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System, description properties

System description is tlie compilation of tlie process/plant information needed for tlie risk analysis. For e. ample, site locations, environs, weatlier data, process flow diagrams (PFDs), piping an instnmientation diagrams (P IDs), layout drawings, operating and maintenance procedures, technology documentation, process chemistry, and tliermophysical property data may be required. [Pg.450]

Applicable to large genome-scale systems Description includes regulatory properties... [Pg.189]

These simple molecular orbital pictures provide useful descriptions of the structures and spectroscopic properties of planar conjugated molecules such as benzene and naphthalene, and heterocychc species such as pyridine. Heats of combustion or hydrogenation reflect the resonance stabilization of the ground states of these systems. Spectroscopic properties in the visible and near-ultraviolet depend on the nature and distribution of low-lying excited electronic states. The success of the simple molecular orbital description in rationalizing these experimental data speaks for the importance of symmetry in determining the basic characteristics of the molecular energy levels. [Pg.103]

In most general terms, physical chemistry has as its task the compact, quantitative description of the properties and behavior of matter. Within this framework we can make a useful, if sometimes arbitrary, distinction between systems whose properties do not change with time and those systems whose properties are time-dependent. Chemical kinetics is that branch of physical chemistry concerned with the study of the latter systems, and in particular with the subgroup of those systems whose chemical composition is changing with time, i.e., systems in which chemical reactions are occurring. [Pg.3]

For the description of systems whose properties are changing with time, we may propose an extension of our previous definition. A minimum description of a kinetic system is the statement of the necessary and sufficient information which will permit us, at each instant in time to construct (in principle, if not in practice) a similar system having identical properties. [Pg.4]

None of these rules is foolproof. However, they are useful guidelines, and the combination of relatively simple techniques can often be used to get a good estimate of the relative stability of polymorphs under a variety of conditions, information which is useful in understanding polymorphic systems, the properties of different polymorphs and the methods to be used to selectively obtain any particular polymorph (see Section 3.2). As noted above, much of that information can be included in the energy/temperature diagram, and the actual preparation of that diagram from experimentally determined quantities is described in Sections 4.2 and 4.3 following the description of the techniques used to obtain those physical data. [Pg.42]

The method is based on a combination of the DARC system (Description, Acquisition, Retrieval and Computer-aided design) and the PELCO (Perturbation of an Environment Limited Concentric and Ordered) procedure. Moreover, it accounts for the simultaneous representation of all the data set compounds and the population of the compounds structurally contained in them the data set compounds, which are those compounds for which a molecular property has been experimentally evaluated, generate an ordered multidimensional space that constitutes a —> hyperstructure. [Pg.179]

In this chapter we continue the quantitative development of thermodynamics by deriving the energy balance, the second of the three balance equations that will be used in the thermodynamic description of physical, chemical, and (later) biochemical processes. The mass and energy balance equations (and the third balance equation, to be developed in the following chapter), together with experimental data and information about the process, will then be used to relate the change in a system s properties to a change in its thermodynamic state. In this context, physics, fluid mechanics, thermodynamics, and other physical sciences are all similar, in that the tools of each are the same a set of balance equations, a collection of experimental observ ations (equation-of-state data in thermodynamics, viscosity data in fluid mechanics, etc.), and the initial and boundary conditions for each problem. The real distinction between these different subject areas is the class of problems, and in some cases the portion of a particular problem, that each deals with. [Pg.45]

The statistical collection and representation of the weather conditions for a specified area during a specified time interval, usually decades, together with a description of the state of the external system or boundary conditions. The properties that characterize the climate are thermal (temperatures of the surface air, water, land, and ice), kinetic (wind and ocean currents, together with associated vertical motions and the motions of air masses, aqueous humidity, cloudiness and cloud water content, groundwater, lake lands, and water content of snow on land and sea ice), nd static (pressure and density of the atmosphere and ocean, composition of the dry ir, salinity of the oceans, and the geometric boundaries and physical constants of the system). These properties are interconnected by the various physical processes such as precipitation, evaporation, infrared radiation, convection, advection, and turbulence, climate change... [Pg.171]

The reader s attention will instantly be attracted by the point, that here, in the description of the system, chemical properties are mentioned as well. Additionally, a (logical) definition of the discipline of meteorology is given by the inclusion of atmospheric chemistry. Also, a differentiation between the concepts of air and atmosphere can be made out in the sense that air is seen as a substantial (that is, chemical) composite, which behaves within the atmosphere according to geo-physi-cal laws. Now, the WMO becomes inconsistent with its description of meteorological elements (that is, the system parameters of the state of the atmosphere), as no (atmospheric) chemical properties are numerated ... [Pg.328]

