Development of a web-based interface for a wireless sensor network monitoring system
- Authors: Gumbo, Sibukele
- Date: 2007
- Subjects: Wireless LAN , Sensor networks , Wireless communication systems , Web sites -- Design , User interfaces (Computer systems)
- Language: English
- Type: Thesis , Masters , MSc (Computer Science)
- Identifier: vital:11372 , http://hdl.handle.net/10353/68 , Wireless LAN , Sensor networks , Wireless communication systems , Web sites -- Design , User interfaces (Computer systems)
- Description: In the recent past, wireless sensor technology has undergone advancements in its autonomous data collecting aspects, and has become an area worth investigating in relation to structural monitoring applications. The system described in this thesis aims at acquiring, storing and displaying overhead transmission line related data collected from a wireless sensor network. Open source tools were used in its development and implementation. The inherent linearly aligned topology of transmission line monitoring devices is not without shortcomings; hence analysis of linear node placement, hardware and software components was carried out to determine the feasibility of the system. Their limited data processing capabilities has motivated the development of a post processing wireless sensor application in order to present any collected structural data in an understandable format.
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- Date Issued: 2007
Enhancing phosphorus availability in some phosphate fixing soils of the Transkei region, South Africa using goat manure
- Authors: Gichangi, Elias Maina
- Date: 2007
- Subjects: Phosphorus in agriculture , Soils -- Phosphorus content , Phosphatic fertilizers , Soils -- Phosphorus content -- South Africa -- Transkei
- Language: English
- Type: Thesis , Doctoral , PhD (Soil Science)
- Identifier: vital:11960 , http://hdl.handle.net/10353/80 , Phosphorus in agriculture , Soils -- Phosphorus content , Phosphatic fertilizers , Soils -- Phosphorus content -- South Africa -- Transkei
- Description: Low availability of soil phosphorus (P) caused by strong sorption of P is a major constraint to agricultural production in most South African soils, particularly those from the high rainfall areas. The aim of this study was therefore to investigate whether combined addition of goat manure with inorganic P fertilizers could enhance P availability in some P fixing soils of the Transkei region, South Africa. The study addressed the following specific objectives (i) to assess P sorption capacities and requirements of selected soils and their relationship with selected soil properties and single point sorption test, (ii) to assess the effects of goat manure and lime addition on P sorption properties of selected P fixing soils (iii) to assess the temporal changes in concentration of inorganic and microbial biomass P fractions following application of inorganic fertilizer P with goat manure in a laboratory incubation experiment, and, (iv) to assess the effects of goat manure application with inorganic phosphate on inorganic and microbial biomass P fractions, P uptake and dry matter yield of maize. Sorption maxima (Smax) of seven soils examined ranged from 192.3 to 909.1 (mg P kg-1) and were highly and positively correlated with sorption affinity constant (r = 0.93, p = 0.01) and organic C (r = 0.71, p = 0.01). The amount of P required for maintaining a soil solution concentration of 0.2 mg P l-1 ranged from 2.1 to 123.5 mg P kg-1 soil. Soils collected from Qweqwe (a Cambisol), Qunu (an Acrisol), Ncihane (a Luvisol) and Bethania (a Ferralsol) had lower external P requirement values and were classified as lower sorbers, whereas soils from Ntlonyana (a Planosol), Chevy Chase (a Ferralsol) and Flagstaff (a Ferralsol) were classified as moderate sorbers. The results suggested that P availability could be compromised in 43 percent iii of the soils studied and that measures to mitigate the adverse effects of P sorption were needed to ensure that P is not a limiting factor to crop production, where such soils are found. Goat manure addition at varying rates (5, 10 and 20 tha-1 dry weight basis) to two of the moderately P fixing soils from Chevy Chase and Flagstaff, reduced P sorption maxima (Smax) compared to the control treatment. Phosphate sorption decreased with increasing amounts of goat manure in both soils but the extent of reduction was greater on Chevy Chase soil than on Flagstaff soil. The relative liming effects of the different rates of goat manure followed the order 20 t GM ha-1 > 10 t GM ha-1 > 5 t GM ha-1. In a separate experiment, addition of inorganic P at varying rates (0, 90, 180, and 360 kg P ha-1) to Flagstaff soil increased labile P fractions (resin P, biomass P and NaHCO3-Pi) and the increases were greater when goat manure was co-applied. The control treatments contained