Dust accumulation on photovoltaic (PV) panels degrades PV panels' performance; leading to decreas... more Dust accumulation on photovoltaic (PV) panels degrades PV panels' performance; leading to decreased power output and consequently high cost per generated kilowatt. Research addressing the severity of dust accumulation on PV panels has been ongoing since the 1940s, but proposed solutions have tended to increase the cost of PV systems either from oversizing or from cleaning the system. The objective of this work, therefore, is to design and implement a low-cost affordable automated PV panel dust cleaning system for use in rural communities of Sub-Saharan Africa (SSA); where financial resources are limited and significantly strained in meeting livelihood activities. Complete design and implementation details of a prototype system are provided for easy replication and capitalization on PV systems for sustainable energy needs. The system detects dust based on the innovative use of light-dependent resistors. Testing and observation of the system in operational mode reveal satisfactory performance; measured parameters quantify a power output increase of 33.76% as a result of cleaning dust off the PV panel used in the study.
Today, many industrial and domestic electronic appliances and equipment (devices) are exposed to ... more Today, many industrial and domestic electronic appliances and equipment (devices) are exposed to power disturbances such as voltage variations of the AC mains supply which often lead to damage of the electronic devices. As these devices are quite sensitive to power disturbances, there is a need for a tripping system that can help avoid any damage to devices in use. The objective of this work is to build a system that monitors line voltage and protects appliances from unacceptable voltage variations. The system consists of a tripping mechanism that monitors the input voltage and trips according to the limits provided. An Arduino Uno microcontroller is used to determine the voltage level through a voltage divider circuit. The system's novelty and innovation lie in its flexibility. It offers the user the ability to define different overvoltage and undervoltage threshold values depending on the specific appliances used in the household. In operation, the system displays the voltage state (overvoltage, normal voltage, overvoltage) and alerts the user by sending an SMS via a GSM modem. The system is valuable for industrial and domestic applications, especially in developing economies such as those of Sub-Saharan Africa, where overvoltage and undervoltage are acute problems.
Many industrial installations in developing countries start-up as small factories, without regard... more Many industrial installations in developing countries start-up as small factories, without regard for the need of compensation of reactive power, leading to significant financial losses in the long term. By improving the power factor, the customer can reduce its power demand and potentially increase efficiency of their equipment. A PIC microcontroller is used to switch capacitor banks to compensate for the reactive power. In order to determine the size of the capacitor bank needed, the microcontroller calculates the phase difference between the voltage and the current. The results obtained based on the lagging power factor for three test loads show an improvement in the power factor from 0.52 to 0.96 under different test load conditions.
An electricity market is a trading platform provided by the actors in the electricity sector to s... more An electricity market is a trading platform provided by the actors in the electricity sector to sell and buy electricity while maintaining the stability of the transmission network and minimizing energy losses. The management of electrical energy for rational use consists of all the operations that the consumers can carry out in order to minimize their electricity bill, while the producers optimize their benefits and the transmission infrastructure. The reduction of active and reactive power consumption and the smoothing of daily and yearly load profiles are the main objectives in this work. Many developed countries already have properly functioning electricity markets, but developing countries are still in their infancy of deregulated electricity markets. The major tools used in smoothing the load profiles include decentralized generation, energy storage and demand response. A load power smoothing control strategy is proposed to smooth the load power fluctuations of the distribution network. The required power change is determined by evaluating the power fluctuation rate of the load, and then the required power change is allocated to some generators or to some stored reserves. Otherwise, the consumers are made to curtail their power consumption. The ideas proposed in this work provide important opportunities for energy policy makers and regulators. These ideas would only be feasible if there exists real-time communication among the actors in the electricity market. The results indicate that as much as 1100 Megawatt-hours of energy can be stored for smoothing the load profile, when applied to the Southern Interconnected Grid of the Cameroon power system; and that Time of Use (TOU) pricing could be used instead of rotating blackouts in case of energy shortage.
