Characterization of various garden grass species for energy conversion in a down draft biomass gasifier
- Authors: Mkosi, Lungisa
- Date: 2016
- Subjects: Biomass energy Greenhouse gases Renewable energy sources
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/5817 , vital:29399
- Description: Energy plays a vital role in socio-economic development and raising living standards of human beings. The overreliance on fossil fuels results in the depletion of fossil fuels as well as environmental pollution from the green-house gases that result from the use of fossil fuels. Biomass feedstock are able to ameliorate this situation by utilizing the CO2 that has been used by plants during photosynthesis. This study investigated the suitability of the three garden grass species (Chloris gayana, Cynodon dactylon and Pennisetum clandestum) as biomass feedstock for gasification purposes. The three garden grass species were collected at the Alice Campus of the University of Fort Hare. These grass species were characterized using elemental analyser (CHNS), FT-IR, EDX and TGA. The Activation energy (Ea) of the three grass species were 48.22 kJ/mol for P. clandestum, 36.8 kJ/mol for C. gayana and 258 kJ/mol for C. dactylon. Of the three grass species, C. gayana had the lowest Activation energy of 36.8 kJ/mol and also had the highest maximum efficiency of 69 percent compared to 65.3 percent for P. clandestum and 63.5 percent for C. dactylon. Actual gasification was not carried out but the results on maximum efficiency were obtained from computer simulation of gasification.
- Full Text:
- Date Issued: 2016
Chemical composition and in vitro ruminal degradation of diets containing Vachellia karro leaf meal and their effect on physiological responses of indigenous Xhosa lop-eared goats
- Authors: Mfisi, Khanyisa
- Date: 2021-09
- Subjects: Ruminants--Feeding and feeds , Animal nutrition
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20719 , vital:46460
- Description: The objective of this study was to determine the chemical composition and in vitro ruminal dry matter degradation (DMD) of Vachellia karro leaf meal-containing diets and their effect on feed intake and physiological responses of indigenous Xhosa lop-eared goats. Experimental diets containing 0 percent (Treatment 1), 15 percent (Treatment 2) and 30 percent (Treatment 3) Vachellia karroo leaf meal were mixed with grass hay and crushed maize. Samples of each diet were analysed for chemical composition and in vitro ruminal DM degradability. A total of 18 eight-month-old indigenous Xhosa lop-eared goats, initially weighing 20.81 ± 1.83 kg were randomly assigned to each diet in a Completely Randomized Design. The goats were confined in individual well-ventilated roofed pens and each dietary treatment had a total of 6 goats. The feed was offered at a rate of 3 percent of live weight twice a day, at 08:00 in the morning and at 16:00 in the afternoon. The experimental feeding trial lasted for 80 days, where 10 days was allowed for adaptation. Goat live weight, Average daily feed intake (ADFI), and Body condition scores (BCS) were recorded weekly FAMACHA scores and fecal eggs counts were also determined weekly. Blood samples were collected via vein puncture on the last day of the feeding trial for determination of glucose, total cholesterol, albumin and blood urea. Significantly higher (P < 0.05) crude protein (CP) and condensed tannins (CT) levels were observed in Vachellia karroo containing diets., while acid detergent fibre (ADF) and neutral detergent fibre (NDF) were significantly higher (P < 0.05) in the control diet. During early hours of incubation, DMD was similar (P > 0.05) across all dietary treatments. At 12 to 72 hours, the DMD was significantly higher (P < 0.05) in Vachellia karroo containing diets except at 48 hours. Correlation between DMD and NDF, ADF and fat was only visible at 24 hours. Fibre (ADF and NDF) were negatively related to DMD, while fat was positively related. A positive correlation was observed between DMD and DM, CP and ADFI. The body weight and BCS of goats was similar (P > 0.05) in all dietary treatments (P > 0.05). The ADFI was significantly higher (P < 0.05) in Vachellia karroo supplemented goats. Faecal egg count and FAMACHA scores were significantly higher (P< 0.05) in the control group compared to the Vachellia karroo supplemented treatments; while glucose levels were significantly higher in goats supplemented with Vachellia karroo compared to non-supplemented goats. Cholesterol levels were similar (P > 0.05) across all experimental groups. Goats consuming 30 percent of Vachellia karroo leaf meal had higher (P < 0.05) creatinine levels than the non-supplemented treatment. Urea levels were significantly higher (P < 0.05) in goats fed 30 percent of Vachellia karroo leaf meal than other treatments. It was concluded that the inclusion of Vachellia karroo leaves improves diet quality, diet degradability, average daily feed intake and physiological responses. , Thesis (MSc) (Animal Science) -- University of Fort Hare, 2021
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- Date Issued: 2021-09
Chemical evaluation, in vitro ruminal dry matter (DM) degradability and ruminal biological activity of common browse tree fruits of Alice
- Authors: Sondzaba, Bavuyise
- Date: 2020-01
- Subjects: Ruminants
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20882 , vital:46695
- Description: The objective of this study was to investigate the effect of species variations on chemical composition and in vitro ruminal degradability of Vachellia karroo, Grewia Occidentalis, Diospyros Lycioides and Ziziphus Mucronata fruits harvested from communally grazed lands in Alice, Eastern Cape Province, South Africa. The browse fruits were collected between February and May and analysed for crude protein (CP), dry matter (DM), ash, neutral detergent fibre (NDF), acid detergent fibre (ADF), organic matter (OM) and acid detergent lignin (ADL), condensed tannins (CT), macro minerals (Calcium (Ca), Magnesium (Mg), Potassium (K), Sodium (Na) and Phosphorus(P)) and micro minerals (Ion (Fe), Zinc (Zn), Manganese (Mn) and Copper (Cu)). There was significant variation (P<0.05) in chemical composition between browse fruits. The CP content differed significantly amongst the browse fruits, but all contained enough to meet the maintenance requirements of ruminants. Fruits from V. Karroo had higher (P<0.05) CP (182.26 g/kg DM), DM (896.50 g/kg DM) and ash (55.60 g/kg DM) contents compared to other browse species, while D. Lycioides fruits had higher (P<0.05) OM (951.60 g/kg DM) content than other browse fruits. Fruits harvested from G. Occidentalis had higher (P<0.05) ADF (513.27 g/kg DM), NDF (577.22 g/kg DM) and ADL (223.20 g/kg DM) content compared to other browse fruits. Fruits from V. Karroo had higher (P<0.05) CT (269.33 g/kg DM) content followed by Z. Mucronata (187.46 g/kg DM), while D. Lycioide (54.22 g/kg DM) and G. Occidentali (66.65 g/kg DM) had the same CT contents (P>0.05). There was a significant variation between browse species in macro and micro mineral contents. Fruits from G. Occindelis (43.93 g/kg DM) and V. Karroo (43.44 g/kg DM) had higher (P<0.05) Ca content compared to Z. Mucronata (24.06 g/kg DM) and D. Lycioides (20.06 g/kg DM). Ziziphus Muronata had higher (P<0.05) P (1.96 g/kg DM) content than other browse fruits. Fruits form V.karroo had higher Mg (4.75 g/kg DM), K (11.50 g/kg DM) and Na 3888 g/kg DM) content compared to other browse species. Fruits from V. Karroo showed significantly higher micro mineral content compared to other species. In terms of dry matter degradability (DMD), incubation time had an apparent effect on degradability of browse fruits except at 4 hours. The DM degradability increased with the increase of time and after 48 hours DMD was found to be satisfactory since it was above the prescribed 40 to 50 percent. However, the presence of condensed tannins had an effect on ruminal degradability of browse fruits. It was concluded that browse fruits have the potential to be used as protein supplements during the dry season since they contain moderate levels of crude protein. However, caution should be taken when feeding these browse fruits since they contain condensed tannins that affect rumen degradability. , Thesis (MSc) (Chemistry) -- University of Fort Hare, 2021
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- Date Issued: 2020-01
Chemical transformation and phytochemical studies of bioactive constituents from extract of callistemon citrinus (curtis) skeels
- Authors: Larayetan, Rotimi Abisoye
- Date: 2018
- Subjects: Callistemon Wild flowers
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9122 , vital:34272
