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Enhancing the saccharolytic phase of sugar beet pulp via hemicellulase synergy

  • Authors: Dredge, Roselyn Ann
  • Date: 2010
  • Subjects: Sugar plantations , Sugar plantations -- South Africa , Sugar beet industry -- South Africa , Saccharomyces cerevisiae -- Biotechnology , Biomass energy industries -- South Africa
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:3955 , http://hdl.handle.net/10962/d1004014 , Sugar plantations , Sugar plantations -- South Africa , Sugar beet industry -- South Africa , Saccharomyces cerevisiae -- Biotechnology , Biomass energy industries -- South Africa
  • Description: The sugar beet (Beta vulgaris) plant has in recent years been added to the Biofuel Industrial Strategy (Department of Minerals and Energy, 2007) by the South African government as a crop grown for the production of bio-ethanol. Sugar beet is commonly grown in Europe for the production of sucrose and has recently been cultivated in Cradock and the surrounding areas (Engineering News, 2008). The biofuel industry usually ferments the sucrose with Saccharomyces cerevisiae to yield bio-ethanol. However, researchers are presented with a critical role to increase current yields as there are concerns over the process costs from industrial biotechnologists. The beet factories produce a pulp by-product removed of all sucrose. The hemicellulose-rich pulp can be degraded by microbial enzymes to simple sugars that can be subsequently fermented to bio-ethanol. Thus, the pulp represents a potential source for second generation biofuel. The process of utilising microbial hemicellulases requires an initial chemical pre-treatment step to delignify the sugar beet pulp (SBP). An alkaline pre-treatment with ‘slake lime’ (calcium hydroxide) was investigated using a 23 factorial design and the factors examined were: lime load; temperature and time. The analysed results showed the highest release of reducing sugars at the pre-treatment conditions of: 0.4 g lime / g SBP; 40°C and 36 hours. A partial characterisation of the Clostridium cellulovorans hemicellulases was carried out to verify the optimal activity conditions stated in literature. The highest release of reducing sugars was measured at pH 6.5 – 7.0 and at 45°C for arabinofuranosidase A (ArfA); at pH 5.5 and 40°C for mannanase A (ManA) and pH 5.0 – 6.0 and 45°C for xylanase A (XynA). Temperature studies showed that a complete loss of enzymatic activity occurred after 11 hours for ManA; and 84-96 hours for ArfA. XynA was still active after 120 hours. The optimised lime pre-treated SBP was subsequently degraded using various combinations and percentages of C. cellulovorans ArfA, ManA and XynA to determine the maximal release of reducing sugars. Synergistically, the highest synergy was observed at 75% ArfA and 25% ManA, with a specific activity of 2.9 μmol/min/g protein. However, the highest release of sugars was observed at 4.2 μmol/min/g protein at 100% ArfA. This study has initiated the research within South Africa on SBP and its degradation by C. cellulovorans. Preliminary studies show that SBP has the potential to be utilised as a second generation biofuel source.
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  • Date Issued: 2010

Environmental constraints affecting farmers in the Great-Kei Region

  • Authors: Mtintsilana, Tando
  • Date: 2010
  • Subjects: Agriculture -- Environmental aspects , Agricultural ecology , Agricultural conservation , Farm management
  • Language: English
  • Type: Thesis , Masters , MBA
  • Identifier: vital:8622 , http://hdl.handle.net/10948/1502 , Agriculture -- Environmental aspects , Agricultural ecology , Agricultural conservation , Farm management
  • Description: The sustainable use of the environment for agriculture has become a global priority, requiring urgent solutions in view of intensifying competition. The South African government and the agricultural sector drafted a strategic plan for South African Agriculture. In this plan it was argued that the potential for the horizontal expansion of agricultural production is limited with one of the limitations being that unused high and medium potential land is scarce. This implies that the challenge for higher agricultural production is immense because primarily it would have to come from increased efficiency. All businesses are confronted by change at some time in their history in which agribusiness in South Africa has been subjected to changes in its past. In this era of hyper competition, agribusinesses are faced with constant change. It is how businesses deal with that change that will determine how successful they will remain in the future. The main problem of this research was to determine if farmers in the Great-Kei Region have the appropriate strategies in place to manage environmental constraints effectively. Therefore, the identification and isolation of prominent environmental constraints, through literature review and survey data gathered and analysed, would assist agribusinesses in the planning and prioritising of investments. The investment would be aimed at facilitating the development and sustainable growth in the Great-Kei Region. In this study, a quantitative, descriptive and non-experimental research design was followed. The target population of the study was farmers with farming businesses operating in the Great-Kei Region. There was data obtained from the Eastern Cape Department of Agriculture provincial office in Komga servicing the Great-Kei Region. The data obtained were lists of registered commercial farmers from the Komga iv Agricultural Association and emerging farmers operation in the region. The data obtained did not include all the farmers operating in the Great-Kei Region. The combined sum of farmers from both lists was 38 farmers (N = 38). The population N = 38 was used as a sampling frame representing the population of farmers in the Great-Kei Region. The population of this study consisted of owners or farm managers running the farming businesses and excludes other farm employees employed at the farms. Farmers with agribusinesses in the area who produced either livestock farming or crop farming or both were included for the study. The results of the survey revealed key findings, which enabled the researcher to draw meaningful conclusions and recommendations. The recommendations suggested how farmers can overcome the identified macro, micro and internal environmental constraints affecting them in the Great-Kei Region. Further identification of strategies currently employed by farmers in managing environmental constraints and the competency levels, indicated where gaps resided with strategies currently employed by farmers and where possible change would be required.
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  • Date Issued: 2010

