Techno-economic feasibility study of bioethanol production from a combined cellulose and sugar feedstock in Nigeria: 1-modeling, simulation and cost evaluation

Bioethanol, as a renewable energy, is vital for energy security and pollution control; but its large scale uses need to be studied for different regions. In this study, a bioethanol plant with a processing capacity of 148 million liters/annum was modelled and simulated. This was done with the aid of a process simulator. The study involved process modelling and simulation, material and energy balances, energy efficiency evaluation, and total capital and manufacturing cost estimation. The study shows that the simulated plant will be 63 % energy efficient and that the plant will yield 148 million liters of bioethanol from the processing of 402 metric tonnes of crushed sugarcane with a capital of $51 million and manufacturing cost of$ 89 million per annum. Thus, this suggests that the modelled plant would be able to produce 368 thousand liters of bioethanol from a metric tonne of crushed sugarcane with a capital of 0.34 $/liter and manufacturing cost of 0.61$/liter per annum, based on the conditions adopted for the study.Keywords: Process, Modelling, Simulation, Biofuel, Bioethanol, Cellulose, Suga

Effect of ethyl acetate, time and particle size on the kinetics of the oleoresin extraction process

The kinetics of the extraction of oleoresin from ginger using ethyl acetate as the solvent was studied in this work. The effects of particle size and extraction time on oleoresin’s solvent extraction were analyzed to obtain optimization data. The temperature of the process was kept constant at 40 °C. The Ginger particle sizes ranged between 250–1200 μm at extraction times ranging between 10–70 min. Experimental data generated were fitted into an empirical model to determine the kinetic parameters. The oleoresin yield increases with increasing extraction time up to an optimum time, after which the yield remains constant and decreasing particle size. The results obtained for the kinetics studies reveal that with the introduction of the constant term accounting for the diffusion step separately (as an addition) into a single step first-order model (Patricelli’s first order model) raises from 87 % fitness of the model into becoming 99 % with the experimental data. And this improved form of Patricelli’s first-order model was found to have shown as good agreement with Patricelli’s 2-step kinetic model. These findings further confirm the oleoresin extraction process in the presence of ethyl acetate was found to be first-order kinetics involving two steps mechanism where the use of a single-step first-order model (Patricelli’s first-order kinetic model) and the choice of using ethyl acetate must have contributed to the strong resistance present in the first step of the extraction mechanism especially for the smaller particle size (250 μm). In getting the extraction yield improved, this study, therefore, recommends the use of small particle sizes (< 250 μm), higher temperatures (> 40 °C), and better alternative solvents like ethanol

Meta-analysis of fraud, waste and abuse detection methods in healthcare

Fraud, waste and abuse have been a concern in healthcare system due to the exponential increase in the loss of revenue, loss of reputation and goodwill, and a rapid decline in the relationship between healthcare providers and patients. Consequently, fraud, waste and abuse result in a high cost of healthcare services, decreased quality of care, and threat to patients’ lives. Its enormous side effects in healthcare have attracted diverse efforts in the healthcare industry, data analytics industry and research communities towards the development of fraud detection methods. Hence, this study examines and analyzes fraud, waste and abuse detection methods used in healthcare, to reveal the strengths and limitations of each approach. Eighty eight literatures obtained from journal articles, conference proceedings and books based on their relevance to the research problem were reviewed. The result of this review revealed that fraud detection methods are difficult to implement in the healthcare system because new fraud patterns are constantly developed to circumvent fraud detection methods. Research in medical fraud assessment is limited due to data limitations as well as privacy and confidentiality concerns.Keywords: abuse, fraud, healthcare, waste, fraud detection method

Insight from the study of acidity and reactivity of Cr2O3 catalyst in propane dehydrogenation: a computational approach

By converting low-value commodity fuels into high-value products, like polymer precursors, chemical and other intermediates, the dehydrogenation of light paraffin (such as ethane and propane) into olefins, can add significant value to the refining processes that generate propane. In this study, the parameterised method 3 (PM3) approximation of semi empirical theory was employed to study the acidity and reactivity of chromium (III) oxide catalyst in the dehydrogenation of propane into propylene. Ammonia and pyridine were used computationally as molecular probes for the evaluation of the Lewis acidity of the catalyst sites. The propane adsorption and dissociation activation energies were also evaluated. The study showed that the chromium sites are highly acidic and reactive compared to the oxygen sites. In particular, the study showed that the chromium site is the main active site in the promotion of propane dehydrogenation into propylene, over chromium (III) oxide catalyst. Keywords: Acidity, Reactivity, Dehydrogenation, Propane, Chromium