only 17.2 and 27.5 mg P kg-1 of resin extractable P in the un-amended and manure amended treatments, respectively which increased to 118.2 and 122.7 mg P kg-1 on day 28 of incubation. Biomass P concentration was increased from 16.8 to 43.9 mg P kg-1 in P alone treatments but the fraction was greatly enhanced with manure addition, increasing it from 32.6 to 97.7 mg P kg-1. NaOH-Pi was the largest extractable Pi fraction and ranged from 144.3 to 250.6 mg P kg-1 and 107.5 to 213.2 mg P kg-1 in the unamended and manure amended treatments, respectively. Dry matter yield and P uptake by maize grown in the glasshouse were highly and significantly (p = 0.05) correlated with the different P fractions in the soil. The correlations followed the order resin P (r = 0.85) > NaOH-Pi (r = 0.85) > NaHCO3-Pi (r = 0.84) >> biomass P (r = 0.56) for dry matter yield at 6 weeks after planting. At 12 weeks after planting, goat manure had iv highly significant effects on resin P and biomass P but had no effect on NaHCO3-Pi and NaOH–Pi. The combination of biomass P, resin P and NaHCO3-Pi explained 75.8 percent of the variation in dry matter yield of which 63.0 percent of the variation was explained by biomass P alone. The greatest increase in biomass P occurred when added P was co-applied with 5 or 10 tha-1 goat manure. The predictive equation for maize dry matter yield (DM) was: DM (g) = 1.897 biomass P + 0.645 resin P (r = 0.73). Resin P was the fraction that was most depleted due to plant uptake and decreased by 56 to 68 percent between the 6th week and the 12th week of sampling indicating that it played a greater role in supplying plant available P. The results therefore suggested that the use of goat manure may allow resource poor farmers to use lower levels of commercial phosphate fertilizers because of its effect to reduce soil P sorption. In addition, higher increases in biomass P due to manure addition observed at lower rates of added P indicated that goat manure has potential for enhancing bioavailability and fertilizer use efficiency of small inorganic P applications.
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- Date Issued: 2007
Growth performance, carcass characteristics and meat quality of Nguni, Bonsmara and Angus steers raised on natural pasture
- Authors: Muchenje, Voster
- Date: 2007
- Subjects: Cattle -- Feeding and feeds , Cattle -- Growth , Nguni cattle , Aberdeen -- Angus cattle , Bonsmara cattle , Meat industry and trade -- Quality control
- Language: English
- Type: Thesis , Doctoral , PhD (Animal Science)
- Identifier: vital:11580 , http://hdl.handle.net/10353/199 , Cattle -- Feeding and feeds , Cattle -- Growth , Nguni cattle , Aberdeen -- Angus cattle , Bonsmara cattle , Meat industry and trade -- Quality control
- Description: The objective of the current study was to compare tick loads, growth, carcass characteristics and meat quality of Nguni, Bonsmara and Angus steers raised on natural pasture. A total of 30, 7-month old steers each of Bonsmara and Angus, and 40 Nguni steers were kept at the University of Fort Hare Farm till slaughter at 18 months. Monthly weights of the steers were recorded. Carcasses were electrically stimulated. The m. longissimus thoracis et lumborum was sampled for the measurement of meat colour, pH, drip loss, sarcomere length (SL), water holding capacity (WHC), cooking losses, myofibrillar fragmentation length (MFL), Warner Bratzler shear force (WBSF), fatty acid profiles and sensory characteristics of the steers. Urine samples were collected at the slaughter line for the determination of stress hormone concentrations. The Nguni had the lowest tick load (P < 0.05) while the Angus had the highest tick load (P < 0.05). Tick load did not affect the growth rate and carcass characteristics of the steers. Bonsmara and Angus steers had higher (P < 0.05) carcass weight and dressing percentage than the Nguni steers. Meat quality characteristics were similar (P > 0.05) among all the breeds, except that Nguni meat was darker (L*) (P < 0.05) than meat from the other two breeds. The Bonsmara had the highest (P > 0.05) concentrations while the Nguni had the lowest (P > 0.05) concentrations of stress hormones. There were significant (P < 0.05) correlations between WB values of meat aged for two and 21 days in Nguni and Bonsmara, but not in Angus. The correlations among stress responsiveness hormones and meat quality were breed-dependent. Except monounsaturated fatty acids (MUFA) and the n-6/n-3 ratio, fatty acid profiles among the breeds were similar (P > 0.05). Cholesterol levels among the breeds were similar (P > 0.05). The Nguni had the best (P < 0.05) sensory characteristics, such as flavour and tenderness. It can be concluded that while the Nguni is a small framed breed, its meat quality is similar to that of Bonsmara and Angus and has the best meat taste when raised on natural pasture.
