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Insecticide resistance in the blue tick, Boophilus Decoloratus Koch, in South Africa

- Whitehead, G B

  • Authors: Whitehead, G B
  • Date: 1960
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:5897 , http://hdl.handle.net/10962/d1013426
  • Description: The work described in this dissertation was undertaken in an attempt to obtain a better understanding of the causes and relationships of insecticide resistance in Blue Tick, Boophilus decoloratus Koch, which has become an acute problem in some localities of the country. The work was undertaken at the Research Department of African Explosives and Chemical Industries Limited over a period of six years from 1953 to 1958. An attempt has been made to keep up to date with the published literature on the various aspects of these investigations up until the end of 1958. Information gained from the literature subsequent to end of 1958 has been made use of but it has not been possible for a number of reasons to follow all recent developments in the various aspects of insecticide resistance published during 1959. In the execution of this work assistance has been obtained from colleagues better equipped in the field of organic chemistry, biochemistry and statistics, than the author. Where information so gained has been used it has been duly acknowledged. Considerable assistance was rendered by laboratory assistants who were responsible for performing the considerable amount of routine collection, breeding and testing of the biological material. The blue tick is not a convenient experimental organism for studies on insecticide resistance. Even with the best facilities the tick cannot be bred satisfactorily and in consequence all supplies had to be collected from naturally-occurring populations. Although this had decided advantages in some aspects of the work, a great deal of useful information might have been obtained if certain strains of ticks could have been maintained. The lack of a standard sensitive reference strain has been a considerable disadvantage which could not be overcome and which has influenced the manner in which this work has been carried out. Because the tick could not be bred artificially the work could only be undertaken with unfed larvae and fully engorged adult females . Larvae are extremely small and in consequence could only be handled in batches while the fully engorged female is sluggish and contains a large quantity of semi-digested mammalian blood which invariably interfered with chemical or biochemical studies.
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  • Date Issued: 1960

Rhodes University Graduation Ceremony 1960

- Rhodes University

  • Authors: Rhodes University
  • Date: 1960
  • Language: English
  • Type: text
  • Identifier: vital:8094 , http://hdl.handle.net/10962/d1004409
  • Description: Rhodes University Graduation Ceremonies in the University Great Hall on Saturday, 2nd April, 1960, at 11 a.m. [and] 23rd April, 1960, at 11 a.m.
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  • Date Issued: 1960

Some aspects of the chemistry of zirconium compounds relating to their combination with collagen

- Williams-Wynn, David Ernest Arthur

  • Authors: Williams-Wynn, David Ernest Arthur
  • Date: 1960
  • Subjects: Zirconium compounds , Collagen
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4513 , http://hdl.handle.net/10962/d1013456
  • Description: [Summary] Some properties of zirconium compounds in aqueous solution have been determined using physico-chemical techniques. Zirconium oxychloride was used as the source of zirconium in all detailed investigations; zirconium sulphate was used in a few cases for comparative purposes. The Stokes diaphragm cell method has been used to determine the diffusion coefficient of zirconium in hydrochloric acid solution. It was found that the diffusion coefficient fell progressively with time, a limiting value being reached 4 to 5 weeks after dissolving the salt, and it was demonstrated that particles in the aged solutions were more homogeneous than in freshly prepared solutions. The limiting values were concentration dependent; dilute solutions had a lower diffusion coefficient than the more concentrated solutions when measured at the natural pH. In the presence of added acid the rate of diffusion was increased until a limiting value was reached in 0.5 M acid. The addition of alkali or complexing acids reduced the rate of diffusion.
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  • Date Issued: 1960

The contribution of the Anglican church to education in the Cape

- Rawlins, G E

  • Authors: Rawlins, G E
  • Date: 1960
  • Subjects: Church and education -- South Africa , Church of England -- Education -- South Africa , Education -- South Africa -- Cape of Good Hope
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1978 , http://hdl.handle.net/10962/d1013055
  • Description: In his "Onderwys in Kaapland, 1652 - 1939", Dr. P.S. du Toit makes special references to the educational work of the Anglican Church, indicating that there is some contribution. This attitude has as its aim to expose more of the reef of which the outcrops receive attention by Dr. du Toit ... much can happen between 1807 and 1829, and some of what did is described in these pages. One of Dr. du Toit's interests is the effect of the attempt to make English and instruction in English the basis of all education. Chap. 1, p. 1.
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  • Date Issued: 1960

