scholarly journals Bombardment of the heavy isotope of hydrogen by α-particles

1934 ◽  
Vol 143 (850) ◽  
pp. 724-730 ◽  
Keyword(s):  
Heavy Isotope ◽  
Proton Group ◽  
Actual Structure ◽  
Conservation Of Energy ◽  
Difference Of Opinion ◽  
Mass Spectrograph ◽  
The Masses ◽  
Primary Unit ◽  
Unusual Type ◽  
Α Particles

The constitution of the heavy isotope of hydrogen, of mass 2, raises a number of interesting questions on which there is at present considerable difference of opinion. We know that the nuclear charge of this element is 1, and its atomic mass has been accurately determined by Bainbridge as 2·0136, using his modified form of mass spectrograph. As regards the actual structure of the nucleus, a number of possibilities must be considered. In the first place the nucleus may be a primary unit or composite. And secondly, if the diplon is composite it may consist either of two protons and a negative electron, or, as seems more probable of a proton and a neutron closely combined. From a consideration of the general evidence of the transformations which give rise to neutrons, Chadwick concludes that the mass of the neutron in the free state is 1·0067. The sum of the masses of the neutron and hydrogen atom (1·0078) is 2·0145, while the observed mass of diplogen is 2·0136, indicating that the binding energy of the combination is somewhat less than 1 million electron volts. From other considerations Curie and Joliot have suggested that the neutron may have a mass a high as 1·012. On the other hand, Lawrence concludes that the mass of the neutron may be as low as 1·0006. This value is deduced from observations on the transformation of a number of elements by bombardment with fast diplons. With many elements he observed the ejection of a proton group of about 18cm. range, and considers that these are produced by the breaking up of the diplon, in the strong nuclear field of the transformed atom, into a neutron and a proton. In order to reconcile his observations with the principle of the conservation of energy, it is necessary to assume that the mass of the neutron is much smaller that the value deduced by Chadwick, and in fact very nearly equal to unity. On Lawrence's view, the diplon is a nucleus of an unusual type, for it possesses about 5 million volts of excess energy, which can be released under appropriate conditions.

scholarly journals Some nuclear transformations of beryllium and boron and the masses of the light elements

1935 ◽  
Vol 150 (869) ◽  
pp. 241-258 ◽  
Keyword(s):  
Spontaneous Emission ◽  
Periodic Table ◽  
Small Error ◽  
The Other ◽  
Light Elements ◽  
Mass Energy ◽  
Present Communication ◽  
Mass Data ◽  
The Masses ◽  
Α Particles

In a recent paper we showed that the nuclear transformations produced in lithium by bombarding the element with protons and with ions of heavy hydrogen were in complete accord with the laws of the conservation of mass-energy and of momentum. At the same time we pointed out that there were serious discrepancies between the mass-data and the transformation-data in some other cases, and we stressed the fact that the concordance for lithium was one between mass-differences, and gave no test of the correctness or otherwise of the absolute masses in terms of O 16 = 16·000. In the present communication we present the results of experiments on the transformation of beryllium and boron by protons and by ions of heavy hydrogen. It is shown that it is not possible to interpret these results on the mass-data at present available, and we indicate how the difficulties may be overcome by the assumption of a single small error in the mass-spectrographic value for the mass of He 4 . Beryllium So far as it is known beryllium consists of a single isotope,* the mass of which according to Bainbridge is 9·0155. This mass is greater than that of two α-partieles and a neutron (8·0043 + 1·0080§ = 9·0123) by nearly three million volts, and hence great difficulties have been en­countered in nuclear theory in accounting for the observed stability. It had been found by Rayleigh|| that the mineral beryl contained an abnormal quantity of helium, while the experiments of Curie-Joliot and of Chadwick¶ had shown that beryllium gave a copious emission of neutrons when bombarded by α-particles, but the most careful search has failed to give any evidence whatever for a spontaneous emission of particles from the element. Both lithium and boron, of atomic numbers 3 and 5 respectively, are very easily transformed by bombardment wit protons and with ions of heavy hydrogen, so that it was to be expected that beryllium, which lies between them in the periodic table, would also give effects when bombarded by the same ions. Observation of the energies evolved if the reactions are known with certainty, should then lead to values for the mass of Be 9 in terms of the masses of the other products of the transformations, which can be used to check the mass found by Bainbridge.

scholarly journals Historical and Evolutionary Analysis of Reasons and Causes of Objections of Orientalism on Prophet’s Biography