Ernesto "Che" Guevara : a psychobiographical study

  • Authors: Kolesky, Candice
  • Date: 2010
  • Subjects: Guevara, Che, 1928-1967 , Psychology -- Biographical methods
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:9864 , http://hdl.handle.net/10948/1512 , Guevara, Che, 1928-1967 , Psychology -- Biographical methods
  • Description: Psychobiography is a qualitative approach to exploring and understanding the life story of an individual through the lens of psychological theory. The application of theory is typically done on the finished lives of well-known or enigmatic people. This study explores and describes the psychological development across the lifespan of Ernesto “Che” Guevara, by applying the Individual Psychology of Alfred Adler. Che Guevara was an Argentine Marxist revolutionary, physician, author, guerrilla leader, and major figure of the Cuban Revolution. Since his death, his image has become a symbol for revolution within popular culture. Extensive data has been examined in this work to ensure an accurate description of Guevara’s life. Alexander’s model of identifying salient themes was used to analyze the data within a conceptual framework derived from the theory. Guevara was fiercely loyal to his cause, at the expense of the lives of many Cuban citizens as well as his own family, whom he spent little time with. He justified this with his firmly held belief that the end justified the means and that he was always fighting for the greater good. He quite literally dedicated his life to his cause, which is the reason that he has become a modern day symbol for revolution. It is however unfortunate that this came at such a great personal expense.
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  • Date Issued: 2010

Establishing a framework for an integrated, holistic, community based educational support structure

  • Authors: Pieterse, Glynis
  • Date: 2010
  • Subjects: Curriculum planning -- South Africa , Competency-based education -- South Africa , Inclusive education -- South Africa , Teachers -- Training of -- South Africa
  • Language: English
  • Type: Thesis , Doctoral , DEd
  • Identifier: vital:9510 , http://hdl.handle.net/10948/1158 , Curriculum planning -- South Africa , Competency-based education -- South Africa , Inclusive education -- South Africa , Teachers -- Training of -- South Africa
  • Description: The restructuring of South African education, after the country’s first non-racial democratic elections in 1994, coincided, with the development of inclusive education in international education. The implementation of inclusive education, internationally, was guided by the Salamanca Statement of 1994 and the international “Education for All” movement. Education White Paper 6 (2001), serves as the blueprint for implementing inclusive education in South Africa. This investigation argues that the successful implementation of the inclusive education system is dependent on the development of an effective, quality education support structure. Such an educational support structure is one that should reflect a holistic, integrated and community based approach to support. Based on this presupposition, the primary research aim of this investigation was the establishment of a framework for a holistic, integrated, community based education support structure to do justice to learners with mainly external barriers to learning (LSEN) and educators finding themselves in an inclusive classroom in Nelson Mandela Metropole and surrounding areas. In order to understand how such a framework can be established, the following guiding secondary research questions were posed: • What was the international perspective on the implementation of inclusive education? • What was the nature of educational provisioning for learners with barriers to learning (LSEN) before 1994, and the implementation of inclusive education policies thereafter? • What were the practical implications of implementing Education White Paper 6 (Department of Education, 2001) for the support roles of education support providers in South African schools? • What is the support challenges facing learners and educators within inclusive classrooms in Nelson Mandela Metropole and surrounding areas? • What support structures are currently available at the different levels of the education system? This investigation was completed from a phenomenological perspective. A constructivist approach to data collection and data analysis was followed, as the investigator did not attempt to prove or disprove theory, but rather to understand the phenomena under investigation from the viewpoint of participants. iv The sample, selected by means of non-probability purposive and theoretical sampling techniques, included 120 educators from 85 different schools in Nelson Mandela Metropole and surrounding areas. In addition, 4 education officials, 4 members of community organisations and 2 teacher union representatives were selected to the sample. Through the process of data analysis, accomplished through the principles inherent to grounded theory, two themes and sub-themes were identified. The investigator presented a discussion on the two themes and sub-themes. This discussion was followed by a proposal for the establishment of a framework for a holistic, integrated, community based educational support structure. The investigation was completed by recommendations related to the primary and secondary research questions. The investigation concluded that the implementation of inclusive education is severely hampered by strong exclusionary factors that are principally related to socio-economic backlogs that have not been successfully addressed by the current government.
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  • Date Issued: 2010

Estuarine use by spotted grunter Pomadasys commersonnii in a South African estuary, as determined by acoustic telemetry

  • Authors: Childs, Amber-Robyn , Cowley, Paul D , Næsje, T F , Booth, Anthony J , Potts, Warren M , Thorstad, Eva B , Økland, F
  • Date: 2010
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/124428 , vital:35612 , https://doi.org/10.2989/A JMS.2008.30.1.12.462
  • Description: Estuaries are important in the life history and the maintenance of the diversity of coastal fish species because of their function as nursery areas for juveniles as well as feeding grounds for adults (Cyrus 1991). The dependence of many fish species on estuaries is well documented (e.g. Wallace et al. 1984, Lenanton and Potter 1987, Blaber et al. 1989, Whitfield 1990, Hoss and Thayer 1993). Spotted grunter Pomadasys commersonnii (Haemulidae) (Lacepède 1801) is an estuarine-dependent species which spawns in the KwaZulu-Natal inshore coastal waters, between August and December (Wallace 1975b, Wallace and van der Elst 1975, Harris and Cyrus 1997, 1999). The eggs and larvae are transported southwards by the Agulhas Current, and juveniles between 20 mm and 50 mm TL recruit into the KwaZulu-Natal and south-eastern Cape estuaries (Wallace and van der Elst 1975, Whitfield 1990). Juvenile spotted grunter make use of the abundant food resources in estuaries, where they grow rapidly and remain for a period of 1–3 years (Wallace and Schleyer 1979, Day et al. 1981). Upon attaining sexual maturity (at between 300 mm and 400 mm TL), they return to the marine environment (Wallace 1975b). Some adults, however, return to estuaries to feed and to regain condition after spawning (Wallace 1975b, Whitfield 1994). The return of post-spawning fish coincides with increased catches by fishers in estuaries between July and January. These events are known as ‘grunter runs’ (Wallace 1975a, Marais and Baird 1980, Marais 1988, Pradervand and Baird 2002). It is suggested that adults spend up to several months in estuaries, before moving back to sea where they undergo gonadal development and ultimately spawn (Wallace 1975b, Wallace and van der Elst 1975). It is believed that adult fish also enter estuaries in a prespawning state to gain condition en route to their spawning grounds in KwaZulu-Natal (Webb 2002).
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  • Date Issued: 2010

Ethics-oriented learning in environmental education workplaces: An activity theory approach

