Optimal power system VAr planning

A technique is presented for planning the future reactive power requirements of a power system. The problem is formulated as a mathematical optimization problem based on a linearized power system model. An efficient dual simplex linear programming technique coupled with relaxation and contingency analysis is used for solution. The approach reduces the dimensionality of the problem significantly, thereby allowing for more rapid calculations and more case studies to be performed. The effectiveness of the scheme is demonstrated using the IEEE 30-bus and IEEE 188-bus system

Optimal power system VAr planning

A technique is presented for planning the future reactive power requirements of a power system. The problem is formulated as a mathematical optimization problem based on a linearized power system model. An efficient dual simplex linear programming technique coupled with relaxation and contingency analysis is used for solution. The approach reduces the dimensionality of the problem significantly, thereby allowing for more rapid calculations and more case studies to be performed. The effectiveness of the scheme is demonstrated using the IEEE 30-bus and IEEE 188-bus system

Adaptive virtual MIMO single cluster optimization in a small cell

Adaptive Virtual MIMO optimized in a single cluster of small cells is shown in this paper to achieve near Shannon channel capacity when operating with partial or no Channel State Information. Although, access links have enormously increased in the recent years, the operational system complexity remains linear regardless of the number of access nodes in the system proposed. Adaptive Virtual MIMO optimized in a single cluster performs a theoretical information spectral efficiency, almost equal to that of the upper bounds of a typical mesh network, up to 43 bits/s/Hz at a SNR of 30dB while the BER performance remains impressively low hitting the 10−6 at an SNR of about 13 dB when the theoretical upper bound of an ideal small cell mesh network achieves the 10−6 at a SNR of 12.5 dB. In addition, in a sub-optimum channel condition, the channel capacity and BER performance of the proposed solution is shown to drastically delay saturation even for the very high SNR

Instructional Strategies for Effective Teaching and Learning of Creative Arts: The Dilemma of Generalist Teachers in Ghana

Creative Art was introduced into Ghana s primary school curriculum in 2007 Comprising Performing Literary and Visual Arts Creative Art was intended to foster creativity development among primary pupils However Creative Art is taught by generalist classroom teachers who lack the specialized training knowledge skill and experience to identify efficient teaching-learning strategies that allow pupils to actively participate in art making experiences This study adopted action research to guide 20 Lower Primary teachers in two schools to design and teach activity-based lessons in drawing colourwork weaving printmaking composition and assemblage to 95 pupils using clay crayons drums cardboard glue among other resources The intervention workshops proved that in-service education and training could build the professional capacity of generalist teachers in Ghana to effectively implement the Creative Arts curriculum for primary schools Ghana Education Service should train primary teachers if the objective of developing creative thinkers through Creative Arts could be achieve

Challenges towards renewable energy: an exploratory study from the Arabian Gulf region

Considering the importance of energy for social and economic development, access to clean, affordable and reliable energy has been adopted as one of the United Nations sustainable development goals that all countries aim to achieve by 2030. However, much of the world's energy is still produced from fossil fuels and thus the progress towards clean and renewable energy is slow. This paper explores the key challenges towards renewable energy in Gulf Cooperation Council countries blessed with plenty of oil and gas reserves. The key challenges identified through literature review were ranked using a quantitative approach through the data collected from a selective sample across the six countries. These challenges in order of importance were found to be policies and regulations, manpower experience and competencies, renewable energy education, public awareness, costs and incentives for renewable energy and government commitment. The findings could be helpful to decision makers and government organisations in the region to develop strategies to overcome these identified challenges

Exploring safety climate factors in construction

This paper aims to explore and to make explicit of the existing safety climate assessment tools and dimensions. The concept of safety climate is firstly discussed with a review of different safety climate factors from the published literature. A qualitative research method was employed to explore the safety climate factors through a systematic review using four databases and specific keywords. A total of 68 papers were selected for the screening process. The screening process allowed to select the final 18 safety climate assessment tools and papers consisting of 98 safety climate factors spanning over a period of 39 years (1980-2019). Construction organisations may consider these factors to assess the current maturity level of their safety climate and to develop plans to achieve the required level. It is recommended that the factors discussed in this paper may be validated first before they are incorporated in the assessment of safety climate

An integrated connectivity risk ranking for phosphorus and nitrogen along agricultural open ditches to inform targeted and specific mitigation management