2020 ◽  
Vol 2 (1) ◽  
pp. 274-296
Author(s):  
Bakht Shaid ◽  
Hafiz Muhammad Sani
Keyword(s):  
Large Scale ◽  
Human Society ◽  
Evolutionary Analysis ◽  
Not Given ◽  
Islamic History ◽  
Difference Of Opinion ◽  
The Difference ◽  
Mutual Relations ◽  
The Masses ◽  
Islamic Civilization

سیرت طیبہ پر استشراقی فکر کے اعتراضات کے اسباب و عوامل کا تاریخی و ارتقائی جائزہ Over the course of time and with the rapid increase in human population need for mutual relations become crucial. Resultantly on behalf of this closeness, separation, anti-standpoints and comparisons also emerged. As the time passed by hatred and hypocrisy and other social vices spread on large scale. Thus human society was waiting for such liberator who may lead and work for the betterment of this society. With the dawn of Islamic civilization all such issues were not only resolved but also provided with a model for containing the difference of opinion and multiple traditions under its unique worldview. Islamic History presents itself as a model where the minorities were provided with the opportunities of participating in political, social, educational and collective affairs. Thus in a society where tyranny, injustice, un-forbearance, religious intensity, terrorism and the activities of violating the human rights were very common, were substituted by the Islamic ideal  of forbearance. It is argued here that the solution of all these issues was only in religion contrary to what is being claimed about an idea of social harmony where religion is not given its due position. Today its our dire need to develop a sense of harmony, modesty, affection and peacefulness among the masses of various religions of Pakistani society. It is further argued that for this very noble cause all the religious scholars and their followers can come forward playing their pertinent role.  

Comparison of the Masses of He andH1on a Mass-Spectrograph

1933 ◽  
Vol 43 (2) ◽  
pp. 103-105 ◽  
Author(s):  
K. T. Bainbridge
Keyword(s):  
Mass Spectrograph ◽  
The Masses

Isotope effect on the thermodynamic quantities of gaseous uranium hexafluoride

1976 ◽  
Vol 54 (1) ◽  
pp. 160-165 ◽  
Author(s):  
Jan Bron
Keyword(s):  
Partition Function ◽  
Quantum Correction ◽  
Isotope Effects ◽  
Uranium Atom ◽  
Uranium Hexafluoride ◽  
Thermodynamic Quantities ◽  
Heavy Isotope ◽  
Statistical Mechanical ◽  
Lower Temperature ◽  
The Masses

For gaseous UF6 changes in the thermodynamic quantifies ΔG (= ΔA), ΔH (= ΔU), ΔCp (= ΔCv), and ΔS upon isotopic substitution can be determined by using the spectroscopically determined geometry and force field. The differences ΔG etc. are defined as (G238 – Gx), where 238 and x (x = 235, 234, 233, and 232) are the masses of the central uranium atom. The changes in the thermodynamic quantities are related to the logarithm of the partition function ratio of the UF6 species compared. The logarithm of the partition function ratio can be conveniently expressed as a series in temperature and hence, by using statistical mechanical relationships, the changes in thermodynamic quantities can be expressed as a series in temperature.Since these changes form examples of heavy isotope effects the validity and utility of the first quantum correction can be investigated. Uncertainties and trends in the magnitudes of the differences in the thermodynamic quantities due to uncertainties or changes in spectroscopic parameters are discussed by means of the first quantum correction. It has been found that the first quantum correction has little quantitative value in the lower temperature region, but it can be used in that range to explain some observed trends in the isotope effects. Some of the conclusions can also be applied to kinetic and equilibrium heavy isotope effects.

scholarly journals Inter-Faith Harmony and Contemporary Demands: An Analytical Study in the Light of Divine Teachings

2020 ◽  
Vol 2 (1) ◽  
pp. 154-177
Author(s):  
Muhammad Mudassar Shafique ◽  
Abid Naeem
Keyword(s):  
Large Scale ◽  
Analytical Study ◽  
Human Society ◽  
Not Given ◽  
Islamic History ◽  
Difference Of Opinion ◽  
The Difference ◽  
Mutual Relations ◽  
The Masses ◽  
Islamic Civilization

