14 research outputs found

    Gas flaring reduction in nigeria in context of carbon dioxide (CO₂) reduction and utilisation requirements.

    Get PDF
    The growing demand for energy due to a rise in global population and an improved standard of living has resulted in the production, refining and consumption of hydrocarbon fuel. A consequence of this has been an increase in the global rate of natural gas flaring. While natural gas flaring is accepted as a waste of energy and natural resources, as well as a contravention of Nigeria’s current energy policy for sustainable development through natural gas conservation, natural gas flaring is still considered the most cost efficient and effective Associated Natural Gas (ANG) flaring management option in developing countries such as Nigeria. The need to further consolidate routine gas flaring reduction or management techniques has never been greater with the 2030 zero routine flaring initiative by the World Bank fast approaching. While there are several studies on natural gas utilisation techniques, they rarely consider the shortage of practical tools that integrate economic, technical, and regulatory factors into a gas flaring management framework; and also, the intricacies of the existing tools, which often comes at the expense of simplicity, to obtain real-time information output. Thus, the aim of this study was to develop a systematic framework and ANG management tool to aid the reduction of routine natural gas flaring in Nigeria. This research developed a systematic management framework (using a flowchart decision tree technique) and models to further develop a simple, relatively quick, flexible, and user-friendly ANG flaring management tool (using a MATLAB graphical user interface). This was integrated with techno-economic models for the Liquefied Natural Gas, Gas to Methanol and Gas to Wire ANG utilisation options using the ASPEN HYSYS computer software. The tool was then tested with data obtained from three fields A, B and C in the Niger Delta region of Nigeria. Field A is an offshore field in Bayelsa State in the South-West Niger Delta. Field B is an offshore field in Rivers State in the South-South Niger Delta while Field C is an onshore field in Delta State in the South-West Niger Delta. Results obtained showed the choice of Gas to Methanol option as the most optimal for Field A due to its preference for large gas volumes and cost effectiveness, Liquefied Natural Gas for Field B because of its proximity to the Liquefied Natural Gas pipeline infrastructure and Gas to Wire utilisation option for Field C due to its proximity to the electrical grid and high electricity requirements of that area when both economic and technical considerations were taken into account. The addition of further regional profiles within West Africa, as well as the consideration of more ANG utilisation options were among suggested areas for further research.Simms, Nigel J. (Associate)PhD in Energy and Powe

    Middleware architectures for the smart grid: A survey on the state-of-the-art, taxonomy and main open issues

    Get PDF
    The integration of small-scale renewable energy sources in the smart grid depends on several challenges that must be overcome. One of them is the presence of devices with very different characteristics present in the grid or how they can interact among them in terms of interoperability and data sharing. While this issue is usually solved by implementing a middleware layer among the available pieces of equipment in order to hide any hardware heterogeneity and offer the application layer a collection of homogenous resources to access lower levels, the variety and differences among them make the definition of what is needed in each particular case challenging. This paper offers a description of the most prominent middleware architectures for the smart grid and assesses the functionalities they have, considering the performance and features expected from them in the context of this application domain

    Energy-efficient wireless communication schemes and real-time middleware for machine-to-machine networks

