Showing items 46501 - 46520 of 63373

St. Georges Strand, Port Elizabeth

St. Georges Strand, Port Elizabeth

St. Georges Strand, Port Elizabeth north of Swartkops River mouth

St. Hilda's Native College, Enhlonhlweni, Ladysmith Natal. Girls dressmaking, cooking and ironing

St. Hilda's Native College, Enhlonhlweni, Ladysmith Natal. Girls spinning and weaving

St. James Street

  • Type: Image
  • Identifier: vital:14236 , http://hdl.handle.net/10962/d1018160 , MS 10 542 , CD 55
  • Description: The celebration of Queen Victoria’s Diamond Jubilee 1897.
  • Full Text: false

St. Marks Mothers' Union

  • Subjects: St. Marks Mission (Port Elizabeth) -- Photographs
  • Type: still image
  • Identifier: http://hdl.handle.net/10962/52769 , vital:26223 , PIC/M 7368 , This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017.
  • Description: Photograph of the St Mark's Mothers Union, showing a group of women and children picnicking.
  • Full Text: false

St. Marks school rockery

  • Subjects: St. Marks Mission (Port Elizabeth) -- Photographs
  • Type: still image
  • Identifier: http://hdl.handle.net/10962/52777 , vital:26224 , PIC/M 7369
  • Description: Photograph of the St. Marks school rockery, showing five children tending the rockery.
  • Full Text: false

St. Peter's Church, Cradock

St. Petersburg

  • Authors: Krueger, Anton
  • Date: 2009
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/229818 , vital:49713 , xlink:href="https://hdl.handle.net/10520/EJC47812"
  • Full Text:
  • Date Issued: 2009

Stability indicating HPLC-ECD method for the analysis of clarithromycin in pharmaceutical dosage forms: Method scaling versus re-validation.

  • Authors: Makoni, Pedzisai A , Chikukwa, Mellisa , Khamanga, Sandile M , Walker, Roderick B
  • Date: 2019
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/183387 , vital:43984 , xlink:href="https://doi.org/10.3390/scipharm87040031"
  • Description: An isocratic high-performance liquid chromatographic method using electrochemical detection (HPLC-ECD) for the quantitation of clarithromycin (CLA) was developed using Response Surface Methodology (RSM) based on a Central Composite Design (CCD). The method was validated using International Conference on Harmonization (ICH) guidelines with an analytical run time of 20 min. Method re-validation following a change in analytical column was successful in reducing the analytical run time to 13 min, decreasing solvent consumption thus facilitating environmental and financial sustainability. The applicability of using the United States Pharmacopeia (USP) method scaling approach in place of method re-validation using a column with a different L–designation to the original analytical column, was investigated. The scaled method met all USP system suitability requirements for resolution, tailing factor and % relative standard deviation (RSD). The re-validated and scaled method was successfully used to resolve CLA from manufacturing excipients in commercially available dosage forms. Although USP method scaling is only permitted for columns within the same L-designation, these data suggest that it may also be applicable to columns of different designation.
  • Full Text:
  • Date Issued: 2019