- Description: Callistemon citrinus belongs to the family Myrtaceae and exhibits therapeutic activities. The aerial parts of this plant are used to treat different ailments, among them are parasitic infections. The leaves, flowers and stems of Callistemon citrinus were subjected to hydrodistillation. The oils collected were studied by GC-MS analysis for the essential constituents. The overall phenolic content of the leaves oil, radical scavenging, antibacterial action and antioxidant activities of the essential oils of Callistemon citrinus were determined using standard methods, with free radical DPPH or ABTS as reference antioxidants. Chemical transformation of the components was examined for a whole year. A relationship between the chemical change in the volatile oil constituents, antioxidant capacity, percentage yield of the oil of Callistemon citrinus and fluctuation in season has been established. Active phytochemicals present in both ethyl acetate and methanolic extracts of Callistemon citrinus were determined spectrophotometrically. The antimicrobial properties, time of kill, and antioxidant activity of the extracts were explored. The bioactive components were characterized by high level of fatty acids. Squalene, a triterpenoid synthesized in human liver was obtained in the two extracts at varying amounts. The ethyl acetate extract demonstrated strong activity against P. aeruginosa ACC (28.7 ± 1.2 mm), Listeria ACC (26.0 ± 2.0 mm) and Escherichia coli ATCC 35150 (24.0 ± 3.5 mm). Qualitative phytochemical screening revealed the presence of alkaloids, glycosides, saponins, steroids and triterpenoids, fats and oils, flavonoids, phenols and tannins in them. In the quantitative phytochemical determination (total tannin, total flavonoids and flavonols, total phenolic and total antioxidant capacity) were carried out. The minimum time needed to kill the tested bacterial strains totally ranged from 15 to 24 hours. The aqueous extracts used for biosynthesis of nanoparticles were obtained from the fresh aerial parts of the plant. The biosynthesized gold and silver nanoparticles (AuNPs and AgNPs) of the aqueous extracts of the seed, flower and leaf of the plant, which are active as reducing and capping agents, were characterized using UV-VIS spectrophotometry, XRD, SEM, EDS, TEM, and FT IR. The XRD analysis revealed that the AgNPs were crystalline and the TEM showed that the shapes were spherical with an average size of 29 nm. For AuNPs, an average particle size of about 37 nm was confirmed by the TEM while the morphology and composition of the AuNPs were ascertained by SEM and EDS micrographs; uneven spherical shaped nanoparticles were established by the SEM. Both SEM and EDS demonstrated triangular shaped materials made up of silver and oxygen only. Absorption spectra confirmed by UV-VIS signify the dispersed nature of the synthesized nanoparticles with absorption band observed at 280 nm for the leaf AgNPs. FT IR had absorption bands at about 1700 cm-1 establishing the C=O stretching due to the amide bond while the FT IR for the AuNPs showed an absorption peak at 230 cm-1 confirming the presence of gold nanoparticles. The phytochemical investigation, isolation and characterization of the bioactive compounds of various organic crude extracts like hexane, dichloromethane, methanol and ethyl acetate were as well carried out, and the compounds responsible for their medicinal actions were determined. The results from different experiments revealed that the leaves and flowers of Callistemon citrinus possessed phenolic compounds and cyclic ethers with a variety of pharmacological action. The ethyl acetate and methanol crude extracts were found to possess broad spectrum of antimicrobial activities and pharmaceutically essential bioactive components with striking antioxidant capacities that may be used in the synthesis of novel drugs for the management of different ailments. The AuNPs and AgNPs synthesized from the seed, flower and leaf extracts of Callistemon citrinus where found to have prominent antimalarial, antiplasmodial, and antibacterial activities. The biosynthesized nanoparticles inhibit all the bacterial strains used and they were not cytotoxic to Hela cells, confirming their prospect for use as an excellent source for naturally occurring drugs against malaria, cell cytotoxicity, trypanosomes, and microbial infection. Similarly the crude organic extracts and the fractions derived from them exhibited high antimalarial and antitrypanosomal activities, but they were toxic to Hela cells. This is an indication that they will not be safe for use as targeted drugs for mammalian organism.
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- Date Issued: 2018
Chicken feather delipidation by lipolytic bacteria isolated from an aquatic environment
- Authors: Shiri, Tariro https://orcid.org/0000-0002-0290-9854
- Date: 2021-02
- Subjects: Keratin
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21479 , vital:48693
- Description: Keratinous biomass contributes a significant proportion of agro-based wastes in the ecosystem with minimal potentials for valuable product recovery. The generation of huge quantities of chicken feather from poultry processing farms prompts the valorization attempt via diverse avenues. Chicken feathers are a rich source of valuable keratin, yet the overall value chain is rudimentary based on unsustainable recovery techniques involving corrosive chemicals and high energy input processes. Although attempts have been made to extract keratin using microbial techniques successfully, the pre-treatment stage remains dominated by chemical use. Chicken feathers are composed of approximately 91percent keratin, 1percent lipids, and 8percent water. Therefore, lipid removal is a critical step in the valorization process as they contribute to access hindrance of the keratinases and other sulfitolytic systems to keratin. Consequently, the study undertook to explore the environment for lipolytic bacteria capable of degrading chicken feathers' lipid components. Sediment samples were collected for bacteria isolation. The bacteria were evaluated for lipolytic activity, and the potent isolates were identified based on 16S rRNA gene sequencing. The fermentation conditions for the production of extracellular lipases were optimized, and the produced lipases were characterized. Lastly, chicken feather lipids were hydrolysed with lipolytic bacteria. Out of twenty bacteria isolated from the sediment samples, six isolates coded as ACT003, ACT004, ACT010, ACT013, ACT016, and ACT019 showed lipolytic activity on solid media with a respective diameter of 12 mm, 66 mm, 29 mm, 11 mm, 12 mm, and 10 mm. Based on 16S rRNA gene sequencing and phylogenetic analysis, the isolates coded as ACT004 and ACT010 were identified as Bacillus sp. TTs1 and Bacillus sp. TTs2; and the nucleotide sequences were submitted to GenBank (NCBI) with the accession numbers MW556206 and MW556207, respectively. Bacillus sp. TTs1 showed the maximum lipase production of 641.25 U/mL at 72 h, under optimized conditions that included initial pH (5), inoculum size (2percent, v/v), incubation temperature (45 oC), agitation speed (140 rpm), CaCl2 (0.01percent, w/v), yeast extract (1percent, w/v), and tween-80 (10percent, v/v). Similarly, the lipase production by Bacillus sp. TTs2 peaked at 96 h with enzyme activity of 618.8 U/mL in improved fermentation conditions consisting of initial pH (5), inoculum size (2-8percent, v/v), incubation temperature (25 oC), agitation speed (180 rpm), CaCl2 (0.01percent, w/v), yeast extract and peptone (1percent, w/v), and tween-80 (10percent, v/v). The evaluation of chicken feather concentrations on free fatty acid liberation showed that 6-8percent (w/v) chicken feather was adequate with free fatty acids contents of 0.58percent and 0.86percent for Bacillus sp. TTs1 and Bacillus sp. TTs2, respectively. Both isolates' lipases showed remarkable catalytic efficiency at pH and temperature of 7 and 40oC, respectively. The comparative analysis of residual lipids between pre-and post-fermentation indicated a 39.9 ± 7.8percent and 51.2 ± 20.2percent hydrolysis efficiency for Bacillus sp. TTs1 and Bacillus sp. TTs2, respectively. This study's findings indicated the lipolytic potentials of Bacillus spp. and suggest the possibility of a full bio-based approach for chicken feather lipid removal in the valorization of chicken feathers. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
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- Date Issued: 2021-02
Choice of market channels by smallholder vegetable farmers in King Sabata Dalindyebo Municipality in the Eastern Cape province of South Africa
- Authors: Yokwana, Aphelele Lucia
- Date: 2017
- Subjects: Vegetables -- Marketing Farms, Small -- South Africa -- Eastern Cape Vegetable trade -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MAgric
- Identifier: http://hdl.handle.net/10353/11906 , vital:39117