  • Authors: Olvitt, Lausanne L
  • Date: 2010
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/370961 , vital:66398 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122874"
  • Description: In the context of increasing national and global environmental challenges and their implications for the working world, new ethics and practices are being introduced into workplaces that take better account of socio-ecological relations. Little is understood, however, about the nature of ethics-oriented workplace learning. Drawing on Cultural Historical Activity Theory (CHAT), which enables historically and contextually situated relational perspectives to emerge, this paper explores contradictions in the activity systems of two young environmental education learner-practitioners struggling to engage with the ethical dimensions of their professional work and the professional development course they are studying. The study focuses in particular on the environmental values and ethics component of their course – a year-long Learnership in Environmental Education, Training and Development Practices (EETDP). The paper reflects how tensions and contradictions within and between the interacting activity systems of the workplace, the course, and its regulating qualifications authority influence the teaching and learning of the environmental ethics component of the course. Ethics-oriented teaching and learning processes are found to be strongly influenced by the ‘rules’ and ‘mediating tools’ of these interacting systems, but these are often at odds with the ethical perspectives, socio-cultural context and skills of the ‘subject’ and ‘community’. These systemic contradictions can be more fully understood when their cultural and historical origins are made explicit. The analytical process has led to a more nuanced understanding of ethics-oriented teaching and learning in a workplace-based course, and has revealed several areas needing more careful research (particularly the area of environmental discourses) and the explicit and implicit language of ethics.
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  • Date Issued: 2010

Evaluating the impact of public participation on the formulation and implementation of the Integrated Development Plan: the case of the Nelson Mandela Bay Municipality (2004-2008)

  • Authors: Mqulwana, Nimrod Mbuyiseli
  • Date: 2010
  • Subjects: City planning -- South Africa -- Port Elizabeth , Civic improvement -- South Africa -- Port Elizabeth , Regional planning -- South Africa -- Port Elizabeth , Political participation -- South Africa -- Port Elizabeth , Local government -- South Africa -- Port Elizabeth , Community development -- South Africa -- Port Elizabeth
  • Language: English
  • Type: Thesis , Masters , MPA
  • Identifier: vital:11638 , http://hdl.handle.net/10353/d1001247 , City planning -- South Africa -- Port Elizabeth , Civic improvement -- South Africa -- Port Elizabeth , Regional planning -- South Africa -- Port Elizabeth , Political participation -- South Africa -- Port Elizabeth , Local government -- South Africa -- Port Elizabeth , Community development -- South Africa -- Port Elizabeth
  • Description: Local Government has a critical role to play in rebuilding local communities and environments as the basis for a democratic, integrated prosperous and truly non-racial society and this is enshrined in Chapter 7 of the Constitution of the Republic of South Africa Act 108 of 1996. The key focus area of this research study is the evaluation of the impact of Public Participation on the formulation and implementation of the Integrated Development Plan in the Nelson Mandela Bay Municipality for the period 2004 – 2008. This research study has two aims that are related to public participation in the Nelson Mandela Bay Municipality and they are: - To evaluate the impact of public participation in the Integrated Development Plan in the Nelson Mandela Bay Municipality and whether public participation is seen as a vehicle to enhance policy formulation and implementation or not especially with respect to community ownership of the Integrated Development Plan. To provide strategies/mechanisms to remedy the situation. The research study is people focused and the methodogical approach that is used in this investigation is qualitative and quantitative. The target groups for this research is the Community residing in the jurisdiction area of the Nelson Mandela Bay Municipality, Metro Councillors and Municipal Officials.
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  • Date Issued: 2010

Evaluation and management of cover crop species and their effects on weed dynamics, soil fertility and maize (Zea mays L.) productivity under irrigation in the Eastern Cape Province, South Africa

