scholarly journals On the intensity of light reflected from transparent substances

1907 ◽  
Vol 79 (527) ◽  
pp. 18-30 ◽  
Keyword(s):  
Polished Glass ◽  
Reflected Light ◽  
Experimental Errors ◽  
Series Of Experiments ◽  
The Subject ◽  
The Difference ◽  
Reflecting Surface ◽  
Crucial Test ◽  
Careful Comparison ◽  
Theory And Experiment

A careful comparison of theory with experiment as regards the intensity of reflection would seem to suggest itself naturally as a crucial test of the validity of any optical theory. In spite of this, it was not till late in the last century that the problem was seriously undertaken by experimentalists. In 1870 Rood turned his attention to. the subject with the view of testing Fresnel’s laws, and concluded from his experiments “that the reflecting power of glass conforms, in the closest manner, to the predictions of theory.” However, in 1886, this conclusion was shown to be untenable by Lord Rayleigh. The difficulties of measuring the intensity of the reflected light accurately are very considerable, and Rood had contented himself with estimating the transmitted light and deducing the amount that was reflected. Rayleigh showed that when this fact was considered the difference between Fresnel’s formula and Rood’s experimental results might amount to 7 per cent, of the reflected light, a difference much too great to be regarded as insignificant. Rayleigh found from his own experiments that recently polished glass has a reflecting power differing not more than 1 or 2 per cent, from Fresnel’s formula; but that after some months or years the reflection may fall off 10 per cent, or more, and that without any apparent tarnish. About the same time Sir John Conroy carried out a lengthy series of experiments on the same subject. His results were published in the ‘Phil. Trans.,’ 1888, and confirmed those of Lord Rayleigh. There can thus be no doubt of a decided departure from Fresnel’s formula under certain circumstances. The difference is too great to be put down to experimental errors, and there is no evidence of such errors, seeing that the results of experiment are fairly consistent. Nor can there be very much doubt as to the direction in which to look for an explanation of the apparent divergence between theory and experiment. Everything points to a changing condition of the reflecting surface, and this suggests that a consideration of the layer of transition will show how Fresnel’s laws are departed from in this as in some other directions. The object of the present paper is to investigate this matter rather more systematically than appears to have been done hitherto.

II. Researches on explosives.—Fired gunpowder

1875 ◽  
Vol 165 ◽  
pp. 49-155 ◽  
Keyword(s):  
Considerable Time ◽  
Short Account ◽  
Secretary Of State ◽  
Series Of Experiments ◽  
The Subject ◽  
The Difference ◽  
Difficult Subject ◽  
Physical Fact

The investigations which form the subject of this memoir have occupied our attention for a considerable time, having been commenced in 1868. They have been made collaterally with a series of experiments carried on by a Committee appointed by the Secretary of State for War, with the view, among other objects, of determining the most suitable description of powder for use in heavy ordnance, which is still continually increasing in-size; indeed our main object has been to endeavour to throw additional light upon the intricate and difficult subject under investigation by that Committee. There are perhaps few questions upon which, till within quite a recent date, such discordant opinions have been entertained as upon the phenomena and results which attend the combustion of gunpowder. As regards the question alone of the pressure developed, the estimates are most discordant, varying from the 1000 atmospheres of Robins to the 100,000 atmospheres of Rumford; or even, discarding these extreme opinions in favour of views which have been accepted in modern text-books as more reliable, the difference between an estimate of 2200 and of 29,000 atmospheres is sufficiently startling as regards a physical fact of so much importance. The views regarding the decomposition of gunpowder are nearly as various; and we therefore think that a description and discussion of our own researches may be usefully preceded by a short account of the labours of the previous investigators of this subject and of the grounds upon which their conclusions were based.

scholarly journals The latent fermenting powers of bacteria.—Nos. I - Ill

1924 ◽  
Vol 96 (674) ◽  
pp. 156-170 ◽  
Keyword(s):  
Succinic Acid ◽  
Close Relationship ◽  
Glucose Molecule ◽  
Series Of Experiments ◽  
The Subject ◽  
Structural Formulae ◽  
The Many ◽  
Primary Cleavage ◽  
Crucial Test ◽  
Acetic Acids