    Get PDF
    Esta tesis estudia sistemas Machine-to-Machine (M2M) en los que se ejecutan tareas de manera autónoma sin, o con mínima intervención humana. Los sistemas M2M están formados por dispositivos desplegados en un entorno que recolectan información relacionada con una tarea y la envían a aplicaciones para su proceso. Las aplicaciones optimizan estas tareas y responden a los dispositivos con comandos de control. Idealmente, después de configurar las políticas de tareas, los humanos son excluidos del lazo de control. Un importante caso de uso en M2M es la automatización de la red eléctrica, también conocido como Smart Grid, que se trata en esta tesis. Muchos escenarios M2M requieren dispositivos de bajo bitrate, bajo coste y que puedan ser fácilmente desplegables y mantenidos. Una solución adecuada son los dispositivos inalámbricos, alimentados por batería y de capacidades limitadas (con reducida potencia de procesado y memoria). Un bajo mantenimiento requiere años de vida, que sólo pueden conseguirse con protocolos de comunicación altamente eficientes energéticamente. En esta tesis nos centramos principalmente en las capas MAC y de enlace (especialmente en esquemas Cooperative Automatic Repeat Request) para mejorar la eficiencia energética de los dispositivos. Proponemos y evaluamos extensiones de Cooperative MAC para varios estándares como IEEE 802.11, IEEE 802.15.4 y sus revisiones MAC. El transmisor radio de los dispositivos puede ponerse en estado de reposo cuando está inactivo, llevando a cortos periodos de activación (duty-cycle) en dispositivos de bajo bitrate, consiguiendo así un ahorro energético considerable. Dado que la capa MAC controla los estados de reposo de los transmisores radio, los esquemas de Duty-Cycle MAC son el pilar de las comunicaciones energéticamente eficientes. Por ello, en esta tesis diseñamos, analizamos y evaluamos esquemas Cooperative and Duty-Cycled ARQ (CDC-ARQ). CDC-ARQ se basa en la (re)transmisión dinámica de paquetes (dynamic packet forwarding) dependiendo del estado del canal inalámbrico. Cuantificamos las ganancias considerando enlaces inalámbricos de baja potencia con modelos realistas, que sufren efectos de apantallamiento (shadowing) desvanecimientos (fading) de canal, y presentamos las condiciones bajo las cuales CDC-ARQ consiguen mejores resultados que las técnicas estándar de forwarding. Finalmente, determinamos estrategias óptimas de selección de enlace y retransmisión para direct, multi-hop y CDC-ARQ forwarding. Los esquemas de comunicación inalámbricos energéticamente eficientes son adecuados, por ejemplo, para automatización de edificios y hogar, contribuyendo a un buen uso de la energía eléctrica en dichos escenarios. Después de considerar el entorno de dispositivos, la tesis se centra en las aplicaciones, al otro lado de los sistemas M2M. Las aplicaciones típicamente intercambian datos sobre amplias zonas con varios dispositivos remotos. Las técnicas de computación distribuida, estandarizadas e implementadas en plataformas middleware para sistemas M2M, facilitan este intercambio de datos. Los requisitos de comunicación de estas aplicaciones son diversos en términos de latencia, número de actualizaciones, número de dispositivos asociados, etc. Mientras que las soluciones middleware existentes tales como ETSI M2M satisfacen los requisitos de ciertas aplicaciones, dichas soluciones son inadecuadas para los requisitos de latencia de transmisión en tiempo real. Esta tesis propone y analiza modificaciones del ETSI M2M que mejoran el rendimiento en tiempo real. El análisis se ejemplifica