pedagogical observation was used to study the peculiarities of technical and tactical indicators of qualified athletes, as well as their motor abilities; methods of mathematical statistics were used to process the experimental data. Results. A detailed analysis of competitive activity made it possible to determine that the shot phases “Aiming”, “Shot execution – active shot”, “Preparation for the shot” are informative indicators of technical and tactical actions of qualified rifle shooting athletes. The study determined time parameters of the phases during competitive activity. The difference between the average indicators of the athletes with different sports qualifications is at the limit of 2.55 seconds, which suggests that the duration of the restorative processes of the shooter’s body affects the performance of each shot.  Conclusions. A detailed analysis of air rifle shooting among men during competitive activity allowed to determine the difference in technical and tactical fitness between the athletes with different sports qualifications of MSU and CMSU levels: “Aiming” – MSU 950.56 seconds, CMSU 1017.91 seconds; “Shot execution – active shot” – MSU 964.45 seconds, CMSU 952.36 seconds; “Preparation for the shot” – MSU 1678.66 seconds, CMSU 1855.19 seconds, “Total execution time” – MSU 3593.68 seconds, CMSU 3825.47 seconds.


2019 ◽  
Vol 33 (14) ◽  
pp. 1950140
Author(s):  
Chokri Hadj Belgacem

The Stirling’s estimation to [Formula: see text](N!) is typically introduced to students as a step in the derivation of the statistical expression for the heat capacity. However, naïve application of this estimation leads to wrong conclusions. In this paper, firstly, the heat capacity of some semiconductor compounds was calculated using exponential Boltzmann distribution and compared with experimental data. It has shown a disagreement between experimental results and those calculated. Secondly, by applying the more exact Stirling formula, an analytical formulation of Boltzmann statistics using Lambert W function is shown to be a very good model and proves an excellent agreement between calculated and experimental data for heat capacity over the entire temperature range.


PEDIATRICS ◽  
1949 ◽  
Vol 3 (6) ◽  
pp. 869-869
Author(s):  
HERMAN YANNET

This book is an excellently developed presentation of the present status of pain-relieving drugs in obstetrics. It is divided into two sections: The first is devoted to (1) detailed analysis of clinical and experimental data referrable to fetal respiration, and (2) pathologic pulmonary conditions in the fetus and newborn that might be causally related to the labor inhibiting and respiratory depressive effects of many, if not all, the pain-relieving drugs used during delivery. The scope of the section is indicated by some of the chapter headings, i.e., incidence of respiratory injury before birth; respirations before birth; intrauterine pneumonia; atelectasis; asphyxia.


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