Stability of prochlorperazine in solution and in the solid-state

  • Authors: Antunes, Edith Martins
  • Date: 2000
  • Subjects: Phenothiazine
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4536 , http://hdl.handle.net/10962/d1016399
  • Description: Prochlorperazine, a member of the piperazine subclass of phenothiazines, widely used as an anti-emetic, is susceptible to oxidation to sulfoxides. These are main metabolites and degradants of all phenothiazines which are found to be inactive at the dopamine receptors. Prochlorperazine causes photosensitivity effects in patients attributed to dechlorination at C2 with the release of HCI (Huang and Sands, 1967; Nejmeh and Pilpel, 1978; Moore and Tamat, 1980). The aim of this study is to investigate the thermal and photostability of prochlorperazine edisylate and mesylate salts in the solid state and in solution. Prochlorperazine is available as a fine chemical and in a variety of dosage forms, including injectables and tablets. According to ICH guidelines, any degradants greater than 0.1 % are required to be isolated and identified. In order to assess the photostability of the two salts, an HPLC method was developed and validated for linearity, accuracy and precision, selectivity, limit of detection, quantitation and ruggedness. Sulfoxides were synthesised for use as standards in the rate studies according to the well-known hydrogen peroxide method (Owens et al., 1989). The rate of prochlorperazine degradation in solution under various light sources (254 nm UV light, diffuse light and sunlight) was studied. The light sources used abovF were quantified using potassium ferrioxalate as a chemical actinometer). The photodegradation rate was found to be greater in ampoules sealed under nitrogen than air, but the thermal degradation was faster in ampoules sealed with air than those purged with nitrogen. Amber ampoules retarded the rate of degradation under all photolytic conditions. This is a vital consideration for the packaging and storage of prochlorperazine in injectables. Degradation was found to occur mainly by first-order kinetics and the degradation rate decreased in the following order: sunlight » UV light 254 nm > fluorescent I diffuse light. Solid state samples, however, were found to be relatively stable to the various light / heat conditions over a 6 month period when compared to prochlorperazine solutions, but still considerably unstable. Thus both storage and packaging is a vital consideration for prochlorperazine injectables. The thermal behaviour of mixtures of prochlorperazine with standard excipients, was assessed for potential interactions, using differential scanning calorimetry. For most of the excipients (magnesium stearate, stearic acid, Explotab®, AC-Di-Sol®, Encompress® and Ludipress®, lactose and Starch 1500®) disappearance or broadening of the melting endotherm of the drug indicated interactions. Lubritab®, however, was the only 'inert' excipient tested. Liquid chromatography - mass spectrometry (LC-MS) was used to determine the nature of the degradation products. The major degradation pathways included dechlorination and demethylation of the parent drug, as well as sulfoxidation and Noxidation. Prochlorperazine underwent dechlorination and sulfoxidation with subsequent photosubstitution to yield the 2-hydroxy derivative. The solid state photostudies showed the formation of dealkylated, oxidised and hydroxylated products, sulfoxides and dimers. Since N-demethylation, N-oxidation, sulfoxidation and aromatic hydroxylation are reported to occur in the in vitro metabolism of perazine derivatives, it does appear that there is some relationship between metabolites and photoproducts (Breyer, 1974). This study has been successful in providing understanding of the photolytic and thermal degradation pathways of prochlorperazine.
  • Full Text:
  • Date Issued: 2000

Stability of the money demand function and monetary inflation in the East African community

  • Authors: Nsabimana, Adelit
  • Date: 2015
  • Subjects: Monetary policy -- Africa, East , Inflation (Finance) -- Africa, East , Equilibrium (Economics)
  • Language: English
  • Type: Thesis , Doctoral , DCom
  • Identifier: http://hdl.handle.net/10948/9163 , vital:26470
  • Description: This research attempts to evaluate the stability of money demand functions and estimate monetary inflation models in the East African Community (EAC), using quarterly aggregate data that range from 2000Q1 to 2012Q3. We used Johansen co-integration analysis to estimate and analyse the stability of the M3 money demand model for each country member of the EAC. From this estimation, we derived a country-specific measure of money overhang. We compared its forecasting power of future inflation with that of money stock growth, and money stock available in the economy. Regarding country-specific money demand functions, with the exception of Uganda, we identified a reasonable and stable country-specific M3 money demand model. Also, for predicting future inflation, the estimation results showed that M3 money stock growth is more reliable in Burundi and in Kenya, while M3 money overhang is preferable in Rwanda and M3 money stock in Tanzania. As both country-specific and regional (EAC area) information on monetary quantity growth and its impact on price level is important to know in a monetary union, we considered the EAC area as a single market and attempted to estimate the aggregate (EAC area) demand functions for broad money M2 and M3 using Johansen co-integration analysis. The estimated long-run aggregate money demand models M2 and M3 appeared to be stable over the sample period. However, the aggregate M2 and M3 at the EAC level were proven to be weakly exogenous, which should discard them for consideration at the EAC level as the intermediate targets variables in order to achieve the overall objective of price stability in the EAC region. Instead, short-term interest rate should be given a prominent role in monetary policy framework at the EAC level.
  • Full Text:
  • Date Issued: 2015

