The fine structure of the hydrogen α line

1950 ◽  
Vol 202 (1068) ◽  
pp. 127-142 ◽  
Keyword(s):  
Fine Structure ◽  
Large Diameter ◽  
Strong Line ◽  
Doppler Width ◽  
Dirac Theory ◽  
Balmer Series ◽  
Fabry Perot ◽  
Current Densities ◽  
Main Components ◽  
The Individual

A new attempt has been made to resolve spectroscopically the fine structure of the α line, 6563 A, of the Balmer series of heavy hydrogen. A deuterium discharge tube, whose walls were partly of copper, was immersed in liquid hydrogen and run at very low current densities. By this means the Doppler width of the individual lines was sufficiently reduced to enable the satellite between the main components of the ‘doublet’ to be resolved much more completely and to be measured more accurately than was possible before. The spectroscopic resolution was achieved with a Fabry-Perot interferometer of large diameter, mounted internally in a prism spectrograph. The measurements support the assumption that the 2S ½ term is higher than is predicted by the Dirac theory, and lead to the value 0.0369 ± 0.0016 cm. -1 for the amount of the shift, in good agreement with the latest value found by Lamb & Retherford from microwave measurements. The relative widths of the main components and the interval between them also provide qualitative evidence for the shift of the 2S ½ term. The intensities of the lines were found to agree approximately with the prediction of the Dirac theory. The weak line 2P ½ -3S ½ was partly resolved from the neighbouring strong line 2P ½ -3D ½ . The provisional value for the distance between them would indicate that the 3S ½ term is shifted very little, if at all. Further attempts are being made to obtain a more reliable value for this term.

The fine structure of the line 4686 Å of singly ionized helium

1954 ◽  
Vol 226 (1166) ◽  
pp. 377-392 ◽  
Keyword(s):  
Fine Structure ◽  
Quantum Electrodynamics ◽  
Stark Effect ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Resolving Power ◽  
Doppler Width ◽  
Dirac Theory ◽  
Fabry Perot ◽  
In Series

A liquid-hydrogen-cooled discharge tube similar to that formerly used in the investigation of the fine structure of the a-line of heavy hydrogen has now been used to reduce the Doppler width of the components of the line n = 4 -> n = 3 in the spectrum of He + . The resolving power necessary to separate some components was obtained without sacrificing spectral range by using two Fabry-Perot etalons in series mounted externally to a prism spectrograph. For other components a single etalon was used. Eight components were resolved and their separations measured, and a ninth partially resolved. The positions of certain band lines of hydrogen and helium which lie close to the He + complex and overlap it in different orders of interference were also measured. The relative intensities of the components were broadly in agreement with the relative transition probabilities calculated from the Dirac theory, but some anomalies were observed. From the measurements it is deduced that some of the energy levels are displaced from the positions predicted by the Dirac theory: the 3 S 1/2 level upwards by 0.140±0.005 cm -1 , the 4 S 1/2 level upwards by 0.056 + 0.003 cm -1 and the 4 P 1/2 level downwards by 0.011 ±0.003 cm -1 . These displacements of the S 1/2 levels are in good agreement with the predictions of the new theory of quantum electrodynamics, but the theory does not predict a displacement of the 4 P 1/2 level by this amount. The Stark effect could account for part of the discrepancy, but there remains a disagreement with the theory which exceeds the estimated experimental error.

scholarly journals The nuclear spin of iodine I— fine structure in the first spark spectrum

1935 ◽  
Vol 149 (867) ◽  
pp. 269-281 ◽  
Keyword(s):  
Fine Structure ◽  
High Resolution ◽  
Nuclear Spin ◽  
High Frequency ◽  
Complete Resolution ◽  
Electrodeless Discharge ◽  
A Value ◽  
Fabry Perot ◽  
Fine Structures ◽  
The Individual

In an earlier paper on the fine structures of the visible lines in the arc spectra of bromine and iodine an attempt was made to estimate the nuclear spin of iodine, and a tentative value of 9/2 was proposed. The iodine arc lines were excited by a high frequency electrodeless discharge in pure iodine vapour and examined with a silvered Fabry-perot interferometer. The fine structures in the arc lines are small, and as the patterns are highly complex and the individual components not very sharp, interpretation was difficult. It was concluded with certainty that the nuclear spin was at least equal to 5/2, but one line in particular suggested a value of 9/2. This was indefinite, and in view of the uncertainty a thorough examination of both the arc and spark spectra of iodine has been undertaken. A preliminary notice has already appeared. The first spark spectrum can be more easily studied than the arc spectrum, since the structure are on a very much bigger scale and more complete resolution can be attained. The present work is concerned with the spark lines excited in a hollow cathode discharge. Fine structures in iodine spark lines were first recorded long ago by Wood and Kimura who excited the lines in a Geissler tube and examined them with a transmission echelon. Murakawa attempted to analyse the fine structure data, but as the source and instrument employed by Wood and Kimura were not able to give the high resolution attained here, the deductions made from these data, although generally correct, are uncertain and require further examination; for many of the line structures are much more complex than as reported by these earlier observers.

