scholarly journals X. A critical study of spectral series.—Part V. The spectra of the monatomic gases

1920 ◽  
Vol 220 (571-581) ◽  
pp. 335-468 ◽  
Keyword(s):  
Fractional Part ◽  
Critical Study ◽  
Definite Function ◽  
Numerical Comparison ◽  
Ordinary Sense ◽  
Rare Gases ◽  
Present Communication ◽  
General Survey ◽  
General Reader ◽  
Significant Figures

The present communication has two objects. Its subject matter is an attempt to obtain some knowledge of the series relations in the spectra of the group of the monatomic rare gases Ne to Raem, whilst the methods employed will serve to illustrate the fundamental importance as instruments for further research of the new facts brought to light in the previous communications. The importance of the first object will be generally acknowledged, but it does not yet seem to be realised how definite and exact those new relationships are, even in their as yet undeveloped form, and how powerful an instrument is placed in our hands for the analysis of spectra. It may be well therefore to commence by a brief résumé of some of these laws as applied in the succeeding pages. Further, as the establishment of the results obtained must by its nature depend on the numerical comparison of a very large number of lines in all five spectra, and as this evidence must be fully set out to enable a specialist judgment to be formed on it, the communication has unfortunately become very lengthy. The mass of detail will perhaps be rather dreary to the general reader not specially interested in this line of study. It is apt also to hide by its amount and complexity the general conclusions arrived at. I propose therefore to give a slight general survey of these conclusions before giving the evidence. As is well known the wave-numbers of series lines depend on four types of sequences p(m), s(m), d(m), f(m ) , and that in any one series they depend on the differences between one sequent of one type and the successive terms of the sequence of another type. These sequences are all of the form N{ø( m )} 2 where N is Rydberg's constant and ø( m ) is of the form m +fraction, the fraction being, as a rule, determinable as a decimal to six significant figures. Our aim is to discover the properties of these functions. The fractional part depends in some way on the order m , although whether it can be considered a definite function of m in the ordinary sense is doubtful. This fractional part will be referred to as the mantissa, and in dealing with it, it will be regarded as multiplied by 10 6 , i. e ., as if the decimal point were removed.

scholarly journals X. A critical study of spectral series.—Part IV. The structure of spark spectra

1918 ◽  
Vol 217 (549-560) ◽  
pp. 361-410
Keyword(s):  
Great Majority ◽  
Special Care ◽  
The Other ◽  
Critical Study ◽  
Spectral Series ◽  
Rare Gases ◽  
Present Communication ◽  
The Way

The spectrum of an element produced by the electric spark is in general fundamentally different from that produced by the arc. The latter is marked by the predominance of groups of lines forming series associated with one another, and by lines related to these series in definite ways. In the former very few series have been discovered, the lines are very much more numerous, and the great majority are weak. Both kinds vary very much according to the way in which they are produced, and this is specially the case with spectra produced by the spark. Even when they are produced by similar methods by different observers—as, for instance, by Eder and Valenta, and by Exner and Haschek—there will be found a large number in one not included in the other and vice versâ . It is even questionable whether it is possible to draw a distinct and definite line of demarcation between the two, e. g ., in the cases of Cu and Ba, to take two instances; the arc spectra—with very numerous lines—in many respects have analogies with those of the spark. But very little is known as to the structure of the latter, beyond the fact that in some of them sets of lines with the same frequency differences are met with. The present communication is an attempt to throw some light on this question. The material at disposal is so vast that it is necessary to limit the discussion to a few elements, and even in them to restrict it to certain relations only. The elements selected are silver and gold. It had originally been intended to include also copper and barium as illustrating the transition from one to the other kind of spectra. But their inclusion would have rendered the present communication unduly long, whilst their omission enables us to confine the discussion to the elaboration of a single principle. The reason for the selection is that the author has had occasion to study with special care for other purposes the spectra of Ag and Ba, whilst those of Au and Cu—belonging to the same group as Ag—were specially investigated to see if the results afforded by Ag were supported by them. That of Cu was also interesting, as in the arc there are a very large number of doublets and triplets discovered by Rydberg; indeed the origins of some of the frequency differences observed were first suggested by the case of Cu in which their values are comparatively small. But it required the support of the larger values afforded by Ag and Au to firmly establish the relations. Similar relations have been found in many other elements. The spectra of the rare gases from Ne to RaEm are built on a precisely similar plan, and in fact a map for some of the Kr lines was drawn many years ago on the plan of those given here for Ag and Au, although at that time the origin of the differences was not known.

