A Treatment Option or Source of Bacterial Pathogen Transmission? The Case of Herbal Mixture in Nigeria

Herbal mixture such as agbo, has been used in recent years in Nigeria to treat various sicknesses including malaria, typhoid, dysentery and cholera. However, the bacteriological quality and safety is of paramount importance spurring the argument whether it is treatment option or sources of pathogen transmission. Hence this study was conducted to investigate the bacteriological analysis of agbo herbal preparations. Samples of herbal mixture were purchased from five different markets (Uselu, New Benin, Oba, Santana and Ogida Markets) in Benin City, Edo State, Nigeria. Bacteriological analysis was carried out using pour plate isolation method. Identification of isolated bacteria was based on their cultural, morphological, biochemical and molecular techniques. Antibiotic sensitivity pattern was carried out using disk diffusion method. The plasmid profile of multiple drug resistance bacterial genes isolated was also analyzed. Bacteriological analyses showed that the total bacterial counts (TBC) of all the test herbal samples obtained from the various markets ranged from 0.04 x 104 to 1.13 x 104cfu/ml. Eight bacterial species were identified and they include; Bacillus cereus, Bacillus subtilis, Escherichia coli, Lactobacillus casei, Serratia marcescens, Micrococcus varians, Pseudomonas aeruginosa and Staphylococcus aureus. The least occurring bacterial isolates were Serratia marcescens and Pseudomonas aeruginosa (5.26%) while the highest occurring was Bacillus cereus (21.05%). Isolated bacteria were resistant to commonly used antibiotics. Plasmid profile revealed presence of plasmid genes in the bacterial isolates. Since applications of herbal medicines for curative purposes is on the increase, there is need to monitor and ensure its bacteriological quality before distributing to final consumers

Assessing Stochastic and Intelligent Threats in the Norwegian Petroleum Industry, Current Approach(s) and Enhancement with Game Theory influenced Risk Assessment Approach (GIRA)

Master's thesis in Risk managementIn the Norwegian petroleum industry quantitative risk assessments QRA’s are carried out to assess risk as well as for accounting for uncertainties given the strength of background knowledge available to the assessors. The NORSOK Z-013 standard is used as a guideline for doing this in practice. This thesis focuses on enhancing the current quantitative risk assessment approach being used in the industry by combining it with the game theory. It is from this synergy that a new approach termed ‘GIRA’ game theory influenced risk assessment was suggested in this research work. As the boundaries for innovation are pushed in the industry, likewise are the threats from petroleum activities increasing. These threats can be stochastic or intelligent in nature, because of this increase in risk there needs to be improvement in the methodology to unravel these threats. The GIRA approach provides the necessary robustness to combat the increasing complex nature of threats facing the industry. Previous research has been carried out in this field by notable researcher’s such as Vicki Bier and Terje Aven. Vicki Bier suggests a strategy for allocating resources efficiently in combating intelligent threats. Also, the research work carried out by Prof. Aven in the correct use of QRA’s in the industry is exemplary. However, there exist some gaps in these researches, the work done by Bier is a justification for investment to combat intelligent threats such as terrorism and does not cover much about stochastic threats. As for the research work done by Prof Aven, with the increase in the threat level exposure in the industry there is need to see the limitations of a QRA, hence why it should be improved upon. The GIRA approach is a strategy that will be able to address the limitations of the QRA because of the two-step analyses process, first by a QRA then analysis of the QRA result with the GIRA approach. A case study about an ignited process leak was carried out to show how the GIRA approach will be used in practice. It is believed that by applying the GIRA approach extensively in the Norwegian petroleum industry, a more robust analysis will be available to present a complete picture of risk from intelligent and stochastic threats to decision makers

Implementation of linear, double-linear, and nonlinear fatigue damage accumulation rules for fatigue life prediction of offshore drilling top-drive tie-rods

The offshore oil and gas industry has been exposed to major challenges over the last decade, particularly demanding cost cuts and more effective technical solutions. Predictive systems and remaining life assessments for both machine and structural components are known to be one of the core areas that has gathered much attention lately. This paper focuses on multiaxial fatigue that is a problem in number of engineering structures and equipment. The ability to properly assess and quantify multiaxial fatigue of offshore equipment and structures has major benefits for owners of engineering assets both in terms of technical and safety integrity. Traditionally, Palmgren-Miner's damage rule is used for life estimation involving multiaxial fatigue due to its ease of use. There are however some known shortcomings with Palmgren-Miner's rule namely: it does not consider the loading sequences. This for instance can result in overestimation of fatigue life in scenarios where stress amplitudes are decreasing, and moreover underestimation of fatigue life in scenarios where stress amplitudes increase. This research work thus involves closely studying the application of Palmgren-Miner's linear damage rule, Manson's double linear damage rule, and Subramanyan's non-linear damage rule for the purpose of enhancing the predictability of damage as well as accuracy of fatigue life assessments. Each of these techniques were applied for tie-rods of an offshore drilling top-drive having a known stress history. The loading histories were provided by a drilling company. The torque and axial force values are transformed to stress components for the corresponding critical spots. The "rainflow" counting technique is applied to the obtained stress histories and the mean stress effect is considered for the damage accumulation calculations. The fatigue life prediction of the three models are justified and discussed. This research work was aimed at contributing towards the utilization of more robust fatigue life estimation techniques such as Manson's double linear damage rule and simplified non-linear damage rules which capture the true nature of the fatigue that equipment's are subjected to, and thus to improve the reliability of the fatigue life predictions.publishedVersio

The first record of Mesoturrilites (Ammonoidea) from Hokkaido: (Studies of the cretaceous ammonites from Hokkaido and Sakhalin-LXXXIII)

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