The fine structure of the α -line of heavy hydrogen

1951 ◽  
Vol 208 (1093) ◽  
pp. 277-284 ◽  
Keyword(s):  
Fine Structure ◽  
Hydrogen Atom ◽  
Relativistic Theory ◽  
Liquid Hydrogen ◽  
Strong Component ◽  
Balmer Series ◽  
Radiation Theory ◽  
Fabry Perot ◽  
The Difference ◽  
Weak Satellite

In continuation of work reported earlier (Kuhn & Series 1950), the weak satellite 2 P 1/2 –3 S 1/2 in the α-line 6561 Å of the Balmer series of heavy hydrogen has been resolved. The light was produced as before in a U-tube cooled by liquid hydrogen, and analyzed by a double Fabry-Perot interferometer with spacings in the ratio 1:2. The satellite was found to be at a distance 0·1326±0·001 cm. -1 from the neighbouring strong component 2 P /2 –3 D 1/2 , in disagreement with the distance 0·1409 cm. -1 predicted by the Dirac relativistic theory of the hydrogen atom. The difference 0-0083 + 0·002 –0·003 cm. ‒1 (where the limits also include possible errors in certain corrections) is interpreted as an upward shift of the 3 S term, and is compared with the value 0·0104 cm. –1 predicted by the radiation theory of Bethe and others (see, for example, Bethe, Brown & Stehn 1950).

scholarly journals The nuclear spin of iodine II-Fine structure in the arc spectrum and a fine structure perturbation effect

1935 ◽  
Vol 152 (877) ◽  
pp. 663-672 ◽  
Keyword(s):  
Fine Structure ◽  
Hollow Cathode ◽  
Nuclear Spin ◽  
High Frequency ◽  
Electrodeless Discharge ◽  
Partial Resolution ◽  
Fabry Perot ◽  
Fine Structures ◽  
The Individual ◽  
Perturbation Effect

The arc spectrum of iodine was first examined for fine structure by Wood and Kimura,* who failed to detect structure in any of the fines. The failure was probably due to the use of an unsatisfactory source and to the smallness of the resolving powers employed. The author then examined the iodine arc spectrum that was emitted by a high frequency electrodeless discharge in pure iodine vapour, using a variable gap Fabry-Perot interferometer as the resolving instrument. Structure was observed in eleven fines and an attempt at analysis was made. The nuclear spin of iodine was then unknown and, as only partial resolution was achieved, interpretation proved to be very difficult and ambiguous. Furthermore, at that time the existence of fine structure perturbations was not yet even suspected and, as will be shown later, one of the important s terms is perturbed. The nuclear spin of iodine was determined* from extensive measurements of the fine structures in the lines of the first spark spectrum. The lines produced in a water-cooled hollow cathode were investigated and, owing both to the sharpness of the individual components and to the relatively wider structures associated with the ionized atom, an unambiguous value for the spin was found (5/2). Knowing the spin with certainty, this can now be applied to the interpretation of the structures in the arc lines. However, realizing the superiority of the hollow cathode as a source, a complete re-examination of the spectrum was made. This revealed the fact that the previous measurements were all approximately correct, the differences being accounted for by the higher resolution now attained.

scholarly journals Behavioral and Antennal Responses of Tribolium confusum to Varronia globosa Essential Oil and Its Main Constituents: Perspective for Their Use as Repellent

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4393
Author(s):  
Cesar Auguste Badji ◽  
Jean Dorland ◽  
Lynda Kheloul ◽  
Dimitri Bréard ◽  
Pascal Richomme ◽  
...  
Keyword(s):  
Essential Oil ◽  
Tribolium Confusum ◽  
High Dose ◽  
Synthetic Chemicals ◽  
Stored Product Pest ◽  
Indigenous Plant ◽  
Main Components ◽  
Electroantennogram Recordings ◽  
The Individual ◽  
Main Component