Inter-Faith Harmony and Contemporary Demands: An Analytical Study in the Light of Divine Teachings بین المذاہب ہم آہنگی اور عصر ی تقاضے : الہامی تعلیمات کی روشنی میں تجزیاتی مطالعہ Abstract Over the course of time and with the rapid increase in human population need for mutual relations become crucial. Resultantly on behalf of this closeness, separation, anti-standpoints and comparisons also emerged. As the time passed by hatred and hypocrisy and other social vices spread on large scale. Thus human society was waiting for such liberator who may lead and work for the betterment of this society. With the dawn of Islamic civilization all such issues were not only resolved but also provided with a model for containing the difference of opinion and multiple traditions under its unique worldview. Islamic History presents itself as a model where the minorities were provided with the opportunities of participating in political, social, educational and collective affairs. Thus in a society where tyranny, injustice, un-forbearance, religious intensity, terrorism and the activities of violating the human rights were very common, were substituted by the Islamic ideal  of forbearance. It is argued here that the solution of all these issues was only in religion contrary to what is being claimed about an idea of social harmony where religion is not given its due position. Today it’s our dire need to develop a sense of harmony, modesty, affection and peacefulness among the masses of various religions of Pakistani society. It is further argued that for this very noble cause all the religious scholars and their followers can come forward playing their pertinent role. Keywords: Interfaith harmony, present era, divine books, religious personalities, Peace

scholarly journals XI. The effects of vitamins C deficiency on tooth structure in guinea-pigs

1934 ◽  
Vol 223 (494-508) ◽  
pp. 489-510 ◽  
Keyword(s):  
Vitamin C ◽  
Guinea Pigs ◽  
Practical Significance ◽  
Dental Disease ◽  
Human Teeth ◽  
Actual Structure ◽  
Tooth Structure ◽  
Difference Of Opinion ◽  
The One ◽  
Dental Lesions

Much attention has been given in the last few years to the effects of deficiency of vitamins D and A on dental and parodontal structure; extended clinical tests have been carried out; and the deduction has been drawn that a deficiency of these factors is a not infrequent cause of such common dental ailments as caries and pyorrhoea alveolaris. Vitamin C has received relatively little consideration in this connection; in fact doubt is expressed as to whether it has any practical significance for clinical dental disease, and difference of opinion exists even on the fundamental issue as to whether a deficiency of the vitamin is in any way injurious to the teeth. Thus, on the one side, Mrs. Mellanby (1929) found that lack of vitamin C had no influence on tooth structure in puppies, and concluded it was “improbable that the actual structure of human teeth is greatly affected by a deficient intake of vitamin C.” At the other extreme Howe (1920, 1921, 1923) claimed that by feeding guinea-pigs on a scorbutic diet he had been able to produce with regularity all of the better-known dental lesions seen clinically in humans, including alveolar resorption, spongy gums, pockets and pus formation, together with caries and irregularities in the teeth themselves. He drew the deduction that vitamin C deficiency is an important factor in the aetiology of human dental disease. It will be generally conceded that further work is necessary to clear up the present unsatisfactory position.

scholarly journals Bakerian Lecture.— A new mass-spectrograph and the whole number rule

1927 ◽  
Vol 115 (772) ◽  
pp. 487-514 ◽  
Keyword(s):  
Accurate Determination ◽  
Resolving Power ◽  
Fundamental Importance ◽  
Cavendish Laboratory ◽  
New Instrument ◽  
Whole Number ◽  
Mass Spectrograph ◽  
Final Design ◽  
Set Up ◽  
The Masses

The original mass-spectrograph was set up in the Cavendish Laboratory in 1919. Its resolving power was sufficient to separate mass lines differing by about 1 in 130 and its accuracy of measurement was about 1 in 1000. These capabilities sufficed to determine with fair certainty the isotopic constitution of over 50 elements, and to demonstrate that, with the exception of hydrogen, the masses of all atoms could be expressed as integers on the scale O = 16 to one or two parts in one thousand. An account of these researches has already been published. The instrument itself was not actually dismantled until March, 1925, but some years before then it had been realised that for advance in two directions of fundamental importance, namely, the resolution of the mass lines of the heavier elements and the measurement of the divergences from the whole number rule, a considerably more powerful instrument would be required. The Department of Scientific and Industrial Research, to whom I should like now to express my thanks, provided a liberal grant to defray the expenses of construction, and preliminary work on the instrument was commenced in 1921. The application of the method of accelerated anode rays led to an unexpected lengthening of the useful life of the original apparatus so that it was considered best to hold up construction of the new one in order that the final design might have the advantage of all accumulated experience. In the meanwhile one of its objects, the measurement of the divergences from the whole number rule, had been attacked by Costa in Paris, using a mass-spectrograph of his own design capable of an accuracy of 1 in 3000. This admirable piece of work will be referred to later. The accurate determination of these divergences is of fundamental importance since it is one of the few avenues by which the problem of the structure of the nuclei of atoms can be approached, and it was worth making every effort to push the accuracy of analysis to its extreme limit. It was finally decided that the increase of resolution could best be obtained by doubling the angles of electric and magnetic deflection, and sharpening the lines by the use of finer slits placed further apart, in addition special methods were considered for the necessary increase of accuracy in measurement. After numerous setbacks all these objects have been successfully carried out. The new instrument has five times the resolving power of the old one, far more than sufficient to separate the mass lines of the heaviest element known. Its accuracy is 1 in 10,000 which is just sufficient to give rough first order values of the divergences from whole numbers.