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- Date Issued: 2007
Rural internet connectivity: a development in Dwesa-Cwebe, Eastern Cape, South Africa
- Authors: Mandioma, Martin
- Date: 2007
- Subjects: Internet -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Computer Science)
- Identifier: vital:11376 , http://hdl.handle.net/10353/78 , Internet -- South Africa -- Eastern Cape
- Description: This thesis presents aspects of Internet connectivity in rural South Africa. The work looks at government initiatives being undertaken to connect rural communities to up-to-date information networks. Various projects that seek to connect rural areas of South Africa, as well as other remote areas around the world, are discussed. These projects present many novel ideas that have been successfully used to link rural communities in remote areas with the information age. In particular, wired and wireless access technologies that can be implemented to connect remote communities to the Internet are discussed. A field test utilizing GPRS, VSAT and WiMAX was implemented in Dwesa-Cwebe, Eastern Cape Province, South Africa. VSAT proved to offer better Internet connectivity in terms of throughput and latency. WiMAX was then successfully implemented to relay the signal over the remote area of Dwesa-Cwebe, thus effectively providing Internet connectivity to an area with limited cell phone coverage and no telephone lines.
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- Date Issued: 2007
The classification of some fuzzy subgroups of finite groups under a natural equivalence and its extension, with particular emphasis on the number of equivalence classes
- Authors: Ndiweni, Odilo
- Date: 2007
- Subjects: Fuzzy sets , Maximal functions , Finite groups , Equivalence classes (Set theory)
- Language: English
- Type: Thesis , Masters , M Sc (Mathematics)
- Identifier: vital:11587 , http://hdl.handle.net/10353/88 , Fuzzy sets , Maximal functions , Finite groups , Equivalence classes (Set theory)
- Description: In this thesis we use the natural equivalence of fuzzy subgroups studied by Murali and Makamba [25] to characterize fuzzy subgroups of some finite groups. We focus on the determination of the number of equivalence classes of fuzzy subgroups of some selected finite groups using this equivalence relation and its extension. Firstly we give a brief discussion on the theory of fuzzy sets and fuzzy subgroups. We prove a few properties of fuzzy sets and fuzzy subgroups. We then introduce the selected groups namely the symmetric group 3 S , dihedral group 4 D , the quaternion group Q8 , cyclic p-group pn G = Z/ , pn qm G = Z/ + Z/ , p q r G Z Z Z n m = / + / + / and pn qm r s G = Z/ + Z/ + Z/ where p,q and r are distinct primes and n,m, s Î N/ . We also present their subgroups structures and construct lattice diagrams of subgroups in order to study their maximal chains. We compute the number of maximal chains and give a brief explanation on how the maximal chains are used in the determination of the number of equivalence classes of fuzzy subgroups. In determining the number of equivalence classes of fuzzy subgroups of a group, we first list down all the maximal chains of the group. Secondly we pick any maximal chain and compute the number of distinct fuzzy subgroups represented by that maximal chain, expressing each fuzzy subgroup in the form of a keychain. Thereafter we pick the next maximal chain and count the number of equivalence classes of fuzzy subgroups not counted in the first chain. We proceed inductively until all the maximal chains have been exhausted. The total number of fuzzy subgroups obtained in all the maximal chains represents the number of equivalence classes of fuzzy subgroups for the entire group, (see sections 3.2.1, 3.2.2, 3.2.6, 3.2.8, 3.2.9, 3.2.15, 3.16 and 3.17 for the case of selected finite groups). We study, establish and prove the formulae for the number of maximal chains for the groups pn qm G = Z/ + Z/ , p q r G Z Z Z n m = / + / + / and pn qm r s G = Z/ + Z/ + Z/ where p,q and r are distinct primes and n,m, s Î N/ . To accomplish this, we use lattice diagrams of subgroups of these groups to identify the maximal chains. For instance, the group pn qm G = Z/ + Z/ would require the use of a 2- dimensional rectangular diagram (see section 3.2.18 and 5.3.5), while for the group pn qm r s G = Z/ + Z/ + Z/ we execute 3- dimensional lattice diagrams of subgroups (see section 5.4.2, 5.4.3, 5.4.4, 5.4.5 and 5.4.6). It is through these lattice diagrams that we identify routes through which to carry out the extensions. Since fuzzy subgroups represented by maximal chains are viewed as keychains, we give a brief discussion on the notion of keychains, pins and their extensions. We present propositions and proofs on why this counting technique is justifiable. We derive and prove formulae for the number of equivalence classes of the groups pn qm G = Z/ + Z/ , p q r G Z Z Z n m = / + / + / and pn qm r s G = Z/ + Z/ + Z/ where p,q and r are distinct primes and n,m, s Î N/ . We give a detailed explanation and illustrations on how this keychain extension principle works in Chapter Five. We conclude by giving specific illustrations on how we compute the number of equivalence classes of a fuzzy subgroup for the group p2 q2 r 2 G = Z/ + Z/ + Z/ from the number of fuzzy subgroups of the group p q r G = Z/ + Z/ + Z/ 1 2 2 . This illustrates a general technique of computing the number of fuzzy subgroups of G = Z/ + Z/ + Z/ from the number of fuzzy subgroups of 1 -1 = / + / + / pn qm r s G Z Z Z . Our illustration also shows two ways of extending from a lattice diagram of 1 G to that of G .