Stability studies on some substituted aminobenzoic acids

  • Authors: Rotich, Moses Kipngeno
  • Date: 2003
  • Subjects: Aminobenzoic acids Aminobenzoic acids -- Stability Salicylic acid
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4347 , http://hdl.handle.net/10962/d1005012
  • Description: he thermal behaviour in the solid state of various substituted aminobenzoic acids (3-aminobenzoic acid (3-ABA), 4-aminobenzoic acid (4-ABA), 3-aminosalicylic acid (3-ASA), 4-aminosalicylic acid (4-ASA), and 5-aminosalicylic acid (5-ASA), as well as the "parent" benzoic acid (BA) and salicylic acid (SA) as reference substances, and possible decomposition products: 2-aminophenol (2-AP), 3-aminophenol (3-AP) and 4-aminophenol (4-AP), has been examined. The various sets of isomers studied showed considerable and interesting differences. Most sublimed well before melting, generally with an increasing rate of mass loss beyond their very different melting points. The existence of ranges of isomers allows for the comparison of their behaviour, including such aspects as melting, vaporisation, and the influence of products on the course of decomposition of initially-solid reactants. The differences in behaviour of 4-ASA and 5-ASA were the most remarkable, with 5-ASA being far more stable and apparently not decarboxylating readily, while 4-ASA sublimed at temperatures below the melting point, becoming less stable and decarboxylating in the liquid form. There is also a marked difference in the thermal behaviour of 3-ASA, as compared with 4-ASA and 5-ASA. It decarboxylated at higher temperatures (260°C) than 4-ASA (150°C). The addition of the possible decomposition products to these compounds showed faster decomposition for 4-ASA mixed with 3-AP. The sodium salts of 3-ASA and 4-ASA decarboxylate while that of 5-ASA did not. Binary mixtures of the substances listed above with beta-cyclodextrin (BCD), hydroxypropylbeta-cyclodextrin (HPBCD) and gamma-cyclodextrin (GCD) were prepared (by simple physical mixing or by kneading with a solvent) and were then examined for possible interactions using DSC, TG-FTIR, HSM, XRD and NMR. Generally, kneaded mixtures showed greater changes in thermal behaviour from that of the individual components than the physical mixtures, but changes in the physical mixtures were also significant. Comparison of the effects of the different CDs on the thermal behaviour of individual ASA isomers showed that HPBCD has the greatest interaction with 3-ASA and 5-ASA, followed by GCD, while BCD generally showed the least interactions. For 4-ASA, the effect of GCD is more marked than for 3-ASA and 5-ASA. GCD has the largest molecular cavity.
  • Full Text:
  • Date Issued: 2003

Stable Covalent pH-Sensitive Metallophthalocyanines Thin Monolayer Films for Selective Detection of Neurotransmitters

  • Authors: Idowu, Abosede Omowumi Atinuke
  • Date: 2021-10-29
  • Subjects: Uncatalogued
  • Language: English
  • Type: Doctoral theses , text
  • Identifier: http://hdl.handle.net/10962/192922 , vital:45279
  • Description: Thesis (PhD) -- Faculty of Humanities, Science, Chemistry, 2021
  • Full Text:
  • Date Issued: 2021-10-29

Stable isotope ratios indicate differential omnivory among syntopic rocky shore suspension-feeders

  • Authors: Richoux, Nicole B , Vermeulen, Ilke , Froneman, P William
  • Date: 2014
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/68261 , vital:29224 , https://doi.org/10.1007/s00227-013-2358-6
  • Description: Publisher version , We utilised stable isotope ratios to assess differences in diet among three indigenous and syntopic rocky shore suspension-feeders (mussels Perna perna, barnacles Tetraclita serrata, and polychaetes Gunnarea gaimardi). We also determined the spatial and temporal variability in the suspension-feeder diets by collecting specimens on two occasions from two regions adjacent to hydrologically distinct river mouths (i.e. one with larger annual freshwater throughput than the other). The results showed that the isotopic niches (used as proxies for trophic niches) of the three species did not overlap and that the barnacles occupied a trophic position (3.4) well above those of the mussels (2) and polychaetes (2.6). We ascribed the interspecific differences primarily to the disparate feeding mechanisms used by the species. Large-scale regional (~50 km) differences in suspension-feeder diets were apparent, but not small-scale (up to a few km north and south of each estuary mouth). The regional differences in diet resulted from the increased availability of estuarine-origin suspended particulate matter (SPM) and zooplankton in the region adjacent to the river with relatively larger freshwater output, although overall incorporation of zooplankton versus mixed SPM into consumer diets was relatively consistent between regions and through time. Temporal shifts in suspension-feeder diets were apparent from stable carbon isotope ratios in the consumers. Our results showcase the measurable effects of regional-scale processes that can alter the food sources for dominant primary consumers in the rocky intertidal, thus potentially affecting entire food webs through bottom-up processes. The clear evidence for trophic niche partitioning offers valuable insights into how potentially strong competitors can coexist.
  • Full Text: false
  • Date Issued: 2014

