Non-linear system Identification and control of Solvent-Based Post-Combustion CO2 Capture Process

Solvent-based post-combustion capture (PCC) is a well-developed technology for CO2 capture from power plants and industry. A reliable model that captures the dynamics of the solvent-based capture process is essential to implement suitable control system design. Typically, first principles models are used, however, they usually require comprehensive knowledge and in-depth understanding of the process. In addition, the high computational time required and high complexity of the first principles models makes it unsuitable for control system design implementation. This thesis is aimed at the development of a reliable dynamic model via system identification technique as well as a suitable process control strategy for the solvent-based post-combustion CO2 capture process. The nonlinear autoregressive with exogenous (NARX) inputs model is employed to represent the relationship between the input variables and output variables as two multiple-input single-output (MISO) sub-systems. The forward regression with orthogonal least squares (FROLS) algorithm is implemented to select an accurate model structure that best describes the dynamics within the process. The prediction performance of the identified NARX models is promising and shows that the models capture the underlying dynamics of the CO2 capture process. The model obtained was adopted for various process control system design of the solvent-based PCC process (conventional PI, MPC, and NMPC). For the conventional PI controller design, multivariable control analysis was carried out to determine a suitable control structure. Control performance evaluation of the control schemes reveals that the NMPC scheme was suitable to control the solvent-based PCC process at flexible operations. Findings obtained from the thesis underlines the advancement in dynamic modelling and control implementation of solvent-based PCC process

Modeling of Orthogonal Frequency Division Multiplexing (OFDM) for Transmission in Broadband Wireless Communications

Orthogonal Frequency Division Multiplexing (OFDM) is a multi carrier modulation technique that provides high bandwidth efficiency because the carriers are orthogonal to each other and multiple carriers share the data among themselves. The main advantage of this transmission technique is its robustness to channel fading in wireless communication environment. This paper investigates the effectiveness of OFDM and assesses its suitability as a modulation technique in wireless communications. Several of the main factors affecting the performance of a typical OFDM system are considered and they include multipath delay spread, channel noise, distortion (clipping), and timing requirements. The core processing block and performance analysis of the system is modeled usingMatlab

Usefulness of Accounting Theory and Practices on Large Business Organizations in Nigeria

The study was about the impact of accounting theory and practice on performance of large scale business in Nigeria. The objective of the study was to examine the effect and usefulness of accounting theory and practice on financial performance of large firms. The research was carried out, using Coscharis Group Limited as the case study. Primary Data was collected through simple random sampling and using self-administered questionnaires for 20 respondents. Secondary Data was gotten from the company's annual reports on return on equity for the period 2014-2016. The primary and secondary data were consolidated for analysis. Multiple Linear Regression was used to analyze the data to test for the relationship between the accounting theory and practice variables (Positive Accounting Theory(PAT), Financial Reporting(FR), Auditing Practice (AP) and Budgeting) and Financial Performance(Return on Equity). Findings revealed that accounting theory and practice have significant relationship with the financial performance of large companies in Nigeria. It further shows that variables of accounting practice have significant effect on financial performance of large firms in Nigeria. It is recommended that quoted and unquoted organizations should ensure there is consistency in the accounting theory and practice adopted in preparation of their records to enhance stability in their financial performance

Dehydration Characteristics of Taro Root (Colocasia Esculenta) Slices using a Refractance WindowTM Dryer

This report presents the dehydration characteristics of Taro (Colocasia esculenta) root slices dried at 65, 75, 85 and 95oC in a fabricated laboratory scale Refractance WindowTM dryer; the Taro root slices were 3.0, 4.5 and 6.0 mm thick. Moisture content and water activity variation data were taken during the drying operation for the process conditions selected. For the process conditions studied, the times required to dehydrate the moisture content to 0.11 g-water/g-solid varied between 55 to 260 minutes. For a given slice thickness, the drying times to reach the 0.11 g-water/g-solid moisture content decreased as the drying temperature increased. Also, for a given drying temperature, the drying times required to reach the 0.11 g-water/g-solid moisture content increased with slice thickness. The effective moisture diffusivity varied from 8.14 x 10-08 to 9.53 x10-07 m2/s for the process conditions studied. While moisture diffusivity data on the Refractance WindowTM dryer, was not found in the literature, the moisture diffusivity values estimated, were within the range observed for other equipment. The moisture diffusivity parameters determined in this study, are important because they are useful in the design, modelling, and optimisation of such dryers