scholarly journals The accurate determination of the energy released in certain nuclear transformations

1935 ◽  
Vol 149 (867) ◽  
pp. 406-416 ◽  
Keyword(s):  
Accurate Determination ◽  
Relative Mass ◽  
Depth Of Penetration ◽  
Conservation Of Energy ◽  
Direct Measurements ◽  
Counting Chamber ◽  
Linear Amplifier ◽  
Time Required ◽  
The Masses

During the last few years, very definite information has been obtained on the various modes of transformation of certain elements, particularly of lithium, when bombarded by protons and heavy hydrogen. The nature of these transformations has received strong confirmation by examining the effects produced when each of the isotopes of lithium of mass 6 and 7 is separately bombarded. Sufficient quantity of these two isotopes—of the order of a microgram—has been obtained to settle the groups of liberated particles to he ascribed to each isotope under the two types of bombardment. In the pioneer experiment on these transformations, the range in air of the emitted α -particles or protons was approximately determined by finding the thickness of mica required to stop the particles In general, no special precautions were taken to measure the ranges in air with accuracy. The counting chamber and the first valve of the linear amplifier were Usually mounted on rubber sponge to avoid disturbances due to vibration, so that the position of the counting chamber relative to the source was difficult to fix with certainty. In addition, even in the most favourable cases, the range of the particles is difficult to measure with the same accuracy as the range of a group of α -particles emitted from a clean radioactive source. Apart from the probability variations dependent on the number of particles counted, the intensity of the bombarding source is liable to vary capricious during the time required for a complete experiment. Moreover, the straggling of the particles is more pronounced than in the usual radioactive case, partly on account of the difficulty of preserving a smooth radiating surface under intense bombardment, and partly also on account of the sensible depth of penetration of the bombarding ions. The actual stopping power of mica relative to air for the fast particles is not known with the certainty desired, introducing a serious difficulty in accurate measurements. In order to test whether the conservation of energy holds in these transformations, it is necessary to know the energy of the emitted particles with considerable precision. With this information, we are able to deduce the relative mass numbers of the isotopes involved, and thus obtain a check on the values obtained by direct measurements with various types of mass spectrograph. When there is clear evidence of the mechanism of transformation, the measurement of the energy changes allows us to deduce with considerable certainty the masses of new isotopes which in some cases are produced during transformations.

Qaddafi and Islam in Libya

1984 ◽  
Vol 1 (1) ◽  
pp. 61-81
Author(s):  
Mohamed A. El-Khuwas
Keyword(s):  
Judicial System ◽  
Political Life ◽  
Religious Leaders ◽  
Crucial Importance ◽  
Islamic Theology ◽  
The People ◽  
Political Symbol ◽  
Islamic Faith ◽  
The Masses ◽  
Primary Unit

Islam, the dominant religion, has had a special place in traditionalLibyan society, where the overwhelming majority of the people areSunni Muslims, accepting the Quran and the Sunna as the primarysources of the Islamic faith. “Religion has dominated all facets of life,“significantly affect(ing) the structures, values, and attitudes of Libyansociety. It is a primary unit of loyalty and identity.”’ Mu’ammar al-Qaddafi, a devout Muslim, acknowledges that the effect of Islam is “verysignificant on everyone of us. We cannot deny that religion is an essentialfactor in the lives of all peoples.”Prior to the Qaddafi-led coup in 1969, religious organizations andleaders played a major role in the educational, social and political life ofthe country, particularly in the institutions that regulated the society.Notable religious leaders not only dominated the judicial system but alsoimportant political committees and advisory councils. In this respect,Libya was a typical, traditional society where religion was entangled inthe web of national politics.This has been evident throughout Libyan history. The SanusiyyahBrotherhood, a militant Sufi religious order founded in the nineteenthcentury, played a crucial role in the national resistance against Italiancolonial rule and, subsequently, contributed to the shaping of thecountry’s destiny in the post-independence period. Between 1951-1969,religion was “a political symbol of crucial importance in controlling andmobilizing the masses.” King Mohammed Idris al-Sanusi, who wastrained in Islamic theology and law (Sharia), used his position as Grand ...

Sign in / Sign up

Export Citation Format

Share Document