Call number: LD2668 .T4 1938 Y31 / Master of Science

Graduation date: 1954

PART I: This work is part of an investigation to determine activity coefficients at infinite dilution (1'73) of hydrocarbons dissolved in the industrially important polar solvent tetrahydrothiophene-l, l-dioxide (sulfolane), by medium pressure gas liquid chromatography (g.l.c.). In this work the activity coefficients at infinite dilution for a series of l-alkenes (C6-CS) , l-alkynes (C6-CS) , and cycloalkanes (C7 and Cs) have been measured in the polar solvent, sulfolane, at 303.15 K and 313.15 K. The activity coefficients of some of the solutes discussed in this work would be difficult to determine by any other method because of their low solubility in sulfolane. The mixed second virial coefficients used in this work were determined assuming the principle of corresponding states, the Hudson and McCoubrey combining rules for T~2' the Lorentz rule for V~2' and the McGlashan-Potter equation. PART II: Unrefined sugar contains organic colour material originating In the sugarcane or formed during the extraction and purification processes. Sugar colour must be within the limits of acceptability for direct or indirect consumption. In this work, a cost effective technique to separate colourants from sugar through a sucrose packed medium pressure chromatographic column was investigated. Three dimensional perspective plots of wavelength/absorbance/time were developed to provide insight into the nature of the sugar colourants and to provide a means of investigating various decolourisation systems. In addition to the above experiment a procedure was developed to remove colourant species from unrefined sugar samples and from samples taken during the refining process for chemical analysis. In this work only one technique - gas chromatography-mass spectroscopy was used to identify the species. / Thesis (M.Sc.)-University of Natal, Durban, 1996.

The main objective of this work is to propose a mechanism for the transfer of impurities into the sucrose crystal. To this end the transfer of impurities into the sucrose crystal was investigated, under crystallisation conditions similar to those found industrially. Most of the impurities, namely, colour bodies, potassium, calcium and starch, were selected on the basis of their industrial importance, but some exotic species, namely lithium and nickel, were chosen to represent other mono- and di-valent ions respectively, and dyes, such as methylene blue, which have been used in work with single crystal sucrose crystallisation, were included to make the results more general. A parameter to measure the rate at which impurities are transferred into the sucrose crystal was proposed. Experiments, carried out in a pilot plant evaporative crystalliser, were performed to establish the effect of selected factors on both the concentrations of impurities found in the sucrose crystal, and on the rate at which these impurities are incorporated into the crystal. All the factors selected, namely the rate of crystallisation, the temperature, the concentration and type of impurity, the diffusivity of the impurity in concentrated sucrose solutions, and the crystal dimensions, are shown to influence the rate of impurity transfer. Only the concentration in the feed and type of impurity, however, affect the final concentration of the impurity in the crystal. Concepts involving partition coefficients and adsorption isotherms were also investigated. The experimental data did not fit the adsorption isotherm models well, but the values obtained for the partition coefficients were similar to those quoted in the literature when exchange types of reactions are operative. Activation energies have been measured, both for the rate of crystallisation of sucrose, and for the rates of impurity transfer. The values obtained, particularly for the rate of impurity transfer, indicate that a transport mechanism is effective. The experimental results have been used to investigate the relevance of two models, one involving a two-step approach and the other an interfacial process, for the incorporation of the impurity into the sucrose crystal. The results obtained indicate that the interfacial breakdown model describes the transfer of all the impurities studied here, except for starch. / Thesis (Ph.D.)-University of Natal, Durban, 1998.

Submitted in partial fulfilment of the academic requirements for the Degree of Master's Degree in Technology: Chemical Engineering, ML Sultan Technikon, 2001. / There are two process operations in the sugar factory that directly affect the recovery of sugar from evaporated syrup, namely crystallisation (boiling) and centrifugal operation. Successful automation of the vacuum pans (boiling) has been implemented using brix (total dissolved solids) control, but to date on-line measurement of continuous centrifugal performance has not been successfully accomplished in South Africa. The purpose of this investigation was to continue the preliminary work performed by Tongaat Hulett Sugar in developing a purity meter for the measurement of sugar purity (sucrose content) in a continuous centrifugal. This instrument would provide the centrifugal operator with a reliable tool to perform on-line measurement of sugar purity and would also facilitate the automation of the centrifugal / M