  • Authors: Murungu, Farayi Solomon
  • Date: 2010
  • Subjects: Crops -- South Africa , Conservation of natural resources -- South Africa -- Eastern Cape , Agriculture -- South Africa -- Eastern Cape , Soil percolation -- South Africa -- Eastern Cape , Soil permeability -- South Africa -- Eastern Cape , Irrigation farming -- South Africa -- Eastern Cape , Corn -- South Africa -- Eastern Cape , Soil fertility -- South Africa -- Eastern Cape
  • Language: English
  • Type: Thesis , Doctoral , PhD (Crop Science)
  • Identifier: vital:11866 , http://hdl.handle.net/10353/335 , Crops -- South Africa , Conservation of natural resources -- South Africa -- Eastern Cape , Agriculture -- South Africa -- Eastern Cape , Soil percolation -- South Africa -- Eastern Cape , Soil permeability -- South Africa -- Eastern Cape , Irrigation farming -- South Africa -- Eastern Cape , Corn -- South Africa -- Eastern Cape , Soil fertility -- South Africa -- Eastern Cape
  • Description: The current interest in conservation agriculture (CA) 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. Cover crops that are usually grown under CA to provide soil cover, may offer secondary benefits, depending on the farming system. The concept of growing cover crops is a relatively new phenomenon to smallholder farmers. Production of large biomass yields and weed suppression from cover crops were major challenges affecting success and uptake of CA technologies by smallholder irrigation farmers. Coupled with this, low soil fertility limit maize productivity and reduce water use efficiency on smallholder irrigation schemes in what is largely a water strained agro-ecology in South Africa. While cover cropping can increase maize productivity, benefits of different types of mulch are not well understood, leading to challenges in selecting the most appropriate cover crop species to grow in the Eastern Cape Province (EC) of South Africa (SA) which has a warm temperate climate. With respect to any new technology, smallholder farmers are more interested in the economic benefits. Cover crops have been defined as leguminous or non-leguminous plants used for ground cover in various temporal and special configurations used in crop or animal production systems. The purpose of these cover crops is to improve on or more of the following: soil erosion, availability and cycling of N, P, K, Ca and other nutrients, soil moisture and water infiltration, and weed or pest control (Eilitta et al., 2004).. Improvement of animal or human diet may be additional goals. This definition accommodates diverse systems which may include intercrop and sole-cropping systems. In the Eastern Cape Province of South Africa, a government initiative has promoted the growing of winter cover crops in smallholder irrigation schemes (Allwood, 2006). In other parts of Africa, legume food crops have been simultaneously grown with cereal staples to improve both soil cover and human diet (Eilitta et al., 2004). Winter experiments were undertaken in 2007 and 2008 to evaluate biomass accumulation, C and N uptake, weed suppression and response to fertilization. Winter cover crops planted included; oats (Avena sativa), grazing vetch (Vicia dasycarpa), faba bean (Vicia faba), forage peas (Pisum sativum) and lupin (Lupinus angustifolius). After cover crops were terminated, the effects of residues on weeds, fertility, moisture conservation and maize productivity were undertaken in the 2007/08 and 2008/09 summer seasons. Field studies were also done in the 2007/08 and 2008/09 summer seasons to investigate effects of strip intercropping patterns (3:2; 4:2; and 6:2 patterns) of maize (cv. PAN 6479) with mucuna (Mucuna pruriens) or sunnhemp (Crotalaria juncea) on maize productivity and summer cover crop biomass production. In a separate experiment effects of relay intercropping sunnhemp, mucuna and sorghum (Sorghum bicolor) on biomass accumulation and maize productivity were investigated. Decomposition, N and P release from both winter cover crops and summer cover crops were also assessed in laboratory incubation experiments. Oats, grazing vetch and forage peas cover crops produced mean dry mass of 13873 kg/ha, 8945.5 kg/ha and 11073 kg/ha, respectively, while lupin had the lowest dry mass of 1226 kg/ha over the two seasons. Oats responded to fertilization while, there was little or no response from the other winter cover crops. Oats and grazing vetch also reduced weed density by 90 % and 80 % respectively while lupin only reduced weed density by 23 % in relation to the control plots. Nitrogen uptake was 254 kg N/ha for oats while it was 346 kg N /ha for grazing vetch. In the subsequent summer season, grazing vetch and forage pea residues significantly (P < 0.01) improved soil inorganic N. Oat and grazing vetch residues significantly (P < 0.05) reduced weed dry masss and weed species diversity compared to plots with lupin residues and the control. Lack of maize fertilization tended to reduce maize yields but not for maize grown on grazing vetch residues. From an economic perspective, grazing vetch resulted in the highest returns. Decomposition of winter cover crops was much faster for grazing vetch followed by forage peas and lastly oats. Oats had 40 % ash free dry mass remaining after 124 days while grazing vetch and forage peas had 7 % and 16 % respectively. Maximum net mineralized N and P were greater for grazing vetch (84.8 mg N/kg; 3.6 mg P/kg) compared to forage peas (66.3 mg N/kg; 2.7 mg P/ha) and oats (13.7 mg N/kg; 2.8 mg P/kg). In the strip intercropping trials, sunnhemp achieved the highest biomass yield of 4576 kg/ha in the 3:2 pattern while mucuna achieved 1897 kg/ha for the same strip pattern. The 3:2 strip intercropping pattern slightly depressed yields, however, yield reduction was more pronounced in the first season where water stress was experienced. Growing maize on previous cover crop strips failed to increase maize productivity probably due to weed growth during the fallow reducing mineral N in these strips. Decomposition was faster in sunnhemp leaves and mucuna compared to sunnhemp stems. Sunnhemp stems had about 65 % of ash free dry mass remaining after the end of the experiment at 132 days while just over 10 % of mucuna and sunnhemp leaves still remained. Mucuna mineralized 60 mg N/kg and 3.2 mg P/kg and sunnhemp mineralized 45 mg N/kg and 3.5 mg P/kg. Relay intercropping did not significantly (P > 0.05) affect maize biomass and grain yield. Sorghum experienced the largest drop in biomass when relay-intercropped with maize. Mucuna resulted in the highest N uptake (271 kg N/ha) in sole cropping while sorghum had the lowest (88 kg N/ha). Grazing vetch results in high biomass yields with minimal fertilizer application in a warm-temperate climate. Grazing vetch mulch is also the most cost effective mulch for better early weed control, improving soil mineral N status, water conservation and ultimately enhanced maize productivity in smallholder irrigation maize-based systems. The 3:2 pattern maximizes summer cover crop biomass yields compared to the 6:2 and 4:2 patterns. However, the 3:2 pattern may slightly depress yields in a water stressed environment. Relay intercropping mucuna, sunnhemp and sorghum into a maize crop at 42 days after maize sowing has no effect on maize productivity while cover crop biomass yields are low. Having a long winter fallow period after maize harvesting, a common practice in the study area, reduces the positive impact of legume cover crops on soil mineral N. Results suggest that winter cover crops may result in weed control, soil fertility and maize yield improvement benefits while a long fallow period may cancel-out these benefits for summer cover crops. Grazing vetch is a cost effective cover crop that produces high maize yields with minimal fertilizer input. Maize growing on oat mulch requires more fertilizer application than crops growing on grazing vetch mulch. Conservation agriculture systems in which summer cover crops are grown alongside the maize crop with a long winter fallow period do not produce the intended CA benefits.
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  • Date Issued: 2010

Evaluation and mapping of the spatial variability of soil fertility at Zanyokwe Irrigation Scheme in the Eastern Cape, South Africa

Evaluation of antidiarrhoeal and toxicological properties of Hermannia Incana cav.: a South African medicinal plant

