A novel approach for the identification of critical nodes and transmission lines for mitigating voltage instability in power networks

Abstract: Voltage collapse is a major issue combating the effectiveness and optimal operation of modern power systems in recent times. This has been a great threat to the security and the reliability of a modern power system and has been a growing concern to power system engineers, researchers and the utilities recently. A prompt identification of the sets of transmission lines whose outage could lead to a cascading failure and the sets of nodes where voltage collapse could erupt is therefore a vital issue for a reliable and secure power system operation. An alternative approach to solving these problems is therefore presented in this paper. The problem is viewed from the graph-theoretical perspective, considering the topological properties of the networks. Application of the fundamental circuit theory is employed and the Bus-to-Line matrix (BLM) is formulated. This matrix provides insights about the interconnections of the components within the network. This valuable information is captured and used for identifying the critical elements where a suitable location for reactive power support could be placed to avoid voltage collapse of the network. The effectiveness of the proposed approach is tested using a simple 10-bus power network. The results obtained are compared with that obtained from the existing approaches. The results obtained show a strong correlation and agreement and proved the efficiency of the proposed approach

Solving optimal generation dispatch problem in power networks through pso and lambda iteration techniques

Efficient solution to the problem of economic dispatch of network generators has been a growing concern to power system utilities in recent times. This is aimed at determining the optimal allocation of the total network demand among the available generating units such that the total cost of generation is reduced while maintaining an acceptable generation output subject to specified system constraints. This paper, therefore, attempts to resolve this issue from two main perspectives; Lambda Iterative-based approach and Particle Swarm Optimization (PSO) technique. The theoretical backgrounds as well as the mathematical formulations for the two approaches are presented. The standard IEEE 14-Bus, IEEE 30-Bus and the Indian 62-Bus networks are used as case studies to present illustrative examples for the approach. The simulation results obtained using the two approaches are presented and compared. The comparisons of the results obtained show that the two approaches are suitable for providing efficient solutions to economic dispatch problems in large power networks.Keywords: economic dispatch; network demands; lamda iterative; particle swarm optimization;generation cos

Evaluation of the Implementation of Primary Prevention Guidelines for the Treatment of Hypertension

AbstractHypertension is a chronic disease that is associated with increased risk of cardiovascular mortality. This Doctor of Nursing Practice project was a quality improvement initiative that addressed the gap in practice that the nurse practitioners (NPs) were not consistently following the American College of Cardiology (ACC) and American Heart Association (AHA) recommended guidelines for the treatment of hypertension. The purpose of the project was to evaluate whether the NPs were consistently using the guidelines to treat patients with hypertension after an educational intervention. The project used a before-after approach to evaluate the consistency of using the guidelines in treatment of hypertension. The “Plan Do Act Study” (PDSA) model was used as the framework for the project. Evidence was obtained from the databases CINAHL, CINAHL plus, EBSCOhost, Medline, Google Scholar, and PubMed. Three months of retrospective and prospective data were analyzed. All the data reviewed had the diagnosis code of I1.0. The data reviewed 3 months prior to NPs’ education revealed high blood pressure (BP) readings and poor documentation of patient education by NPs, while the prospective data reviewed revealed lower BP readings and increased documentation of patient education. Thus, the findings showed an improvement in hypertension management with the use of the ACC/AHA guidelines by the NPs. Consistent use of the ACC/AHA guidelines by the NPs is recommended, which will increase patient knowledge and compliance. The project contributed to positive social change by adopting the ACC/AHA guidelines to reduce morbidity and mortality in cardiovascular disease in the patients seen in the clinic

Assessment of the Hydropower Potential of Kangimi Reservoir in Kaduna State Nigeria

This study evaluated the hydropower potentials of the Kangimi reservoir (KR) and found that the Kangimi reservoir can potentially generate 1.109MW and 0.692 MW if the KR dam axis is respectively placed at 612m and 604m above mean sea level. These levels represent the upper and the lower limits at which the proposed hydropower scheme can suciently release water from Kangimi reservoir to conjunctively meet the water demands for the newly proposed hydropower and designed water supply and irrigation purposes. This hydro electric power potential of the reservoir can suciently meet the 872.566 KW total estimated energy needs of the communities surrounding the KR. The study further assessed and highlighted all the possible impacts, implications and requirements for developing this proposed Kangimi small hydro power scheme to improve the socio-economic development of the neighboring communities around KR.Keywords: hydropower potentials, Kangimi reservoir, small hydropower plant, rural development, energy need

Tailwater recycling for hydro-power generation, Niger River

In this paper an alternative source of water for the effective running of the Kainji and Jebba hydro-power stations were found in recycling the Jebba tailwater to the headwaters of the Malendo river systems. The result shows that a recycle of 60% of the flow at Lokoja back to Kainji reservoir will guarantee adequate supply of the daily water requirements for the generation of the full installed capacities of 760MW and 540MW of electricity at Kainj and Jebba

Comparison of nutritional values of brown and white beans in Jos North Local Government markets