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- Date Issued: 2007
The effects of goat kraal manure, sewage sludge and effective microorganisms on the composting of pine bark and the nutritional value of the composts
- Authors: Mupondi, Lushian Tapiwa
- Date: 2005
- Subjects: Compost , Fertilizers , Sewage sludge as fertilizer , Goats , Manures , Compost plants
- Language: English
- Type: Thesis , Masters , MSc Agric (Soil Science)
- Identifier: vital:11171 , http://hdl.handle.net/10353/d1001008 , Compost , Fertilizers , Sewage sludge as fertilizer , Goats , Manures , Compost plants
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- Date Issued: 2005
A systems approach to marketing in less developed agriculture with reference to Bululwane Irrigation Scheme
- Authors: Zenda, Sipho Macriba
- Date: 2002
- Subjects: Farm produce -- South Africa -- Marketing , Farms, Small -- South Africa , Sustainable agriculture -- South Africa , Agricultural development projects -- South Africa , Irrigation farming -- South Africa
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11192 , http://hdl.handle.net/10353/d1001045 , Farm produce -- South Africa -- Marketing , Farms, Small -- South Africa , Sustainable agriculture -- South Africa , Agricultural development projects -- South Africa , Irrigation farming -- South Africa
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- Date Issued: 2002
Post-harvest Physiology and Technology: AGH 313
- Authors: Maphaha, M F , Eiasu, B
- Date: 2001-06
- Language: English
- Type: Examination paper
- Identifier: vital:17579 , http://hdl.handle.net/10353/d1009925
- Description: Post-harvest Physiology and Technology: AGH 313, degree examination June 2011.
- Full Text: false
- Date Issued: 2001-06
Research Techniques in Pasture Managament: AGP 602
- Authors: Sikhalazo, Dube , Dziba, L
- Date: 2000-11
- Language: English
- Type: Examination paper
- Identifier: vital:17709 , http://hdl.handle.net/10353/d1010114
- Description: Research Techniques in Pasture Managament: AGP 602, degree examination November 2009.