Maximum Power Point Tracking Using the Incremental Conductance Algorithm for PV Systems Operating in Rapidly Changing Environmental Conditions
Smart Grid and Renewable Energy
Maximum Power Point Tracking (MPPT) is an important process in Photovoltaic (PV) systems because... more Maximum Power Point Tracking (MPPT) is an important process in Photovoltaic (PV) systems because of the need to extract maximum power from PV panels used in these systems. Without the ability to track and have PV panels operate at its maximum power point (MPP) entails power losses; resulting in high cost since more panels will be required to provide specified energy needs. To achieve high efficiency and low cost, MPPT has therefore become an imperative in PV systems. In this study, an MPP tracker is modeled using the IC algorithm and its behavior under rapidly changing environmental conditions of temperature and irradiation levels is investigated. This algorithm, based on knowledge of the variation of the conductance of PV cells and the operating point with respect to the voltage and current of the panel calculates the slope of the power characteristics to determine the MPP as the peak of the curve. A simple circuit model of the DC-DC boost converter connected to a PV panel is used in the simulation; and the output of the boost converter is fed through a 3-phase inverter to an electricity grid. The model was simulated and tested using MATLAB/Simulink. Simulation results show the effectiveness of the IC algorithm for tracking the MPP in PV systems operating under rapidly changing temperatures and irradiations with a settling time of 2 seconds. Keywords Modeling, Simulation, PV System, Maximum Power Point Tracking (MPPT), Incremental Conductance Algorithm, MATLAB/Simulink
This study presents an intelligent approach for load frequency control (LFC) of small hydropower ... more This study presents an intelligent approach for load frequency control (LFC) of small hydropower plants (SHPs). The approach which is based on fuzzy logic (FL), takes into account the non-linearity of SHPs-something which is not possible using traditional controllers. Most intelligent methods use twoinput fuzzy controllers, but because such controllers are expensive, there is economic interest in the relatively cheaper single-input controllers. A nonlinear control model based on one-input fuzzy logic PI (FLPI) controller was developed and applied to control the non-linear SHP. Using MATLAB/Simulink SimScape, the SHP was simulated with linear and non-linear plant models. The performance of the FLPI controller was investigated and compared with that of the conventional PI/PID controller. Results show that the settling time for the FLPI controller is about 8 times shorter; while the overshoot is about 15 times smaller compared to the conventional PI/PID controller. Therefore, the FLPI controller performs better than the conventional PI/PID controller not only in meeting the LFC control objective but also in ensuring increased dynamic stability of SHPs.
Several challenges are associated with the development, adoption and deployment of biogas digeste... more Several challenges are associated with the development, adoption and deployment of biogas digesters in developing countries. Amongst these challenges is a comprehensive and systematic procedure for the design of digesters suitable for rural communities. This paper proposes the Flexible Biogas Digester System (FBDS) as a viable option for rural communities in developing countries and provides a detailed step-by-step procedure for its design. The biogas production process is a function of the digester operating factors which may be grouped into physical, process and performance parameters. The physical design parameters include the digester volume, the volume of the biogas storage tank, and the volume of the installation pit. The process parameters include total solid content of the slurry (TS), organic loading rate (OLR), digester operating temperatures, pH of the slurry inside the digester. The performance parameters include biogas production rate, biogas productivity and biogas quality. The Net Present Value and the Levelised Cost of Energy are presented for simple economic evaluation of the FBDS.
Health-2000: An Integrated Large-scale Expert System for the Hospital of the Future
Methods of Information in Medicine, 1997
Decision making and management are problems which plague health systems in developing countries, ... more Decision making and management are problems which plague health systems in developing countries, particularly in Sub-Saharan Africa where there is significant waste of resources. The need goes beyond national health management information systems, to tools required in daily micro-management of various components of the health system. This paper describes an integrated expert system, Health-2000, an information-oriented tool for acquiring, processing and disseminating medical knowledge, data and decisions in the hospital of the future. It integrates six essential features of the medical care environment: personnel management, patient management, medical diagnosis, laboratory management, propharmacy, and equipment management. Disease conditions covered are the major tropical diseases. An intelligent tutoring feature completes the package. Emphasis is placed on the graphical user interface to facilitate interactions between the user and the system, which is developed for PCs using Pascal, C, Clipper and Prolog.