The glucose toxicity has been recognized over the last several years as a factor contributing to both impaired insulin secretion and insulin resistance in patients with diabetes. However, the molecular mechanisms that underlie the changes in glucose transport activity induced by hyperglycemia have not been fully understood. The purpose of the present investigation is to determine if acute hyperglycemia affects an activation of glucose transport and also if hyperglycemic-induced change in insulinstimulated glucose transport is mediated via a PKC-dependent signaling system. Animals were anesthetized, and the soleus (SOL) muscles were isolated and clamped at their resting length. After a 10 minute recovery period the muscles were transferred to preincubation vials containing KHB supplemented with 4 or 16 mmol of glucose and 16 mmol/1 mannitol with or without insulin and/or inhibitors for 30 minutes. Following an incubation series to prepare the muscle, the muscle was incubated in radioactive 3-0- [3H] methylglucose and [14C] mannitol for 10 min. in the presence/absence of insulin and inhibitors, and the amount of glucose transport was measured. A total of 100µU/ml insulin with 4 mM glucose led to increase glucose transport by 155%, whereas the same amount of insulin with 16 MM glucose led to 80% increment in glucose transport. Also, 16 mM glucose in the absence of insulin induced an increase of glucose uptake by apporoximately 50% compared with 4 MM glucose. However, the addition of insulin reduced that difference to 5.3%. The conventional PKC inhibitor GF 109203X in the muscle incubated with 16 MM glucose led to a decrease in insulin-stimulated glucose transport (1l%), whereas the inhibitor with 4 mM glucose induced a decrease in insulin-stimulated glucose transport (24%). These findings suggest that glucose can directly regulate glucose transport activity by a mechanism that possibly involves a facilitated GLUT1 transporter activity. In addition to the mass action of glucose, the hyperglycemic-induced increase in insulin stimulated glucose transport may be partially mediated via a PKC-dependent signaling system. / School of Physical Education

Submitted in fulfilment of the academic requirements for M-Tech in Chemical Engineering, ML Sultan Technikon, 2001. / The purpose of this investigation was to identify and then optimise the factors that affect the decolourisation during the carbonatation process. Batch carbonatation tests, carried out in a pilot plant in the laboratory, were performed to establish the effect of selected factors on the decolourisation of melt. / M

The drying of sugar is the last step in the recovery of solid sugar from sugar-cane. To ensure that the sugar can be transported and stored, the final moisture content leaving the sugar mill must be carefully controlled. Data spanning periods of normal plant operation were collected at the Tongaat-Hulett Ltd Darnall sugar mill. These measurements were reconciled to achieve instantaneous mass and energy balances across the sugar dryer. Using these measurements, a general model has been developed to simulate the sugar drying. It includes ten compartments through which the sugar and drying air flow, with a mass and energy balance in each compartment. It was assumed that a "film" around the sugar crystal is supersaturated, and that crystallisation is still occurring. A sorption isotherm determining the equilibrium moisture content of the sugar, at which point mass transfer ceases, was included. The model has been matched to process measurements by adjusting the heat and mass transfer coefficients. A Dynamic Matrix Controller was developed and tested off-line on the model, using the reconciled measurement sequences. The controller manipulated the inlet air temperature in order to control the exit sugar moisture content. The model predictive control format successfully dealt with the large process dead-time (5 minutes). / Thesis (M.Sc.Eng.)-University of Natal, Durban, 2001.