con tres aplicaciones Smart Grid, una relacionada con la automatización del hogar y edificios, y las otras dos con la monitorización y control del flujo de potencia de la red eléctrica.This thesis studies emerging Machine-to-Machine (M2M) systems that execute automated tasks without, or with minimum human intervention. M2M systems consist of devices deployed in the field to collect task-related information and send it to remote applications for processing. The applications optimise the tasks and issue control commands back to the devices. Ideally, after configuring the task policies, humans are excluded from the control loop. A prominent and urgent M2M use case concentrates on the automation of the electric power grid, also known as Smart Grid, that is considered in the thesis. Many M2M scenarios require devices that are low-rate, low-cost and can be easily deployed and maintained. A fitting solution are wireless, battery-powered and resource-constrained devices (with limited processing power and memory). Low-maintenance requires years of lifetime, that can only be achieved with unprecedented energy efficiency of communication protocols. Specifically, we focus on the MAC and link layers in this thesis (especially on the Cooperative Automatic Repeat Request schemes) to improve the energy efficiency of the devices. Cooperative MAC extensions to the various standard technologies such as IEEE 802.11, IEEE 802.15.4 and its MAC amendments are proposed and evaluated. The radio transceiver of a device can be put to sleep state when inactive, yielding very low duty-cycles for low-rate devices, and thus achieving significant energy savings. Since the MAC layer controls the radio transceiver sleep states, duty-cycled MAC schemes are the cornerstone of the energy-efficient communication schemes. To that end, Cooperative and Duty-Cycled ARQ (CDC-ARQ) scheme has been designed, analysed and evaluated in this thesis. CDC-ARQ is based on dynamic packet forwarding depending on the current state of the wireless channel. The benefits are quantified by considering realistic wireless low-power links that experience shadowing and multipath fading channel effects. The conditions under which CDC-ARQ outperforms the standard forwarding techniques are presented. Finally, optimal link selection and retransmission strategies are determined for direct, multi-hop or CDC-ARQ forwarding. The studied energy-efficient wireless schemes are suitable e.g. for home and building automation which can contribute to the efficient use of the electric power in homes and buildings. After considering the device domain, the focus of this thesis turns to the applications at the other end of the M2M system. The applications typically exchange data over wide areas with many remote devices. Distributed computing techniques facilitate this data exchange, standardised and implemented in the middleware platform for M2M systems. The communication requirements of these applications are diverse in terms of data latency, update rate, number of associated devices etc. While the existing middleware solutions such as ETSI M2M fully support communication requirements of some applications, the solution is inadequate when it comes to the real-time latency constraint. Some suitable upgrades that improve the real-time performance of data exchange in ETSI M2M middleware are analysed in the thesis. The analysis is exemplified with three Smart Grid applications, one related to the home and building automation and the other two concerned with monitoring and control of the power flow in the electric grid