Fault Diagnosis in an Expert System for Health Services Management in the Tropics
Methods of Information in Medicine, 1997
An integrated large-scale expert system called Health-2000, for the management of health services... more An integrated large-scale expert system called Health-2000, for the management of health services in regions where tropical diseases are endemic, has been designed. This system combines knowledge and databases, the contents of which are operated upon by an inference engine, to produce usable information. The system allows a host of applications, ranging from medical diagnosis to fault detection and preventive maintenance of biomedical equipment. The theoretical background and approach used in the development of the fault diagnosis and equipment maintenance sub-system of Health-2000 is presented. Model-based knowledge acquisition, and an extension of the Failure Modes, Effects and Criticality Analysis are two methodologies applied to build its knowledge bases. The inference engine which supports backward and forward chaining, operates on numerical and non-numerical facts, and uses fuzzy logic to handle vague and uncertain knowledge. Fault isolation proceeds in a top-down fashion, from equipment sub-system, to modules and components.
Journal of healthcare information management : JHIM, 2008
The Internet is transforming the US economy. Though it continues to lag behind other industries, ... more The Internet is transforming the US economy. Though it continues to lag behind other industries, healthcare has begun to incorporate this technology on a wider scale to reduce costs and more effectively address quality and patient-choice issues. This article presents the background of the US healthcare system, examines the application of e-health, advocates for the integration of e-health components and discusses the roles of major stakeholders in e-health as the basis for the strategic planning, initiation and implementation of integrated e-health systems. Strategic planning provides the opportunity for an insightful view and consideration of the impacts, expectations and responses of e-health stakeholders while implementing integrated e-health solutions for access to more cost-effective and better patient care delivery.
The empowerment and quality health value propositions of e-health
Health Services Management Research, 2010
E-health, as well as its value and benefits, has been characterized as a concept defined in vario... more E-health, as well as its value and benefits, has been characterized as a concept defined in various ways depending on intended audience and use. Attempts to define, characterize and appreciate e-health inadvertently portray it as something out of main stream academia; thus, undermining the relevance and importance of the transformation capabilities of e-health on the practice of health care from the individual and organizational perspectives. In order to contribute towards an understanding and appreciation of e-health as a main stream concept, we propose the use of existing models, theories and principles in support of e-health. Specifically, the empowerment theory and the principles of quality health will be used to discuss the value proposition of e-health. An understanding of the e-health value proposition is important, because it helps organizations to develop a shared vision and context, which in turn keeps organizations focused and realistic as they expend resources and adopt ...
With growing interest in KM-related assessments and calls for rigorous assessment tools, the obje... more With growing interest in KM-related assessments and calls for rigorous assessment tools, the objective of this study was to apply SEM techniques to refine and cross-validate the KMI, a metric to assess the degree to which organizations are engaged in knowledge management (KM). Unlike previous KM metrics research that has focused on scales, we modeled the KMI as a formative latent variable, thereby extending knowledge on formative measures and index creation from other fields into the KM field. The refined KMI metric was tested in a nomological network and found to be robust and stable when cross-validated; thereby demonstrating consistent prediction results across independent data sets. The study also verified the hypothesis that the KMI is positively correlated with organizational performance (OP). Research contributions, managerial implications, limitations of the study, and direction for further research are discussed. DOI: 10.4018/978-1-60566-709-6.ch009
The knowledge management index (KMI) has been proposed as a parsimonious and useful tool to help ... more The knowledge management index (KMI) has been proposed as a parsimonious and useful tool to help organizations gauge their knowledge management (KM) capabilities. This may be the first step in understanding the difference between what an organization is currently doing and what it needs to do in order to maintain and improve its performance level. At the macro level, the index enables organizations to compare themselves with each other. At the micro level, it calls attention to areas needing improvement in current and future KM initiatives. In either case, the KMI provides a robust indicator and basis for business decision-making and organizational support and development. This paper presents a holistic approach to KM that relates key knowledge management processes (KMP) and critical success factors (CSF) needed to successfully implement it. By juxtaposing these processes and success factors, we create Belardo’s matrix that will enable us to characterize an organization and estimate...
