Failure diagnostics

Abassi Z, Karram T, Ellaham S, ei al. Implications of the natriuretic peptide system in the pathogenesis of heart failure diagnostic and therapeutic importance. Pharmacol Ther 2004 102 223 1. 

THERAP CAT Ammonia deloxicant (hepatic failure) diagnostic aid (pituitary function). 

In the past, the acronym MTTR stood for "Mean Time To Repair." The term was changed in lEC 61508 because of confusion as to what was included. Some thought that Mean Time To Repair included only actual repair time. Others interpreted the term to include both time to detect a failure (diagnostic time) and actual repair time. The term "Mean Dead Time (MDT)" is commonly used in some parts of the world and means the same as Mean Time To Restore. 

The failure diagnostic list of each system can help you to diagnose the failure of the system and find out the causes of failure. 

Three forms of VLCAD deficiency (14.5) are known, i.e. a (lethal) neonatal cardiomyopathic form, a childhood form with recurrent Reye-like episodes, and an adolescent/adult muscular form [6]. The latter may be accompanied by severe rhabdomyolysis and sometimes renal failure. Diagnostic criteria are the abnormal plasma acylcarnitine and organic acid profile (Ci4 i, Ci4 2 and Ci6 i) and the Cg-Cio dicarboxylic aciduria, especially in young patients. 

Herrera, O., Merida, W, and Wilkinson, D. P. 2009. Sensing electrodes for failure diagnostics in fuel cells. Journal of Power Sources 190 103-109. 

New approaches in the field of machine safety also cause changes in the conditions for their maintenance. The ISO/TS 16949 Standard for the automobile industry and its suppliers mainly requires the implementation of predictive maintenance to increase the quality level. The directive on machine safety states a requirement to be followed at the stage of construction and design in case of automated devices, and if deemed necessary, other devices, a connecting device must be provided for mounting [a] failure diagnostics device. ... 

The development of computer capabiUties in hardware and software, related instmmentation and control, and telecommunication technology represent an opportunity for improvement in safety (see COMPUTER TECHNOLOGY). Plant operators can be provided with a variety of user-friendly diagnostic aids to assist in plant operations and incipient failure detection. Communications can be more rapid and dependable. The safety control systems can be made even more rehable and maintenance-free. Moreover, passive safety features to provide emergency cooling for both the reactor system and the containment building are being developed. 

Reliability. There has been a significant rise in interest among pump users in the 1990s to improve equipment reflabiUty and increase mean time between failures. Quantifiable solutions to such problems are being sought (61). Statistical databases (qv) have grown, improved by continuous contributions of both pump manufacturers and users. Users have also learned to compile and interpret these data. Moreover, sophisticated instmmentation has become available. Examples are vibration analysis and pump diagnostics. 

W. Clemmens, M. Sabourin, and T. Rao, Detection of Catalyst Failure Using On-Board Diagnostics, SAE 900062, Society of Automotive Engineers, Warrendale, Pa., 1992. 

The system must produce diagnostic and failure prediction information in a timely manner before serious problems occur on the machines monitored. 

Appraisal costs - cost incurred in detecting failures, such as reviews, assessments, inspections, audits, tests including test and diagnostic equipment... 

The other main application area for predictive error analysis is in chemical process quantitative risk assessment (CPQRA) as a means of identifying human errors with significant risk consequences. In most cases, the generation of error modes in CPQRA is a somewhat unsystematic process, since it only considers errors that involve the failure to perform some pre-specified function, usually in an emergency (e.g., responding to an alarm within a time interval). The fact that errors of commission can arise as a result of diagnostic failures, or that poor interface design or procedures can also induce errors is rarely considered as part of CPQRA. However, this may be due to the fact that HEA techniques are not widely known in the chemical industry. The application of error analysis in CPQRA will be discussed further in Chapter 5. 

While providing many advantages, simplified data acquisition and analysis also can be a liability. If the database is improperly configured, the automated capabilities of these analyzers will yield faulty diagnostics that can allow catastrophic failure of critical plant machinery. 

Simplified diagnostics Identification of specific failure modes of plant equipment requires manual analysis of data stored in the computer s memory. The software program should be able to display, modify and compare stored data in a manner that simplifies the analysis of the actual operating condition of the equipment. 

The addition of unique narrowbands that monitor specific machine components or failure modes add more diagnostic information. 

Relatively selective stimulation of Pi-adrenergic receptors can be achieved with dobutamine. This is a racemic drug of which both isomers activate the Pi-receptor, and in addition the (-) isomer activates ( -receptors whereas the (+) isomer activates p2-receptors the simultaneous activation of ai- and p2-receptors results in no major net effect on peripheral resistance, and thus the overall cardiovascular effects are mediated by Pi-stimulation leading to increases in cardiac contractility and output. Dobutamine is used for the short-term treatment of acute cardiac failure and for diagnostic purposes in stress echocardiography. 

Aspects of point 1 have aheady been included in Sections 23.2.2.1 and 23.2.2.2. Regarding point 2, a new diagnostic test for discontinuities is outlined in Section 23.5.2, absorption in Section 23.4.2, and ED failures in Sections 23.5.1.1 and 23.5.1.2. As to point 3, the ubiquitous phenomenon of permeation, which occurs wherever fluid containment by elastomers exists, is examined below. 

VN input. Complete loss, even if strongly suggested by failure of differentiation in the early embryo, needs to be re-evaluated by a search for diagnostic VN-genome sequences. 

Dementia is the loss of function in multiple cognitive domains that occurs over a longer period of time, usually months to years. Diagnostic features include memory impairment and at least one of the following aphasia (deterioration of speech), apraxia (impaired ability to execute motor activities despite intact motor abilities, sensory function, and comprehension of the required task), agnosia (failure to recognize or identify objects despite intact sensory function), or disturbances in executive functioning.1... 

Review any additional diagnostic tests to determine if treatment may be needed to prevent/minimize complications (e.g., emboli, congestive heart failure). 

Consider again a batch polymerization process where the process is characterized by the sequential execution of a number of steps that take place in the two reactors. These are steps such as initial reactor charge, titration, reaction initiation, polymerization, and transfer. Because much of the critical product quality information is available only at the end of a batch cycle, the data interpretation system has been designed for diagnosis at the end of a cycle. At the end of a particular run, the data are analyzed and the identification of any problems is translated into corrective actions that are implemented for the next cycle. The interpretations of interest include root causes having to do with process problems (e.g., contamination or transfer problems), equipment malfunctions (e.g., valve problems or instrument failures), and step execution problems (e.g., titration too fast or too much catalyst added). The output dimension of the process is large with more than 300 possible root causes. Additional detail on the diagnostic system can be found in Sravana (1994). 

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