    Medical application of the Internet of Things (IoT): prototyping a telemonitoring system

    Get PDF
    The Internet of Things (IoT) is a technological paradigm that can be perceived as an evolution of the internet. It is a shift from the traditional way of connecting devices to the internet, both in number and diversity of connected devices. This significant and marked growth in the number and diversity of devices connected to the internet has prompted a rethink of approaches to interconnect devices. The growth in the number of connected devices is driven by emerging applications and business models and supported by falling device costs while the growth in the diversity is driven by the reduction in the cost of manufacturing these devices. This has led to an increase in the number of users (not limited to people) of the internet. According to statistics by the ITU, by the end of 2015, about 3.2 billion people were using the Internet. Significantly, 34% of households in developing countries had Internet access, with more than 80% of households in developed countries. This indicates that it is realistic to leverage the IoT in living spaces. Appreciating this potential, many sectors of society are already positioning themselves to reap the benefits of this great promise. Hence the health sector would do well to adopt this technological paradigm to enhance service delivery. One specific area where the health sector can benefit from the adoption of the IoT is in telemonitoring and the associated early response to medical emergencies. Statistics and research show that there are areas in the medical field, that still need improvement to enhance service delivery. The Nursing Times has summed up these areas into four categories. The first one is a need to have a regular observation of patients and their vital signs. Here, health service providers (SPs) need to adopt creative and non-obtrusive methods that will encourage patients' participation in the monitoring of these vital signs. As much as possible, vital signs readings should be taken at convenient locations and times. Therefore, devices that have consistent internet access and are usually a part of daily life for most patients, such as the mobile phones would prove to be a key enabler of regular observation of vital signs. Furthermore, miniaturization of the vital signs monitoring or sensing devices would be a key step towards realizing this scenario. A lot of work is already being done to miniaturize these devices and make them as much a part of daily life as possible, as evidenced by advancements in the field of fitness and wearables. To map this use to the medical field, a system needs to be created that would allow for the aggregation of these disparate measuring and monitoring devices with medical information management systems. The second potential area of improvement is in the early recognition of deterioration of the patients. With regular observation of patients, it is possible to recognize deterioration at its early stage. Taking cognizance of the different needs of the various stakeholders is important to achieve the intended results. The third potential area of improvement is in the communication among stakeholders. This has to do with identifying the relevant data that must be delivered to the stakeholders during the monitoring and management process. Lastly, effective response to medical concerns is the other potential area of improvement. It is noted that patients do not generally get the right response at the right time because the information does not reach the rightly qualified personnel in good time. The regular and real-time capture of vital signs data coupled with added analytics can enable IoT SPs to design solutions that automate the management and transmission of medical data in a timely manner. This work addresses how the medical sector can adopt IoT-based solutions to improve service delivery, while utilizing existing resources such as smartphones, for the transmission and management of vital signs data, availing it to stakeholders and improve communication among them. It develops a telemonitoring system based on IoT design approaches. The developed system captures readings of vital signs from monitoring devices, processes and manages this data to serve the needs of the various stakeholders. Additionally, intelligence was added to enable the system to interpret the data and make decisions that will help medical practitioners and other stakeholders (patients, caregivers, etc.) to more timely, consistently and reliably provide and receive medical services/assistance. Two end user applications were developed. A cloud-based web application developed using PHP, HTML, and JavaScript and an Android mobile application developed using Java programming language in Android studio. An ETSI standards-compliant M2M middleware is used to aggregate the system using M2M applications developed in Python. This is to leverage the benefits of the standards-compliant middleware while offering flexibility in the design of applications. The developed system was evaluated to assess whether it meets the requirements and expectations of the various stakeholders. Finally, the performance of the proposed telemonitoring system was studied by analyzing the delay on the delivery of messages (local notifications, SMS, and email) to various stakeholders to assess the contribution towards reducing the overall time of the cardiac arrest chain of survival. The results obtained showed a marked improvement (over 28 seconds) on previous work. In addition to improved performance in monitoring and management of vital signs, telemonitoring systems have a potential of decongesting health institutions and saving time for all the stakeholders while bridging most of the gaps discussed above. The captured data can also provide the health researchers and physicians with most of the prerequisite data to effectively execute predictive health thereby improving service delivery in the health sector

    Harnessing XMPP for Machine-to-Machine Communications & Pervasive Applications

    Get PDF
    An ever increasing number of interconnected embedded devices, or Machine-to-Machine (M2M) systems, are changing the way we live, work and play. M2M systems as a whole are typically characterized by the diversity in both the type of device and type of network access technology employed, and such systems are often still today task-specific and built for just one specific application. Smart lighting, remote monitoring and control of all kinds of consumer devices and industrial equipment, safety and security monitoring devices and smart health and fitness products, exemplify this revolution of intercommunicating machines. However, the differences in communication technologies and data formats among such devices and systems are leading to a huge complexity explosion problem and a strongly fragmented market, with no true interoperability. Due to these problems, the full potential of M2M technology has yet to be fulfilled. In this paper, we examine the suitability of the Extensible Messaging and Presence Protocol (XMPP) and experiment with its potential to rise to the challenge of machine-to-machine communications and meet the needs of modern pervasive applications. Experimental implementations and some proof-of-concept solutions are also presented

    Organizational Characteristics, Knowledge Management Strategy, Enablers and Process Capability: Knowledge Management Performance in U.S. Software Companies