In the series of communications published in the 'Proceedings of the Royal Society' from 1914 to 1921 the writer (1) has traced the fluctuations in the various products of the degradation of carbohydrates under the influence of B . coli , and, amongst the various relationships which are to be seen, has drawn attention to the specially close relationship between succinic and acetic acids. A glance at the structural formulæ of these substances is sufficient to give the impression that a relation between them is most likely; but when we reflect upon the origin of succinic acid from carbohydrates we are faced with the difficulty that succinic acid is among the few end-products of fermentation which contain four carbon atoms. According to an earlier theory of the degradation of carbohydrates by bacteria (2), which runs parallel with the generally accepted theory of fermentation by yeast (3), (4), there is first a cleavage of the molecule of six carbon atoms into two molecules of three carbon atoms. On this theory succinic acid would have to be reformed by a resynthesis. But although this theory of primary cleavage into two triad molecules is true in very many cases, it is, according to the many results which the writer has accumulated lately, certainly not the whole truth, for there are other lines of break-down of the glucose molecule. That such might be the case was hinted at two years ago, but it was desired to accumulate more evidence. This evidence forms the subject of this and following communications. and a more comprehensive theory of fermentation by bacterial enzymes is propounded, which in brief is this: that carbohydrates can be split anywhere between two carbon atoms, so that a molecule of six may break up into two threes, three twos, a two and a four, and so on. The idea underlying the glycerine experiments was this: if succinic acid arises by the splitting of a molecule of glucose into a tetrad and a dyad molecule, then none should arise from the glycerine; whereas, if succinic acid is formed by a re-synthesis from two dyad molecules, it should arise from glycerine as well as from glucose. This, as will be seen later, was not the crucial test it appeared to be at the time; yet the results of the fermentation of glycerine are of interest, leading as they did to a series of experiments which revealed latent fermenting powers in bacteria.

scholarly journals X. On the reflection and refraction of light at the surface of a magnetized medium

1891 ◽  
Vol 182 ◽  
pp. 371-396
Keyword(s):  
Polarized Light ◽  
Electromagnetic Theory ◽  
Theoretical Explanation ◽  
Reflection And Refraction ◽  
Reflected Light ◽  
Series Of Experiments ◽  
Reflecting Surface

1. The object of this investigation is to endeavour to ascertain how far the electromagnetic theory of light, as at present developed, is capable of giving a theoretical explanation of Dr. Kerr’s experiments on the effect of magnetism on light. In the first series of experiments polarized light was reflected from the polished pole of an electromagnet, and it was found that when the circuit was closed, so that the reflecting surface became magnetized perpendicularly to itself, the reflected light exhibited certain peculiarities, which disappeared when the circuit was broken.

Differences in mechanisms of intelligence among vertebrates

1985 ◽  
Vol 308 (1135) ◽  
pp. 53-65 ◽  
Keyword(s):  
Comparative Research ◽  
Rank Order ◽  
Vertebrate Species ◽  
Rapid Improvement ◽  
Series Of Experiments ◽  
The Subject ◽  
The Difference ◽  
Efficient Learning ◽  
Learning Sets ◽  
Serial Reversal

Much comparative research aimed at establishing differences in intelligence among vertebrates has failed to convince the sceptic, because it has concentrated on a single experimental paradigm (such as learning sets), while employing a diverse array of species in the hope of establishing a rank ordering of intelligence. The sceptic can insist that such research has not even established that there are any differences in mechanisms of intelligence between any pair of vertebrate species, let alone elucidated the nature of the difference, and even the unsceptical will doubt that such research is ever likely to establish a rank order of intelligence. It is more informative to concentrate on fewer species, but a broader range of experimental paradigms. Thus, studies of serial reversal learning have consistently suggested that goldfish do not show such rapid improvement as do rats. One explanation of this might be that rats learn more effectively than goldfish to use the outcome of one trial to predict the outcome of the next. The suggestion is supported by finding other experimental paradigms, such as alternation learning, which must also tap such a process, and where rats again learn more rapidly than goldfish. Efficient learning-set performance may also depend on this process, but must in addition require the subject to transfer this rule across changes of stimuli. There is reason to believe that not all vertebrates are equally adept at such transfer, and this possibility is explored in a series of experiments studying the transfer of matchingto-sample in pigeons and corvids. The corvids display significantly better transfer and the close similarity in training procedures possible with these subjects makes it unlikely that this is due to differences in these training procedures.

Learning Language Levels in Students Accurate with a History Academic Achievement History

2017 ◽  
Vol 1 (2) ◽  
pp. 137
Author(s):  
Noorlela Binti Noordin ◽  
Abdul Razaq Ahmad ◽  
Anuar Ahmad
Keyword(s):  
Academic Achievement ◽  
Statistical Inference ◽  
Quantitative Data ◽  
Quantitative Methods ◽  
Descriptive Statistics ◽  
Language Test ◽  
The Subject ◽  
The Difference ◽  
Learning Language ◽  
The Relationship

This study was aimed to evaluate the Malay proficiency among students in Form Two especially non-Malay students and its relationship to academic achievement History. To achieve the purpose of the study there are two objectives, the first is to look at the difference between mean of Malay Language test influences min of academic achievement of History subject among non-Malay students in Form Two and the second is the relationship between the level of Malay proficiency and their academic achievement for History. This study used quantitative methods, which involved 100 people of Form Two non-Malay students in one of the schools in Klang, Selangor. This study used quantitative data were analyzed using descriptive statistics and statistical inference with IBM SPSS Statistics v22 software. This study found that there was a relationship between the proficiency of Malay language among non-Malay students with achievements in the subject of History. The implications of this study are discussed in this article.

