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In the present study, the prevalence and risk factors of Cryptosporidium infection among children in the Mnisi community of South Africa were investigated. Stool samples of children under the age of five years old were collected from March to June 2012. For the diagnosis of Cryptosporidium spp. samples were analyzed with the modified Ziehl-Neelsen (ZN) technique. In addition, parents were asked to fill in a questionnaire to identify risk factors for cryptosporidiosis. Cryptosporidium spp. were detected in 5.6% (8/143) of the children and three samples were identified by polymerase chain reaction (PCR) as C. hominis (2/3) and C. meleagridis (1/3). No significant risk factors for the infection of Cryptosporidium were found, due to low prevalence, low significance of diagnostic tests used and the unequal distribution of samples for each risk factor. Further studies are needed to investigate risk factors of Cryptosporidium infection in children.

In the present study, the prevalence and risk factors of Cryptosporidium infection among children in the Mnisi community of South Africa were investigated. Stool samples of children under the age of five years old were collected from March to June 2012. For the diagnosis of Cryptosporidium spp. samples were analyzed with the modified Ziehl-Neelsen (ZN) technique. In addition, parents were asked to fill in a questionnaire to identify risk factors for cryptosporidiosis. Cryptosporidium spp. were detected in 5.6% (8/143) of the children and three samples were identified by polymerase chain reaction (PCR) as C. hominis (2/3) and C. meleagridis (1/3). No significant risk factors for the infection of Cryptosporidium were found, due to low prevalence, low significance of diagnostic tests used and the unequal distribution of samples for each risk factor. Further studies are needed to investigate risk factors of Cryptosporidium infection in children.

In this paper, damping power system oscillations with active power and ac voltage modulations of VSC-HVDC is analyzed with the aim of gaining a physical insight into this problem. Enhanced system stability property of the compensated system is shown through detailed analysis. The effects of system parameters and operating conditions on the degree of damping are achievable. It is shown that the feedback signals of frequency deviation are appropriate for both two modulations. The effectiveness is demonstrated through the digital simulation studies using the PSCAD/EMTDC software package, which shows that VSC-HVDC can contribute significantly to damping power system oscillations.

The paper develops two new approaches based on alternative analytical expressions to determine the optimum sizes and power factors of distributed generation (DG) units at various locations for minimizing power losses and a methodology to identify the best location. These approaches can be easily adapted to accommodate different types of renewable DG units (i.e., biomass, wind and photovoltaic) for minimizing energy losses by considering the time-varying demand with all possible operating conditions of DG units. The results obtained on a 69-bus distribution system demonstrate that the proposed methods based on one load level can be adequate to determine the location, size and power factor of DG unit for minimizing energy losses.

A review of the issues for supporting learning of power engineering in Australia is presented in this paper. The learning needs of students and the support available in blended learning and through distance educations are explored in this review. Specific software tools to assist the learning environment are appraised and the relevance for the next generation of power engineers assessed.

Load in distribution networks is normally measured at the 11kV supply points; little or no information is known about the type of customers and their contributions to the load. This paper proposes statistical methods to decompose an unknown distribution feeder load to its customer load sector/subsector profiles. The approach used in this paper should assist electricity suppliers in economic load management, strategic planning and future network reinforcements.

The presence of large number of single-phase distributed energy resources (DERs) can cause severe power quality problems in distribution networks. The DERs can be installed in random locations. This may cause the generation in a particular phase exceeds the load demand in that phase. Therefore the excess power in that phase will be fed back to the transmission network. To avoid this problem, the paper proposes the use of distribution static compensator (DSTATCOM) that needs to be connected at the first bus following a substation. When operated properly, the DSTATCOM can facilitate a set of balanced current flow from the substation, even when excess power is generated by DERs. The proposals are validated through extensive digital computer simulation studies using PSCAD and MATLAB.

Australia is rich in renewable energy resources such as wind, solar and geothermal. Geographical diversity of these renewable resources combined with developing climate change policies poses a great challenge for the long term interconnection planning. Intermittency of wind and solar potentially driving the development of new transmission lines bring additional complexity to power system operations and planning. This paper provides an overview of generation and transmission planning studies in Australia to meet 20% renewable energy target by 2020. Appraisal of the effectiveness of dispersed energy storage, non schedulable peaking plants, wide area controls and demand management techniques to aid the penetration of renewables is presented in this paper

The security of power transfer across a given transmission link is typically a steady state assessment. This paper develops tools to assess machine angle stability as affected by a combination of faults and uncertainty of wind power using probability analysis. The paper elaborates on the development of the theoretical assessment tool and demonstrates its efficacy using single machine infinite bus system.

Current unbalance is a significant power quality problem in distribution networks. This problem increases further with the increased penetration of single-phase photovoltaic cells. In this paper, a new approach is developed for current unbalance reduction in medium voltage distribution networks. The method is based on utilization of three single-phase voltage source converters connected in delta configuration between the phases. Each converter is controlled to function as a varying capacitor. The combination of the load and the compensator will result in a balanced load with unity power factor. The efficacy of the proposed current unbalance reduction concept is verified through dynamic simulations in PSCAD/EMTDC.