    Get PDF
    Currently, the effect of knowledge management has not been clearly defined or understood and a proper framework for assessing the status of knowledge management is lacking. Most studies examined the relationships among critical factors of knowledge management separately and the empirical research is based on only a few cases or small samples where generalizing the results is significantly reduced. The development of a universal model is necessary as a means to measure relevant constructs. This correlational (explanatory) online survey research is the first to explore the relationships among organizational characteristics, knowledge management strategy, knowledge management enablers, knowledge management process capabilities, and knowledge management performance. Two research questions and 14 hypotheses and related sub-hypotheses were examined. The survey consisted of an 8-item Knowledge Management Strategy Scale, a 26-item modified Knowledge Management Enablers Scale, a 27-item Knowledge Management Process Capability Scale, and a 5-item Knowledge Management Scale. Using a simple random sampling plan, 212 participants from U.S software companies completed an online survey. Multiple regression, moderated multiple regression, and two way ANOVA were used to analyze the data. Of the 14 hypotheses and sub-hypotheses, ten were supported, one was partially supported, and three were not supported. Findings indicated that (a) system orientation and human orientation strategies are significant positive explanatory variables of knowledge management process capability, knowledge management enablers, and knowledge management performance; (b) technology and organizational culture of knowledge management enablers are significant positive explanatory variables of knowledge management process capability and knowledge management performance; (c) the decentralization dimension may inversely affect knowledge management process capability and knowledge management performance; (d) annual sales in dollars was a significant positive explanatory variable of knowledge management strategy and knowledge management process capability; (e) knowledge management process capability is a mediator between knowledge management strategy and organizational characteristics, and knowledge management performance; and (f) companies with a balance of a high degree of human orientation and system orientation strategies have a positive significant relationship with knowledge management performance. The limitations of the study regarding generalization, and recommendations for future research to replicate the study in other countries, are also included

    Bibliography of Lewis Research Center technical publications announced in 1984

    Get PDF
    This compilation of abstracts describes and indexes the technical reporting that resulted from the scientific and engineering work performed and managed by the Lewis Research Center in 1984. All the publications were announced in the 1984 issues of STAR (Scientific and Technical Aerospace Reports) and/or IAA (International Aerospace Abstracts). Included are research reports, journal articles, conference presentations, patents and patent applications, and theses

    Stem Cell Therapy for Spinal Cord Injuries

    Get PDF
    Stem cell-based therapies are an emerging branch of medicine with the purpose of restoring tissue function for patients with serious injuries, such as a spinal cord injury. As a result, scientists and engineers are increasing research efforts in the field of regenerative medicine. Due to the delicate nature of stem cells, producing the large quantity required for a successful therapy has proved challenging. In recent years, research has shown the potential of stem cell-based therapies, and thus there is a need for the commercialization of these treatments. The proposed facility targets the demand for spinal cord injury treatments and can support production for both clinical trials and a commercial release. Bioreactors designed specifically for the culture and growth of stem cells have flexibility in their ability to support different stem cell lines for various therapies. Small reactors in parallel can easily adapt to changes in production size. This process also takes advantage of the best options currently available for purification and preservation to maximize the product yield. Due to the strict regulations set in place by the FDA and lack of adequate funding, there is an untapped market for stem cell therapies for spinal cord injuries. Approximately 250,000 people in the United States suffer from spinal cord injuries, varying in severity, and this patient base increases at a rate of 12,000 new injuries every year (“Spinal Cord Injury Facts and Figures”, 2009). Future markets include expansion into Europe and Asia. There are two steps to this proposal: the upstream process and the downstream process. The upstream process includes the scale-up, differentiation, and purification of human embryonic stem cells; the downstream process consists of the scale-up of neurons for injection. The upstream process will be built initially and yield enough cells for clinical trials, without incurring the capital costs of building the entire plant. Upon success of the clinical trials, the downstream process will be built for maximum production. The profitability of this proposal is based on running 26 batches a year at 1.02x1010 cells per batch or 2.66x1011 cells per year. By targeting 5,000 patients, two percent of the current market, and charging 45,000perdose,aprofitableprofilecanbecreated.Assuming5045,000 per dose, a profitable profile can be created. Assuming 50% production capacity the first year and a ten-year plant life, the ROI, NPV, and IRR of the proposal are 226.09%, 961,892,600, and 242.81% respectively. Using a 50% production capacity allows for higher profit margins upon expansion. The proposed plan will meet the need of this growing market
    corecore