The Idea of a Meaningful Synthesis of Marxist and Non-Marxist Systems of Political Economy as a Mirror of Intellectual Turmoil (About V.T. Ryazanov’s Book «Modern Political Economy: Prospects of Neo-Marxist Synthesis»)

2019 ◽  
pp. 74-98
Author(s):  
A.B. Lyubinin
Keyword(s):  
Economic Theory ◽  
Political Economy ◽  
Economic Status ◽  
Economic Science ◽  
Objective Reality ◽  
Commodity Production ◽  
Subjective Assessments ◽  
The Subject ◽  
The Difference ◽  
Political Economic

Review of the monograph indicated in the subtitle V.T. Ryazanov. The reviewer is critical of the position of the author of the book, believing that it is possible and even necessary (to increase the effectiveness of General economic theory and bring it closer to practice) substantial (and not just formal-conventional) synthesis of the Marxist system of political economy with its non-Marxist systems. The article emphasizes the difference between the subject and the method of the classical, including Marxist, school of political economy with its characteristic objective perception of the subject from the neoclassical school with its reduction of objective reality to subjective assessments; this excludes their meaningful synthesis as part of a single «modern political economy». V.T. Ryazanov’s interpretation of commodity production in the economic system of «Capital» of K. Marx as a purely mental abstraction, in fact — a fiction, myth is also counter-argued. On the issue of identification of the discipline «national economy», the reviewer, unlike the author of the book, takes the position that it is a concrete economic science that does not have a political economic status.

Research of the activity and viability of spermatozoa at different concentrations and proportions of diluents after incubation

2020 ◽  
pp. 88-95
Author(s):  
Svitlana Lobchenko ◽  
Tetiana Husar ◽  
Viktor Lobchenko
Keyword(s):  
Plasma Concentration ◽  
Incubation Time ◽  
Coefficient Of Variation ◽  
Incubation Medium ◽  
Wide Range ◽  
Series Of Experiments ◽  
The Subject ◽  
Boar Spermatozoa ◽  
Native Plasma ◽  
Better Than

The results of studies of the viability of spermatozoa with different incubation time at different concentrations and using different diluents are highlighted in the article. (Un) concentrated spermatozoa were diluented: 1) with their native plasma; 2) medium 199; 3) a mixture of equal volumes of plasma and medium 199. The experiment was designed to generate experimental samples with spermatozoa concentrations prepared according to the method, namely: 0.2; 0.1; 0.05; 0.025 billion / ml. The sperm was evaluated after 2, 4, 6 and 8 hours. The perspective of such a study is significant and makes it possible to research various aspects of the subject in a wide range. In this regard, a series of experiments were conducted in this area. The data obtained are statistically processed and allow us to highlight the results that relate to each stage of the study. In particular, in this article it was found out some regularities between the viability of sperm, the type of diluent and the rate of rarefaction, as evidenced by the data presented in the tables. As a result of sperm incubation, the viability of spermatozoa remains at least the highest trend when sperm are diluted to a concentration of 0.1 billion / ml, regardless of the type of diluent used. To maintain the viability of sperm using this concentration of medium 199 is not better than its native plasma, and its mixture with an equal volume of plasma through any length of time incubation of such sperm. Most often it is at this concentration of sperm that their viability is characterized by the lowest coefficient of variation, regardless of the type of diluent used, which may indicate the greatest stability of the result under these conditions. The viability of spermatozoa with a concentration of 0.1 billion / ml is statistically significantly reduced only after 6 or even 8 hours of incubation. If the sperm are incubated for only 2 hours, regardless of the type of diluent used, the sperm concentrations tested do not affect the viability of the sperm. Key words: boar, spermatozoa, sperm plasma, concentration, incubation, medium 199, activity, viability, rarefaction.