Stable isotopes dynamics of macrophytes along Umtata River in the Eastern Cape of South Africa

  • Authors: Mzamo, Sanele Caleb
  • Date: 2013
  • Subjects: Stable isotopes -- Macrophytes , South Africa -- Eastern Cape
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:18485 , http://hdl.handle.net/11260/d1007205
  • Description: The decline of freshwater ecosystems, generally result from land use activities in the river catchment and is of great concern worldwide. This study was conducted along Umtata River in the Eastern Cape province of South Africa between May 2010 and April 2011. The study was aimed at identifying macrophytes families (to species level) and determining the stable isotope signatures (C:N ratios, δ13C and δ15N) and to relate their isotopic signatures to the land use activities along the river catchment. Analysis of variance was performed to test the effect of sites and sampling period on the C:N ratios, δ13C and δ15N signatures. There were 16 macrophyte families represented by 26 species recorded along the river. There was only a significant difference in sites and sampling period in δ15N (p< 0.05). The highest C:N ratios value (30.75±9.65‰) was recorded in the upper reaches while the lowest value (6.10±2.35‰) occurred in the lower reaches. The δ13C values varied throughout the length of the river with highest values (-19.63±5.44‰) obtained in the middle reaches. Spatial variation was evident in δ15N throughout the length of the river and showed increase from the upper reaches to middle reaches and decreased towards lower reaches. The δ15N ranged from 3.92±2.43‰ in the upper reaches to 10.02±4.56‰ in the middle reaches. Temporal variation in δ15N was also evident throughout the sampling period with highest peak in May (9.77± 4.49‰) and lowest in February (0.50±2.49‰) respectively. The highest values of isotope signatures at spatial level demonstrated the true reflection of urban development, sewage discharge and agricultural activities taking place along the river system. Continued monitoring is recommended that may ultimately come up with a better management options for the communities living within the study area, and also to better enhanced land utilization.
  • Full Text:
  • Date Issued: 2013

Staff accomodation

  • Date: 1984
  • Subjects: Rhodes University -- History , Rhodes University -- Employees , Rhodes University -- Employees -- Housing
  • Type: Image
  • Identifier: http://hdl.handle.net/10962/40276 , vital:24967 , PIC/M 5517 , This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017.
  • Full Text: false
  • Date Issued: 1984

Staff Conditions of Employment as at 26 January 1999 as approved by NUMSA Central Committees and National Executive Committees

  • Authors: NUMSA
  • Date: 1999
  • Subjects: NUMSA
  • Language: English
  • Type: text
  • Identifier: http://hdl.handle.net/10962/173753 , vital:42407
  • Full Text:
  • Date Issued: 1999

Staff development policy

  • Authors: Chemical Workers Industrial Union (CWIU)
  • Date: 1995
  • Subjects: CWIU
  • Language: English
  • Type: text
  • Identifier: http://hdl.handle.net/10962/170184 , vital:41866
  • Description: CWIU is committed to the development of all its staff members. Therefore all staff members will have the opportunity to further their skills and. education supported by the Union. 1.1. The primary objective is to ensure that the aims and objectives of the union are achieved through an efficient,effective and excellent staff; 1.2. In addition,the union believes that individual staff members should have the opportunity to realise their full potential; Therefore,in implementing a Staff Development policy a balance will be achieved between organisational needs,which are primary,and personal needs of staff members.
  • Full Text:
  • Date Issued: 1995
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