Essential oils of aromatic plants represent an alternative to classical pest control with synthetic chemicals. They are especially promising for the alternative control of stored product pest insects. Here, we tested behavioral and electrophysiological responses of the stored product pest Tribolium confusum, to the essential oil of a Brazilian indigenous plant, Varronia globosa, collected in the Caatinga ecosystem. We analyzed the essential oil by GC-MS, tested the effects of the entire oil and its major components on the behavior of individual beetles in a four-way olfactometer, and investigated responses to these stimuli in electroantennogram recordings (EAG). We could identify 25 constituents in the essential oil of V. globosa, with anethole, caryophyllene and spathulenole as main components. The oil and its main component anethole had repellent effects already at low doses, whereas caryophyllene had only a repellent effect at a high dose. In addition, the essential oil abolished the attractive effect of the T. confusum aggregation pheromone. EAG recordings revealed dose-dependent responses to the individual components and increasing responses to the blend and even more to the entire oil. Our study reveals the potential of anethole and the essential oil of V. globosa in the management of stored product pests.

scholarly journals Biological Effect of Different Spinach Extracts in Comparison with the Individual Components of the Phytocomplex

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 382
Author(s):  
Laura Arru ◽  
Francesca Mussi ◽  
Luca Forti ◽  
Annamaria Buschini
Keyword(s):  
Antioxidant Defense ◽  
Extraction Methods ◽  
Oxidizing Agent ◽  
Endogenous Reactive Oxygen Species ◽  
Dependent Activity ◽  
Main Components ◽  
The Individual ◽  
Dose Dependent ◽  
Higher Doses ◽  
Oxidative Insult

The Mediterranean-style diet is rich in fruit and vegetables and has a great impact on the prevention of major chronic diseases, such as cardiovascular diseases and cancer. In this work we investigated the ability of spinach extracts obtained by different extraction methods and of the single main components of the phytocomplex, alone or mixed, to modulate proliferation, antioxidant defense, and genotoxicity of HT29 human colorectal cells. Spinach extracts show dose-dependent activity, increasing the level of intracellular endogenous reactive oxygen species (ROS) when tested at higher doses. In the presence of oxidative stress, the activity is related to the oxidizing agent involved (H2O2 or menadione) and by the extraction method. The single components of the phytocomplex, alone or mixed, do not alter the intracellular endogenous level of ROS but again, in the presence of an oxidative insult, the modulation of antioxidant defense depends on the oxidizing agent used. The application of the phytocomplex extracts seem to be more effective than the application of the single phytocomplex components.

Critical examination of various approaches used for analysing helical cables

1994 ◽  
Vol 29 (1) ◽  
pp. 43-55 ◽  
Author(s):  
M Raoof ◽  
I Kraincanic
Keyword(s):  
Large Diameter ◽  
Numerical Results ◽  
Hertzian Contact ◽  
Critical Examination ◽  
First Order ◽  
Wide Range ◽  
End Conditions ◽  
Parametric Studies ◽  
The Individual ◽  
Fixed End

Using theoretical parametric studies covering a wide range of cable (and wire) diameters and lay angles, the range of validity of various approaches used for analysing helical cables are critically examined. Numerical results strongly suggest that for multi-layered steel strands with small wire/cable diameter ratios, the bending and torsional stiffnesses of the individual wires may safely be ignored when calculating the 2 × 2 matrix for strand axial/torsional stiffnesses. However, such bending and torsional wire stiffnesses are shown to be first order parameters in analysing the overall axial and torsional stiffnesses of, say, seven wire stands, especially under free-fixed end conditions with respect to torsional movements. Interwire contact deformations are shown to be of great importance in evaluating the axial and torsional stiffnesses of large diameter multi-layered steel strands. Their importance diminishes as the number of wires associated with smaller diameter cables decreases. Using a modified version of a previously reported theoretical model for analysing multilayered instrumentation cables, the importance of allowing for the influence of contact deformations in compliant layers on cable overall characteristics such as axial or torsional stiffnesses is demonstrated by theoretical numerical results. In particular, non-Hertzian contact formulations are used to obtain the interlayer compliances in instrumentation cables in preference to a previously reported model employing Hertzian theory with its associated limitations.