M.Tech. / Impaired glucose tolerance, as determined by an oral glucose tolerance test, is the inability of the blood glucose regulatory mechanisms in the body to return the blood glucose levels to normal physiological levels after the ingestion of a meal (Guyton and Hall, 2006). Mollentze and Levitt (2006) report on various studies that were conducted in South Africa on the prevalence of impaired glucose tolerance and diabetes mellitus and they illustrate that there is an incidence of impaired glucose tolerance as high as 10.2% in certain communities and that impaired glucose tolerance may result in diabetes mellitus. A study has shown that cinnamon controls blood sugar levels by increasing insulin sensitivity resulting in better blood sugar level control (Jarvill-Taylor et al, 2001). The above research was done on cinnamon in the crude form but there is no research on Cinnamomum verum in a homoeopathic potency. The aim of the research was to evaluate the effect of Cinnamomum verum 1X on glucose tolerance in non-diabetic males after an oral glucose tolerance test. A double-blind pre-test post-test placebo controlled study on thirty healthy adult males between the ages of eighteen and forty years was conducted. The participants were recruited by means of an advertisement at the University of Johannesburg Health Clinic. Inclusion criteria comprised: no medication for one month prior to the study with a normal fasting blood sugar level of more than 3.0 but less than 6.0 mmol/l (Oussama, 2006); systolic blood pressure between 100 and 140 mmHg and diastolic blood pressure between 70 and 90 mmHg. At the first consultation the participant data was obtained and an oral glucose tolerance test was performed. The participants were issued with 100 ml of either Cinnamomum verum 1X or a placebo and a weekly checklist to complete. After two weeks the participant data was recorded again and the oral glucose tolerance test was repeated. The Mann-Whitney U-test was used to analyse between the group data statistically and the Wilcoxon Signed-Rank test was used to perform the within-group analysis. The mean fasting blood glucose level of the experiment group changed from 4.71 mmol/l to 4.49 mmol/l. This was a statistically significant reduction, p = 0.025 (< 0.05). The reduction in the blood glucose level after the oral glucose tolerance test of the experiment group was also found to be statistically significant, p = 0.001 (< 0.05) with the mean value changing from 5.86 mmol/l to 5.40 mmol/l. It was concluded that the homoeopathic remedy, Cinnamomum verum 1X taken orally twice daily, was more effective than the placebo in reducing the fasting blood glucose level and the blood glucose level after an oral glucose tolerance test in non-diabetic males between the ages of eighteen and forty years with normal initial fasting blood glucose levels within a time period of two weeks.

Thesis (MPH.) -- University of Limpopo, 2014 / Objective: The purpose of this study was to determine the prevalence of impaired glucose tolerance, impaired fasting glucose, undiagnosed type 2 diabetes and its associated risk factors among adults patients attending the outpatient department of a level one hospital in a rural community of Barkley West, South Africa. Research methodology: This was a cross-sectional survey conducted by a simple random sampling of adults patients F 30 years old. Patients were screened using the American Diabetes Association and the World Health Organisation criteria. First, patients underwent the 75g oral glucose tolerance test and secondly, the 12-hours fasting plasma glucose tests after pre-test results of 5.5 mmol/L were obtained considered as positive for screening. To determine the prevalence of IGT, IFG, and undiagnosed type 2 diabetes; tests were conducted using both the capillary finger puncture and the laboratory methods. To ensure validity and reliability, each patient underwent two tests (fasting and random) by the capillary finger puncture method and two tests (fasting and random) by the laboratory method. Results: Eighty-five (85) questionnaires were distributed, supervised and returned by a research assistant, which brought the response rate to 100%. All patient known living with diabetes mellitus was not included in the study. The prevalence of IGT was 34.1% [34% for females and 9.4% for males] and that for IFG was 23.6% [25% for females and 6.0% for males]. The prevalence of undiagnosed type 2 diabetes discovered during the survey was 9.3% by 2-hours 75g glucose tolerance test [8.2% for females and 1.1% for males] and that by 12-hours fasting plasma glucose, the prevalence was 5.8% [4.7% for females and 1.1% for males].The associated risk factors were physical inactivity, overweight and obesity, unhealthy diet, alcohol consumption, hypertension, smoking habit, family history of diabetes, social deprivation and poverty. The prevalence of hyperglycaemia was also high among female patients due to a higher BMI with 25% overweight (females 18% overweight, males 7% overweight) and 75% obese (females 54% of obesity, males 21% of obesity); higher waist circumference with higher abdominal fat (females 71.7% had a W/C F 88 cm, males 28% had a W/C F 102 cm.); and a larger waist-to-hip ratio (females 61.1% had WHR > 0.85, males 7% had a WHR > 1.0). The sensitivity, specificity, positive and negative predictive values for IGT were 34%, 86%, 25%, and 86% and those for IFG were 24%, 86%, 19%, and 86% respectively. IGT sensitivity was greater than IFG sensitivity. xi Conclusion: There was a high prevalence of IGT, IFG and undiagnosed type 2 diabetes specifically among female patients. The ten percent difference of sensitivity between the two tests showed that the WHO diagnostic criteria produced more patients with the pathology than the ADA diagnostic criteria do. Patients attending the outpatient department of a level one hospital in Barkley West are at high risk of developing type 2 diabetes and remain unidentified, undetected, unscreened, undiagnosed and untreated. Obesity at primary health care level in the rural community of Barkley West needs to be addressed. . Keywords: Impaired glucose tolerance, prevalence, diabetes, screening, anthropometric measurements