A critical evaluation of the analytical method used for the separation and estimation of copper and nickel
- Authors: Sismey, J E
- Date: 1948
- Subjects: Copper -- Analysis , Nickel -- Analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4519 , http://hdl.handle.net/10962/d1014335
- Description: [From Introduction]. This thesis deals with the determination of copper and nickel both separately and in each other's presence. The work is divided into two sections, one of which treats the subject from the theoretical side while the other contains an account of the practical work performed by the author. In the theoretical section, an attempt is made to summarise the better-known methods for the determination of copper and nickel, and at the same time, to incorporate such improvements, criticism and variations as have appeared in the literature. The subject is so vast that its summary in so short a space must necessarily be incomplete. Yoe and Server, for example, quote 111 references on the subject of the nickel-dimethylglyoxine with other ions. Only a fraction of the literature was available, and space permitted only a fraction of this to be abstracted in the following pages.
- Full Text:
- Date Issued: 1948
- Authors: Sismey, J E
- Date: 1948
- Subjects: Copper -- Analysis , Nickel -- Analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4519 , http://hdl.handle.net/10962/d1014335
- Description: [From Introduction]. This thesis deals with the determination of copper and nickel both separately and in each other's presence. The work is divided into two sections, one of which treats the subject from the theoretical side while the other contains an account of the practical work performed by the author. In the theoretical section, an attempt is made to summarise the better-known methods for the determination of copper and nickel, and at the same time, to incorporate such improvements, criticism and variations as have appeared in the literature. The subject is so vast that its summary in so short a space must necessarily be incomplete. Yoe and Server, for example, quote 111 references on the subject of the nickel-dimethylglyoxine with other ions. Only a fraction of the literature was available, and space permitted only a fraction of this to be abstracted in the following pages.
- Full Text:
- Date Issued: 1948
A preliminary investigation of the chemical nature of wattle tannin
- Authors: Corbett, John Henry
- Date: 1945
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:21062 , http://hdl.handle.net/10962/6201
- Description: From Introduction: Although the tannins of wattle bark extract are generally considered to be of the class known as condensed tannins, a review of the general chemical nature of the tannins is given for the sake of completeness. This constitutes Part I of the thesis. Part II describes the preliminary investigation of the chemical nature of black wattle extract.
- Full Text:
- Date Issued: 1945
- Authors: Corbett, John Henry
- Date: 1945
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:21062 , http://hdl.handle.net/10962/6201
- Description: From Introduction: Although the tannins of wattle bark extract are generally considered to be of the class known as condensed tannins, a review of the general chemical nature of the tannins is given for the sake of completeness. This constitutes Part I of the thesis. Part II describes the preliminary investigation of the chemical nature of black wattle extract.
- Full Text:
- Date Issued: 1945
A preliminary investigation of the determination of ionic mobilities by conductometric titration
- Authors: Festenstein, Gerald Norman
- Date: 1947
- Subjects: Ionic mobility , Conductometric analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4472 , http://hdl.handle.net/10962/d1011810 , Ionic mobility , Conductometric analysis
- Description: The determination of ionic mobilities by conductometric titration was first suggested by Barker, Rowler and Shuttleworth in discussing the theory of conductometric titration of acids, bases and neutral salts. Intro. p. 1.
- Full Text:
- Date Issued: 1947
- Authors: Festenstein, Gerald Norman
- Date: 1947
- Subjects: Ionic mobility , Conductometric analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4472 , http://hdl.handle.net/10962/d1011810 , Ionic mobility , Conductometric analysis
- Description: The determination of ionic mobilities by conductometric titration was first suggested by Barker, Rowler and Shuttleworth in discussing the theory of conductometric titration of acids, bases and neutral salts. Intro. p. 1.