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- Date Issued: 2000-11
Analysis of decision making in smallholder irrigation practice: a case study of Shiloh and Zanyokwe irrigation schemes in Central Eastern Cape, South Africa
- Authors: Isaac, Agholor Azikiwe
- Subjects: Irrigation farming -- South Africa -- Eastern Cape , Farms, Small -- South Africa -- Eastern Cape , Agricultural extension work -- South Africa -- Eastern Cape , Crops -- Irrigation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Agricultural Economics)
- Identifier: vital:11215 , http://hdl.handle.net/10353/d1019766 , Irrigation farming -- South Africa -- Eastern Cape , Farms, Small -- South Africa -- Eastern Cape , Agricultural extension work -- South Africa -- Eastern Cape , Crops -- Irrigation -- South Africa -- Eastern Cape
- Description: The study was conducted in Zanyokwe and Shiloh smallholder irrigation schemes located in Eastern Cape Province at Amathole and Chris Hani districts respectively. The choice of Zanyokwe and Shiloh smallholder irrigation scheme for this study is mainly supported by the fact that it had a substantial level of crop farming activity taking place especially at Zanyokwe while the Shiloh smallholder irrigation specialises dairy farming. The study examined decision making in smallholder irrigation practice with particular reference to Shiloh and Zanyokwe irrigation schemes. The general objective of the thesis was to analyse and model the determinants of SIS farmer‟s decision making. The specific objectives of the study are as follows: to investigate the determinants of decision making among smallholder irrigation farmers; to examine the relationship between household and farm characteristics and institutional factors that explain decision making in smallholder irrigation scheme; assess the contribution of smallholder irrigation farming to household food security; and determine the production and marketing constraints of smallholder farmers‟ in both schemes. The theoretical and conceptual framework of the study gave a detailed discussion on the determinants of decision making of households. The theories used to understand household behaviour under different assumptions were variously discussed. Comprehensive illustrations of analytical framework of the study were also conceptualised. This study used a survey design, quantitative and qualitative research methodologies involving the use of questionnaires and focus group discussions. The data was coded and analysed using the Statistical Package for Social Science (SPSS). However, frequencies, percentages, bar and pie chart was also computed to describe the data. In consideration of the conceptual framework of the study, the agricultural household model was adopted to analyse smallholder farmer‟s household decision making. Twenty one explanatory variables identified in the conceptual framework of the study were discussed and some of these identified variables were incorporated into the model. The logistic regression model was used as a method of analysis because it can estimate the probability of a certain event occurring and it accommodates a lot of variables which can be ranked in order to illustrate which variables are significant. In the binary logistic model used, seven variables (farm experience, size of farmland, land rights/PTO, water sufficiency, farm asset, market information and production variation) out of the twelve predictor variables were found to have significant effect on influencing household decision making in Shiloh smallholder irrigation scheme, while five variables (gender, age, education, road distance and extension access) were not significant. Of the seven significant variables, four had positive signs (land rights/PTO, water sufficiency and market information); which means that an increase in either of these variables may be associated with an increase in household decision making in Shiloh. The other three predictor variables (farm experience, farm asset and product variation) had negative signs; this means an increase in either of these variables may be associated with a decrease in decision making. In Zanyokwe, six variables (farm experience, land rights/PTO, water sufficiency, farm asset, market information and production variation) out of the twelve predictor variables were found to have significant impact on influencing household decision making, while six variables (gender, age, education, size of farm land, road distance and extension access) were not significant. Of the six significant variables, two had positive signs (water sufficiency and farm asset); which means that an increase in either of these variables may be associated with an increase in household decision making in Zanyokwe. The other four predictor variables (farm experience, land rights/PTO, market information and product variation) had negative signs; this means an increase in either of these variables may be associated with a decrease in decision making. The study concludes that smallholder agriculture is essential for employment generation and food security of households. It is apparent that household food security will not be achieved without giving attention to the role played by smallholders‟ farmers in South Africa. It is pertinent to promulgate an efficient policy programme to address the diversity of smallholders‟ situations and identify the main constraints on investment. Therefore, all spheres of government, the private sector and NGOs should consider investment in smallholder agriculture through coordinated strategies and political support. This study also recommends that government should develop a strategic Smallholder Investment Plan which would improve investments in smallholder agriculture.
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Climate smart soil management: a win-win response to climate change and food security challenges
- Authors: Mnkeni, Pearson
- Subjects: Food security , Population growth , Soil degration , Climate change , Global warming , Conservation agriculture , Organic materials
- Language: English
- Type: Inaugural lecture
- Identifier: vital:11980 , http://hdl.handle.net/10353/d1011255 , Food security , Population growth , Soil degration , Climate change , Global warming , Conservation agriculture , Organic materials
- Description: Sub-Saharan Africa faces a major food security challenge as a result of projected fast increases in population growth and continuing declining per capita food availability. This calls for accelerated increases in productivity to meet expected increases in food demand. However, the soils from which the extra production is to come from are highly degraded, especially in South Africa where a large proportion of the land is ranked as having high degradation potential. This is compounded by the increasing climate change challenge which will render more land unfavourable for production. The climate change is mainly caused by global warming believed to be a result of increasing greenhouse gas emissions. The link between soil carbon, food security, and climate change will be explained in this paper. It will be shown that the high degradation status of South African soils is related to their low organic carbon contents. Efforts to restore their productivity must include strategies to minimize further loss of organic matter and encouraging carbon sequestration. Some interventions investigated with the help of my students and collaborators are presented. They include use of farmer available organic materials that can be applied to soils to improve soil carbon sequestration and fertility status; use of cyanobacteria to improve soil carbon sequestration and soil biogeochemical performance; and the adoption of conservation agriculture.
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