Performance on demand

The development of automated luminometers is focused primarily on devices that achieve high sample throughput rates, typically through the use of 96 and 384 well microtitre plates. Whilst suited for many applications, these systems require a skilled operator and often do not provide rapid results when the time taken to prepare the microtitre plate is included in the assay time. An instrument that can perform on demand, automated, near real time analysis using a variety of luminescent assay protocols has been developed. The instrument has been designed to automate various luminescent assays including adenylate kinase (AK) assays and those that use magnetic separation steps in conjunction with bioluminescence. ... 

In the present paper, only the low demand mode of operation is assumed (i.e. the safety function is only performed on demand, and not more than one per year). The target failure measure is then defined by the average probability of dangerous failure on demand of the safety function (PFDavg), and the associated SIL is determined by Table 1. Note that these definitions stem from lEC 61508, 2009 revision, which are more precise than in the first edition. 

Low demand mode Where safety function is only performed on demand to transfer equipment under control (EUC) into a specified safe state and the frequency of demand is less than one per year. Fig. VII/1.4-1 is an example of demand mode of operation. This is because normally the level in the tank will be maintained by sensors Sn and control valve Cy, but in case of a high level to avoid a hazardous situation, separate protection sensors will come into play and close the shutdown valve Sy. So safety comes on demand. 

High demand mode Where safety function is only performed on demand to transfer EUC into a specified safe state and the frequency of demand is greater than one per year. 

The details of any demands on the system, and system performance on demand, should be recorded including data on any spurious trips, any revealed failures of the system or its components and, in particular, any failures identified during proof testing. 

Equipment and products for which continued performance or performance on demand is critical belong in Class 3. Equipment downtime cannot be tolerated, and the eqnipment must function when required (e.g., life support systems, flight control systems). PCTs in this class are suitable for applications in which high levels of assistance are required and service is essential. 

CLASS 2 Dedicated Service Electronic Prodncts Class 2 includes products where continued performance and extended life is required, and for which uninterrupted service is desired but not critical. Typically the end-use environment would not cause failures. CLASS 3 High-Perforniance Electronic Prodncts These include products where continued high performance or performance-on-demand is critical, equipment downtime cannot be tolerated, end-use environment may be uncommonly harsh, and the equipment must function when required. Examples include life support or other critical systems. 

Class 3, hig -performance electronic products These products include commercial and military equipment for which continned performance or performance on demand is imperative. 

Performance on Demand - A New Era in Polymer Science (A Case Study Using Conducting Polymers)... 

The notion of Performance on Demand is not alien to polymer research scientists. Usually however, Uie demand has come from engineers and has been aimed at the polymer scientist with a view to achieving a desired level of performance from both researcher and material. In most instances the time lag associated witli the demand and tiie response has been much longer tlian either the engineer or tlie researcher would like. 

This article, will deal with the former (simpler) approach which requires die polymer to have sufficient dynamic character to perform on demand in response to application of external stimuli by us humans. We see tliis as tlie first step in tlie creation of truly intelligent materials. We also see that tliis simpler approach will in itself have major ramifications on numerous technologies. For example ... 

This simple yet elegant polymerisaUon process allows the dynamic properties (and hence die ability to obtain performance on demand) to be (pre)determined at the time of assembly. 

Having created conducting polymer structures and developed appropriate lines of communication. We can assemble systems whereby tlie material s properties can be controlled in-situ. Then performance on demand is possible. Tlie degree of control available and how this can be utilised is best illustrated by considering some areas of application currently being developed in our laboratories. 

The principal physical properties influencing ink performance ate surface tension and viscosity. High surface tension is desired for good droplet formation and capillary refill in dtop-on-demand ink jet. Low viscosity is desired because less energy is required to pump and eject ink. Conductivity is also an important parameter. Continuous ink-jet inks must have some conductivity to allow for charging. Low conductivity is generally preferred for impulse, particularly thermal ink jet, because excess ions can cause corrosion of the printhead. 

A logic model that graphically portrays the combinations of failures that can lead to a particular main failure (TOP event) or accident of interest. Given appropriate data, fault tree models can be quantitatively solved for an array of system performance characteristics (mean time between failures, probability of failure on demand, etc.)... 

Failure on Demand. Certain components are required to start, change state, or perform a particular function at a particular time. Failure to do so is a failure on demand. ... 