scholarly journals III. A critical study of spectral series.— Part I. The alkalies H and He

1911 ◽  
Vol 210 (459-470) ◽  
pp. 57-111 ◽  
Keyword(s):  
Principal Series ◽  
Atomic Weight ◽  
Spectral Lines ◽  
Critical Study ◽  
Spectral Series ◽  
Observational Error ◽  
Present Communication ◽  
Present Purpose

The following investigation was commenced some years ago, at a time when the discussion as to the atomic weight of Radium raised the question as to the dependence on their atomic weights of the wave-lengths of corresponding spectral lines of different elements of the same group. The arguments were necessarily vague and unconvincing in the absence of any exact knowledge as to the connection of wave­-length with atomic weight, even supposing such connection existed. Our knowledge of series spectra is chiefly—one might say almost wholly—due to the sets of very exact measurements of Kayser and Runge, and of Runge and Paschen, supplemented by extensions to longer and shorter wave-lengths by Bergmann, Konen and Hagenbach, Lehmann, Ram age, and Saunders. These have been only quite recently added to by Paschen and by the remarkable extension of the Sodium Principal series up to 48 terms by Wood. A most valuable feature of Kayser’s work was the publication of possible errors of observation. This has rendered it possible to test with certainty whether any relation suggesting itself is true within limits of observational error or not. In fact, without this, the investigation, of which the present communication forms a first part, could not have been carried out. So far as the author knows, Saunders is the only other observer who has accompanied his observations with estimates of this kind. Others have given probable errors—practically estimates of the exactness with which they can repeat readings of that feature of a line which they take to be the centre—an estimate of little value for the present purpose. In deducing data from a set of lines it is thus possible to express their errors in terms of the original errors in the observations, and limits to the latter give limiting variations to the former. We therefore know with certainty what latitude in inferences is permissible, and are often enabled to say that such inference is not justifiable.

VIII. A critical study of spectral series.— Part III. The atomic weight term and its import in the constitution of spectra

1914 ◽  
Vol 213 (497-508) ◽  
pp. 323-420
Keyword(s):  
Periodic Table ◽  
Principal Series ◽  
Atomic Weight ◽  
The Other ◽  
Critical Study ◽  
Spectral Series ◽  
Present Communication ◽  
The Real ◽  
Real Relation ◽  
The One

The doublet and triplet separations in the spectra of elements are, as has long been known, roughly proportional to the squares of their atomic weights, at least whenelements of the same group of the periodic table are compared. In the formulæ which give the series lines these separations arise by certain terms being deducted from the denominator of the typical sequences. For instance, in the alkalies if the p -sequence be written N/D m 2 , where D m = m +μ+α/ m the p -sequence for the second principal series has denominator D—Δ, and we get converging doublets; whereas the constant separations for the S and D series are formed by taking S 1 (∞) = D 1 (∞) = N/D 1 2 and S 2 (∞) = D 2 (∞)= N/(D 1 —Δ) 2 . It is clear that the values of Δ for the various elements will also be roughly proportional to the squares of the atomic weights. For this reason it is convenient to refer to them as the atomic weight terms. We shall denote them by Δ in the case of doublets and Δ 1 and Δ 2 in the case of triplets, using v as before to denote the separations. Two questions naturally arise. On the one hand what is the real relation between them and the atomic weights, and on the other what relation have they to the constitution of the spectra themselves ? The present communication is an attempt to throw some light on both these problems.

scholarly journals Aira (Poaceae): a new generic record for Nicobar Islands, India

2016 ◽  
Vol 8 (6) ◽  
pp. 8948
Author(s):  
Kumar Vinod Chhotupuri Gosavi ◽  
Arun Nivrutti Chandore ◽  
Mayur Yashwant Kamble
Keyword(s):  
New Record ◽  
Relevant Literature ◽  
Grass Species ◽  
Critical Study ◽  
Andaman And Nicobar Islands ◽  
Present Communication ◽  
Taxonomic Analysis ◽  
Plant Exploration ◽  
Nicobar Islands ◽  
Generic Record

During plant exploration of Andaman and Nicobar in 2014, we were collected some interesting grass specimens from Kamorta Islands of Nicobar. After critical study and taxonomic analysis the unidentified grass species has identified as an Aira caryophyllea L.  Perusals of relevant literature were revealed that, the genus Aira L. has so far not reported from Andaman and Nicobar islands. Hence, it is reported in present communication for new record to the Andaman and Nicobar Islands. 

