Element common objects

A control system or scheme is characterized by an output variable (e.g., temperature, pressure, liquid level, etc.) that is automatically controlled through the manipulation of inputs (input variables). Suppressing the influence of external disturbances on a process is the most common objective of a controller in a chemical plant. Such disturbances, which denote the effect that the external world has on a process, are usually out of reach of the human operator. Consequently, a control mechanism must be introduced that will make the proper changes on the process to cancel the negative impact that such disturbances may have on the desired operation of the process. Control engineers usually refer to the combination of a sensing element and a control device with a set point as a control loop. ... 

In corrective maintenance, the objective is to restore the system to its designed state. To illustrate the factors which go into maintainability, it is simplest to concentrate on the corrective case of Figure 1 since this contains all the elements common to the others. 

The choice of contract type will depend upon the type of work, and the level of control which the oil company wishes to maintain. There is a current trend for the oil company to consider the contractor as a partner in the project (partnering arrangements), and to work closely with the contractor at all stages of the project development. The objective of this closer involvement of the contractor is to provide a common incentive for the contractor and the oil company to improve quality, efficiency, safety, and most importantly to reduce cost. This type of contract usually contains a significant element of sharing risk and reward of the project. 

The most common IDPs are black objects having approximately solar elemental composition except for very volatile elements such as the noble... 

Analytical x-ray instruments ate used to characterize materials in several different ways. As with medical x-ray instmments there are analytical instmments that can produce images of internal stmctures of objects that are opaque to visible light. There are instmments that can determine the chemical elemental composition of an object, that can identify the crystalline phases of a mixture of soHds, and others that determine the complete atomic and molecular stmcture of a single crystal. These ate the most common appHcations for x-ray iastmments. 

Another element that exhibits allotropy because of variations in the crystal structure is tin. The common allotrope is tin metal, also known as a alpha) tin, which is stable at ambient temperatures. The other allotrope, which generally occurs as a gray powder and is known as p beta) tin, but also as tin pest, is formed only at very low temperatures when tin cools down to temperatures below -18°C, the ordinary allotrope, a tin, is converted to p tin, and the transformation is irreversible under ordinary temperatures. Tin objects exposed to temperatures below -18°C in very cold regions of the world, for example, are generally severely damaged when part of the tin converts to tin pest. In extreme cases, when exposure to low temperatures extends for long periods of time, the allotropic conversion may result in the transformation of tin objects into heaps of gray p-tin powder. 

The Model-View-Controller (MVC) architecture (or some variant) is commonly used in the design of user interfaces. A user-interface element is associated with a single model—the object that acts as the source of the information presented, and the recipient of user requests. Each element is designed as a pair of a view, which deals with the presentation aspects of information from the model and a controller, which is responsible for interpreting user inputs and gestures for the view and the model. The view and controller roles are combined into a single object in some variants. 

Biological extractions are carried out to determine if biologically important elements are at levels that are sufficient, yet not toxic, for plant needs. Acid soil extraction to determine the biologically available plant nutrients is the most common type of extraction of soil carried out. The objective is to extract a portion, not all, of a particular nutrient or metal that is correlated to the amount available to plants. The plants of primary interest are crop plants such... 

---