- Full Text:
- Date Issued: 1947
A statistical study of the errors involved in the sampling and chemical analysis of soils and plants, with particular reference to citrus and pineapples
- Steyn, Willem Johannes Abraham
- Authors: Steyn, Willem Johannes Abraham
- Date: 1958
- Subjects: Soil chemistry , Plants -- Analysis , Soils -- Analysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4506 , http://hdl.handle.net/10962/d1013291
- Description: 1. Accurate and reproducible methods for the determination of N and acid- extractable P in soils are described. The variations in N, P, and K found by intensive sampling of three different soil types are presented. 3. Suggestions for the adequate sampling of soils for various purposes arc given. 4. A study is presented of the preparative stages in leaf analysis (washing, drying, grinding and storage) as applied to citrus and pineapple leaf material. Likely errors are pointed out and procedures whereby these may be minimised are described. 5. A reliable wet-ashing procedure for obtaining leaf solutions is described. 6. Accurate and reproducible methods for the determination of total N, P,. K, Ca, Mg, Na, Fe, Mn, Zn and Cu in citrus and pineapple leaves are presented. 7. It is shown that diurnal variations in nutrient concentrations occur in citrus and pineapple leaves. 8. The variations in N, P, K, Ca, Mg, Na, Fe, Mn, Zn and Cu, occurring from tree to tree in 3 different Navel orange blocks are presented. It is shown that if all these elements are to be represented . to within 10% of the mean values on a 19 : 1 probability level, all the trees in the blocks would have to be sampled. Reasonable sampling procedures for various purposes are suggested. 9. The variations in N, P, K, Ca, Mg, Fe, Mn, Zn and Cu, occurring in 3 different Cayenne pineapple plantations are presented and described. Suitable sampling procedures are suggested.
- Full Text:
- Date Issued: 1958
- Authors: Steyn, Willem Johannes Abraham
- Date: 1958
- Subjects: Soil chemistry , Plants -- Analysis , Soils -- Analysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4506 , http://hdl.handle.net/10962/d1013291
- Description: 1. Accurate and reproducible methods for the determination of N and acid- extractable P in soils are described. The variations in N, P, and K found by intensive sampling of three different soil types are presented. 3. Suggestions for the adequate sampling of soils for various purposes arc given. 4. A study is presented of the preparative stages in leaf analysis (washing, drying, grinding and storage) as applied to citrus and pineapple leaf material. Likely errors are pointed out and procedures whereby these may be minimised are described. 5. A reliable wet-ashing procedure for obtaining leaf solutions is described. 6. Accurate and reproducible methods for the determination of total N, P,. K, Ca, Mg, Na, Fe, Mn, Zn and Cu in citrus and pineapple leaves are presented. 7. It is shown that diurnal variations in nutrient concentrations occur in citrus and pineapple leaves. 8. The variations in N, P, K, Ca, Mg, Na, Fe, Mn, Zn and Cu, occurring from tree to tree in 3 different Navel orange blocks are presented. It is shown that if all these elements are to be represented . to within 10% of the mean values on a 19 : 1 probability level, all the trees in the blocks would have to be sampled. Reasonable sampling procedures for various purposes are suggested. 9. The variations in N, P, K, Ca, Mg, Fe, Mn, Zn and Cu, occurring in 3 different Cayenne pineapple plantations are presented and described. Suitable sampling procedures are suggested.
- Full Text:
- Date Issued: 1958
Base exchange in soils : a study of the reproducibility of base exchange values for some South African soils, as indicated by leaching with normal ammonium acetate solution
- Authors: Pienaar, D J
- Date: 1946
- Subjects: Soil chemistry , Soils
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4489 , http://hdl.handle.net/10962/d1013038
- Description: A very reliable method for the total analysis of the ammonium acetate leachate has been outlined. This is both simple and straight forward and is more rapid than any which have been seen in the literature. It is particularly applicable where a worker must perform a large number of routine analyses in the minimum of time. Shirley (29) and other workers have shown that 1000 ml. of leaching solution is generally necessary to extract all the exchangeable gases. The present investigation has shown that the time of leaching makes no appreciable difference to the amounts of bases replaced, as long as this exceeds four hours. Two alternative methods have been introduced for the rapid determination of the total exchangeable bases in a soil and there are considered to be more reliable than that of Bray and White. It is suggested that the two new methods might yield a still greater degree of accuracy if larger aliquots were to be used for each determination. It is further pointed out that the values obtained by the chloride methods are more likely to represent correct values than the sum totals of the bases as determined individually, since these are arrived at by summing the results of four different estimations, each of which is liable to experimental error, whereas in the chloride methods there is only one perfectly straightforward determination. The values for the total exchangeable bases in the soils examined were found to vary over the range 2.50 to 14.28 m.e. per 100 g. soil, with a variance of up to ± 0.2sm.e. per 100 g., corresponding to a percentage error of up to ± 4.7%. These figures are based on the analysis of 12 separate leachings of each soil with normal ammonium acetate solution of pH 7.00. This rather wide variance can be attributed to the fact that the exchangeable bases in some soils are more easily replaceable than in other soils. It is regretted that the shortage of time and the non-availability of a complete range of samples of all typical South African soils has prevented the attainment of an original objective, namely, a statistical evaluation of the base exchange figures for all South African soil types. It would also have been of great interest to have been able to establish exactly the composition of the double salt of calcium and magnesium, whose existence has been postulated to explain the effect of the Ca/Mg ratio on the results yielded by the first chloride method. Summary, p. 67-68.