Applying the Knowledge Management Index to predict the organizational performance
Management: Journal for Theory and Practice Management, 2007
The knowledge management index (KMI) has been proposed as a cost-conscious and useful tool to hel... more The knowledge management index (KMI) has been proposed as a cost-conscious and useful tool to help organizations gauge their knowledge management capabilities. This may be the first step in understanding the difference between what an organization is currently doing and what it needs to do in order to maintain and improve its performance level. Previous research examined the KMI at its macro level. Although the authors found a positive correlation between the index and performance in the pilot study, they cautioned on the interpretability of the results given the small sample size of 6 organizations in this study. Using a much larger sample of 38 organizations, this study sought to re-validate the claim of a positive correlation between the KMI and performance. We used the same instrument as in the previous study on the KMI and targeted both public and private organizations. KMIs (realized and perceived) were calculated for both sectors. At the macro level, we used the realized KMI ...
Knowledge has been recognized as a key organizational resource. Yet, despite commitment in knowle... more Knowledge has been recognized as a key organizational resource. Yet, despite commitment in knowledge management (KM), many researchers and organizations overlook the need to engage in the alignment of knowledge-related resources with business-related strategies (knowledge strategic alignment). Although many reasons may be advanced for the lack of research and practice on knowledge strategic alignment, two reasons stand out. First, the alignment concept is difficult to understand and measure (Chan, Huff, Barclay & Copeland, 1997), and second, the KM field is relatively new and lacks appropriate frameworks, models, and methodologies for expected research and practice (Earl, 2001). The objectives of this chapter are twofold: The first is an attempt to respond to the call for frameworks, models, and methodologies for research in KM; and the second is an attempt to “simplify” the understanding of the alignment concept within the KM field. To attain both objectives, we first review the KM...
Today, citizens have grown accustomed to highly customized products and services from private sec... more Today, citizens have grown accustomed to highly customized products and services from private sector firms. As a result, they have begun to demand that government agencies become similarly responsive as well. In order to address the ever-increasing expectations of its citizens, governments will need to become more customer-centric. Some government agencies have begun to do this through such IT-enabled initiatives as e-commerce and e-government. This chapter presents a case study of a successful IT project, MACROS, designed to help implement a new vision of business for state agencies within New York State. This new vision requires greater organizational and system transparency, and a culture of collaboration and sharing that is essential to learning how to better serve citizens. The discussion of the methodology employed in the 701 E. Chocolate Avenue,
This paper presents a detailed design of a photovoltaic (PV) system for use in the rural electrif... more This paper presents a detailed design of a photovoltaic (PV) system for use in the rural electrification of remote settlements that are far off from the electricity grid. Since investment in building transmission lines from the grid to these localities is not viable, a good solution is an installation in these areas of standalone photovoltaic systems. The design process comprises the choice and dimensioning of the solar panels, the battery storage, DC-AC inverter, and mini transmission grid to the different homes. The design is for a 15 kW PV system including an economic evaluation and analysis using Hybrid Optimization of Multiple Energy Resources (HOMER) software. Data on the average monthly solar radiation and temperature were obtained from various sources, including, Photovoltaic Geographical Information System (PVGIS) for Africa. From this data the study area receives a monthly average solar insolation of 6.16 kWh/m 2 /day with the worst month being August with 5.22 kWh/m 2 /day. The total daily electrical energy consumption is estimated to be about 72.525 kWh. Simulation results using HOMER software shows that the overall capital cost of the PV system components is $122,337, a replacement cost of $12,889 and an operation and maintenance cost of $29,946 over 10years. A financial analysis of the system showed that the design was both viable and sustainable with low maintenance cost.
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