Ground-State Energy Calculation of Helium Atom Using Quantum Monte Carlo CASINO-Code

We report an improved variational Monte Carlo (VMC) calculation of the ground-state energy of the helium atom, using quantum Monte Carlo (QMC) CASINO – code. The VMC ground-state energy is studied with a single determinant Slater-Jastrow trial wave-function formed from Hartree-Fock orbitals. The optimization of orbitals improved the agreement between the variational Monte Carlo and recent experiment. The calculated ground-state energy result is –2.903692762 ± 0.000023 a.u., which is in good agreement with the most recent experimental value –2.903693775 a.u. obtained by Bergeson et al. A more accurate trial function for importance sampling and the use of Jastrow–function combine to yield a ground-state energy which is 5 significant figures more accurate than that of previous quantum Monte Carlo calculations. Keywords: CASINO code, QMC, VMC, Helium atom, Reblocked-standard-erro

Thermodynamic and Economic Evaluation of Gas Turbine Power Plants

Thermodynamic analysis and economic feasibility of a gas turbine power plant using a theoretical approach are studied here. The operating conditions of Afam Gas Power Plant, Nigeria are utilized. A modern gas turbine power plant is composed of three key components which are the compressor, combustion chamber, and turbine. The plants were analyzed in different control volumes, and plant performance was estimated by component-wise modeling. Mass and energy conservation laws were applied to each component, and a complete energy balance conducted for each component. The lost energy was calculated for each control volume, and cumulative performance indices such as thermal efficiency and power output were also calculated. The profitability of the proposed project was analyzed using the Return on Investment (ROI), Net Present Worth (NPW), Payback Period (PBP), and Internal Rate of Return (IRR). First law analysis reveals that 0.9 % of the energy supplied to the compressor was lost while 99.1 % was adequately utilized. 7.0 % energy was generated within the Combustion Chamber as a result of the combustion reaction, while 33.2 % of the energy input to the Gas Turbine was lost, and 66.8 % was adequately converted to shaft work which drives both compressor and electric generator. Second law analysis shows that the combustion chamber unit recorded lost work of 248.27 MW (56.1 % of the summation), and 77.33 MW (17.5 % of the summation) for Gas Turbine, while air compressor recorded 11.8 MW (2.7 %). Profitability analysis shows that the investment criteria are sensitive to change in the price of natural gas. Selling electricity at the current price set by the Nigerian Electricity Regulation Commission (NERC) at zero subsidies and an exchange rate of 365 NGN/kWh is not profitable, as the analysis of the investment gave an infinite payback period. The investment becomes profitable only at a 45 % subsidy regime

SME’s disinclination towards subcontracting in the public sector markets : an attributional perspective

Purpose - This study aims to examine the causes of SME’ disinclination towards subcontracting in public sector markets. Previous studies have revealed that UK SMEs are reluctant to do business with the public sector through the subcontracting route, but the reasons for this lack of enthusiasm have not been widely researched. Design/methodology/approach- Drawing on semi-structured interviews with SMEs competing for public contracts in North West England, a qualitative study was performed, from which several themes emerged. Findings- The findings were synthesised into a framework underpinned by attribution theory, to portray situationally and dispositionally caused factors which were used to interpret SMEs behaviour. Originality- The paper contributes in a unique way to an emerging discourse on how subcontracting can facilitate the access of SMEs to government procurement spending. It adds to knowledge regarding the explanatory power of attribution theory– from its base in social psychology

Supply chain integration: Myths and realities

supply chain participants in parallel with the nature of fragmentation within the UK construction industry. The paper presents a brief literature review on construction procurement and how it is used to integrate the supply chain within construction industry, through two case studies, using case study research methodology. The current status of the UK construction industry is also presented to support the argument through latest published statistics. The paper analyses the argument and concludes that the UK construction practice/industry needs both integration and fragmentation within its project supply chains in order to deliver the clients requirement as a finished facility. Both presented case studies are public sector construction client and maintenance projects. The biggest implication of the above is that public sector clients operate under defined guidance through different policies, which influences the way they procure work and integrate their project supply chain. The authors, in the future, would test their arguments in the future research with the private sector clients. The current structure of a supply chain on a particular project within an emerging procurement method is integrated upstream and fragmented downstream. That means, the supply chains are not fully integrated in practice and consist of both integration and fragmentation element. Authors also argue that there is nothing wrong in having fragmentation within the industry; in fact it is healthy. The paper&#039;s main contribution is to start the debate and give justification through evidence that the UK construction practice/industry is both socially integrated as well as fragmented