The cost of discipleship and the reward of righteousness

- Samson, Robert McNeil

  • Authors: Samson, Robert McNeil
  • Date: 1960
  • Subjects: Jesus Christ -- Teachings , Christian life -- Biblical teaching
  • Language: English
  • Type: Thesis , Bachelor , BDiv
  • Identifier: vital:1272 , http://hdl.handle.net/10962/d1013158
  • Description: CHAPTER ONE. In the Old Testament we meet with the problem of suffering and reward, and the attempts made to resolve it. It becomes the one great problem after the time of the Exile. Most commentators are agreed that it grew to hold that place in relation to the increase of importance of the individual in Hebrew thinking. While certain aspects of the problem are presented in Jeremiah, Ezekiel, Isaiah, and Psalm 73, the most important contributions are made by the Deuteronomist and the poet who wrote the Book of Job. The Deuteronomist theory presents the belief that there is a rigid correspondence between the sins of the individual and his suffering. The reply in Job makes it clear that this is not so. Job himself passes through the desperate situation of feeling deserted by God to a certain faith that whatever happens to him, God is faithful. CHAPTER TWO. Jesus' teaching on "discipleship". Basically Jesus's teaching centres around Mark 8 : 34, "Whosoever will come after me, let him deny himself and take up his cross, and follow me". The cost of discipleship from this point of view means, then, that even as Jesus Himself bears the cross for the salvation of the world, so the disciple is called upon to bear that cross in association with his Lord. Jesus offers the reward of both a present foretaste and a future consummation of eternal life, as the disciple shares in His resurrection. St. Paul's teaching of "Life in Christ". The central teaching of Paul is found in Romans 6 : 11, "Likewise reckon ye also yourselves to be dead indeed unto sin, but alive unto God through Jesus Christ our Lord." The cost of discipleship is death, the death of self- will. It means being crucified with Christ. The reward of the righteous man is both a present and future participation in the risen life of Christ. CHAPTER THREE The need of man. Because man is a sinner, being estranged from God in whose image he was created, he stands in need of being reconciled to God. This he cannot do himself because, to his sin, he is not able to make the full sacrifice of his self-will. "Man requires to be put right with God because as a matter of fact he is not right." The Christ. Only in the person of the God-man is God able to effect man's resolution. Jesus, the Christ, who alone of all men did not participate in the sinfulness of man, is this God-man, realising in Himself the fact that salvation can only be wrought by one who is both God and man. The necessity of the Cross. The death of the Christ is seen to be necessary both from the side of man and from that of God. It was essential that the Christ should give His life for man; everything for His purpose of salvation turns on the will to die. He must give himself to reconcile man to God. The sacrifice of the Cross. Seen in the context of the Old Testament sacrificial system, what is important about the sacrifice of the Christ is that on the cross He offered up His life for man. The sacrifice of the Christ is both in the category of divine revelation and that of human response. It is the love of God in its utter self-offering making a way whereby the sinner might be reconciled to Him. The use of the Ransom Theory of the atonement is regarded as inadequate for expressing this cost. Basically it is a costly sacrifice because it is the self-offering of the Son of God upon the cross. CHAPTER FOUR The New Testament picture. A closer analysis is made of the New Testament teaching of discipleship, where it is seen that it is required of men that he should make, like the Christ, the costly sacrifice of himself. Soren Kierkegaard. This existential thinker felt the need of awakening men to a full recognition of the costliness of life. Despair. Man, due to his state of sinfulness is in despair, for "sin can be defined as despair at not willing to be oneself or not willing to be oneself before God." It is necessary to make the leap of faith to pass from this despair. The Three Stages. These are the aesthetical, ethical and religious stages. The individual must enter the last by making the leap of faith out of his despair; and this leap means the costly commitment of the self to the Christ. "Purify your hearts." In this book, Kierkegaard analyses man's double-mindedness. He comes to two conclusions. "If anybody would will the Good truly, then he must with knowledge of himself be ready to renounce all double-mindedness. If anybody would will the Good truly, then he must be ready to do all for the Good, and suffer for for the Good." His teaching on the cost of discipleship could be summed up thus : "The negating of one's finite self, or the negating of one's finitude means for him nothing less than the conscious sacrifice of all that is finite." Paul Tillich. Tillich deals with the ultimate problem of being and non-being, and in the "Courage to be" he develops the reactions of the individual when he is faced with the possibility of his non-being. The individual can either lose himself in his world by the courage to be as a part, or lose his world in himself by the courage to be as himself. These two forms of courage are transcended by the courage to accept acceptance, which is the ultimate courage to be, in which the individual accepts the fact that though he is sinful, yet God accepts him. This courage is the outcome of faith, which is found in an encounter with the New Being, in which the self is lost in the Christ, being found also in the Christ. The disciple surrenders himself that he may be made more truly himself. CHAPTER FIVE In this chapter an attempt is made to analyse the reward of righteousness. This reward is firstly seen to be the outcome of the life of discipleship and not its motive. Basically it is found in the new quality of life which is called eternal life. It is a reward both in the future and in the present. In the future it is the fullness of life in communion, peace and joy in the presence of God. In the present it is a foretaste of that life which is to come, a present possession in the midst of finitude of communion, peace and joy with God. Ultimately this means participation in the resurrection of the Christ. CHAPTER SIX We can conclude from this thesis, then, that Jesus the Christ is the prototype of the Christian. Discipleship is costly because it means participation in His utter self-offering of Himself; and the righteous man, who is the one who by faith commits himself to and in the Christ, is rewarded with the new quality of eternal life. The death and resurrection of Jesus the Christ are the criteria of the cost of discipleship and the reward of the righteous man.
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  • Date Issued: 1960