  • Authors: Appidi, Jaipal Reddy
  • Date: 2010
  • Subjects: Sterculiaceae , Medicinal plants -- South Africa -- Eastern Cape , Diarrhea , Botany, Medical
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:11304 , http://hdl.handle.net/10353/259 , Sterculiaceae , Medicinal plants -- South Africa -- Eastern Cape , Diarrhea , Botany, Medical
  • Description: Hermannia incana Cav. (Sterculiaceae), known as sweet yellow bells, is a medicinal plant used by the people of the Eastern Cape for the treatment of stomach-ache and diarrhoea. It has purgative and diaphoretic effects. It is a prostrate herb with yellow flowers and sparsely hairy and slightly glandular leaves, occurring in grassland and marshes in the Eastern Cape Province of South Africa. Based on the ethnomedical uses of this plant, the research project was designed to evaluate its antidiarrhoeal and toxicological properties. An ethnobotanical study of plants used for the treatment of diarrhoea in the Eastern Cape Province was carried out, using a questionnaire which was administered to herbalists, traditional healers and rural dwellers. This survey indicated a total of 17 plant species from 14 families. Elephantorrhiza elephantine (Burch.) Skeels, Hermannia incana Cav., Pelargonium reniforme Curt., Alepidea amatymbica Eckl. & Zeyh. and Bulbine latifolia (L.f.) Roem. et Schult. were the most frequently mentioned and highly recommended plants for the treatment of diarrhoea by both the traditional healers and rural dwellers. The root, bark and leaves are the common parts of plants used, while decoctions and infusions are the main methods of preparation. The agar dilution method was used to study the antimicrobial activity. The methanol extracts of the plant showed appreciable activity against Gram-positive and Gram-negative bacteria at concentrations ranging from 0.5 to 7.0 mg/ml. The acetone and water extracts of both the leaves and the roots showed moderate activity against Gram positive bacteria and less activity against Gram negative bacteria. All the extracts inhibited the growth of the fungi Aspergillus flavus, Aspergillus niger, and Mucor hiemalis with growth inhibition ranging from 54.31 percent to 96.67 percent at 0.1-10 mg/ml. None of the extracts suppressed the growth of Candida albicans at the maximum concentration (10 mg/ml) tested. iii In the in vivo antidiarrhoeal evaluation using Wistar rats, the aqueous extract at all the doses tested, significantly prolonged the time of induction of diarrhoea and also reduced the frequency of diarrhoeal episodes and fecal parameters (total number, number of wet, fresh and dry weight and water content of the faeces). The percentage inhibition of defecation and intestinal content (enteropooling) were increased in dose dependent manner. The doses also reduced the intestinal transit time of charcoal, masses and volumes of intestinal fluid (gastrointestinal motility). These results are indications of antidiarrhoeal property of H. incana leaf extract with the 600 mg/kg body weight of the extract being the most effective. In the toxicological evaluation using Wistar rats, the oral administration of the extract did not produce any significant effect on the liver and kidney body weight ratios, RBC, HB, PCV, MCV MCH, MCHC, RCDW, WBC, neutrophils, monocytes and basophils cholesterol, triacylglycerol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and atherogenic index. The extract also did not affect the levels of sodium, potassium, chloride, inorganic phosphorus, urea, creatinine, total protein, globulin, albumin, total and conjugated bilirubin. The activities of alkaline phosphatase, gamma glutamyl transferase and alanine aminotransaminase in the serum were increased by the extract whereas aspartate aminotransaminase was decreased. The levels of LUC, platelets, lymphocytes and eosinophils were significantly affected at 600 mg/kg body weight. The available evidence in this study suggests that the extract of H. incana leaf is mild, parameter and dose specific. The structure and distribution of foliar appendages on the leaves of this plant were investigated with the JEOL (JSM-6390LV) scanning electron microscope (SEM). Both glandular and non-glandular trichomes were observed. Long stalked glandular trichomes were present on both the abaxial and adaxial surfaces while short stalked glandular trichomes were present only on the adaxial surface. Glandular trichomes were capitate while nonglandular trichomes were stellate with many arms. Energy dispersive X-ray spectroscopyiv SEM showed that Al, Ca, K, Na, Ti and Si were the major constituents of the crystals analyzed from the leaf surfaces. The phytochemical screening of H. incana revealed the presence of bioactive antidiarrhoeal agents such as alkaloids, tannins, saponins, phenolics, triterpenes, cardiac glycosides, flavonoids, cardenolides and dienolides. Two flavonoids, epicatechin and 3, 5, 7, 2’ tetra-hydroxy flavone-3- O--D-glucopyranoside were isolated from the leaves of the plant through bio-active guided fractionation. Both these compounds were screened against diarrhoea causative organisms (Echerichia coli, Shigella flexneri, Bacillus cereus and Staphylococcus aureus) and exhibiting minimum inhibitory concentrations ranging from 12.5 to 100 μg/ml. The findings from this research have generally justified the traditional use of this plant for the treatment of diarrhoea in this province.
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  • Date Issued: 2010

Evaluation of cover crop species for biomass production, weed suppression and maize yields under irrigation in the Eastern Cape Province, South Africa