- Description: The study investigates the choice of market channels by smallholder vegetable farmers in King Sabatha Dalindyebo Municipality, in the Eastern Cape Province of South Africa. Vegetables as a group of horticultural crops are important for their contribution as an income support to a large proportion of the rural households. However, enhancing vegetable farmers to reach markets and actively engage in the markets is a key challenge influencing vegetable production in South Africa. The perishable nature of vegetables demands effective marketing channels. The main objective of the study was to investigate factors affecting vegetable farmers’ choice of market channels in King Sabata Dalindyebo Municipality in the Eastern Cape Province. The study adopted a multistage stratified sampling method. Multi-stage sampling was done in which the first stage involved selecting respondents from the different wards in the King Sabata Dalindyebo Municipality. This was done through stratification by separating vegetable smallholder farmers and homesteads within that area (different villages within the area). This was followed by employing quota sampling through the different households and smallholder farmers within those areas in order to determine households and smallholder farmers that are able to provide the needed information concerning the choice of market channels. By stratified random sampling based on village, project membership and smallholder farmers, a sample of 110 heads of households was chosen for the study in eight different wards of KSD. The sampling for this study was based on a large sampling technique of n ≥ 30 as there is no information regarding the population of the total number of homesteads and smallholder farmers that are under each traditional leader (chief) in these study sites. This sample comprises homesteads and smallholder farmers that took part in vegetable production. A structured questionnaire together with field observations and measurements were adopted for obtaining information from household respondents. Descriptive statistics (percentages, means, frequency tables and figures) and a Multinomial logistic regression model have been used to analyze the data. From the Multinomial logistic regression results, farming experience is positively related to choice of farm gate market channel at 1percent level of significance. The age of vegetable farmers was positively related to the choice of direct to consumer market channel at 5percent significance level. The level of education of the vegetable farmers was positively related to the choice of direct to consumer market channel at 5percent significance level. Moreover, the results also showed that the inputs used are positively related to the choice of farm-gate as well as direct to consumer market channels at 5percent significance level. Similarly, means of transportation used and choice of marketing channel of the vegetable farmers are positively related at 1percent significance level at the direct to consumer choice of market channel. Furthermore, access to extension services indicated a positive relationship to the choice of market channel amongst the smallholder vegetable farmers for the direct to consumer at 5percent level of significance which is insignificant for that of the farm-gate. There is therefore, need for strong extension support in assisting the farmers to diversify their production, provide market information thereby enhancing production and opening up channels for market accessibility. This is seen to enhance rural households’ livelihood outcomes in agricultural production thereby improving the choice of market channels by smallholder vegetable farmers and alleviating poverty and improving food security. More so, the government and research institutes need to organize workshops and extension programs in famer’ training for more efficiency in their vegetable production and marketing.
- Full Text:
- Date Issued: 2017
Classification of Distinct Fuzzy Subgroups of the Dihedral Group Dp nq for p and q distinct primes and n ∈ N
- Authors: Nxala, Baphumelele Ellen
- Date: 2018
- Subjects: Fuzzy mathematics Fuzzy sets
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14516 , vital:39997
- Description: In this dissertation, we classify distinct fuzzy subgroups of the dihedral group Dpnq, for p and q distinct primes and n ∈ N, under a natural equivalence relation of fuzzy subgroups and a fuzzy isomorphism. We aim to present formulae for the number of maximal chains and the number of distinct fuzzy subgroups of this group. Our study will include some theory on non-abelian groups since the classification of distinct fuzzy subgroups of this group relies on the crisp characterization of maximal chains. We give the definition of a natural equivalence relation introduced by Murali and Makamba in [67] which we will use in this study. Based on this definition, we introduce two counting techniques that we will use to compute the number of distinct fuzzy subgroups of Dpnq. In this dissertation, we use the criss-cut counting technique as our primary method of enumeration, and the cross-cut method serves as a means of verifying results we obtain from our primary method. To classify distinct fuzzy subgroups of this group, we begin by investigating the dihedral groups Dpnq, for p and q distinct primes and specific values of n = 2 and 3 to observe a trend. We classify the flags of these groups using the characterization of flags introduced in [93]. From this characterization, we then present formulae for the number of distinct fuzzy subgroups attributed to the flags of Dp 2q and Dp 3q . To generalise results for Dpnq, for p and q distinct primes and n ∈ N, we characterize the flags of this group and classify them as either cyclic, mdcyclic for 1 ≤ m ≤ n, or b-cyclic. Finally, we establish a general formula for the number of distinct fuzzy subgroups obtainable from these flags. We conclude by comparing results obtained from using our general formula to those obtained by other researchers for the same group. Based on the results from this study, we give an outline of future research work
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- Date Issued: 2018
Coastal urban climate change adaptation and disaster risk reduction assessment: the case of East London city, South Africa
- Authors: Busayo, Emmanuel Tolulope https://orcid.org/ 0000-0002-9274-2145
- Date: 2021-05
- Subjects: Climate change mitigation , Climatic changes , Emergency management
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20938 , vital:46756
- Description: The increasing incidences of climate change and its registered negative effects have disturbed the entire world, with the coastal areas being the worst hit. Given the fact that coastal areas are becoming centres of global population settlement. An attempt to explore climate change-related disasters and risks is an important aspect in building communities' adaptation and resilience, especially for the most vulnerable global south. Consequently, climate change adaptation (CCA) and disaster risk reduction (DRR) have become fundamentally linked to offering sustainable solutions to address climate change and related disaster risk problems witnessed frequently in recent years. However, the assessment of synergy between CCA and DRR for coastal areas remains fragmented, vague and limited, especially for Sub-Saharan Africa and thus the need for exploration. Furthermore, the urban populace and planning stakeholders are grappling with the challenges of seeking ways to integrate adaptation measures into human livelihoods and planning systems. Also, considering complex issues inhibiting sustainable planning, for example, poor communication of climate risks affecting coastal areas, little records of hazards disclosure and disaster history, inundation and/or sea level rise etc warranted further investigation. Accordingly, the synergies between CCA and DRR in addressing various climate change-related disaster risks, especially for the coastal areas and cities was explored in this study. To this end, given the complexity of CCA and DRR, trio-theories were adopted, which included Resilience Theory (RT), Social Vulnerability Theory (SVT) and Protective Motivation Theory (PMT) as the study’s theoretical underpinnings using East London Coastal City as a case study. Consequently, a multi-method approach was employed using a review of literature, bibliometric analysis, field survey, geographic information system (GIS), and remote sensing. The first objective reveals that there is a need for convergence and harmonisation of CCA and DRR policy, programme, and practice to improve sustainable planning outcomes. Accordingly, the study proposed the adoption of a problem analysis model (PAM) for place function sustainability and local or community level resilience building. The second objective revealed that the Sendai framework for disaster risk reduction has not been fully operationalised at the local and global scales. However, in South Africa, there are efforts to streamline DRR across manifold sectors through the Integrated Urban Development Framework (IUDF). Therefore, disaster risk managers and climate change adaptation stakeholders at the local level need to embrace the position of the SFDRR to possibly offer sound and sustainable results to the most vulnerable. In addition, a bibliometric analysis on climate change adaptation from 1996 – 2019 highlights the need for more African countries' engagement and cross-collaboration between developing and developed countries in CCA research to advance sustainable solutions and improve resilience. The third objective revealed the need for more awareness, flexibility, and adaptability among stakeholders at various levels as fundamental ingredients for CCA and DRR sustainable planning outcomes. The fourth objective highlighted that floods were recorded as the most predominant hydro-meteorological hazard (n=118, 81.9percent) in the East London, coastal city. Finally, the fifth objective portrayed that many communities, populace, buildings (types), and areas are exposed to flood disaster risks, especially, communities such as Nahoon Park Valley, Sunrise on Sea, Beacon Bay, Buffalo, Gonubie, and East London are among the most vulnerable. The study recommends that early action and warning systems should be adopted, and allocation proper building codes to boost awareness to reduce the potential flood disaster risks. Moreover, the study reveals the significance of local flood disaster risk mapping in advancing CCA and DRR to ensure the implementation of coherent spatial planning for sustainable planning outcomes. The overall lessons learnt from this study are vital in contributing to the attainment of the sustainable development goals (SDGs) such as goal 11: sustainable cities and communities, and goal 13: climate action, including the seven targets and four priorities for action of the Sendai framework at a local level. The study results are deemed critical in guiding city planners, decision-makers, disaster risk managers, local communities among others towards the development of a more resilient coastal community. In general, the study calls for the integration of CCA and DRR initiatives to be premised on PAM for sustainable planning outcomes to achieve sustainable development goals and reduction of fatalities from climate-related disasters. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05