The diary of C. L. Stretch - a critical edition and appraisal

- Crankshaw, Grahame Bruce

The frontier in South African English verse : 1820-1927

- Taylor, Avis Elizabeth

  • Authors: Taylor, Avis Elizabeth
  • Date: 1960
  • Subjects: South African poetry (English) -- 19th century , South African literature (English) -- History and criticism , South Africa -- In literature
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:2318 , http://hdl.handle.net/10962/d1013347
  • Description: The concept of a distinctively South African poetry in English has been, and still is, derided as a "pipe dream" as part of the fallacy which stems from the desire for a "national" literature. In 1955, for instance, C.J. Harvey (in an article containing much common sense as well as sound literary judgment) denounced the self-conscious hunting for "Local Colour" which engrosses so many South African writers. Harvey claimed: "Our civilization is not "South African", except in trivial details, it is Western European, and more specifically as far as poetry written in English is concerned, English ... ". There is a serious error of emphasis here. It would be more accurate to say that our ancestors brought Western European civilization to this continent. To imagine that this civilisation has not undergone and is not still constantly suffering a subtle but far-reaching metamorphosis in Africa would be to fly in the face of reality. White South Africans do not only carry the same identity-card but they can be distinguished from Frenchmen, Englishmen or Irishmen by more than "trivial details". This thesis is an examination of some af the earliest English written in southern Africa, particularly of the verse produced by our poetasters and near-poets. It attempts, during the course of this examination, to call attention to a few of the more significant changes which have arisen as the result of the importation of Western civilsation to an African frontier. Further I hope to show some at the varying ways in which these differences affected the white pioneer and how this has been reflected in our verse since pioneering times. In this sense the Frontier may be thought of as the background against which South African English writers developed certain characteristic traits. Intro., p. 1-2.
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  • Date Issued: 1960

The junior secondary course of the Cape Province and the dull-normal child : (a pilot study based on research in the Border area and the North-Eastern districts)

- Loots, Francois Jacobus

The thermal decomposition of silver oxide

- Herley, Patrick James

  • Authors: Herley, Patrick James
  • Date: 1960
  • Subjects: Silver oxide -- Thermal properties , Decomposition (Chemistry)
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4525 , http://hdl.handle.net/10962/d1015017
  • Description: [From Introduction]. The thermal decomposition of solids is characterized by the formation and growth of nuclei at sites on the surface of the solid or within the crystal lattice. Such nuclear formation is favoured by disorganisation of the crystal either by mechanical damage, or by the presence of impurities. Disorganisation results in positions which have a high thermodynamic instability. The nuclei are likely to be formed initially at the corners and the edges of the crystal since these are more prone to damage. Careful handling and storage in vacuo often leads to a large reduction in their number, while deliberate scratching of the surface facilitates their production. The number of potential sites for nuclear formation is also increased by pre-irradiation with ultra-violet light, though there are indications that a different type of nucleus may be produced. Nucleation can be facilitated by pre-irradiation with electrons, neutrons, X-rays, gamma-rays and atomic particles. The nature of the nuclei is not always clearly defined, but it is generally accepted that they are composed of solid reaction products e.g. in the decomposition of barium azide and silver oxalate, nuclei of metallic barium and silver, respectively, are formed.
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  • Date Issued: 1960