  • Authors: Musunda, Bothwell Zvidzai
  • Date: 2010
  • Subjects: Cover crops , Biomass energy -- South Africa -- Eastern Cape , No-tillage , Conservation of natural resources -- South Africa -- Eastern Cape , Agriculture -- South Africa -- Eastern Cape , Agricultural systems -- South Africa -- Eastern Cape , Weeds
  • Language: English
  • Type: Thesis , Masters , MSc Agric (Crop Science)
  • Identifier: vital:11867 , http://hdl.handle.net/10353/347 , Cover crops , Biomass energy -- South Africa -- Eastern Cape , No-tillage , Conservation of natural resources -- South Africa -- Eastern Cape , Agriculture -- South Africa -- Eastern Cape , Agricultural systems -- South Africa -- Eastern Cape , Weeds
  • Description: Achieving high biomass yields of cover crops has been a challenge to the success of Conservation Agriculture (CA) practices in the Eastern Cape (EC). A study was conducted to evaluate strategies for optimizing cover crop biomass production. Trials were carried out to screen summer and winter cover crops, as well as evaluate intercropping patterns and planting dates for biomass, weed suppression and subsequent maize yield under irrigation. Four summer legume cover crop species were evaluated under a Randomised Complete Block Design (RCBD) design. The cover crops were fertilized with 13.34 kg ha-1 of N, 20 kg ha-1 P and 26.66 kg ha-1 K. In the 2008/09 summer season a maize crop was superimposed on the 2007/08 screening trial under no-till. The crop was fertilized with 60 kg ha-1 of N. An intercropping trial was conducted over two seasons as a way of investigating the best way of incorporating cover crops into farmers cropping systems. This was done bearing in mind the limitation of resources such as land. The trial evaluated 3 factors laid as a 2 x 2 x 3 factorial arranged in a split-plot design. The main factor was cover crop planting date (planting at maize planting or 2 weeks after maize planting). The sub plot factor was intercropping pattern (strip intercropping and between row intercropping). A trial was also conducted to evaluate the effect of planting date (End of April and mid May) and four winter legume cover crop species on cover crop biomass, weed suppression and maize grain yield. The experiment was laid out as a Randomised Complete Block Design (RCBD) replicated 3 times. In the subsequent summer season a maize crop was superimposed on the winter trial to test the residual effects of the cover crop species. Another study was conducted to evaluate winter cereal cover crop species for biomass accumulation, weed suppression and subsequent maize grain yield. The cover crops as well as a weedy fallow control plot treatments were laid out as a Randomised Complete Block Design replicated 3 times. In the subsequent summer season a maize crop was superimposed on the site under no-till to evaluate the residual effect of the cover crops on maize. The results showed sunhemp, cowpea and lablab as the best cover crops with high biomass and weed suppression whilst mucuna was the least. Sunhemp consistently yielded higher cover biomass averaging 11200 kg ha-1 over the two seasons whilst mucuna had a consistently lowest average biomass yield of 4050 kg ha-1. These cover crops were above the critical 6 t ha-1 for effective weed suppression. There was a significant (p<0.01) relationship of cover crop dry weight and weed dry weight in both seasons. Subsequent maize grain yield was significantly higher in the sunhemp plots (64.2 %) than the weedy fallow plot. Mucuna, lablab and cowpea had maize grain yield increases of 16.6%, 33% and 43.2% respectively. Intercropping cover crops at maize planting yielded higher cover crop dry weights than a delay in intercropping cover crops. A delay in intercropping resulted in significantly higher average maize grain yield of 4700 kg ha-1 compared to intercropping at maize planting (3800 kg ha-1) and sole maize (4300 kg ha-1) over the two seasons. Strip intercropping also yielded higher (5000 kg ha- 1) average maize grain yield compared to row intercropping (3600 kg ha-1) and sole maize (4300 kg ha-1). There was a significant (p<0.05) relationship between cover crop dry weight in the 2007/08 season and maize grain yield in the 2008/09 season. Early planting grazing vetch gave the highest biomass yield of 8100 kg ha-1 whilst early planted red clover had the lowest biomass of 635 kg ha-1. Low weed dry weights were also obtained from the early planted grazing vetch as opposed to the other treatments. There was a significant (p<0.001) relationship of cover crop dry weight and weed dry weight. In the subsequent 2008/09 summer season early planted grazing vetch had the highest maize yield of 7500 kg ha-1 which was 56.3 % more than the weedy fallow plot had 4800 kg ha-1. The weedy fallow plot also had high weed infestation than the cover crop plots. There were significant (p<0.01) relationships between cover crop dry weight and maize grain yield, winter weed dry weight and maize grain yield and summer weed dry weight and maize grain yield. The results also showed triticale (13900 kg ha-1) as the best winter cover crop for biomass production. Italian ryegrass (6500 kg ha-1) produced the least amount of biomass. In The subsequent maize crop white oats gave highest maize grain yield (6369 kg ha-1) which was 33 % more than the weedy fallow plot (4784 kg ha- 1). There were also significant (p< 0.01) relationships of maize grain yield and winter weed dry weight, maize grain yield and summer growing weeds. The various studies demonstrated that there is opportunity for high biomass production under small scale farmers irrigated conditions using cover crops both in winter and summer. Best bet cover crops were sunhemp, cowpea and lablab for summer and triticale, white oats, barley, Italian ryegrass and grazing vetch for winter. Cover crops can also be incorporated into farmers cropping systems as sole crops or intercrops within the maize based cropping systems. Strip intercropping can be used by farmers as a way of introducing cover crops. Critical to achievement of high biomass is the time of planting cover crops with high biomass when planting is done early. A 2 week delay in strip intercropping cover crop into maize can be used as a way of incorporating cover crops into farmers cropping systems with minimal maize yield reduction.
  • Full Text:
  • Date Issued: 2010

Evaluation of plant extracts used in ethno-veterinary control of gastro-intestinal parasites in village chickens in the Eastern Cape Province of South Africa

Evaluation of water service rendering in the Amathole District Municipality

  • Authors: Mqolo, Abner Zamindawo
  • Date: 2010
  • Subjects: Municipal government -- South Africa -- Eastern Cape , Municipal services -- South Africa -- Eastern Cape , Water-supply -- South Africa -- Eastern Cape , Municipal water supply -- South Africa -- Eastern Cape , Water-supply, Rural -- South Africa -- Eastern Cape
  • Language: English
  • Type: Thesis , Masters , MPA
  • Identifier: vital:11639 , http://hdl.handle.net/10353/d1001248 , Municipal government -- South Africa -- Eastern Cape , Municipal services -- South Africa -- Eastern Cape , Water-supply -- South Africa -- Eastern Cape , Municipal water supply -- South Africa -- Eastern Cape , Water-supply, Rural -- South Africa -- Eastern Cape
  • Description: The rural areas of Amathole district municipality continue to experience difficulty in accessing water services. The people experience problems despite the fact that the Amathole district municipality, since 2003 has been made a water service authority in its municipal area, which consists of eight local municipalities, namely; Mnquma, Mbashe, Nkonkobe, Amahlathi, Great Kei, Ngqushwa, Nxuba, and Buffalo City. With the water service authority powers devolved from national government to the district municipalities the intention was to speed service delivery. This study investigates the causes of the delays in water service delivery experienced in rural areas of this district municipality. The Buffalo City local municipality is excluded in the study because Buffalo City has as well been given the responsibility of being the water service authority in its municipal area. This study used the questionnaires as data collection tool, and it was distributed to these respondents; chief officials, councilors, and citizens. Due to vastness of the target population sampling was used to reduce the bulkiness of the data. The questionnaire content is based on the phases of the systems theory to see if the policy making processes of the Amathole district municipality are carried out in accordance with the systems theory. The study has found that the citizens are not adequately involved in all the policy processes including the policy analysis and evaluation. This has been found to be a contributory factor in the ineffectiveness of the municipality water service delivery.The spheres of government that operate in silos compromised policy analysis and evaluation of the municipality, and disjuncture of the delivery programs of the spheres and state enterprises caused a huge service delivery challenges for this municipality. The study has confirmed that the Amathole district municipality is experiencing problems, delays, and challenges that make it to be ineffective as a water service authority.
  • Full Text:
  • Date Issued: 2010

Exploratory study on empowering rural communities of O.R Tambo District with special reference to Mqanduli