Commensal bacteria belonging to the Staphylococcus Acinetobacter and Stenotrophomonas genera as reservoirs of antibiotic resistance determinants in the environment of Nkonkobe Municipality, Eastern Cape Province , South Africa
- Authors: Adegoke, Anthony Ayodeji
- Date: 2012
- Subjects: Acinetobacter infections Drug resistance in microorganisms Staphylococcal infections Bacterial diseases
- Language: English
- Type: Thesis , Doctoral , Degree
- Identifier: http://hdl.handle.net/10353/6539 , vital:30551
- Description: A study to assess the potentials of some commensal bacteria that belong to Staphylococcus, Acinetobacter and Stenotrophomonas genera as reservoirs of antibiotic resistance determinants in the environment of Nkonkobe Municipality of the Eastern Cape Province, South Africa, was carried out using standard microbiological and molecular techniques. A total of 120 Staphylococcus isolates which consisted of Staphylococcus haemolyticus (30%), Staphylococcus aureus (23.3%) from pig; Staphylococcus capitis (15%) from goat; Staphylococcus heamolyticus (5%) and Staphylococcus xylosus (15%) from cattle and other Staphylococci (11%) from dead chicken and pigs were isolated. About 23.3% of these isolates were coagulase positive and 76.7% were coagulase negative. This difference in prevalence along coagulase production divide was statistically significant (p < 0.05). Eighty-six Acinetobacter species (Acinetobacter baumannii/calcoaceticus and Acinetobacter haemolyticus) were also isolated from Alice and Fort Beaufort towns samples, while 125 Stenotrophomonas maltophilia isolates were from grass root rhizosphere (96%) and soil butternut root rhizosphere (4%). Between 75-100% of the Staphylococccus species were resistant to Penicillin G, tetracycline, sulphamethaxole and nalidixic acid; about 38 % were methicillin resistant, consisting of 12.6% methicillin resistant Staphylococcus aureus (MRSA) from pig and a total of 12% vancomycin resistant were observed. Also, 12% of the isolates were erythromycin resistant while 40.2 % were resistant to the third generation cephalosporin, ceftazidime. The antibiotic resistance genes vanA, VanB, eryA, eryB, eryC were not detected in all the phenotypically resistant Staphylococccus species, but mec A gene and mph genes were detected. In the Acinetobacter species, a wide range of 30-100% resistance to penicillin G, ceftriazone, nitrofurantoin, erythromycin, and augmentin was observed. Polymerase chain reaction (PCR) revealed the presence of Tet(B) and Tet(39) genes in these species, while Tet (A), Tet(M) and Tet(H) were absent. Also, 9.3% of the Acinetobacter species showed phenotypic production of extended spectrum beta lactamases (ESBLs) while 3.5% were positive for the presence of blaCTX-M-1 genes. The Stenotrophomonas maltophilia isolates showed varying resistance to meropenem (8.9%), cefuroxime (95.6 %), ampicillin-sulbactam (53.9%), ceftazidime (10.7%), cefepime (29.3 %), minocycline (2.2%), kanamycin (56.9%), ofloxacin (2.9%), levofloxacin (1.3%), moxifloxacin (2.8%), ciprofloxacin (24.3%), gatifloxacin (1.3%), polymyxin B (2.9 %), cotrimoxazole (26.1%), trimethoprim (98.6%), aztreonam(58%) and Polymyxin B (2.9 %). The isolates exhibited significant susceptibility to the fluoroquinolones (74.3-94.7 %), polymycin (97.1%) and meropenem (88.1%). Only sul3 genes were the only sulphonamide resistance gene detected among the trimethoprim-sulphamethoxazole resistant isolates. The observed multiple antibiotic resistance indeces (MARI) of >2 for Staphylococcus species, Acinetobacter species and Stenotrophomonas maltophilia suggest that they have arisen from high-risk sources where antibiotics are in constant arbitrary use resulting in high selective pressure. The presence of tetracycline resistance genes in Acinetobacter species justifies the observed phenotypic resistance to oxytetracycline and intermediate resistance to minocycline. High phenotypic resistance and the presence of some resistance genes in Staphylococcus species is a possible threat to public health and suggests animals to be important reservoirs of antibiotic resistance determinants in the environment. Indiscriminate use of antibiotics induces this kind of antibiotic resistance and should be discouraged. Personal hygiene is encouraged as it reduces the load of Acinetobacter species contacted from the environment that may be difficult to control. Commensal Stenotrophomonas maltophilia are as important as their clinical counterparts due to their roles in opportunistic infection, antibiotic resistance and their associated genes, especially sul gene. Personal hygiene is hereby advocated especially when in contact with soil, plants and plants’ rhizospheric soil
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- Date Issued: 2012
Comparative analysis of characteristics of the various sugarcane bagasse types in terms of gasification
- Authors: Kula, Mpumezo
- Date: 2016
- Subjects: Bagasse Sugarcane -- Breeding Coal gasification
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13392 , vital:39656
- Description: The insight that the fossil fuel reserves are limited, together with concerns over security of supply (i.e. the oil crises), initiated the first raise of interest in biomass and all other renewable energy forms. However, the concern grew that global warming and the resulting climate change were enhanced by carbon dioxide (CO2) emissions resulting from fossil fuel consumption. Meanwhile, biomass energy is thought to account for 14–15percent of total world energy consumption. Hence, the exploitation and utilization of biomass energy are effective and necessary for relieving the pressures caused by environmental pollution and fossil fuel shortage (Lv et al., 2010). Recently, extensive research aimed at converting biomass to useful energy have been carried out, especially pyrolysis and gasification, which are particularly suitable for the effective and efficient utilization of biomass. Sugarcane bagasse is the main byproduct of sugarcane mill, ready available at the production site so that it may be a suitable raw material for the production of biofuels, chemicals, and electricity. Among the methods that have been previously studied, is this particular study we explore thermochemical process, gasification. The properties of sugarcane bagasse relevant to gasification are briefly reviewed. The compositions of the bagasse as a fuel are variable, especially with respect to inorganic constituents important to the critical problems of sintering, fouling and slagging. Alkali and alkaline earth metals, in combination with other fuel elements such as silica and sulfur, are responsible for many undesirable reactions in a gasifier system. The three sugarcane bagasse types namely washed, unwashed and the depithed sugarcane bagasse were subjected in different types of characterization to review and compare their characteristics for gasification. Ultimate analysis was used to determine the elemental compositions and this was helpful in estimating the energy input of the materials. Elemental compositions were determined with the CHNS analyzer which gave the percent compositions of each fuel in terms of Carbon, Hydrogen, Nitrogen, Sulphur as well as Oxygen (by difference) and the SEM/EDX which gave the elemental composition of the materials as can be viewed from the EDX. The proximate analysis which is the physical characterization of the materials was carried out to preview the behavior of the sugarcane bagasse when subjected into high temperatures as the gasification process uses very high temperatures. These were determined by the TGA and the volatile matter content; fixed carbon content, moisture content and ash content were extrapolated from the resulting thermogram. SEM images for surface structures of the bagasse and FTIR for the structural functionality and bonding structures. The characterization of the bagasse was conducted to compare their gasification properties.
