Decision Making on Oil Extraction under Z-information

AbstractIn modern conditions, the refining process is complicated and ambiguous, requiring a precise knowledge of all the internal and external factors. However, in many cases, it is impossible to get complete information. Therefore, the process of oil production takes place in conditions of uncertainty accompanying the various situations. A partial absence of beliefs and fuzziness are some of the aspects of uncertainty. In this paper we consider a somewhat different framework for representing our knowledge. Zadeh suggested a Z-number notion, based on a reliability of the given information. In this study we apply Z- information to decision making on oil extraction problem and suggest the framework for decision making on a base of Z-numbers. The method associates with the construction of a non-additive measure as a lower prevision and uses this capacity in Choquet integral for constructing a utility function

Legal and ethical requirements for developing a medical MOOC: Lessons learnt from the Paediatric Physical Examination Skills MOOC

Massive open online courses (MOOCs) are increasingly being integrated into medical education. The production of a MOOC demonstrating physical examinations of children raised the issue of legal and ethical consent for the use of images and video-recordings of children. The present article shares the valuable lessons we learned around the legal and ethical consent required, and the operational issues that will be essential to comply with these legal and ethical considerations. This information may be valuable to other educators, especially those in similar resource-constrained settings,who are planning to create medical MOOCs

Particulate matters pollution in selected areas of Nigeria: Spatial analysis and risk assessment

The increasing rate of unregulated emissions of particulate matters from different sources in Nigeria is of great concern. This study therefore focused on monitoring particulate matters (PM2.5 and PM10) level in some municipal areas in Nigeria. The study also simulated the dispersion pattern of the particulate matters and assessed the health risk of particulate matter exposure. PM2.5 and PM10 level in the selected areas were quantified for 8 months using Centre for Atmospheric Research (CAR) satellite-based sensors. Hybrid single-particle Lagrangian integrated trajectory (HYSPLIT) model was used to simulate the dispersion pattern and the dispered particulate matter position. The risk assesment was estimated by air quality index (AQI) using World Health Organization (WHO) guideline for PM2.5 and PM10 as the standard. The result showed that the levels of PM2.5 and PM10 on monthly average basis for the selected areas were all above the WHO guideline. The dispersion model and potential particulate matter position revealed that it takes almost 12 hours for any released particulate matter to be fully dispersed and that majority of the dispersed particles were found within 100 m. The AQI level of PM2.5 ranged from 65.13 to 927.07 while PM10 AQI ranged from 73.51 to 256.65 for the selected regions, which showed poor and unhealthy air quality. Also, the inhabitants of the studied areas are at high risk of particulate matters exposure which may lead to a reduced life expectancy over a long period of exposure. This study however concluded that a more robust measure should be put in place to ensure an improved air quality

Adsorption of hexavalent chromium from aqueous solution using cationic modified rice husk: Parametric optimization via Taguchi design approach

The current work study the adsorption capacity of modified rice husk for the removal of Cr(VI) from aqueous solution. The rice husk was prepared and modified cationicaly. The cationic modified risk husk (cRH) was characterized by scanning electron microscopy (SEM) and fourier transform infrared (FTIR) spectroscopy. Also, point-of-zero pH (pHzero), specific surface area (m2/g) and bulk density (g/cm3) of the cRH were determined. The adsorption process was optimized by considering four independent process parameter at three variation levels using Taguchi design approach. The results showed the bulk density (0.392 g/cm3) and surface area (192 m2/g) which revealed the presence of numerous sorption sites on the cRH. Also the SEM micrograph showed the pores of different sizes which favoured the adsorption of Cr(VI). Taguchi experimental design predicted initial Cr (VI) concentration of 25 mg/L, contact time of 90 min, 2 g cRH dosage and pH of 2 as the optimum conditions to achieve 91.48% removal efficiency. The optimized condition was verified and 91.13% removal efficiency was achieved. The experiment data fitted well to Langmuir model indicating anion species monolayer adsorption on the cRH homogeneous surface. Also, the process is in better agreement with pseudo-second-order kinetic model, indicating a chemisorption controlled process. Thus, the study revealed that cationic modified rice-husk is suitable for the removal of Cr(VI) from aqueous solution

Oilfield produced water assessment from onshore treatment facilities in Niger Delta: Water quality susceptibility and suitability for soil irrigation

The abundance of natural fossil fuel in the Niger Delta of Nigeria has instituted generation of oilfield produced water (PW) in large volume. This constitutes environmental pollution when discharged outside the permissible limit given by Nigerian Upstream Petroleum Regulatory Commission (NUPRC). PW can be used for soil irrigation if its constituents are remediated after treatment. This research assessed the physicochemical properties of untreated and treated samples of oilfield PW from Awoba, Imo River and Kolo creek oil fields of Niger Delta using electrometric, argentometric, colorimetric, titration, atomic absorption spectroscopy, APHA and HACH standard methods. Oil-treatment facilities effectiveness was investigated by comparing laboratory results for treated-PW with the permissible regulatory values of NUPRC. The pH, salinity hazard, sodium hazard, boron, chloride, TDS, carbonate and nitrate of treated-PW were measured to check the suitability of treated-PW quality for soil irrigation. Measured values were compared with the permissible standard of US EPA. Sodium adsorption ratio (SAR) and electric conductivity (EC) were used to determine the level of sodium and salinity hazards respectively. The results indicated that none of the untreated-PW samples complied with NUPRC permissible limit. Physicochemical properties of treated-PW revealed samples to be close to or within approved NUPRC standards except in few cases. All the measured parameters of treated-PW from Awoba and Imo River oil fields conformed to the US EPA standard value except their ECs and SAR of Imo River oil field which measured 2.46 and 2.93 ds m−1, and 2.57 respectively. However, all other parameters measured for treated-PW from Kolo creek oil field did not conform to the standard except pH and nitrate which measured 7.7 and 4.86 mg/L respectively. In conclusion, oil treatment facilities should be more robust to degrade a wide range of recalcitrant compounds in PW pollutants in order to minimize the impacts of toxic compounds in PW on the environment