  • Authors: Mbelu, Ntandokazi Busisa
  • Date: 2010
  • Subjects: Rural development Rural population Social services, Rural South Africa -- Eastern Cape
  • Language: English
  • Type: Thesis , Masters , M Sw
  • Identifier: vital:18479 , http://hdl.handle.net/11260/d1009453
  • Description: The aim of the study was to explore development of rural communities in the Mqanduli Administrative Area. The exploratory study was further conducted to examine delivery of service to these rural communities. One of the objectives was to empower rural communities for purposes of improving their daily living standards and also to bring about social change.In determining the sample size, forty (40) respondents were selected from Mqanduli Administrative Area. Out of the forty (40) respondents, thirty (30) respondents were selected from the Mqanduli community members, five (5) were O.R.Tambo District Municipality stakeholders and the other five (5) were Social workers from Mqanduli Administrative Area. The instrument utilized to collect data was a questionnaire. Data was analysed using the quantitative and qualitative measure. The outcome of the study indicates that the majority of rural communities in the Mqanduli Administrative Area were in dire need of empowerment which will enable these disadvantaged communities towards development and social change.
  • Full Text:
  • Date Issued: 2010

Exploring and expanding learning processes in sustainable agriculture workplace contexts

  • Authors: Mukute, Mutizwa
  • Date: 2010
  • Subjects: Sustainable agriculture -- Africa, Southern Sustainable development -- Study and teaching -- Africa, Southern Permaculture -- Zimbabwe Organic farming -- South Africa Farmers -- Social conditions -- Africa, Southern Farmers -- Economic conditions -- Africa, Southern Farmers -- Training of -- Africa, Southern
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:1539 , http://hdl.handle.net/10962/d1003421
  • Description: The focus of this study is to explore and expand farmer learning processes in sustainable agriculture workplace contexts. It examines change oriented learning processes in the context of three sustainable agriculture practices. The study begins by discussing the history and emergence of environmental discourses and approaches; sustainable agriculture; and the histories of three kinds of sustainable agriculture practices: Permaculture, Organic Farming and Machobane Farming System. It also traces the evolution of agricultural extension approaches within the wider context of education for sustainable development. The main focus of the study is an exploration of how farmer learning can be mediated through an expansive learning process. The study methodology surfaces some of the contradictions in sustainable agriculture and learning activity systems that farmers encounter in learning and practising sustainable agriculture. It uses these contradictions as sources of expansive learning in and between the respective activity systems of farmers, sustainable agriculture facilitators, agricultural extension workers (conventional) and organic entrepreneurs. As shown in the study, the expansive learning processes result in the modelling, implementation and reviewing of solutions to contradictions being faced in the learning and practice of sustainable agriculture. The study also proposes a number of tools that can be adapted and used by development farmers and agricultural trainers to examine and expand learning as well as build farmer agency. The study was conducted in three case study sites in Lesotho, South Africa and Zimbabwe. In Zimbabwe the study is located in Hwedza district in the St Margaret Primary School and community that learn, practise and facilitate the learning of Permaculture within the Schools and Colleges Permaculture Programme (SCOPE). The second study site is in South Africa: Durban urban and peri-urban areas where a community of organic farmers, facilitators and entrepreneurs coordinate the marketing of their produce through Isidore Farm and Earth Mother Organic and support each other to learn and practise organic farming. The third study site is based in the Mafeteng and Mohale‟s Hoek districts of Lesotho where the focus was on farmers who learn and practise the Machobane Farming System (MFS) and are supported in this by the Rural Self Development Association (RSDA) and the Machobane Agricultural Development Foundation (MADF). Drawing on three sensitising concepts of dialectics, reflexivity and agency, the study worked with Cultural Historical Activity Theory (CHAT) underpinned by critical realism to reveal how farmer learning is mediated and expanded. The theory of practice/habitus also provided a useful theoretical lens with which to examine data generated. Using a two-phased, multiple embedded case study approach, the study worked within the broad framework of social learning. It used semi-structured individual and group interviews, observations and document analysis to explore learning processes and generate „mirror‟ data. This data was then used in Change Laboratory Workshops, within the Developmental Work Research methodology, where double stimulation and focus group discussions contributed to expanding learning processes. Drawing on critical realism the study used inductive, abductive and retroductive modes of inference to analyse data in each case study as well as across case studies. The findings of the study reveal that farmer learning is influenced by both intrinsic motives, such as identity, and extrinsic motives which are primarily associated with economic, ecological and health benefits. Farmers learn through scaffolding and mediating tools that link everyday and scientific knowledge. They also learn from fellow farmers through observation, practising and experimentation. Some of the issues that were raised in connection with farmer learning processes are: language; time to learn, practice and appropriate concepts; time to improve the natural resource base while at the same time improving income generation; and responses to climate change. The study also found that farmer learning and practice of sustainable agriculture in the case studies investigated, is influenced by past and current agricultural and educational policies; societal values and attitudes; social and cultural backgrounds; work affordances and gender relations; quality of training offered; poverty; and, HIV and AIDS. In the second phase of the study, which built on the problematic situations being encountered by research participants (sustainable agriculture farmers, sustainable agriculture facilitators, extension workers, and organic marketers) to surface contradictions, the main finding was that the expansive learning process has potential to enhance farmer learning and practice of sustainable agriculture. It does this by mobilising distributed cognition among participants as well as their preparedness to act. Through the expansive learning processes in each case study, research participants were able to question their practices, surface contradictions, model solutions and implement them, and thus build individual, collective and relational agency reflexively. Observation of this required micro-analysis of agentive talk and reflective talk. The study contributes in-depth insight into participatory research and learning processes, especially within the context of people-centred learning and innovation in the agricultural development arena. It provides empirical and explanatory insight into how change oriented social learning can emerge and be expanded in Education for Sustainable Development, explaining learning and change relationships in three sustainable agricultural practices. It also provides learning and extension tools to work with contradictions that arise from intentionality, experience, context and history in farming and training activity systems. Its key contribution lies in providing in-depth insight into mobilisation of human agency and reflexivity in change oriented sustainable agriculture learning and development, processes that are critical for responding to contemporary socio-ecological issues and risks.
  • Full Text:
  • Date Issued: 2010

Exploring self concept and social identities in the context of online intimate relationships