Rhythm

2018 ◽  
Author(s):  
Lexi Eikelboom
Keyword(s):  
Social Sciences ◽  
Twentieth Century ◽  
Human Existence ◽  
Embodied Experience ◽  
Giorgio Agamben ◽  
The Social ◽  
Contemporary Philosopher ◽  
The Subject ◽  
The Difference ◽  
Theoretical Category

This book argues that, as a pervasive dimension of human existence with theological implications, rhythm ought to be considered a category of theological significance. Philosophers and theologians have drawn on rhythm—patterned movements of repetition and variation—to describe reality, however, the ways in which rhythm is used and understood differ based on a variety of metaphysical commitments with varying theological implications. This book brings those implications into the open, using resources from phenomenology, prosody, and the social sciences to analyse and evaluate uses of rhythm in metaphysical and theological accounts of reality. The analysis relies on a distinction from prosody between a synchronic approach to rhythm—observing the whole at once and considering how various dimensions of a rhythm hold together harmoniously—and a diachronic approach—focusing on the ways in which time unfolds as the subject experiences it. The text engages with the twentieth-century Jesuit theologian Erich Przywara alongside thinkers as diverse as Augustine and the contemporary philosopher Giorgio Agamben, and proposes an approach to rhythm that serves the concerns of theological conversation. It demonstrates the difference that including rhythm in theological conversation makes to how we think about questions such as “what is creation?” and “what is the nature of the God–creature relationship?” from the perspective of rhythm. As a theoretical category, capable of expressing metaphysical commitments, yet shaped by the cultural rhythms in which those expressing such commitments are embedded, rhythm is particularly significant for theology as a phenomenon through which culture and embodied experience influence doctrine.

scholarly journals XIV. On the absorption of gases by solids

1881 ◽  
Vol 32 (212-215) ◽  
pp. 407-408
Keyword(s):  
Royal Society ◽  
Hydraulic Press ◽  
Careful Examination ◽  
Solid Matter ◽  
Chemical Action ◽  
High Pressure And Temperature ◽  
Solid Iron ◽  
Series Of Experiments ◽  
The Subject ◽  
Very High

During the progress of the investigations which I have from time to time had the honour of bringing under the notice of the Royal Society, I have again and again noticed the apparent disappearance of gases inclosed in vessels of various materials when the disappearance could not be accounted for upon the assumption of ordinary leakage. After a careful examination of the subject I found that the solids absorbed or dissolved the gases, giving rise to a striking example of the fixation of a gas in a solid without chemical action. In carrying out that most troublesome investigation, the crystalline separation of carbon from its compounds, the tubes used for experiment have been in nine cases out of ten found to be empty on opening them, and in most cases a careful testing by hydraulic press showed no leakage. The gases seemed to go through the solid iron, although it was 2 inches thick. A series of experiments with various linings were tried. The tube was electro-plated with copper, silver, and gold, but with no greater success. Siliceous linings were tried fusible enamels and glass—but still the' tubes refused to hold the contents. Out of thirty-four experiments made since my last results were published, only four contained any liquid or condensed gaseous matter after the furnacing. I became convinced that the solid matter at the very high pressure and temperature used must be pervious to gases.

scholarly journals The enzymes of B. coli communis . Part V.—(a) anaerobic growth followed by anaerobic and aerobic fermentation. (b) the effects of aeration during the fermentation

1921 ◽  
Vol 92 (644) ◽  
pp. 135-150
Keyword(s):  
Anaerobic Growth ◽  
Aerobic Growth ◽  
Aerobic Fermentation ◽  
The Subject ◽  
The Difference ◽  
Effect Of Oxygen ◽  
Present Section ◽  
Ferment Glucose

In the present communications the effect of oxygen upon the fermentation of glucose and upon the growth of the bacteria, in so far as this affects fermentation, is considered. To this end the organisms have been grown both aerobically and anaerobically, and subsequently made to ferment glucose, both aerobically and anaerobically, with the object of comparing the products of decomposition in the two cases. There are clearly two problems : firstly, the effect of exposure to oxygen during growth upon the subsequent fermentation, whether aerobic or anaerobic, and, secondly, the effect of oxygen admitted during the fermentation. The first question relates to the part played by oxygen in the formation of enzymes, the second to the part played by oxygen in their action on carbohydrates. The first question is considered, though in but a preliminary way, in Section A, the second, more fully, in Section B. Section A. Object of the Experiments . Two results were aimed at in these experiments. Firstly, to compare the products of fermentation of glucose anaerobically, after anaerobic growth, with the products of fermentation anaerobically after previous growth aerobically. And, secondly, to obtain information as to the effect of introducing oxygen during the fermentation itself. This latter consideration, however, though brought to notice by these experiments, is considered only incidentally here because it forms the subject of Section B. In the present section we wish to direct attention particularly to those differences which exist between the fermentation after anaerobic and aerobic growth, not upon the effect of aeration during the fermentation. To point out the difference which previous growth aerobically or anaerobically has made, several analyses from previous experiments are included in Table IV side by side with the completely anaerobic experiments of Tables I, II, and III.

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