A Coupled Euler-Lagrange CFD Modelling of Droplets-To-Film

In this paper, a droplet to film interaction model technique is presented. In the proposed approach, the liquid and gas continua are modelled using an enhanced Volume of Fluid (VoF) technique while the droplets are tracked using a Lagrangian framework and are coupled to the Eulerian phases using source terms. The eventual target application is an aeroengine bearing chamber in which oil is found as droplets, shed from the bearings, splashing on impact, separated from wall surfaces at obstacles or simply re-entrained, and as a continuum oil film coating the bearing chamber outer walls which it also cools. In finite volume CFD techniques, a prohibitively large number of cells would be required to describe the details of the droplet impact phenomenon. Based on published correlations, the splashing droplets are created and tracked as Lagrangian particles. The flowing film and the gas continua are handled with an enhanced Volume of Fluid technique

Socio-Economics Impacts Of Erin-Ijesha Water Fall, Erin-Ijesha, Osun State, Nigeria

The study examines the socio – economic impact of Erin Ijesha waterfall, Erin Ijesha in Osun State in Nigeria. Another name for the waterfall is Olumirin Waterfall which is situated within the enclave of Erin Garden. Structured questionnaires were used to elicit information from respondents on the impacts of the waterfall within the community and the State in general. Direct benefits derived from the waterfall include: drinking water, irrigation for agricultural land, tourism activities, fishing and it has contributed significantly to the overall well -being of the people of the area. It was discovered that the full potentials of the waterfall are yet to be harnessed due to lack of commitment from stakeholders especially the Government to invest in the development of the waterfall. Developing the waterfall will not only be a source of revenue to the government, it will equally generate substantial employment, thus reducing the burden of unemployment in the State and the Country at large. KEYWORDS: Waterfall, Socio-economic, Impact, Potential, Harnes

An Efficient Seven-Step Block Method for Numerical Solution of SIR and Growth Model

In this article, a new implicit continuous block method is developed using the interpolation and collocation techniques via Power series as the basis function. A constant step length within a seven-step interval of integration was adopted. The selected grid points were evaluated to get a continuous linear multistep method. The evaluation of the continuous method at the non-interpolation points produces the discrete schemes which form the block. The basic properties of the block method were investigated and found to be consistent, zero stable and hence convergent. The new method was tested on real life problems namely: SIR and Growth model. The results were found to compare favourably with the existing methods in terms of accuracy and efficiency.  Keywords: Block method, Growth Model, implicit, power series and SIR model

Political corruption and the Nigerian civil war

Purpose: The purpose of this thesis was to describe instances of political corruption in post-independence Nigeria and to relate such instances and its contribution to the outbreak of civil war in 1966. Method: The method of research was mainly library research. The Sam Houston University was used extensively. Other library facilities utilized include the following: Texas Southern University; University of Houston, and the Houston Public Library. Materials were also obtained from the University of Ife and the University of Lagos, both in Nigeria. Personal experience was also utilized. Findings: The fundamental error in post-independence Nigerian politics was that political parties were based on tribes. Because political officials owe their allegiance to the tribal groups, tribalism became a salient factor in the maintenance of politically corrupt relations. At the time under study, it was found that political corruption in Nigeria had attained anarchical dimension. Political officials were elected into office by actually using force and coercion to obtain votes. Because the Judicial System was incapacitated in performing its constitutional obligation of protecting the rights of the public, the civilians consequently lost faith in the rules of law and Nigeria was thrust into a series of bloody crises which later precipitated the civil war

Knowledge, attitude and willingness to accept Caesarean Section among women in Ogbomoso , southwest Nigeria

Introduction: Caesarean section (CS) is a common procedure in obstetrics and has contributed immensely to improving maternal and foetal outcome; there are still concerns about the knowledge, attitude and willingness to accept the procedure among women especially those in the developing world.Objective: This study seeks to assess the level of knowledge, attitude and acceptance of women about CS in Ogbomoso. These women were more educated than most of their counterparts in South Sudan but because of the political situation we are unlikely to get similar data from South Sudan and therefore this study is of interest.Methodology: This is a descriptive study which was carried out in four health facilities. Respondents were selected using the systematic random technique with a sample interval of 2. A semi-structured questionnaire was used for data collection. Data were analysed using the statistical package for social sciences (SPSS), version 16.Results: Of the 410 respondents, 63.2% of the women have a good knowledge of CS as a method of delivery. When CS was compared to vaginal delivery, 33.5% said that CS was preferable to vaginal delivery because the pain involved was much less; this view was however disagreed upon by 54.8% of the respondents. Only 75.6% of the respondents were ready to accept CS if there was a need for it.Conclusion: Mothers should be educated on the process involved in Caesarean delivery, the indication, advantages and complications in order to help them make the right informed decision.Keywords: Women knowledge, attitude, Caesarean section, Nigeri