  • Authors: Van Staden, Phillip
  • Date: 2010
  • Subjects: Self , Group identity , Online dating
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:9881 , http://hdl.handle.net/10948/1276 , Self , Group identity , Online dating
  • Description: Many South Africans are developing online relationships. Due to the anonymous and artificial context of the online environment it is possible that a person’s identity differs within the on- and offline environment. Sternberg’s (1986) Triangular Model of Love as well as Rogers’ Self Theory (1951) were utilized as a theoretical base for investigating online identity and intimacy. Using a qualitative, exploratory design, the study explored this phenomenon by analysing open ended questionnaires administered online to people in intimate online relationships. Participants were selected by means of non-probability snowball sampling. The findings indicated that Internet socialisers vary in their experience of their online identities. Individuals may have a multitude of genuine online selves, each one represented differently depending on the anonymity and level of intimacy in the relationship. Selfdisclosure and deception play an important role in identity representation and exploration and both are experienced as being affected by the online context.
  • Full Text:
  • Date Issued: 2010

Exploring the use of interactive teaching and learning strategies in HIV and AIDS education

  • Authors: May, Melissa
  • Date: 2010
  • Subjects: AIDS (Disease) -- South Africa -- Prevention , AIDS (Disease) -- Study and teaching -- South Africa , Education -- South Africa
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:9480 , http://hdl.handle.net/10948/1510 , AIDS (Disease) -- South Africa -- Prevention , AIDS (Disease) -- Study and teaching -- South Africa , Education -- South Africa
  • Description: Schools play a major role in shaping the attitudes, opinions and behaviour of young people and so are ideal environments for teaching the social, as well as biological aspects of HIV and AIDS. However, literature indicates that learners are displaying “AIDS fatigue” and may be resistant to teaching around HIV and AIDS. In order to enhance learner engagement and learning, there is therefore a need for teachers to employ interactive teaching and learning strategies that are interactive, inexpensive and fun. This dissertation outlines the research design of an investigation into how such strategies can be used in HIV and AIDS prevention education. An action research design was made use of in this study and the manner in which several teachers presented HIV and AIDS education to his/her learners was initially observed. In addition, qualitative interviews were used to determine the teachers‟ need for development in this regard. Based on the findings of the problem identification step, teachers were introduced to active teaching and learning strategies and supported to implement them. Evaluation and refinement of the strategies, developmental workshops and training followed, which in turn lead to recommendations and the formulation of guidelines to influence teacher education with regard to HIV and AIDS prevention education.
  • Full Text:
  • Date Issued: 2010

Extending Java’s communication mechanisms for multicore processors

  • Authors: Wells, George C
  • Date: 2010
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/430526 , vital:72697 , https://citeseerx.ist.psu.edu/document?repid=rep1type=pdfdoi=4068ed60c317e81dc70288cf36ff586dc057233f
  • Description: With the current trend towards the increased use of multicore proces-sors, there is a growing need for simple, efficient parallel programming mechanisms. While Java has good support for multithreaded and dis-tributed application development, our research into tuple-space systems for multicore processors highlighted a gap in the concurrency facilities available in Java. This arises in the context of independent applications (running in separate virtual machines) that need to synchronise their ac-tivities or communicate with each other. There are several possible solu-tions to this problem, ranging from extensions to the language and/or runtime environment through to the use of distributed programming methods. Using the latter introduces considerable performance over-heads, and so we explored the use of the Java Native Interface in order to take advantage of the interprocess communication (IPC) facilities pro-vided by the underlying operating system. The analysis and comparison of the performance of the standard approaches and our prototype library suggest that there are real benefits to be gained by alternative ap-proaches to the provision of IPC mechanisms for independent Java programs executing on multicore systems. We hope that these findings will spur further investigation of this problem and other possible solu-tions.
  • Full Text:
  • Date Issued: 2010

Fabrication and characterization of single walled carbon nanotubes-iron phthalocyanine nano-composite

  • Authors: Akinbulu, Isaac A , Nyokong, Tebello
  • Date: 2010
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/262622 , vital:53537 , xlink:href="https://doi.org/10.1039/C0NJ00395F"
  • Description: Nano-composite of single walled carbon nanotubes (SWCNTs) and iron phthalocyanine, peripherally tetra-substituted with diethylaminoethanethiol (complex 2), was fabricated and characterized by infra red (IR) spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM technique gave a convincing image of the nano-composite. Self-assembled monolayer (SAM) film of the composite (SWCNT-2-SAM) was formed on gold electrode. Its surface properties were investigated, relative to that of 2-SAM film, by cyclic voltammetry and scanning electron microscopy (SEM). Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry, using [Fe(CN)6]3− as redox probe, were used to investigate the dynamics of electron transport in the SWCNT-2-SAM film. Lower charge transfer resistance, RCT, of the SWCNT-2-SAM modified Au electrode, relative to that of the 2-SAM modified Au electrode, was an indication of enhanced electron transport in the presence of SWCNT. The SAM film of the nano-composite showed better electrocatalytic behaviour, relative to that of 2-SAM film, towards the oxidation of the insecticide, carbofuran. The electrode (SWCNT-2-SAM) showed good selectivity for carbofuran, in the presence of diazinon (a non-electroactive interferent) and at lower concentration of the electroactive interferents (chlorpyrifos and dichlorfos).
  • Full Text:
  • Date Issued: 2010

Facile electrocatalytic oxidation of diuron on polymerized nickel hydroxo tetraamino-phthalocyanine modified glassy carbon electrodes

  • Authors: Mugadza, Tawanda , Nyokong, Tebello
  • Date: 2010
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/261269 , vital:53379 , xlink:href="https://doi.org/10.1016/j.talanta.2010.02.037"
  • Description: The facile electro-oxidation of diuron occurred at a glassy carbon electrode (GCE) modified with polymerized nickel tetraamino-phthalocyanine (NiTAPc), containing O–Ni–O bridges represented as poly-Ni(OH)TAPc-GCE. The oxidation of diuron occurred at a potential which is 60 mV less than that of poly-NiTAPc (without O–Ni–O bridges) and was accompanied by enhanced catalytic currents. The catalytic rate constant and the diffusion constant were found to be 5.91 × 102 mol−1 L s−1 and 6.43 × 10−6 cm2 s−1, respectively. The linear concentration range of diuron was 3.0 × 10−5 to 3.5 × 10−4 mol L−1 with a limit of detection (LOD) of 3.3 × 10−7 mol L−1 (3δ notation) and a sensitivity of 12.9 A mol−1 L cm−2.
  • Full Text:
  • Date Issued: 2010
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