Legionella pneumophila, found in engineered water systems such as HVAC cooling towers, poses a significant public health risk. Culture, though routinely used to quantify L. pneumophila, has several disadvantages including long turnaround time, low sensitivity, and inter-laboratory variability. In this study, we validated the performance of an on-site quantitative polymerase chain reaction (qPCR) detection system for L. pneumophila in accordance with International Standards Organization Technical Specification 12869:2012. We evaluated specificity, limit of detection and quantification, and calibration curve linearity. Additionally, we evaluated whole system recovery and robustness using samples taken from taps and evaporative cooling towers. We then compared the system's performance against laboratory culture and laboratory qPCR across 53 cooling towers in a 12-week in-field study. We found that concordance between on-site qPCR and culture was both laboratory- and site/sample-dependent. Comparison of laboratory qPCR with on-site qPCR revealed that laboratory results were highly variable and showed little concordance. Some discordance may be explained by time delay between sample collection and testing (‘shipping effect’) which may lead to inaccurate reporting. Overall, our study highlights the value of on-site qPCR detection of L. pneumophila, demonstrates that laboratories are prone to misreporting results due to shipping effects, and reveals significant discordance between laboratory qPCR and culture.
The switching/modulation properties of a vertical-cavity semiconductor optical amplifier (VCSOA) are investigated. We report on maximum extinction ratio, carrier recombination lifetime, and modulation bandwidth of an optically pumped VCSOA operated in reflection mode. A 35dB output signal extinction ratio was measured for a 7dB pump power modulation. The carrier recombination lifetime was investigated by short pulse optical pumping and detection by means of a streak camera. The extinction ratio analysis and the measured carrier lifetime suggests switching times on the order of 10ps. Frequency response measurements revealed a modulation bandwidth of 1.8GHz for operation in the saturated regime.
This paper is about BP's experience with Collaborative Real-time Environments (CoRE) including the Houston Monitoring Center (HMC), which has resulted in enhanced safety, rig site monitoring and its associated planning, and improved operational efficiencies. Real Time Monitoring Centers have been utilized by industry for some years to improve operational efficiency in drilling processes. BP (operator) has explored extending the effectiveness of such centers by embedding them in a CoRE. In its Gulf of Mexico operations area, this operator has been rigorously applying real-time data monitoring technologies on critical operations with the intent to enhance both safety and operational efficiency through more informed operational decision making. The results of this focused operation will be described in this paper.The term CoRE is used to describe the physical atmosphere and office arrangement of integrated teams, both operations and subsurface, sophisticated data monitoring applications and communications tools from the office to the rig site. Remotely monitoring key rig site data using highly trained and skilled personnel in a newly designed environment called a CoRE, has resulted in improvements in procedural discipline, efficacy in human factors as they relate to drilling and completion operations, and significantly improved operational decision making. These processes are underpinned by highly resilient systems and meticulous planning, delivering an uptime greater than 99.5%. To improve resilience of the system, the ability to transfer monitoring operations to an alternative location within a short time has been demonstrated repeatedly. This paper will describe the principles and demonstrated results from the CoRE philosophy.An additional benefit of having key data streaming onshore is regulatory compliance verification by the operations team, which also would allow external review by a regulator. This enhances the compliance verification significantly and allows additional items to be verified or inspected in less time and with less impact on the field operations. The potential benefits to both internal and external stakeholders including regulatory personnel are also described in this paper.The paper will detail the operator's journey on real time data monitoring of drilling operations which has been utilized by the company for several years. Included is a description of the numerous benefits resulting from applying advanced technologies in real-time monitoring (RTM) to the area of operational decision making including being aligned to potential future industry guidelines or standards. This paper describes the management practices which can be used to foster confidence between geographically separated team members because acceptance by field operations personnel is key to the success of any remote monitoring activity. Finally, the overarching management approach which has contributed to the success of this integrated effort is described by this paper.
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