scholarly journals A critical study of spectral series. Part I. - The alkalies, H and He

1910 ◽  
Vol 83 (561) ◽  
pp. 226-228 ◽  
Keyword(s):  
Critical Study ◽  
Spectral Series ◽  
Present Communication ◽  
Wave Numbers ◽  
Observational Errors ◽  
Insight Into

It is generally recognised that one of the most hopeful means of gaining an insight into the structure of the atom is study of the spectra of the elements, and at present especially of the series spectra. Before, however, it is possible it is necessary to have a more definite knowledge of the relationships between the various series of the same element, and corresponding series in different elements. With this end in view, the author began some years ago a systematic discussion of the data accumulated, using for this purpose the estimated errors of observation on these spectra. These possible errors give limits of possible variation for the different constants involved, and permit of safe conclusions being drawn. The present communication gives the results affecting the spectra of the alkalies, hydrogen and helium. The chief results arrived at are the following:- 1. The wave numbers of any one series can practically all be represented within observational errors by a formula based on a modification of Rydberg's form, viz.:- n = A - N/( m + μ + α/m ) 2 .

scholarly journals Critical study of literature written by “Kavi Ratna” Sri Sri Krishna Semwal

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Madan Mohan Nauriyal
Keyword(s):  
Prime Minister ◽  
Critical Study ◽  
Present Communication ◽  
Indian Culture ◽  
The One

In the present communication a critical study is presented on the literature written by Sri Sri Kreshna Semwal. He has composed various poems combining his devotional expressions,satirical, eclectic, character based and emotional sources.”Bhakti Rasamritam Stuti Kavya” composed by Sri Sri Kreshna Semwal is filled with the extracts of basis devotion of indian culture. This is a unique collection of devotional songs. In this, there is an incarnation of Kavya Ras from the worship of different Gods and Goddesses. The poet has composed poetry on devotional expressions as well as on real subjects. On the one hand the poet has written the adornment of Shani, in other he tried to highlight the evil practices of the society by writing "Bhimshatakam". His composition “Indirakeertishatakam” is based on the life of former Prime Minister smt Indira Gandhi. It is tried to analyse the all faces of writings of Sri Sri Kreshna Semwal in this presentation.

scholarly journals A critical study of spectral series. Part III.—The atomic weight term and its import in the constitution of spectra

1913 ◽  
Vol 89 (608) ◽  
pp. 125-127
Keyword(s):  
Periodic Table ◽  
Atomic Weight ◽  
Frequent Occurrence ◽  
Fundamental Importance ◽  
Critical Study ◽  
Spectral Series ◽  
Present Communication ◽  
Wave Numbers ◽  
Actual Relation ◽  
Universal Application

The wave numbers of the lines in a spectrum which form any of the recognised series can be calculated, as is well known, from an expression of the form n = N/D 1 2 — N/D m 2 , where N = 109675 and D m = m + fraction, the fraction being in general a function of the integer m . The constant doublet or triplet separations of S and D series are formed by the deduction of a quantity Δ, or Δ 1 , Δ 2 , in the case of triplets, from D 1 , and it has long been known that these quantities are very roughly proportional to the squares of the atomic weights when elements in the same group are compared. The present communication deals with the actual relation between Δ and the atomic weight, and with the part it plays in the general constitution of spectra. It is shown that there is a definite quantity in connection with each element which is of fundamental importance in the building up of its spectrum. It is proportional to the square of the atomic weight: in fact, if w denote the atomic weight divided by 100 its value is (90·4725 ± 0·013) w 3 . This quantity is of such universal application that it is useful to have a special name for it, and it has been called the oun ( wv ). Its value is denoted by δ 1 , but δ is used for the multiple 4δ 1 , as it is of very frequent occurrence. The evidence for its existence is based on the arc spectra of He, the elements of the Groups I and II, the Al sub-group and Sc of III and the O, S, Se of VI of the Periodic Table—in other words, all those elements in which the series lines have been allocated. It is found:— (1) That the Δ which give the doublet and triplet separations are all multiples of their respective ouns.

