242 research outputs found

    Investigations on corrosion monitor reliability, calibration, and coverage

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    Thickness loss due to internal corrosion and erosion is a critical issue in ferromagnetic steel structures that can cause catastrophic failures. Ultrasonic thickness gauges are widely used for the detection of wall thickness. Recently permanently installed ultrasonic sensors have become popular for the inspection of areas suspected to undergo wall thickness loss. However, these are limited by the high cost and requirement of coupling agents. To address these problems, a novel cost-effective, and smart corrosion monitor based on the magnetic eddy current technique is developed in this research. The performance and reliability of the monitor to track internal wall thickness loss is tested successfully through accelerated and real-life aging corrosion tests. Due to the handling and safety issues associated with the powerful magnets in magnetic techniques, a particle swarm-based optimisation method is proposed and validated through two test cases. The results indicate that the area of the magnetic excitation circuit could be reduced by 38% without compromising the sensitivity. The reliability of the corrosion monitor is improved by utilising the active redundancy approach to identify and isolate faults in sensors. A real-life aging test is conducted for eight months in an ambient environment through an accelerated corrosion setup. The results obtained from the two corrosion monitors confirm that the proposed corrosion monitor is reliable for tracking the thickness loss. The corrosion monitor is found to be stable against environmental variations. A new in-situ calibration method based on zero-crossing frequency feature is introduced to evaluate the in-situ relative permeability. The thickness of the test specimen could be estimated with an accuracy of ± 0.6 mm. The series of studies conducted in the project reveal that the magnetic corrosion monitor has the capability to detect and quantify uniform wall thickness loss reliably

    IL-2: Fine-tuning the Germinal Center Reaction

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    T follicular cells help B cells to drive germinal center formation. In this issue of Immunity, Ballesteros-Tato et al. (2012) demonstrate that high amounts of interleukin-2 inhibit production of this critical T effector subset

    Reliability Improvement of Magnetic Corrosion Monitor for Long-Term Applications

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    Electromagnetic techniques are widely employed for corrosion detection, and their performance for inspection of corrosion is well established. However, limited work is carried out on the development and reliability of smart corrosion monitoring devices for tracking internal or buried thickness loss due to corrosion remotely. A novel smart magnetic corrosion transducer is developed for long-term monitoring of thickness loss due to corrosion at critical locations. The reliability of the transducer is enhanced by using a dissimilar active redundancy approach. The improved corrosion monitor has been tested in the ambient environment for seven months to evaluate the stability against environmental factors and degradation. The monitor is found to show great sensitivity to detect defects due to corrosion. Detection of anomalous patterns in the time series data received from the monitors is accomplished by using Pearson’s correlation coefficient. The critical component of the monitor is identified at the end of the test. Research findings reveal that, compared to the existing corrosion monitoring techniques in the industry, the detection and isolation of faulty sensor features introduced in this study can contribute to reliable monitoring of thickness loss due to corrosion in ferromagnetic structures over an extended period of tim

    Development of Permanently Installed Magnetic Eddy Current Sensor for Corrosion Monitoring of Ferromagnetic Pipelines

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    Permanently installed sensors are a cost-effective solution for corrosion monitoring due to their advantages, such as less human interference and continuous data acquisition. Some of the most widely used permanently installed corrosion sensors are ultrasonic thickness (UT) gauges. However, UT sensors are limited by the need for coupling agents between pipe surfaces and sensors. The magnetic eddy current (MEC) method, on the other hand, does not require couplant and can be used over insulations. With the development of powerful rare earth magnets, MEC sensors with low power consumption are possible, and there is the prospect of using them as permanently installed sensors. A novel wireless magnetic eddy current sensor has been designed and optimized using finite element simulation. Sensitivity studies of the sensors reveal that the excitation frequency is a critical parameter for the detection of corrosion defects. An in-depth explanation of the relationship between the sensitivity of the sensor and the excitation frequency is presented in this paper. The results of an accelerated corrosion test, conducted to simulate the service environment of the sensor, are also discussed. It was observed that the sensor signals are very sensitive to corrosion defects and show no subtle differences due to temperature and humidity changes

    Barriers to colorectal cancer screening in Asia: A systematic review

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    Purpose: Colorectal cancer (CRC) is among the top five cancers afflicting both men and women globally. Once predominantly a Western disease, it has begun to rise in Asian countries as well. This systematic review aims to compile and analyze the various barriers towards colorectal cancer screening in Asia, and to determine if the barriers are consistent throughout the continent.Methods: Article Inclusion criteria for based on year of publication from year 2008 till 2015, has been conducted in Asia, and written in English language. A total of 23 studies were included in this review, chosen via primary search of journal websites and databases, and a secondary search through the reference lists of eligible articles.Results: It was found that major barriers of colorectal cancer screening are; poor education/knowledge, negative perceptions towards screening, aversion to test results, financial constraints, time constraints, lack of physicians’ recommendation, limited/difficult access to screening locations, fatalistic beliefs, low perceived risks, language barriers, confidence in traditional medicine/distrust in Western medicine,ignorance and old age.Conclusion: Lack of knowledge/education is the most critical barrier that is linked to a majority of other barriers that can hinder a person from undergoing CRC screening for early prevention, detection and treatment. Majority of these barriers encountered regarding the poor rates of CRC screening are similar across countries in Asia.Keywords: Colorectal cancer screening, Barrier, Knowledge, Criteria for eligibilit

