Standard Input and Output

When a Perl script reads a line from and prints without using a specified file-handle, it instead uses two automatic filehandles called STDIN and STDOUT. The statements 

The names STDIN and STDOUT are derived from standard input and standard output, an idea popularized by the UNIX operating system. Standard input and standard output are abstract files from which a script can accept input and send output, respectively. When a script is first launched, standard input corresponds to the keyboard and standard output corresponds to the computer screen. On Windows and UNIX systems, standard output appears in the command interpreter window. On Macs, the output appears in a small scrolling window that MacPerl creates specifically for this pmpose. When a Perl script is laimched, the user has the option of changing where standard input and output come from and go to. The user can also arrange for the standard output of one script to be sent to the standard input of another script in assembly-line fashion. This is actually a very powerful facility, but one that is beyond the scope of this chapter. 

To redirect standard input from a file in either Microsoft Windows or UNIX systems, use the less-than ( ) symbol to indicate the file  

Standard input and output can be redirected simultaneously by using both symbols on the same command line  

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The scope and terms used are well defined and includes a listing of standards and codes for reference. The purchaser is required to make decisions regarding gear-rated horsepower and rated input and output speeds. 

To ensure flexibility for possible later additions or changes, the instrumentation has to be selected based on standardized subproducts using national or international norms. These standards are mainly based on the measuring areas and signal types. Typical signals for input and output to the data-based controller (DDC and PTC) are... 

Depending on the control system and components selected, the process variable from the sensors and signals to the actuator control unit is connected either directly or through transducers. Normally, the input and output are adjusted from pneumatic sensors and control units. The signals produced then are transformed into standard electronic values before connecting to the controller s input and output modules,... 

Analog inputs and outputs in data-based (DDC) controllers are usually standardized and record the signals from sensors or transducers as 0(2)-10 VDC or 0(4)-20 mA. The inputs module can also be standardized for resistances, as Pt 100 DIN, Pt 1000 or Ni 1000 DIN (Pr = platinum, Ni = nickel). 

File—Composed of elements (which may be records or other data structures) of the same type sequential files only in standard Wirth Pascal external (physical) files (for input and output) must be declared with the program heading (see Statements ) and internal (temporary) files may be added for use within the program all files except INPUT and OUTPUT must be declared in TYPE and/or VAR sections. 

The enthalpy change, AH, can be calculated for a steady-state process, using H°f, which is the enthalpy of formation of the various output and input components. Under the assumption that the inputs and outputs are at ambient conditions, the enthalpy of the components corresponds to the standard enthalpy of formation of each component. The kinetic and potential energy terms are neglected from the energy balance. It is also assumed that water enters the process as a liquid and hydrocarbon products leave the process as a liquid. All other components are in the gas phase. 

It can be shown that the maximum theoretical work produced (or minimum work required) for a process is related to the change in Gibbs energy of the process, assuming again the inputs and outputs of the process are pure components at standard conditions (Denbigh, 1956 De Nevers and Seader, 1980). 

The operational qualification of computerized systems consists of a group of tests, pooled in functional checks. The tests are carried out step by step on each component. The general approach used is of the gray-box type. More precisely, study the input and output data transmission at intermediate points. The structure of the operational qualihcation may be standardized for all operational qualihcation of computerized pharmaceutical equipment. 

D Dj Do, DR E Ea E° Ea Ec Em, Eoui m-3) diffusion coefficient (m2 s 1) diffusion coefficient of species (m2 s-1) diffusion coefficient of species O and R (m2 s-1) electrode potential (vs. some reference electrode) (V) null or equilibrium potential (V) standard potential (V) interelectrode potential (V) voltage input and output of a circuit (V)... 

There is greater variability in operational inputs and outputs, making it more difficult to standardize and control. 

The input and output information are similar to those for standard molecular simulations. Only microscopic parameters are usually required. A very standard set of parameters such as OPLS is sufficient to perform the computations. In this sense, the theory does not require any kind of adjustable parameters. 

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