Creativity from perspective of axiology

2021 ◽  
Vol 92 (2) ◽  
pp. 10-20
Author(s):  
A. V Kiriakova ◽  
◽  
V.V. Moroz ◽  
Keyword(s):  
Evolutionary Process ◽  
Value Orientations ◽  
Point Of View ◽  
Modern World ◽  
Collective Creativity ◽  
The Social ◽  
Wide Range ◽  
Interdisciplinary Knowledge ◽  
Main Components ◽  
The Individual

Interest in creativity as a subject of research has been growing exponentially since the second half of the 20th century in all areas of human history. A wide range of both domestic and foreign studies allows authors to assert that creativity is a personality trait, inherent to one degree or another. Whereas the development of such trait becomes an urgent necessity in the new reality. The entire evolutionary process of the social development illustrates its dependence on personal and collective creativity. The aim of this research is to study the phenomenon of creativity through the perspective of axiology, i.e. the science of values. Axiology allows us to consider the realities of the modern world from the perspective of not only external factors, circumstances and situations, but also of deep value foundations. Creativity has been studied quite deeply from the point of view of psychology: the special characteristics of a creative person, stages of the creative process, the relationship between creative and critical thinking, creativity and intelligence. Some psychologists emphasize motivation, creative skills, interdisciplinary knowledge, and the creative environment as the main components that contribute to the development of creativity. The authors of the article argue that values and value orientations towards cognition, creativity, self-realization and self-expression are the drivers of creativity. In a broad sense, values as a matrix of culture determine the attitude of society to creativity, to the development of creativity of the individual and the creative class, and to how economically successful a given society will be. Since innovation and entrepreneurship are embodied creativity. Thus, the study of creativity from the perspective of axiology combines the need for a deep study of this phenomenon and the subjective significance of creativity in the context of new realities

scholarly journals Transnational Corruption and the Globalized Individual

2017 ◽  
Vol 15 (3) ◽  
pp. 732-753 ◽  
Author(s):  
Alexander Cooley ◽  
J. C. Sharman
Keyword(s):  
Real Estate ◽  
Transaction Costs ◽  
Capital Flows ◽  
Oecd Countries ◽  
Citizenship Rights ◽  
Financial Access ◽  
Key Informants ◽  
Cross Border ◽  
Main Components ◽  
The Individual

We present a new, more transnational, networked perspective on corruption. It is premised on the importance of professional intermediaries who constitute networks facilitating cross-border illicit finance, the blurring of legal and illegal capital flows, and the globalization of the individual via multiple claims of residence and citizenship. This perspective contrasts with notions of corruption as epitomized by direct, unmediated transfers between bribe-givers and bribe-takers, disproportionately a problem of the developing world, and as bounded within national units. We argue that the professionals in major financial centers serve to lower the transaction costs of transnational corruption by senior foreign officials. Wealthy, politically powerful individuals on the margins of the law are increasingly globalized as they secure financial access, physical residence, and citizenship rights in major OECD countries. These trends are evidenced by an analysis of the main components of the relevant transnational networks: banks, shell companies, foreign real estate, and investor citizenship programs, based on extensive interviews with key informants across multiple sites.

scholarly journals THEORETICAL FUNDAMENTALS OF FORMATION OF THE MOTIVATION SYSTEM AT ENTERPRISE

2020 ◽  
pp. 102-113
Author(s):  
Olha Volodymyrivna Popelo ◽  
◽  
Tetiana Volodymyrivna Zabashtanska ◽  
Kateryna Oleksandrivna Chorna ◽  
◽  
...  
Keyword(s):  
Driving Force ◽  
Motivational Factors ◽  
Maximum Effect ◽  
Foreign Experience ◽  
Staff Motivation ◽  
Motivation System ◽  
Effective System ◽  
Main Components ◽  
The Individual ◽  
Theoretical Foundations

Abstract. In modern conditions of aggravation of competition the question of creation of effective system of motivation of the personnel at the enterprise acquires extreme urgency. The level of employees’thirst for work depends on the chosen system of motivation. That is why company executives need to rationally combine tangible and intangible methods of staff motivation. Foreign experience proves that intangible and tangible methods of motivation play an equally important role in organizing the work of subordinates. That is why the study of the process of choosing a method of staff motivation in the enterprise is becoming increasingly important, which confirms the relevance of the chosen to research topic.The article investigates the theoretical foundations of the formation of an effective system of motivation in the enterprise.The main motives that underliemotivation are highlighted. Motivation theories are outlined and analyzed. The analysis of the main components of the motivation system: tangible and intangible. The factors contributing to the formation of an effective system of motivation in the enterprise are revealed. Possibilities of combination of tangible and intangible types of motivation at the enterprise are substantiated. It has been proven that motivation has a significant impact on the life of every person and is a driving force in any economic activity.Everyone is an individual, so the goal of company leaders is to choose motivational factors in accordance with the individual qualities of employees. To get the maximum effect from the work of subordinates, the manager must determine the motives of each employee

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