Cowpea is an important bean which play significant role in the diets of Africans. It serves as a major source of protein in the absence of sufficient animal protein for the population. Two varieties (white and brown) of  cowpeas (Vigna unguiculata) were analyzed for their proximate and elemental contents. These varieties belong to the same species in the family leguminosae. The brown and white seeds were found to be nutritious. Both contained carbohydrate, protein, fibers and minerals such as calcium, magnesium, potassium, sodium, iron, zinc, manganese and copper. The crude protein was found to be 15.62 and 17.91% with the brown seeds having the higher amount. The carbohydrate content analyzed was found to be 56.80 and 60.57% with the  white seeds having the higher value. The crude lipid gave the least range which is 2.13 to 2.42%. The other parameters, moisture content, crude fiber and total ash contents were 3.56 to 5.08, 13.54 to 14.15 and 4.07 to 4.27%, respectively. Potassium and copper had the highest and lowest concentration in cowpea varieties ranging from 741 to 768 and 0.58 to 0.60 mg/100 g, respectively. There were significant (p<0.05) differences between the potassium, calcium, sodium, magnesium, manganese and zinc concentration of the cowpea varieties, except between iron and copper concentration.Key words: Vigna unguiculata, cowpeas, nutrition, minerals, vitamins

To be seen, heard, and valued. Active engagement as the next frontier for global health conference equity: a view from the global South

Dear Editor, “It is the one who lives in the house who knows where the roof leaks” ~African Proverb. As a Global Surgery researcher in Rwanda, I have lived experience of the challenges to conference equity, having spent for example in one instance, 14 hours at an Embassy’s visa processing station to get to the World Health Assembly, and losing two opportunities to present at international Global Health meetings as a result of visa delays in the past one year. [...

Evaluation of the Implementation of Primary Prevention Guidelines for the Treatment of Hypertension

AbstractHypertension is a chronic disease that is associated with increased risk of cardiovascular mortality. This Doctor of Nursing Practice project was a quality improvement initiative that addressed the gap in practice that the nurse practitioners (NPs) were not consistently following the American College of Cardiology (ACC) and American Heart Association (AHA) recommended guidelines for the treatment of hypertension. The purpose of the project was to evaluate whether the NPs were consistently using the guidelines to treat patients with hypertension after an educational intervention. The project used a before-after approach to evaluate the consistency of using the guidelines in treatment of hypertension. The “Plan Do Act Study” (PDSA) model was used as the framework for the project. Evidence was obtained from the databases CINAHL, CINAHL plus, EBSCOhost, Medline, Google Scholar, and PubMed. Three months of retrospective and prospective data were analyzed. All the data reviewed had the diagnosis code of I1.0. The data reviewed 3 months prior to NPs’ education revealed high blood pressure (BP) readings and poor documentation of patient education by NPs, while the prospective data reviewed revealed lower BP readings and increased documentation of patient education. Thus, the findings showed an improvement in hypertension management with the use of the ACC/AHA guidelines by the NPs. Consistent use of the ACC/AHA guidelines by the NPs is recommended, which will increase patient knowledge and compliance. The project contributed to positive social change by adopting the ACC/AHA guidelines to reduce morbidity and mortality in cardiovascular disease in the patients seen in the clinic

Performance and Economic Analysis of Kainji Hydropower Plant in Nigeria

In this study, performance and economic evaluation of Kainji Hydropower Station in Nigeria from 2008 to 2017 was carried out. Data including total energy generated (MWh), station service consumption (MWh), total energy sent out to the grid (MWh), average inflow rate (m3/s) and average gross operating head (m) were obtained from the efficiency department of the Hydropower station from the year 2008 to 2017. Mathematical models were used based on some key parameters which include: Capacity Factor, Plant Use Factor, Availability, Power Generated and Economic Cost of Outages and Operations. The result reveals that the average power generated within the period under review was 363.53MW, with a maximum of 476.95MW in 2010 and 292.44MW in 2014 as against the installed capacity of 760MW. The Capacity Factor of the plant was between 11.04% (2014) and 40.51% (2008) as against industry best practice of between 50% to 80%. The Plant Use Factor ranged between 38.48% in 2014 to 62.76% in 2010 as against acceptable value of 95% and above, while the plant availability hovers between 28.69% in 2015 and 91.26% in 2009 as against the recommended standard of 99.99%. The study further reveals that the revenue loss due to system downtime was ₦169,134,293,297. This revenue loss is about 66.82% of the revenue generated which is by no means a huge amount. The above values call for the need of a total overhaul of the generating plant in order to salvage the terrible state of these plants

Critical success factors for effective internal construction stakeholder management in Nigeria

In developing countries such as Nigeria, Stakeholder Management (SM) practice is weak. The weakness of this practice often inhibits project goals in terms of time and cost overruns, disputes and lack of trust among the stakeholders. This article reports the results of a study on critical factors for successful SM in construction projects in Nigeria, in order to suggest ways to enhance project performance. The study employed a quantitative survey research design, using self-administered questionnaires distributed to construction practitioners (quantity surveyors, architects, engineers, builders and project managers) on construction sites in two selected geo-political zones of Nigeria. The collected data was analysed, using descriptive and inferential statistics. The results indicated that seven critical factors are important to successful SM in the research environment. These include engagement of competent project leaders and team members, effective communication, promoting good relationships, formulating a clear project mission statement, management support, and a good SM strategy which are instructive to improve SM. The study recommends the prioritisation of competency in the selection of project teams, effective relationship management and improved information dissemination during construction as the precursors of successful SM and project performance. Stakeholders must be adequately identified and analysed to ensure that they are competent for the contract and appropriate for the job. Construction practitioners, especially project leaders, could use identified critical success factors (CSFs) as a road map in the development of appropriate solutions for successfully managing stakeholders associated in the Nigerian construction industry.&nbsp