Rhodeo, Vol. 14, No. 1

  • Date: 1960-04-01
  • Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
  • Language: English
  • Type: Text
  • Identifier: vital:14452 , http://hdl.handle.net/10962/d1019324
  • Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
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  • Date Issued: 1960-04-01

Rhodeo, Vol. 14, No. 2

  • Date: 1960-04-30
  • Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
  • Language: English
  • Type: Text
  • Identifier: vital:14453 , http://hdl.handle.net/10962/d1019325
  • Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
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  • Date Issued: 1960-04-30

Rhodeo, Vol. 14, No. 3

  • Date: 1960-06-24
  • Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
  • Language: English
  • Type: Text
  • Identifier: vital:14454 , http://hdl.handle.net/10962/d1019326
  • Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
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  • Date Issued: 1960-06-24

Rhodeo, Vol. 14, No. 4

  • Date: 1960-08-26
  • Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
  • Language: English
  • Type: Text
  • Identifier: vital:14455 , http://hdl.handle.net/10962/d1019327
  • Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
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  • Date Issued: 1960-08-26

Rhodeo, Vol. 14, No. 5

  • Date: 1960-09-16
  • Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
  • Language: English
  • Type: Text
  • Identifier: vital:14456 , http://hdl.handle.net/10962/d1019328
  • Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
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  • Date Issued: 1960-09-16

"The congregational way" : an historical study of the congregational doctrine of the church

- De Gruchy, John Wesley

  • Authors: De Gruchy, John Wesley
  • Date: 1961
  • Subjects: Congregational churches , Congregationalism
  • Language: English
  • Type: Thesis , Bachelor , BDiv
  • Identifier: vital:1276 , http://hdl.handle.net/10962/d1013317
  • Description: From Preface: In this Ecumenical Age it is necessary that each Christian Communion consider again its particular doctrine of the Church, and restate it for the benefit of the whole Body of Christ. This Thesis is an attempt to show some historical and theological facets of the traditional Congregational doctrine of the Church. However, it must be stated that a full exposition of Congregational ecclesiology is an impossible task for any thesis. Firstly, inherent within Congregationalism is the fear of dogmatizing about matters of faith and practice. It has expressed itself in Statements and Declarations but always with the qualification that these things are 'commonly believed amongst us' Therefore, Congregationalism, while it has a characteristic ecclesiology, has never formulated a rigid pattern of Churchmanship which has to be adhered to by all the Churches. Secondly, a full study of Congregational ecclesiology would entail the study of the practices of every Congregational Church through the ages. That is an impossible task. Therefore, we have been confined to available material; but material which nevertheless expresses what we would regard as traditional congregationalism. Thirdly, a study of this nature must be content merely to state, however critically, what Congregationalists have believed about the Church at various times in the history of Congregationalism. It is impossible to convey the pulse and feeling of the life of a Congregational Church, for it is very important in seeking to understand any Churchmanship, not only to understand its theological form and structure, but also to experience its ' koinonia ' in its common life and worship.
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  • Date Issued: 1961

A critical study of the determination of molybdenum in plant material

- Gore, William Tompson

  • Authors: Gore, William Tompson
  • Date: 1961
  • Subjects: Molybdenum , Plants -- Analysis , Spectrophotometry , Polarography
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4477 , http://hdl.handle.net/10962/d1012071 , Molybdenum , Plants -- Analysis , Spectrophotometry , Polarography
  • Description: 1. Polarographic and spectrophotometric methods for the determination of molybdenum were reviewed. 2. The inclusion of salicylaldoxine in several supporting electrolytes was examined with a view to developing a polarographic procedure, suitable for routine analyses, which did not necessitate a preliminary time-consuming separation stage. A stable molybdenum wave was obtained from an electrolyte having a composition similar to the test solution obtained after the wet digestion of plant material. The height of the wave was found to be, over an optimum range, independent of the reagent concentrations. The wave was however distorted by a maximum, which rendered it unsuitable for quantitative analytical application. 3. The spectrophotometric procedure for molybdenum using thiocyanate is virtually specific and was examined critically. Modifications were found to improve the sensitivity of the procedure, and the stability of the chromatic compound. 4. The modified spectrophotometric procedure is recommended for the routine determination of molybdenum in plant material.
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  • Date Issued: 1961

A study of certain members of the South African xylariaceae, with reference to the use of cultural characters in classification

