Active engineered controls

Percentage of recommendations for administrative controls, active engineered controls, passive engineered controls, and inherently safer alternatives X ... 

Some passive controls will live outside the user interface and may not be apparent to day-to-day operators. For example, HIT systems typically need to exhibit resiliency in their architecture whether brought about through redundancy or other systematic means. These design features represent active engineered controls. However it is common for this to be supported by other more passive controls which require some degree of human intervention. The platforms on which systems reside can often be monitored for availability and performance. In some cases systems may be specifically instrumented to provide metrics on the execution of specific functions or the success of database transactions. Similarly systems may log errors or failed messages which are then made available for inspection by service management personnel. 

The primary philosophy is to follow the principles of inherent safety. This implies a systematic effort to apply the principles of hazard elimination, minimization/ intensification, hazard substitution, moderation/attenuation, and simplification. However, additional controls will still be required to control a hazardous situation, prevent escalation, and mitigate the risk to people, to the environment, asset, and reputation. Preferably, these safeguards will be passive- or active-engineered controls rather than administrative controls (i.e., dependent on direct human intervention). 

Active—Using controls, safety interlocks, and emergency shutdown systems to detect and correct process deviations e.g., a pump that is shut off by a high level switch in the downstream tank when the tank is 90% full. These systems are commonly referred to as engineering controls. 

Such models must be used in conjunction with a model of converter warmup (1) and a model of catalyst deactivation (6) when designing the distribution of active components in a catalyst and converter and the engine control strategy. 

Assessment. An analysis of the hazards present in this laboratory show the most significant hazard to be the release of vapor CSM from engineering controls and into the workplace. The significance of this hazard mandates further efforts in system safety in the form of a Preliminary Hazard List (PHL) and a Preliminary Hazard Analysis (PHA). The user must in this instance take an active role in the design review process. 

Active controls use engineering controls, safety interlocks and emergency shutdown systems to detect process deviations and take appropriate corrective or remedial action. Their effectiveness depends on proper selection, installation, testing, and maintenance. 

Human activities are associated with the use and disposal of a variety of chemicals and chemical products. This is the situation for a householder, a laboratory student, and also the industry worker. Many materials have properties that make them hazardous. They can create physical (fire, explosion) or health hazards (toxicity, chemical bums). However, there are many ways to work with chemicals which can both reduce the probability of an accident and reduce the consequences should an accident occur. Risk minimization depends on safe practices, appropriate engineering controls for chemical containment, the proper use of personnel protective equipment, use of the least amount of material necessary, and substitution of a less-hazardous chemical for a more hazardous one. Before beginning any chemical processing or operation, ask What would happen if. .. The answer to this question requires understanding of the hazards associated with chemicals, the equipment, and the procedure involved. The hazardous properties of the material and its intended use will dictate the precautions to be taken. 

Efforts should be focused at controlling the identified exposures at their sources. Taking this approach limits potential exposure for workers handling the compound and limits the amount of contamination that will migrate from the work area to other areas of the facility. All process equipment, analytical equipment and activity must be contained by some sort of engineering control when... 

The Town of Greenwich plans to begin construction on the earthen cap (engineering control) and conduct preliminary grading and land contouring activities in 2008. Once these activities are completed, the trails, walkways, and other access structures can be completed. By 2010, the Town of Greenwich will likely be using parts or all of the redeveloped Cos Cob power plant site for recreational purposes. 

Combustion instability that leads to performance deterioration and excessive mechanical loads, which could result in reduced life and premature failure, is an important issue with modern gas turbine engines and ramjet and scramjet combustors. Various techniques of passive and active control to reduce combustion instabilities and improve performance are addressed. Since extensive, promising research is being carried out to develop sensors and actuators, these techniques can be used in practical combustors in the near future. The topics covered in Section 3 provide the required chemical, kinetic, and fluid dynamic understanding to help the designer who is involved in active feedback control for combustion systems. 

Validation is described as proof that the system performs as stated. As an engineering control, the LAF system must demonstrably support the intended aseptic or controlled process. Validation of the aseptic manufacturing process and the LAF systems that support terminal sterilization in pharmaceutical manufacturing applications should be carried out in accordance with industry standards. Such validation should be accomplished in three phases, consisting of installation qualification (IQ), operational qualification (OQ), and process qualification (PQ), with full and detailed documentation of all activities and... 

DeLaat, John C., and NASA Glenn Research Center. Active Combustion Control for Aircraft Gas Turbine Engines. NASA/TM 2000-210346. Hanover, Md. NASA Center for Aerospace Information, 2000. 

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