- Full Text:
- Date Issued: 2016
Comparative analysis of zero-tillage and conventional tillage practices in the Amahlathi local municipality of the Eastern Cape province of South Africa
- Authors: Gomo, Zintle
- Date: 2017
- Subjects: Tillage--South Africa--Eastern Cape Farms, Small--South Africa--Eastern Cape No-tillage--South Africa--Eastern Cape
- Language: English
- Type: Thesis , Masters , Agricultural Economics
- Identifier: http://hdl.handle.net/10353/11586 , vital:39087
- Description: The current interest in zero tillage/no-till technologies is a result of the need to reduce excessive land degradation in most crop producing areas as well as to enhance sustainable food production. Farmers are always looking for ways to increase yields and profits and zero-tillage may be a way to achieve this goal. However, a systematic comparative study of the performance of zero-tillage and conventional tillage within the former homeland areas of the Eastern Cape Province is lacking. The broad objective of the study is to comparatively analyze zero tillage and conventional tillage and to determine which practice is more beneficial for the land and farmers in the area. Specifically, the study investigated the relative performance of Zero-tillage and conventional–tillage in terms of quantity produced per farm and per hectare, factors influencing the adoption rate of zero tillage and conventional tillage and to determine the relative impact of zero-tillage and conventional tillage on household income. The study was carried out in Amahlathi Local Municipality in the Eastern Cape Province and employed survey data obtained from 100 respondents using conventional tillage and zero tillage farmers growing spinach, cabbage, beetroot, maize, and potatoes. The study employed a cross-sectional research design. A multistage stratified sampling procedure was used in which the first stage involved selecting respondents from Amahlathi Local Municipally. This was followed by the selection of villages and then the respondents. This was done through stratification of smallholder farmers from the different Villages. This was followed by random sampling which was used to get the sample size for the study. Stata and SPSS were used to analyze the data. Descriptive statistics was used to examine current farming practices in the Eastern Cape Province while Propensity Score Matching was employed to estimate the factors that had an impact on zero tillage adoption as well as the relative impact of zero tillage and conventional tillage on household income. Gross margin analysis was used to estimate profitability of zero tillage and conventional. female farmers are participating more in zero tillage with 63.8percent while males are dominating the conventional tillage with 51.6percent. These results show that females play a crucial role in decision making when it comes to agriculture and adoption of new agricultural technologies. The majority of the farmers involved in the study were young farmers with 58percent from zero tillage and 42percent practically involved in conventional tillage. Moreover, the study showed that 41percent of the respondents practising ZT were married, and about 39percent of the respondents practising conventional tillage were married. The marital status of the respondents suggested that zero-tillage farmers were relatively stable in their farming activities as compared to conventional tillage. The results presented that 52.2percent of the respondents who practised zero tillage were better educated than the 48.4percent of the respondents practising conventional tillage. The respondents that were specialising in zero-tillage, about 41% relied on farming, 6% relied on salaried income and 54percent relied on social grants. On the other hand, respondents that were specialising in conventional tillage about, 26percent relied on farming, 16percent relied on salaried income, while 58percent relied on social grants. The respondents that were specialising in zero-tillage, about 28percent used communal land, 1percent used own land and 71percent used family land. On the other hand, respondents that were specialising in conventional tillage about, 42percent used communal land, 7percent use own land and 52percent used family land. The average household size for both groups of farmers is 5 people per household. Household income distribution for conventional tillage is giving the farmers an average of R3187.10 income while the zero tillage is giving them an income of R2305.80 on average. The study revealed that the landholdings for conventional tillage agriculture tend to be more (1.77 ha) compared to zero tillage (0.79 ha) agriculture. The Propensity Score Matching results indicated that participation in smallholder zero tillage farming contributes to household income. This implies that participating in zero tillage farming can contribute to rural livelihoods, increased income and production yields. The study results showed that households chose different farming systems based on their knowledge, level of education and farming experiences. The gross margin results show that conventional tillage farming households generated more income than zero tillage farming households. Farmers who were involved in conventional tillage farming were complaining that yields and income have decreased with time and they are continuing to decrease while farmers who carried out zero tillage farming indicated that their yields and income have improved considerably and continue to increase with time. Thus, support for adopting and implementing zero tillage practices can be an important factor for improving incomes for rural households. Based on the findings highlighted above, the study recommends provision of farm inputs and continuation of government support with more emphasis on strengthening access to inputs and technical assistance. There is a need for support programmes that would help to motivate farmers for better performance. The programmes include infrastructure developments, research and extension activities.
- Full Text:
- Date Issued: 2017
Comparative performance of 3-kWp ranges Solar Photovoltaic Systems under varying meteorological conditions in Alice, Eastern Cape Province, South Africa
- Authors: Apeh, Oliver Okechukwu https://orcid.org/0000-0003-4076-0613
- Date: 2021-08
- Subjects: Photovoltaic power systems , Solar energy
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21567 , vital:48888
- Description: PVsystem has recently emerged in South Africa as a way to curb the country’s persistent shortage of electricity. A wide effort for the past few decades have targeted at study, testing and demonstration of PV power systems which was established all over the country as an appropriate measure to tackle transportation, agriculture, industry, commercial as well as domestic activities. In view of these drives, both off-grid and grid-connected PV systems are being applied. However, operating a building with an off-grid system is one of the means to providing the possibility of energy access to places far away from the national grid. As an off-grid choice, 50 W SHS is being distributed to customers in distant rustic parts of the country where grid option is difficult to access. But the SHS of the stated capacity can barely generate 0.3 to 0.4 kWh of electric energy per day, even at the optimal solar radiations. In view of this, more efforts are directed at expanding the off-grid systems to accommodate large rural households in South Africa. This thesis is dedicated to a study on the various configurations and components of PV power plant as a way to enhance electricity generations in South Africa. To this effect, different power plants were considered at SolarWatt park, University of Fort Hare with the aim to conduct a comparative analysis of the charge controllers with respect to the charge and discharge rates of their respective batteries. The grid-connected PV power generation was classified into hybrid PV and grid-assisted PV, while off-grid is a BIPV. These power plants generations were installed for the purpose of research level with a total capacity of 11.4 kW. The off-grid system is made up of HIT modules, FlexMax80 charge controller, Victron energy inverter and M-Molar battery bank. The hybrid and grid-assisted systems each consist of 15 polycrystalline modules and Microcare charge controllers. In addition, hybrid comprises SMA Sunny Island inverter and Trojan battery bank whereas grid-assisted consist of Microcare inverter and Hoppercke battery bank. The first part of the experimental work was monitored, and the meteorological parameters which are ambient temperature, solar radiation, relative humidity and wind speed, were measured and evaluated while electrical parameters includes PV current and voltage, MPPT current and voltage, battery current and voltage and inverter current and voltage were also measured and evaluated in the second part of the experiment. This lasted for a period of four years, starting from 1st January 2017 to 31st December 2020. Similarly, the second aspect was to monitor the electrical performance of the three systems and was performed for a period of six months, starting from January to June 2019. During the second experiment, hybrid and grid-assisted systems were reconfigured to function as off-grid systems. Moreover, a detailed data acquisition system designed to measure and record both meteorological and electrical parameters affecting the performance of the systems. The electrical parameters include PV current and voltage, MPPT current, battery current and voltage and inverter current and voltage. Other parameters in the measurements are; inverter efficiency, active and apparent power, while meteorological parameters include; solar irradiance, ambient temperature, relative humidity, wind speed and direction. The meteorological results show that the maximum and minimum mean amount of global solar radiation was 7.34 kWh/m2/day in December and 3.03 kWh/m2/day in June, respectively, while the average radiation and temperature for the typical year were 4.98 kWh/m2/day and 16.88 oC respectively. The solar radiations obtained are within the range in major places in South Africa. Similarly, an average wind speed of 2.5 m/s is experienced in Alice in a year and average solar radiation of 606.06 W/m2 in summer and 346.17 W/m2 in winter. The three lead-acid battery systems monitored under the electrical aspect are M-Molar, Trojan and Hoppecke battery systems. It was established that the charging current decreases gradually from 27.7 to 18.5 A for the M-Molar while Hoppecke and Trojan deceased respectively from 15 to 10 A and 23 to 13 A at the end of each phase by charging it at the maximum power point of the PV array. It was equally found that the M-Molar battery current has the highest rate of charging and quickest rate of discharging in comparison to the other two batteries. Finally, from the results gotten from this research, we may propose that the solar PV system contributes significantly to the satisfaction of the needed electricity in South Africa. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