A laboratory technique for establishing Simulium larvae in an experimental channel

1969 ◽  
Vol 59 (3) ◽  
pp. 533-536 ◽  
Author(s):  
R. C. Muirhead-Thomson
Keyword(s):  
Continuous Flow ◽  
Critical Study ◽  
Laboratory Technique ◽  
Experimental Channel ◽  
Large Numbers ◽  
Significant Figures

A laboratory technique is described which enables large numbers of Simulium larvae from field sources to be established in a narrow 12-in. long experimental channel in the laboratory where they can be maintained in a continuous flow of water. The apparatus was primarily designed for a critical study of the reactions of larvae exposed to various time/concentrations of larvicides and other chemicals. By exposing dense aggregations of many hundred larvae at a time, significant figures can be obtained regarding the number of larvae detached at various intervals during and after exposure to larvicide, and also regarding the subsequent survival or mortality of the different detached fractions.

scholarly journals II. A critical study of spectral series.–Part II. The p and s sequences and the atomic volume term

1913 ◽  
Vol 212 (484-496) ◽  
pp. 33-73 ◽  
Keyword(s):  
Atomic Weight ◽  
Atomic Volume ◽  
Critical Study ◽  
Present Communication ◽  
High Melting Point ◽  
Small Intensity ◽  
Complete Discussion ◽  
Ordinary Type ◽  
The Comparative Study ◽  
Made In

The present communication is in continuation of one presented to the Society in 1909. The greater part of the work was completed at that time, and it was hoped that it would be published shortly afterwards. Certain points, however, arose which the author was anxious to settle, and this led to a consideration of a number of spectra in which series of the ordinary type had not yet been recognised. He hopes to deal with some of the most interesting points which have come to light in the course of that consideration, chiefly connected with the atomic weight term, and the constitution of certain spectra, in an ensuing paper. In the present one the constitutions of the sequences on which the Principal and Sharp series depend, and their relation to the atomic volume of the element, which were brought to light in Part I., are further considered in connection with the spectra of the second and third groups of elements. It was hoped to have included in the third group the high melting-point sub-group Sc, Y, La, Yb, and considerable progress had been made in reducing their spectra. They all show doublet series of S and D types, but their complete consideration would have taken so much time, better devoted to the general constitutional points which had arisen, that it was decided to postpone it. The evident importance, however, of the comparative study of all the elements in the same group of the periodic system made it seem desirable to give some attention to those elements which might possibly fill the gaps. It is generally acknowledged that these belong probably to elements associated with the rare earths, and their atomic weights give some indication of the places they should fill. Their spectra consist of a multitude of lines chiefly of medium or small intensity, and their complete discussion involves a great deal of time and close attention. All those, however, which the author has so far investigated show more or less analogous relationships, intimately connected, and irresistibly suggesting the débris , so to say, of strong lines. The connection is based on certain properties of the atomic weight term referred to above. The evidence of the spectrum of Eu leaves little doubt but that it fills the vacant space between Cd and Hg. Probably the gap between In and Tl is occupied by Gd. A superficial consideration of the spectrum of the latter shows a large number of doublets with a separation of 5000. This number agrees with its atomic weight and its position between In (2212) and T1 (7792). As is well known, the spectrum of Ra is quite analogous to those of the Ca group, whilst possibly the gap between it and Ba may be filled by another radio-active substance. An attempt has been made to allot the S and D series of Eu and Ba and the result is given in Appendix I. In response to suggestions made to me in respect of Part I., I have ventured to give in a second appendix lists of the S and P series lines of the elements considered in the present communication. The type of formula used here and in Part I. has been employed by Mogendorff in a still earlier paper read before the Royal Society of Amsterdam in November, 1906. He there showed that the formula reproduces the lines of Li, Na, Zn, and Tl in the different series with great exactness, and stated that he had also obtained corresponding formulæ for other elements.

Anchoring Fibrils in Arterial Endothelium

1969 ◽  
Vol 27 ◽  
pp. 274-275
Author(s):  
A. Trillo
Keyword(s):  
Carotid Arteries ◽  
Animal Species ◽  
Cell Layer ◽  
Present Communication ◽  
Internal Elastic Lamina ◽  
Endothelial Cell Layer ◽  
Structural Details ◽  
Rats And Mice ◽  
Arterial Endothelium ◽  
Elastic Lamina

There are conflicting reports regarding some fine structural details of arteries from several animal species. Buck denied the existence of a sub-endothelial space, while Karrer and Keech described a space of variable width which separates the endothelium from the underlying internal elastic lamina in aortas of aging rats and mice respectively.The present communication deals with the ultrastrueture of the interface between the endothelial cell layer and the internal elastic lamina as observed in carotid arteries from rabbits of varying ages.

Sign in / Sign up

Export Citation Format

Share Document