ObjectiveAerosol delivery holds potential to release surfactant or perfluorocarbon (PFC) to the lungs of neonates with respiratory distress syndrome with minimal airway manipulation. Nevertheless, lung deposition in neonates tends to be very low due to extremely low lung volumes, narrow airways and high respiratory rates. In the present study, the feasibility of enhancing lung deposition by intracorporeal delivery of aerosols was investigated using a physical model of neonatal conducting airways.MethodsThe main characteristics of the surfactant and PFC aerosols produced by a nebulization system, including the distal air pressure and air flow rate, liquid flow rate and mass median aerodynamic diameter (MMAD), were measured at different driving pressures (4–7 bar). Then, a three-dimensional model of the upper conducting airways of a neonate was manufactured by rapid prototyping and a deposition study was conducted.ResultsThe nebulization system produced relatively large amounts of aerosol ranging between 0.3±0.0 ml/min for surfactant at a driving pressure of 4 bar, and 2.0±0.1 ml/min for distilled water (H2Od) at 6 bar, with MMADs between 2.61±0.1 µm for PFD at 7 bar and 10.18±0.4 µm for FC-75 at 6 bar. The deposition study showed that for surfactant and H2Od aerosols, the highest percentage of the aerosolized mass (∼65%) was collected beyond the third generation of branching in the airway model. The use of this delivery system in combination with continuous positive airway pressure set at 5 cmH2O only increased total airway pressure by 1.59 cmH2O at the highest driving pressure (7 bar).ConclusionThis aerosol generating system has the potential to deliver relatively large amounts of surfactant and PFC beyond the third generation of branching in a neonatal airway model with minimal alteration of pre-set respiratory support.
The prediction of loss of position in the offshore industry would allow optimization of dynamic positioning drilling operations, reducing the number and severity of potential accidents. In this paper, the probability of an excursion is determined by developing binary logistic regression models based on a database of 42 incidents which took place between 2011 and 2015. For each case, variables describing the configuration of the dynamic positioning system, weather conditions, and water depth are considered. We demonstrate that loss of position is significantly more likely to occur when there is a higher usage of generators, and the drilling takes place in shallower waters along with adverse weather conditions; this model has very good results when applied to the sample. The same method is then applied for obtaining a binary regression model for incidents not attributable to human error, showing that it is a function of the percentage of generators in use, wind force, and wave height. Applying these results to the risk management of drilling operations may help focus our attention on the factors that most strongly affect loss of position, thereby improving safety during these operations.
This paper aims to present a method to determine the type of dynamic positioning (DP) incidents that have a more significant risk during drilling operations in the period 2007-2015, according to the element or the type of failure that causes the DP system to fail. Two different classifications are made: 1) according to the element that produces the incident (which has been the traditional classification in the industry) and 2) according to the type of error that arises, the latter being an alternative classification proposed in this paper. The predictable financial losses for each level of severity are used to define the resulting consequences for each case. A risk analysis is performed with the data obtained, showing the potentially more dangerous incidents, either because of their higher number of occurrences or because their consequences are remarkable. According to the classification proposed, the main causes with the higher risk results were power and environmental, according to the traditional classification, and fault/failure. Thus, the power segment’s combination of failures is the riskiest cause during the DP drilling operations.
The main purpose of this research is to present the influence of the oil price drop in the offshore training industry and the actions taken to minimise this effect. In particular, data corresponding to the Offshore Dynamic Positioning (DP) training and certification scheme by the Nautical Institute were used for the research. Since the oil price began to drop by the end of 2014, the oil and gas industry had to make some readjustments to keep the profits and continue in the business. The offshore DP training was affected by this crisis in two ways: the number of candidates starting the certification scheme dropped significantly; and on the other hand, candidates who had already begun the scheme were unable to complete the required number of days to be able to access the DP Simulator course, or for obtaining the DP Operator certificate. During this period, the training and certification scheme has undergone some changes to adapt to the new situation and to try to resolve the problems mentioned above. The analysis of the data shows that the effect of the oil price drop was not initially affecting the training but only began to show the consequences after some months.
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