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- Date Issued: 2021-08
Comparative studies of different ant-hypertensive treatments used for cardiovascular disease patients : a case study of public health facility in the Eastern Cape South Africa
- Authors: Abiodun, Oluwatoyin Victoria
- Date: 2017
- Subjects: Survival analysis (Biometry) Cardiovascular system -- Diseases
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13205 , vital:39519
- Description: Discovery has shown that many deaths arising from cardiovascular disease often show early symptoms of high blood pressure, which makes it the leading risk factor of cardiovascular diseases. There is a distressing rate of 970 million hypertensive patients worldwide, a higher ratio of 640 million are from developing countries, if proper measures are not taken, there will be a higher growth of cardiovascular disease in adults by 2025. The focus of this study was to compare the therapeutic potentials of the anti-hypertensive therapies, drug A (amiloride + furosemide) and drug B (hydrochlorothiazide + enalapril) used in the treatment of cardiovascular disease patients for their capability to lengthen remission duration and survival time. All patients were diagnosed with a type of cardiovascular disorder, therefore patient records were followed up and blood pressure was being monitored for a period of two years. The retrospective data gotten from the public health facility was analysed using survival analysis methods. The results revealed that there was no statistical significance in the distributions of the length of remission and survival time of drug A and drug B patients. Also, in the age category, CVD patients that are 55 and above recover faster with drug A, while CVD patients below 55 shows a better survival with drug B. Then again, estimates from the gender category show a better survival in males using drug A, while the females thrive slightly better using drug B. Among all the risk factors considered in the study, only employment status showed a strong impact on survival time (remission). The findings from this study may help to formulate interventions and strategies that will increase the lifespan of cardiovascular patients and reduce early mortality due to cardiovascular diseases.
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- Date Issued: 2017
Compartmentalization of mineral elements, nutritional factors, biological potentials and phytochemical profiles in the fruits of Musa sinensis L.(Banana) and Musa paradisiaca L.(Plantain): A comparison among soft flesh, peel and boiled peel extract
- Authors: Oyeyinka, Barnabas Oluwatomide https://orcid.org/0000-0003-1191-9365
- Date: 2021-09
- Subjects: Bananas , Plantain banana
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23655 , vital:58274
- Description: Fruits are key contributors to human nutrition and health. However, banana and plantain are typical examples of fruits that have nutritionally under-utilized peel by-products. This study was thus carried out to investigate the compartmental distribution (soft flesh, peel, and boiled peel extract) of mineral elements, nutritional factors, biological potentials, and phytochemical profiles in M. sinensis and M. paradisiaca fruits (ripening stage 4-5), with focus on the peels. Proximal and and antinutritive analyses were done with standard methods of the Association of Official Analytical Chemists (AOAC), while mineral element composition in the fruit components was analyzed with the inductively coupled plasma optical emission spectroscopy (ICP-OES). The pharmacological potential of M. sinensis and M. paradisiaca fruit components was investigated spectrophotometrically by evaluating the polyphenolic constituents (total phenol, proanthocyanidin, flavonoid) and in vitro radical scavenging activities of the aqueous, acetone and ethanol extracts, using DPPH, ABTS, and FRAP assay models. The correlational evaluation of the polyphenolics and antioxidant activity in the components of both fruits using Pearson’s correlational coefficient (r). The proximal assays revealed that moisture content, fiber content, and carbohydratecontent were substantially present in the flesh and peel of M. sinensis and M. paradisiaca, while lipid content was low. The antinutritive results revealed safe levels of alkaloid, oxalate, phytate, and saponin factors in the flesh and peel by-products. Mineral analysis results indicated substantial levels of the macroelements K, Mg, Ca, and P in the peels. Other results revealed that acetone extracts had the highest phenolic, proanthocyanidin and flavonoid constituents respectively, across the soft flesh components ofM. sinensis (119.05 ± 5.80 mgGAE/g; 337.48 ± 13.16 mgCE/g; 602.64 ± 3.65 mgQE/g), M. paradisiaca (114.80 ± 1.49 mgGAE/g; 436.09 ± 36.44 mgCE/g; 777.35 ± 150.95mgQE/g) and the peel component of M. paradisiaca (136.87 ± 5.69 mgGAE/g; 530.06 ± 53.51 mgCE/g; 750.87 ± 55.61 mgQE/g), with an exception of the phenolic content of M. sinensis peel, where it was highest in the ethanol extract (157.19 ± 4.76 mgGAE/g). The ABTS (0.03 mg/mL) and DPPH (0.03 mg/mL) activities were at their highest in the boiled peel extracts of M. sinensis and M. paradisiaca, while ferric reducing power was highest in ethanol extracts across M. sinensis soft flesh, peel, and M. paradisiaca flesh. Acetone extract of M. paradisiaca peel had the highest ferric reducing capacity at peak concentration (0.1 mg/mL). Correlational analysis revealed a negative correlation between respective phenolic, proanthocyanidin, and flavonoid content and the IC50DPPH antioxidant capacity in M. sinensis flesh, M. sinensis peel and M. paradisiaca flesh. Conversely, there was positive correlation between IC50 DPPH with proanthocyanidin and flavonoid in M. paradisiaca peel. Negative correlation was detected between the phenolic, proanthocyanidin and flavonoid contents and IC50ABTS in M. sinensis flesh. Positive correlation was observed between respective phenolic, proanthocyanidin and flavonoid contentwith IC50 ABTS in M. sinensis peel, M. paradisiaca flesh and M. paradisiaca peel. There was negative correlation between the respective phenolic, proanthocyanidin and flavonoid contents and IC50 FRAP in the flesh of M. sinensis, while positive correlation was observed in M. sinensis peel. M. paradisiaca flesh on the other hand, showed positive correlation between the IC50 FRAP and the respective phytochemical contents. However, the peel, there was negative correlation. The correlational evaluation in this study revealed general positive and negative correlational patterns, which implies that no polyphenolic constituent contributed exclusively to antioxidant activity, but rather in combination. Ultrastructure and elemental spectra of M. sinensis and M. paradisiaca exocarps were analysed with electron microscopy (SEM)and energy dispersive x-ray (EDX). Microstructures such as interlocked, polyhedral epidermal cells, ellipsoid-shaped stomata, guard cells, intercellular space, anticlinal-patterned walls, and subsidiary cells were observed. The elemental spectra revealed the presence of elements such as potassium, iron, carbon, oxygen, silicon, and gold, with consistently high to relatively high carbon and oxygen peaks in M. sinensis and M. paradisiaca exocarps. The relative similarity observed in the constituents of a number of the elemental spectra in M. sinensis and M. paradisiaca peels, reflects some degree of relatedness. These outcomes indicate that banana and plantain peel and boiled peel extracts are nutritive, medicinal and potential nutraceuticals, with food preservative, shelf-life and quality enhancement potentials. The instrumentation in this study also have potential relevance in industrial food product analysis. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
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- Date Issued: 2021-09
Computational fluid dynamics design and performance testing of a cyclone heat exchanger used in a gasification plant
- Authors: George, Tomy
- Date: 2019
- Subjects: Computational fluid dynamics Renewable energy sources Biomass gasification
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/19087 , vital:39877
- Description: Renewable energy resources are considered to be the most promising source of energy in the coming centuries owing to its potential to get replenished by the nature itself. However, there are a number of challenges that are to be addressed prior to considering a particular resource as a reliable and effective one according to the energy demand fluctuations. Energy extracted from the biomass available in the nature has a lot of potential especially in the case of producing energy from syngas produced by the controlled burning of wood. This research deals with the minimisation of energy wastage in a gasification plant where syngas is produced from wood and transferred to an internal combustion engine to further generate electrical energy. The syngas produced from the wood is to be fed through a cyclone for purification before it can be fed into the IC engine, where the dust, carbon and other impurities are separated from the syngas by making use of the centrifugal force developed inside the cyclone. This syngas is further cooled and fed into the IC engine in its purest form as specified by the requirements of the engine. It is envisaged that if it is possible to recover the heat energy otherwise wasted in the cyclone and through the cooling circuit, it can be used for preheating the wood or for other minor heating purposes, and thereby the heat wastage can be minimised. Therefore, in this research, a series of numerical investigation conducted which involved the modelling of heat exchanger around a cyclone in order to extract heat from the surface of the cyclone. Two basic design of the Heat exchanger were considered in the study, a rectangular and a conical design. With a water flow rate of 2 l/min in conical design, the heat absorbed by the water was found to be 5.555 kJ/s and in rectangular design, the heat absorbed by the water was 4.872 kJ/s. An experimental analysis conducted to validate the simulation by a rectangular Heat exchanger shows the amount of heat absorbed by the water is 4.87 kJ/s. In a study with variable water flow rate through the jacket, it is observed that heat absorbed by the water in conical heat exchanger is more than heat absorbed by the water in rectangular jacket within the flow rate of 4 l/min. and the heat absorbed by the water in rectangular heat exchanger is higher than conical heat exchanger with water flow rate above 4 l/min.