Restricting oneself with morphology gives no clue to the control over the structure of a system and leads, sooner or later, to internal contradictions in the description of the system s properties. For example, the mentioned section coiitmns a phrase that, by its briefness and clarity, sounds like a law The degree of association increases with increasing concentration of solution and the molecular mass of a polymer (this can often be met,... [Pg.846]

The most commonly used specification for base materials is IPC-4101. This specification presents a classification scheme and specification sheets for the various materials in use. Table 6.2 summarizes the various materials by specification sheet number. Each specification sheet in IPC-4101 includes property requirements for that particular material type. As these specification sheets are updated periodically, it is recommended that the latest revision of this document be reviewed. This is particularly true in light of new requirements for materials that must be compatible with lead-free assembly.Table 6.2 is presented for reference only and is not all-inclusive. UL94 comments in Table 6.2 reference the minimum flammability requirements for that material. Materials may exceed these minimum ratings. Also note that where a non-halogen-based flame retardant is used, it is shown along with the resin system description. Definitions of the UL flammability ratings are given in Chap. 8. [Pg.123]

In a similar way other terms, which are not included explicitly in (1), may be included implicitly. It is therefore hard to judge a priori the accuracy of the model (1) for a certain class of systems and properties. To determine this we have to rely on a comparison of experiments with calculations for this model. For the cases where the model gives a good description, the determination of the parameters from first principles requires an understanding of the types of renormalizations involved. For U and Herbst et al. (1978) have made important progress in this respect, while the hopping parameters are much less well understood. [Pg.108]

We model the entire system probabilistically, by building a stochastic state machine for each element included in the system description. Each state machine has two states - OK and Fail . Depending on the element type, its model in addition to a state machine may include additional properties. For instance, the model of a generator will have a property defining the maximum output power the model of a load includes the power consumed as an additional property, etc. The interested reader may find further details in [2]. [Pg.320]

In any case, there is a system of our safety concern during the safety assurance process. To describe a system comprehensively, we may have varied types of information developed, refined and updated throughout its life cycle, e.g. functions, architecture, task profiles, operation modes, use scenarios, functional and non-functional properties. It has been observed as commonplace that system description of various levels of details can be used for shaping the higher level argument structure in safety cases. Some generic strategies formulated from this information source include ... [Pg.387]

This paper adopts a set-theory framework for the resilience analysis of interconnected infrastructure systems. A detailed description of the system dynamics modeling is provided and invariance properties are analyzed to define and identify the resilience region, as a function of the governing parameters. This allows controlling the characteristics of the system resilience properties by design, operation and maintenance properties as represented by the values of the related parameters. An illustration of the analytical power of the framework adopted is provided on an interconnected interconnected system case study, with detailed discussions of its behavior and response to failures and/or disturbances, based on simulation results. [Pg.205]

Explicitly model of the independencies vs. simulating the behavior of the Cl interconnected within the SoS and assess the strength of interdependencies as an emerging system property. The former is a top-down model which assumes the existence of interdependencies. The latter is bottom-up system description which maps the functional relations among components in different systems. ABM can be regarded as the bottom-up approach CN, SD, and DCST can represent system functionality as bottom-up approaches PN, BN and IIM require the identification of system dependencies and are top-down approaches. [Pg.2064]

To gain an understanding of the composition of the reservoir rock, inter-reservoir seals and the reservoir pore system it is desirable to obtain an undisturbed and continuous reservoir core sample. Cores are also used to establish physical rock properties by direct measurements in a laboratory. They allow description of the depositional environment, sedimentary features and the diagenetic history of the sequence. [Pg.126]

In many experiments the sample is in thennodynamic equilibrium, held at constant temperature and pressure, and various properties are measured. For such experiments, the T-P ensemble is the appropriate description. In this case the system has fixed and shares energy and volume with the reservoir E = E + E" and V=V + V", i.e. the system... [Pg.417]

If these assumptions are satisfied then the ideas developed earlier about the mean free path can be used to provide qualitative but useful estimates of the transport properties of a dilute gas. While many varied and complicated processes can take place in fluid systems, such as turbulent flow, pattern fonnation, and so on, the principles on which these flows are analysed are remarkably simple. The description of both simple and complicated flows m fluids is based on five hydrodynamic equations, die Navier-Stokes equations. These equations, in trim, are based upon the mechanical laws of conservation of particles, momentum and energy in a fluid, together with a set of phenomenological equations, such as Fourier s law of themial conduction and Newton s law of fluid friction. When these phenomenological laws are used in combination with the conservation equations, one obtains the Navier-Stokes equations. Our goal here is to derive the phenomenological laws from elementary mean free path considerations, and to obtain estimates of the associated transport coefficients. Flere we will consider themial conduction and viscous flow as examples. [Pg.671]


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See also in sourсe #XX -- [ Pg.218 ]




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