- Martin, Philip Michael Dunlop

  • Authors: Martin, Philip Michael Dunlop
  • Date: 1961
  • Subjects: Xylariaceae -- South Africa , Hypoxylon , Fungi -- South Africa -- Morphology , Fungi -- South Africa -- Anatomy , Fungi -- Classification , Mycelium
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4265 , http://hdl.handle.net/10962/d1013505
  • Description: [Summary] Sixty-three species, drawn from the genera Rosellinia Hypoxylon, Nummularia, Daldinia, Penzigia and Xylaria, are studied in order to determine whether any correlation exists between various characters of the perfect stage and characters connected with the mycelium in artificial culture that might be used to supplement the existing classification of the Xylariaceae. An examination is made of the morphological and anatomical characters of several stromal types and a statistical method of evaluating differences in ascospore dimension between samples of closely related species is described. Cultural work shows that :- a) Each species group, based primarily on similarity of stromal form, has a characteristic set of cultural characters. b) Members within a Species group can usually be distinguished clearly in culture. The use of cultural characters as an additional criterion in classification is therefore recommended.
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  • Date Issued: 1961

An investigation of solar radio noise in relation to visible phenomena

- Poole, Lex Martin Graham

  • Authors: Poole, Lex Martin Graham
  • Date: 1961
  • Subjects: Solar radio emission , Radio astronomy -- Instruments
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5536 , http://hdl.handle.net/10962/d1013032
  • Description: The work of previous writers on the origin and propagation of solar radio noise, and particularly the correlation with visual events is reviewed, and then the construction of the author's 300 Mc/s receiver described. With a view to the author's project, absorption of electromagnetic radiation in the solar corona is quantitatively discussed, and a method for determining the intensity without absorption of a radio burst is evolved. The main project involves briefly the discovery of any possible relationship between the magnitude of a visual flare and the corrected intensity of an associated radio burst as measured at 125 Mc/s. It is concluded that no definite relation exists, but from this consideration an approximate shape of the instantaneous frequency profile of outburst elements is obtained. An extension of the theory to isolated bursts enables us to predict both this bandshape, and the velocity of an exciting agency moving radially through the corona.
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  • Date Issued: 1961

An investigation of the behaviour and biology of the Citrus Mussel Scale, Lepidosaphes Beckii (Newm.)

- Hulley, Patrick Elliot

  • Authors: Hulley, Patrick Elliot
  • Date: 1961
  • Subjects: Lepidosaphes beckii , Citrus -- Diseases and pests -- South Africa , Scale insects -- Larvae
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5912 , http://hdl.handle.net/10962/d1015459
  • Description: The citrus industry is subject to a number of serious insect pests. Of these, the most important is a sedentary group known as the Armoured Scale Insects (Diaspididae). Ebeling (1950) states that they are of greater economic importance to the industry than all the other pests put together. A great deal has been published on various aspects of the biology, ecology and control of the Diaspididae, much of the work appearing in the books of Quayle (1938), Ebeling (1950) and Bodenheimer (1951). It is very noticeable, however, that the study of the active larvae, or "crawlers", of these insects has been relatively neglected. This lack of work on crawlers is surprising, since they are the only distributive stage in the life cycle of the species. The adult male is also free-living during its brief life span, but takes no part in the actual distribution of the species. It is the position of the female Scale Insect which is important in determining the further spread of the species, since this is the point from which subsequent crawlers will start out on their wanderings. The stage in the life cycle responsible for the position of the female is, of course, the crawler. The crawler is also responsible for the parallel distribution of the male Scales, so that the female can be fertilised. The role of the adult male is confined to the maintenance of the gene flow. From an economic point of view it seems desirable that a complete study be made of the biology of this distributive stage of these important pests.
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  • Date Issued: 1961

An investigation of the polarization of solar radio noise

- Verschuur, Gerrit L.,1937-

  • Authors: Verschuur, Gerrit L.,1937-
  • Date: 1961
  • Subjects: Solar radio emission , Polarimetry
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5547 , http://hdl.handle.net/10962/d1013441
  • Description: CHAPTER I A description of the sun and the type of radio radiation it emits is given. The relation that exists between this and other events occurring on the sun's surface is studied. CHAPTER II The literature dealing with the origin of solar radio noise is reviewed. CHAPTER III The method of specifying polarized radiation and the effect of a magneto- ionic medium on such radiation is discussed. The possible origin of the polarization of solar radio noise is examined and the literature relating to this and to the observations of polarization of solar noise is reviewed. A short outline of the methods used in measuring polarization is given. CHAPTER IV A detailed outline of the construction of a polarimeter is given together with full circuit diagrams and illustrative photographs. CHAPTER V A brief discussion of the operation of the polarimeter, the results obtained and suggestions for its future operation is given.
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  • Date Issued: 1961
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