- Full Text:
- Date Issued: 2019
Consumer perceptions and microbial quality of meat sold in the informal markets of Nkonkobe and Buffalo City municipalities in the Eastern province, South Africa
- Authors: Mazizi, Bulelani Elvis
- Date: 2016
- Subjects: Meat -- Quality -- South Africa --Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/15365 , vital:40401
- Description: The main objective of the study was to determine consumer perceptions and microbial quality of meat sold in the informal markets found in Nkonkobe and Buffalo City Municipalities in the Eastern Cape Province, South Africa. To determine consumer perceptions of the quality of the meat and meat products sold in the informal markets in Nkonkobe and Buffalo City Municipalities, a survey was conducted. A total of 160 consumers from two municipalities in the Eastern Cape (EC) Province of South Africa was randomly sampled and interviewed. A questionnaire was used to gather information about consumer perceptions of meat and meat products sold in the informal markets regarding their knowledge about safety, food-borne diseases, hygiene, and the quality of the meat among others. The study showed that Alice Town has a larger (66.25percent) proportion of consumers with knowledge about foodborne diseases while King Williams’s Town had a larger proportion (48.75percent) of respondents who had no knowledge about Food-borne diseases. However, a large proportion of consumers in King Williams’s Town considered vendor (82.5percent) and environmental hygiene (93.75percent) than in Alice Town. Consumers (83.75percent) in King Williams’s Town viewed the meat from street vendors to be of low quality while a small proportion (18.75percent) of consumers in Alice Town viewed it as the meat of good quality. Alice had a large proportion (61.25percent) of consumers, which had knowledge of the meat safety law than King Williams’s Town. More consumers from King Williams’s Town (31.25percent) agreed that government plays a role while Alice had a small proportion (26.25percent) which disagreed. The results also showed that consumer perceptions about the safety of meat and meat products are focused more on hygiene, neglecting other important aspects such as vending infrastructure. However, most consumers do not have enough knowledge concerning meat safety. The second study determined the microbial quality of meat sold by street vendors based in Alice and Kind Williams Town in the Eastern Cape Province South Africa. A total of 48 fresh and uncooked meat samples (beef, pork, and mutton), 48 surface contact plates and 40 water samples was collected from 4 street vendors from each town for microbial analysis (n=48). After collection, all samples were subjected to Aerobic plate count (APC), Salmonella spp, Staphylococcus aureus (Staph) and Escherichia coli (E. coli). The results revealed that Salmonella spp tested negative across all the meat samples used in the study. However, no significant differences were found in the microbial quality of meat sold by street vendors in Alice and King Williams town. Furthermore, there were no significant differences (P>0.05) between the APC of raw beef (4.8 Log CFU/g), mutton (3.7 Log CFU/g) and pork (2.8 Log CFU/g) and also the cooked beef (1.5 Log CFU/g), mutton (1.3 Log CFU/g) and pork (1.9 Log CFU/g) samples. A similar trend was observed in the values of Staphylococcus aureus (Staph) and Escherichia coli (E. coli) counts in raw and cooked meat samples. However, a positive correlation between Aerobic plate counts (APC) and Staphylococcus aureus (Staph) (P<0.001) and Escherichia coli (E. coli) (P<0.01) was found in the study. It can, therefore, be concluded that there were no differences in the microbial counts of raw and cooked meat sold in the informal markets of Nkonkobe and Buffalo City Municipalities in the Eastern Cape Province, South Africa.
- Full Text:
- Date Issued: 2016
Contribution of home gardens to rural household income in Raymond Mhlaba Local Municipality, Eastern Cape Province, South Africa
- Authors: Alaka, Kolawole O
- Date: 2017
- Subjects: Gardens Food security Sustainable agriculture -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MAgric
- Identifier: http://hdl.handle.net/10353/8176 , vital:31826
- Description: For decades, home gardens have proved to be significant to rural inhabitants by providing a wide range of useful products such as fruits, vegetables and medicine, but there is lack of quantitative information on its benefits and its contributions to income of rural household. The main objective of this study is to investigate contributions of home garden to income of rural household in Raymond Mhlaba Local Municipality, formerly Nkonkobe Local Municipality of Eastern Cape Province South Africa. The stratified random sampling method was applied in order to choose a sample of 160 household that were interviewed by means of semi-structured questionnaires. The study was conducted among 80 households engaging in home gardens and 80 non- participating households in the study area. Frequencies and mean were used to describe the general characteristics of the households as well as ownership patterns of home gardens. In order to determine the factors that influence home gardens ownership binary logistic regression model was used. The overall model show that level of education, total household income and access to land significantly affects ownership of the home garden positively. Social grant has the highest contributions to total household income for both category while income generated from home garden has the second largest share to total household income, this show that the majority of rural households in the study area rely on social grant as their source of income. Cabbage, spinach, potatoes and carrots were the dominant crops in home gardens. In view of research findings, there is still a wide room for further improvement in home gardens practises in study area. Contrary to expectations, home gardens have the potential to improve livelihood significantly if the rural households take the necessary steps to make the production more sustainable. Based on research findings several policy proposals are suggested. These include investment in agricultural programmes that will empower the rural households like Massive food projects, Siyazondla and related home garden initiatives. Home garden is the major source of food and income generation in Raymond Mhlaba Municipality. Therefore, government should provide sufficient credit facilities, extension services together with marketing arrangement in the area.