- Full Text:
- Date Issued: 1946
- Authors: Pienaar, D J
- Date: 1946
- Subjects: Soil chemistry , Soils
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4489 , http://hdl.handle.net/10962/d1013038
- Description: A very reliable method for the total analysis of the ammonium acetate leachate has been outlined. This is both simple and straight forward and is more rapid than any which have been seen in the literature. It is particularly applicable where a worker must perform a large number of routine analyses in the minimum of time. Shirley (29) and other workers have shown that 1000 ml. of leaching solution is generally necessary to extract all the exchangeable gases. The present investigation has shown that the time of leaching makes no appreciable difference to the amounts of bases replaced, as long as this exceeds four hours. Two alternative methods have been introduced for the rapid determination of the total exchangeable bases in a soil and there are considered to be more reliable than that of Bray and White. It is suggested that the two new methods might yield a still greater degree of accuracy if larger aliquots were to be used for each determination. It is further pointed out that the values obtained by the chloride methods are more likely to represent correct values than the sum totals of the bases as determined individually, since these are arrived at by summing the results of four different estimations, each of which is liable to experimental error, whereas in the chloride methods there is only one perfectly straightforward determination. The values for the total exchangeable bases in the soils examined were found to vary over the range 2.50 to 14.28 m.e. per 100 g. soil, with a variance of up to ± 0.2sm.e. per 100 g., corresponding to a percentage error of up to ± 4.7%. These figures are based on the analysis of 12 separate leachings of each soil with normal ammonium acetate solution of pH 7.00. This rather wide variance can be attributed to the fact that the exchangeable bases in some soils are more easily replaceable than in other soils. It is regretted that the shortage of time and the non-availability of a complete range of samples of all typical South African soils has prevented the attainment of an original objective, namely, a statistical evaluation of the base exchange figures for all South African soil types. It would also have been of great interest to have been able to establish exactly the composition of the double salt of calcium and magnesium, whose existence has been postulated to explain the effect of the Ca/Mg ratio on the results yielded by the first chloride method. Summary, p. 67-68.