Introduction: On dairy farms with poorly drained soils and high rainfall, open ditches receive nutrients from different sources along different pathways which are delivered to surface water. Recently, open ditches were ranked in terms of their hydrologic connectivity risk for phosphorus (P) along the open ditch network. However, the connectivity risk for nitrogen (N) was not considered in that analysis, and there remains a knowledge gap. In addition, the P connectivity classification system assumes all source–pathway interactions within open ditches are active, but this may not be the case for N. The objective of the current study, conducted across seven dairy farms, was to create an integrated connectivity risk ranking for P and N simultaneously to better inform where and which potential mitigation management strategies could be considered.Methods: First, a conceptual figure of known N open ditch source–pathway connections, developed using both the literature and observations in the field, was used to identify water grab sampling locations on the farms. During fieldwork, all open ditch networks were digitally mapped, divided into ditch sections, and classified in terms of the existing P connectivity classification system.Results and Discussion: The results showed that not all source–pathway connections were present across ditch categories for all species of N. This information was used to develop an improved open ditch connectivity classification system. Farmyard-connected ditches were the riskiest for potential point source losses, and outlet ditches had the highest connectivity risk among the other ditch categories associated with diffuse sources. Tailored mitigation options for P and N speciation were identified for these locations to intercept nutrients before reaching receiving waters. In ditches associated with diffuse sources, nitrate was introduced by subsurface sources (i.e., in-field drains and groundwater interactions from springs, seepage, and upwelling) and ammonium was introduced through surface connectivity pathways (i.e., runoff from internal roadways). On similar dairy farms where open ditches are prevalent, the integrated classification system and mapping procedure presented herein will enable a targeted and nutrient-specific mitigation plan to be developed. The same methodology may be applied to develop a bespoke integrated connectivity risk ranking for P and N along agricultural open ditches in other areas

The potential impact of moxidectin on onchocerciasis elimination in Africa: an economic evaluation based on the Phase II clinical trial data

BACKGROUND: Spurred by success in several foci, onchocerciasis control policy in Africa has shifted from morbidity control to elimination of infection. Clinical trials have demonstrated that moxidectin is substantially more efficacious than ivermectin in effecting sustained reductions in skin microfilarial load and, therefore, may accelerate progress towards elimination. We compare the potential cost-effectiveness of annual moxidectin with annual and biannual ivermectin treatment. METHODS: Data from the first clinical study of moxidectin were used to parameterise the onchocerciasis transmission model EPIONCHO to investigate, for different epidemiological and programmatic scenarios in African savannah settings, the number of years and in-country costs necessary to reach the operational thresholds for cessation of treatment, comparing annual and biannual ivermectin with annual moxidectin treatment. RESULTS: Annual moxidectin and biannual ivermectin treatment would achieve similar reductions in programme duration relative to annual ivermectin treatment. Unlike biannual ivermectin treatment, annual moxidectin treatment would not incur a considerable increase in programmatic costs and, therefore, would generate sizeable in-country cost savings (assuming the drug is donated). Furthermore, the impact of moxidectin, unlike ivermectin, was not substantively influenced by the timing of treatment relative to seasonal patterns of transmission. CONCLUSIONS: Moxidectin is a promising new drug for the control and elimination of onchocerciasis. It has high programmatic value particularly when resource limitation prevents a biannual treatment strategy, or optimal timing of treatment relative to peak transmission season is not feasible. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13071-015-0779-4) contains supplementary material, which is available to authorized users

Decentralized Solid Waste Management in Rural Ghana: A Case Study of Assin Kushea Community in Assin North Municipality

Management of solid waste continues to be a major developmental challenge for developing countries like Ghana. The current focus and attention have been on the collection and dumping of waste in urban communities where generation rate is high to the detriment of rural communities. In this study, a pilot waste management scheme was undertaken in Assin Kushea, a rural community in the Assin North Municipality, to determine the willingness of the community to sort their waste at source, the quantity of waste generated by the community, and the characteristics of the waste to inform the treatment or disposal options suitable for the community. The results of the study showed that the community generates approximately 20 to 40 kg waste per day which comprises about 77% biological municipal waste (BMW) and 23% of residual waste. Laboratory analysis of the waste showed that the moisture content of the waste was about 68%. The percentage volatile solid was about 85.45%, leaving an ash content of approximately 14.55% all by weight of the waste materials. More than 50% of the sampled population achieved 100% source separation efficiency. Given the composition and characteristics of the waste, and the willingness of the community to sort their waste at source, composting or anaerobic fermentation of the organic waste fraction is recommended as the best waste treatment option for the organic component of the waste for the community