To guarantee shipment on time, you either need to maintain an adequate inventory of finished goods for shipment on demand or utilize only predictable processes and obtain sufficient advanced order information from your customer. When you examine some of the requirements in ISO/TS 16949, you may be tempted to question how you can continually improve performance, reduce costs, and minimize space, material travel, equipment downtime, process variation, etc. and meet 100% on-time shipments. You can t, unless you have a partnership with your customer in which there is mutual assistance to meet common objectives. Without sufficient lead time on orders you will be unlikely to meet the target. However, the standard does acknowledge that you may not always be successful. There will be matters outside your control and matters over which you need complete control. It is the latter that you can do something about and take corrective action should the target not be achieved. 

Conditions of health and age play an important role in human performance. Job demands will determine the general fitness and age of the workers to be employed for a particular job. Recent illness can affect the level of alertness, the required concentration on the job, and the capability to cope with high workload. 

The LER data base served as the primary source of DG failure data, while a data base for DG successes was formed from nuclear plant licensees responses to a USNRC questionnaire (Generic Letter 84-15). Estimates of DG failure on demand were calculated from the LER data, DG test data, and response data from the questionnaire. The questionnaire also provided data on DG performance during complete and partial LOSP and in response to safety injection actuation signals. Trends in DG performance are profiled. The effects of testing schedules on diesel reliability are assessed. Individual failures are identified in an appendix. 

Failure related maintenance demands Whenever a repair is made on a piece of equipment, a complete functional check-out is usually performed on it and the other equipment in the functional loop. Consequently, the number of shutdown and startup demands to repair degraded and incipient failures must be added to the number of catastrophic demand failures to determine total maintenance-related demands. These numbers are gathered from the encoded failure data that are in turn extracted from the raw plant records. 

Many low weight compounds produced by microor-ganism-like formylated peptides as well as endogenous mediators are chemotactic for leukocytes and promote the inflammatory process. The main endogenous compounds are listed in Table 1 and are derived from activated plasma protein cascades that function as amplification mechanisms, are performed and released from activated cells or are de novo synthesized on demand by cells participating in or being affected by inflammatory events. The major modulators of leukocyte adhesion to endothelial cells are listed in Table 2. 

We must next consider more precisely the connection between the description of bodily identical states by the two observers (the requirements of Postulate 1). Quite in general, in fact, a physical theory, and quantum electrodynamics in particular, is fully defined only if the connection between the description of bodily identical states by (equivalent) observers is known for every state of the system and for every pair of observers. Since the observers are equivalent every state which can be described by 0 can also be described by O. Given a bodily state of the same system, observer 0 will ascribe to it a state vector Y0> in his Hilbert space and observer O will attribute to it a state vector T0.) in his Hilbert space. The above formulation of invariance means that there exists a one-to-one correspondence between the vectors Y0> and Y0.) used by observers 0 and O to describe bodily the same state.3 This correspondence guarantees that the two Hilbert spaces are in fact isomorphic. It is, therefore, possible for the two observers to agree to describe states of the system by vectors in the same Hilbert space. A similar statement can be made for the observables there exists a one-to-one correspondence between the operators Q0 and Q0>, which observers 0 and O attribute to observables. The consistency of the theory (Postulate 2) demands, however, that the two observers make the same prediction as the outcome of the same experiment performed on bodily the same system. This requires the relation... 

The use of hydraulic units to drive rubber processing machinery has enabled the elimination of cumbersome gear boxes and their respective couplings. The hydraulic drive unit is fitted directly to the end of the shaft to be driven. It can be controlled fully across the entire speed range and provides full torque from rest, even under heavy load, up to the maximum rotational speed demanded. Shock loads do not affect performance and it has the ability to stop immediately on demand, due to its low inertia, unlike conventional drive systems. The unit requires little maintenance. 

There are no electrolyzers developed specifically for operation with wind turbines. However, the rapid response of electrochemical systems to power variations makes them suitable "loads" for wind turbines. Industrial electrolyzers are designed for continuous operation, mainly because their elevated investment cost requires high-capacity factors for reasonable payback times, but they are subject to a considerable number of current interruptions through their lifetime due to occasional power interruptions, accidental trips of safety systems, and planned stops for maintenance. Current interruptions are more frequent in specialty applications, where electrolyzers supply hydrogen "on demand." Therefore, the discontinuous use of the equipment is not new, and most commercial electrolyzers may be used in intermittent operation although a significant performance decrease is expected with time. In fact, it is not power variation, but current interruptions that may cause severe corrosion problems to the electrodes, if the latter are not protected by the application of a polarization current when idle. 

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