- Full Text:
- Date Issued: 1946
Soil erosion in South Africa
- Authors: Kitto, P H
- Date: 1936
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/193679 , vital:45385
- Description: The development of Soil Science in western Europe, eastern North America, and later in other countries, which, in its modern form only started about the beginning of the last century, might be said to mark the first step in the consideration of Soil Erosion from a scientific aspect, although it was some time before scientists began to concentrate on and study the problem as one which demanded a detailed investigation. Empirically, erosion has been noted and, where the value of the land warranted it, practical methods adopted for its control, in many cases with no small measure of success, for centuries, but the methods adopted were localised to small regions, and the major destruction went on unchecked. The seriousness of this destruction was usually not realised until too late, and striking examples exist of the complete desiccation resulting from this neglect. Those of China, Arabia, Mesopotamia and other countries have often been quoted, and need not be described again here. , Thesis (MSc) -- Faculty of Science, Chemistry, 1936
- Full Text:
- Date Issued: 1936
- Authors: Kitto, P H
- Date: 1936
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/193679 , vital:45385
- Description: The development of Soil Science in western Europe, eastern North America, and later in other countries, which, in its modern form only started about the beginning of the last century, might be said to mark the first step in the consideration of Soil Erosion from a scientific aspect, although it was some time before scientists began to concentrate on and study the problem as one which demanded a detailed investigation. Empirically, erosion has been noted and, where the value of the land warranted it, practical methods adopted for its control, in many cases with no small measure of success, for centuries, but the methods adopted were localised to small regions, and the major destruction went on unchecked. The seriousness of this destruction was usually not realised until too late, and striking examples exist of the complete desiccation resulting from this neglect. Those of China, Arabia, Mesopotamia and other countries have often been quoted, and need not be described again here. , Thesis (MSc) -- Faculty of Science, Chemistry, 1936
- Full Text:
- Date Issued: 1936
Some measurements of the conductivities of dilute potassium chloride solutions
- Authors: Faure, Abraham
- Date: 1954
- Subjects: Potassium chloride
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4471 , http://hdl.handle.net/10962/d1011787
- Description: A constant temperature room has been constructed in which the thermoregulator is controlled by a temperature-sensitive resistance. A thermostat has been constructed in which the 0 temperature is controlled to within 0.001°C. A precision conductance bridge has been built in a very convenient form. Improvements include the replacement of the telephone as null detector by a cathode ray oscilloscope, and the use of a resistance-capacity phase-shift oscillator, which gives a good wave-form. An automatic recycling conductance water still has been built which regularly gives water with a conductivity less than 0.09 micromhos per cm. The conductivities of dilute KCl solutions have been measured, taking special care to prevent errors due to the adsorption of KCl on the surface of glass. Two cells were used for these measurements : a modified Jones cell, and a special conductimetric titration cell. The modified Jones cell has given results in good agreement with the generally-accepted values. The results of the conductimetric titration cell do not agree well with the generally-accepted values; the greatest difference (for the most dilute solution) is 0.4%. The reason for this is not known.
- Full Text:
- Date Issued: 1954
- Authors: Faure, Abraham
- Date: 1954
- Subjects: Potassium chloride
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4471 , http://hdl.handle.net/10962/d1011787
- Description: A constant temperature room has been constructed in which the thermoregulator is controlled by a temperature-sensitive resistance. A thermostat has been constructed in which the 0 temperature is controlled to within 0.001°C. A precision conductance bridge has been built in a very convenient form. Improvements include the replacement of the telephone as null detector by a cathode ray oscilloscope, and the use of a resistance-capacity phase-shift oscillator, which gives a good wave-form. An automatic recycling conductance water still has been built which regularly gives water with a conductivity less than 0.09 micromhos per cm. The conductivities of dilute KCl solutions have been measured, taking special care to prevent errors due to the adsorption of KCl on the surface of glass. Two cells were used for these measurements : a modified Jones cell, and a special conductimetric titration cell. The modified Jones cell has given results in good agreement with the generally-accepted values. The results of the conductimetric titration cell do not agree well with the generally-accepted values; the greatest difference (for the most dilute solution) is 0.4%. The reason for this is not known.
- Full Text:
- Date Issued: 1954
The determination of selenium and tellurium in blister copper and copper concentrates
- Gray, Douglas James Skirving
- Authors: Gray, Douglas James Skirving
- Date: 1940
- Subjects: Selenium , Tellurium , Copper
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4478 , http://hdl.handle.net/10962/d1012090
- Description: Selenium and tellurium do not occur to any great extent in Nature and they are seldom studied in any detail. However, a general understanding of their properties, both physical and chemical, is essential in an investigation of their analytical determination. A general account may be found in many of the text-books on inorganic chemistry, but the following resumè has been included in this dissertation for the sake of completeness.
- Full Text:
- Date Issued: 1940
- Authors: Gray, Douglas James Skirving
- Date: 1940
- Subjects: Selenium , Tellurium , Copper
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4478 , http://hdl.handle.net/10962/d1012090
- Description: Selenium and tellurium do not occur to any great extent in Nature and they are seldom studied in any detail. However, a general understanding of their properties, both physical and chemical, is essential in an investigation of their analytical determination. A general account may be found in many of the text-books on inorganic chemistry, but the following resumè has been included in this dissertation for the sake of completeness.
- Full Text:
- Date Issued: 1940
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