    Rac1 accumulates in the nucleus during the G2 phase of the cell cycle and promotes cell division

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    Rac1 regulates a wide variety of cellular processes. The polybasic region of the Rac1 C terminus functions both as a plasma membrane–targeting motif and a nuclear localization sequence (NLS). We show that a triproline N-terminal to the polybasic region contributes to the NLS, which is cryptic in the sense that it is strongly inhibited by geranylgeranylation of the adjacent cysteine. Subcellular fractionation demonstrated endogenous Rac1 in the nucleus and Triton X-114 partition revealed that this pool is prenylated. Cell cycle–blocking agents, synchronization of cells stably expressing low levels of GFP-Rac1, and time-lapse microscopy of asynchronous cells revealed Rac1 accumulation in the nucleus in late G2 and exclusion in early G1. Although constitutively active Rac1 restricted to the cytoplasm inhibited cell division, activated Rac1 expressed constitutively in the nucleus increased the mitotic rate. These results show that Rac1 cycles in and out of the nucleus during the cell cycle and thereby plays a role in promoting cell division

    ALI: An Extensible Architecture Description Language for Industrial Applications

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    While Architecture Description Languages (ADLs) have gained wide acceptance in the research community as a means of describing system designs, the uptake in industry has been slower than might have been expected. A contributory cause may be the perceived lack of flexibility and, as yet, the limited tool support. This paper describes ALI, a new ADL that aims to address these deficiencies by providing a rich, extensible and flexible syntax for describing component interface types and the use of patterns and meta-information. These enhanced capabilities are intended to encourage more widespread industrial usage

    Towards Performance Related Decision Support for Model Driven Engineering of Enterprise SOA Applications

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    Model Driven Performance Engineering (MDPE) enables early performance feedback in a MDE process, in order to avoid late identification of performance problems which could cause significant additional development costs. In our past work we argued that a synchronization mechanism between development and performance analysis models is required to adequately integrate analysis results into the development process enabling performance related decision support. In this paper we present a solution for this requirement. We present a new multi-view based approach and its implementation enabling systematic performance related decision support. We apply our research on the model driven engineering of process orchestrations on top of SAP’s Enterprise Service Oriented Architecture (Enterprise SOA)

    Assessment of hospital pharmacists' clinical knowledge and practical skill levels for pharmaceutical care in Madinah, Saudi Arabia

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    Purpose: To evaluate hospital pharmacists’ clinical knowledge and practical skill levels for pharmaceutical care.Methods: A quasi-experimental prospective longitudinal study design was used to evaluate the level of clinical skills with problem-based learning (PBL) sessions. Pharmacists’ in three different government hospitals in Madinah, Saudi Arabia recorded their responses or assessments in their work manuals for preparing reports. Instructors encouraged interactive learning by presenting case studies, in which pharmacists had to interpret medical history and clinical assessments of various body systems. Course learning design also focused on drug use evaluation, monitoring plans, and reaching clinical evidencebased decision-making.Results: A total of two hundred and fifty-five (255) hospital pharmacists participated in the study. The study sample was comprised of 128 (50.9 %) males and 127 (49.1 %) females. A significant (p < 0.01) difference was noticed between genders (male: 47.91 ± 7.15, female: 50.31 ± 4.88) for total mean scores of clinical skills. Cronbach’s alpha reliability coefficient for case data recitation was 0.91, while clinical assessment skills coefficient was 0.89. Overall, pharmacists reported that they “agree” (4.01 ± 0.67) that they acquired the ability to use case data recitation taught in the PBL; they also reported a positive evaluation (4.48 ± 0.58) of their ability to perform clinical data assessment.Conclusion: The findings indicate that pharmacist’s self-confidence to perform clinical assessment activities is low. Lack of confidence remains a critical education issue among pharmacists in the study setting.Keywords: Clinical pharmacy, Problem-based learning, Clinical skills, Pharmacist focus group, Therapeutics, Pharmaceutical car

    Experimental determination of heat capacities and their correlation with quantum predictions

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    This article demonstrates an undergraduate experiment for the determination of specific heat capacities of various solids based on a calorimetric approach, where the solid vaporizes a measurable mass of liquid nitrogen. We demonstrate our technique for the metals copper and aluminum, the semi-metal graphite and also present the data in relation with Einstein's model of independent harmonic oscillators and the more accurate Debye model based on vibrational modes of a continuous crystal. Furthermore, we elucidate an interesting material property, the Verwey transition in magnetite occurring around 120-140 K. We also demonstrate that the use of computer based data acquisition and subsequent statistical averaging helps reduce measurement uncertainties.Comment: 16 pages, 8 figures. Partially accepted in American Journal of Physics (2011
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