- Full Text:
- Date Issued: 2017
Copper dithiocarbamate complexes and copper sulfide nanoparticles : Synthesis, characterization and antifungal studies
- Authors: Botha, Nandipha Loveness https://orcid.org/0000-0001-8353-3512
- Date: 2015-01
- Subjects: Copper sulfide , Complex compounds , Nanoparticles
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24283 , vital:62598
- Description: Six dithiocarbamate ligands were synthesized from anisidine, aniline, ethyl aniline, butyl amine, morpholine and piperidine and used to synthesize homoleptic copper(II) dithiocarbamate complexes. The ligands and their corresponding complexes were characterized by conductivity measurement, FTIR and UV-Vis spectroscopy. The ligands were further characterized using NMR spectroscopy. The electronic spectra of the complexes showed that the coordination geometries around the Cu2+ ion is four coordinate square planar. FTIR spectroscopic studies indicated that the dithiocarbamate ligands are bidentately coordinated to the copper ion through the sulfur atoms with the C-S stretching frequencies changing from two peaks in the ligands to single sharp peaks in the corresponding metal complexes. The complexes were used as single source precursors to synthesize copper sulfide nanoparticles. All the six complexes were thermolysed at 180 oC to prepare copper sulfide nanoparticles and three of them were further thermolysed at 120 oC to study the effects of temperature on size and shape of the nanoparticles. All the nanoparticles were characterized with UV-Vis, PL, XRD, TEM, SEM and EDX. The optical properties of the as-prepared CuS nanoparticles showed that they are quantum confined with absorption band edges that are blue shifted compared to bulk CuS and all the as-prepared CuS nanoparticles showed narrow emission curves. The XRD diffraction patterns were indexed to the hexagonal covellite CuS crystalline phase with estimated particle sizes of 15.8-23.24 nm. These sizes are significantly different from the values, 3.02-98.94 nm obtained from TEM studies. The TEM images also showed nanoparticles with varied shapes with some agglomerations. SEM micrographs showed that the morphologies of the nanoparticles are mostly smooth surfaces and EDX spectra analyses confirmed the formation of the nanoparticles. Thermolysis of three of the complexes at 120 oC confirmed that temperature do affect the optical and structural properties of the CuS nanoparticles. Only three complexes soluble in DMSO were screened for their antimicrobial activity. Three complexes C1, C4 and C5 were screened against four fungi organisms, namely: Candida rugosa, Candida neoformans, Candida albicans and Trychophyton mucoides. All the compounds were promising as shown by the minimum inhibitory concentrations determined. C5 was the most active compound against all the organisms. They were also screened against four bacteria organisms and they were all active but not as they were against fungi organisms. , Thesis (MSc) -- Faculty of Science and Agriculture, 2015
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- Date Issued: 2015-01
Correlations between the occurence of virulent helicobacter pylori strains and chronic disease conditions in dyspeptic patients hospitalized in Chris Hani Baragwanath Hospital, Gauteng Province, South Africa
- Authors: Mzukwa, Asisipho
- Date: 2018
- Subjects: Helicobacter pylori infections Helicobacter pylori Bacterial diseases
- Language: English
- Type: Thesis , Masters , Microbiology
- Identifier: http://hdl.handle.net/10353/10885 , vital:35905
- Description: Introduction: Individuals predisposed to different chronic disease conditions such as type 2 diabetes mellitus (T2DM), hypertension (HPT) and human immunodeficiency virus (HIV) might be susceptible to persistent H. pylori colonization, which overtime encourages infection with virulent strains. The presence of different types of H. pylori virulence factors especially cagA, dupA and various combinations of vacA subtypes (s1/m1, s2/m1 and s2m2) confer a higher risk of gastric disease development. Aim: This study seeks to recover H. pylori from gastric biopsy specimen from patients with different chronic disease conditions referred to the GIT unit at Chris Hani Baragwanath Academic Hospital, Soweto, and confirm them and further determine the presence of virulent H. pylori strains in patients with T2DM, HPT and HIV. Methods: Gastric biopsies were obtained from 101 patients with different chronic disease conditions after obtaining consent between August 2017 and February 2018. H. pylori was isolated on selective Colombia blood agar. Presumptive isolates were identified following standard microbiology and biochemical technique. These isolates were confirmed by polymerase chain reaction (PCR) targeting the glmM gene. The H. pylori positive samples were further screened for cagA, dupA and vacA genotypes. Results: H. pylori was recovered from 26 patients, of which 8 were patients with T2DM, 10 with HPT and 8 with HIV. There was no correlation between H. pylori infection and the chronic conditions, but the majority of H. pylori positive participant carried virulent H. pylori strains. The cagA and the dupA genes were more prevalent in T2DM and HPT patients, however the association between these genes and the 2 chronic conditions was not significant. The vacA subtypes common in hypertensive patients compared to the other conditions were the s1m1, s1m2, and s2m2 and the association between these vacA forms and hypertension was significant. Majority of HIV infected patients were found to carry non-virulent H. pylori strains. Conclusion: The prevalence of H. pylori among the general population of patients with T2DM, HPT and HIV was low. Although infected patients are found to be carrying virulent strains of H. pylori, there is no significant association established between the virulent strains and the chronic conditions. Furthermore, HIV-infected patients were found to be carrying non-virulent strains of H. pylori.
- Full Text:
- Date Issued: 2018
Cost and return analysis of smallholder organic crop farms in the Eastern Cape province of South Africa
- Authors: Akharume, Celestine Ohi
- Date: 2017
- Subjects: Farms, Small -- South Africa -- Eastern Cape Profit -- South Africa -- Eastern Cape Organic farming -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MAgric
- Identifier: http://hdl.handle.net/10353/13730 , vital:39703
- Description: Agriculture remains an influential sector in South Africa in terms of its contributions to economic development and poverty reduction, notably in the rural areas. These include providing sufficient and affordable food for the constantly increasing population, providing cheap food for the developing industrial labor force, providing employment and livelihoods and supplying raw materials to the country’s rising domestic industrial sector. Despite phenomenal progress in integrating smallholder farmers into the mainstream economy since democratic reforms in the country, deteriorating soil quality through poor agricultural practices, land erosion, acidification and concerns about production and productivity and compliance with food safety standards are beginning to loom high. Hence, organic farming is identified as one of the sustainable approaches to farming. It is also believed to guarantee substantial net gains and to promote sustainable natural resource management with the possibility of enhancing overall agricultural productivity. Notwithstanding, organic farming is still being perceived negatively in South Africa and there is shortage of empirical studies which focus on cost and return of smallholder organic crop farms. It is in this regard that the study therefore seeks to analyze cost and return of smallholder organic crop farms in the Eastern Cape Province to contribute to knowledge on the relative economic advantages of organic agriculture at the smallholder sector. Specifically, the study profiled the socioeconomic characteristics of smallholder organic crop farmers, determined costs and returns, and estimated profitability and factors that constrain profitability of the smallholder organic crop farms. The research design used in this study was cross-sectional where data were collected at a single point in time. A multi- stage random sampling technique was used to obtain primary data from one hundred and sixty smallholder organic crop farmers (160) with the aid of structured questionnaires. Primary data were collected on demographic and socioeconomic characteristics, variable costs and fixed costs, and returns from the organic crop farms. Data collected were analyzed by Statistical Package for Social Sciences (SPSS) and the descriptive and inferential statistics involved were mean, frequency proportion, gross margin and net income analysis as well as OLS regression analysis. The results of the descriptive analysis showed that the proportions of women involved in organic crop farming were higher than that of men and many of the farmers cultivated on less than 1.0ha. The analysis of the data also showed that smallholder organic crop farms are undoubtedly profitable farm business, with attractive net farm income and lower production costs. The findings further affirmed that factors such as household size, gender, farming experience, number of years in school, farm size, source of labor and access to credit affect profitability and net farm income. Therefore, government is advised to encourage the practice of organic farming by giving short-term loans to smallholder farmers, to enable them invest more in their organic crop farms. There is also need for government to organize workshops and lectures, educating and enlightening individual smallholder organic crop farmers on modern organic farming techniques to enhance profitability of smallholder organic crop farms.
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- Date Issued: 2017