Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Observables and Operators

In order to predict the outcome of an observation of a particular property for a given state of the system, it is necessary to perform appropriate operations such as multiplications or difierentiations on the wavefunction. In particular, a measurable physical quantity or observable has associated with it a quantum-mechanical operator so that [Pg.18]

The numerical value o of the observable is called the eigenvalue of operator O with respect to the state function For an operator to correspond to an observable, that is to produce an eigenvalue, it is necessary that the result of the operation on is a numerical value times the wavefunction. The wave-function is then an eigenfunction of the operator. [Pg.19]

Usually, the problem is to find simultaneously V and the values o that satisfy the eigenvalue equation (2.1), the form of the operator having been previously established. An operator is a symbol telling us to carry out a certain mathematical operation on anything following it. An example is the differential operator O = d/dx. It is easily found that ip=x is not an eigenfunction of this operator [Pg.19]

The wavefunctions can be real or complex functions. In the case of a complex wavefunction of the coordinates x, y,zoi a. particle, the probability of finding the particle at an element of volume dv around an arbitrary point is proportional to [Pg.19]

If ipi and ip2 are eigenfunctions of a linear operator, functions ci i + cz ipz are not eigenfunctions of that operator [Pg.20]


The modifications shown in Fig. 10.46 were installed in the field unit. Reports from field unit operators and observers indicated that the significant improvement shown by the model tests was also exhibited in the field. [Pg.909]

Water monitoring stations are well marked and well studied locations at which water properties can be measured continuously or periodically, and representative water samples can be collected for laboratory analyses. Examples include sites along rivers, lakes, ponds, sea shores, piezometers, wells (both operating and observation wells), and springs. [Pg.394]

Goossens, K.G.W. (April 1995) Reasoning About VHDL Using Operational and Observational Semantics. Rapporto di Ricerca SI/RR 95/06, Dipartimento di Scienze dell Informazione, University di Roma "La Sapienza . [Pg.104]

This example is taken from Swain and Guttman (1983, 2011) and summarized later. Their results derived from a plant visit, review of procedures, interviews with the operators, and observations of the tasks performed. [Pg.239]

ROS IS a complete part of NURESIM in which one can practice as a reactor operator and observe on computer screen the positions of the control rods (longitudinal and transverse cross section) and power display... [Pg.150]

The reservoir model will usually be a computer based simulation model, such as the 3D model described in Section 8. As production continues, the monitoring programme generates a data base containing information on the performance of the field. The reservoir model is used to check whether the initial assumptions and description of the reservoir were correct. Where inconsistencies between the predicted and observed behaviour occur, the model is reviewed and adjusted until a new match (a so-called history match ) is achieved. The updated model is then used to predict future performance of the field, and as such is a very useful tool for generating production forecasts. In addition, the model is used to predict the outcome of alternative future development plans. The criterion used for selection is typically profitability (or any other stated objective of the operating company). [Pg.333]

We are confident that any user of this combined evaluation technique, as well as the development of future test standards for manual ultrasonic testing will benefit from this result, because it allows a greater flexibility in the applicable method without loosing reliability. Often an expensive production of a reference block can be avoided and therefore testing costs are reduced. Since all calculations are performed by a PC, the operator can fully concentrate on his most important duty scanning the workpiece and observing the A-scan. Additional time will be saved for the test documentation, since all testing results are stored in the instrument s memory (the PC s hard drive) with full link to the Software World (Microsoft Word, Excel, etc.). [Pg.818]

Decades of work have led to a profusion of LEERs for a variety of reactions, for both equilibrium constants and reaction rates. LEERs were also established for other observations such as spectral data. Furthermore, various different scales of substituent constants have been proposed to model these different chemical systems. Attempts were then made to come up with a few fundamental substituent constants, such as those for the inductive, resonance, steric, or field effects. These fundamental constants have then to be combined linearly to different extents to model the various real-world systems. However, for each chemical system investigated, it had to be established which effects are operative and with which weighting factors the frmdamental constants would have to be combined. Much of this work has been summarized in two books and has also been outlined in a more recent review [9-11]. [Pg.182]

The significance of establishing a limiting rate of reaction upon encounter for mechanistic studies has been pointed out ( 2.5). In studies of reactivity, as well as settii an absolute limit to the significance of reactivity in particular circumstances, the experimental observation of the limit has another dependent importance if further structural modification of the aromatic compound leads ultimately to the onset of reaction at a rate exceeding the observed encounter rate then a new electrophile must have become operative, and reactivities established above the encounter rate cannot properly be compared with those measured below it. [Pg.125]

The way out of this dilemma is easily stated, although not easily acted upon. It is not adequate to consider any one of these approaches for the explanation of something as complicated as these reactions. Polarity effects and resonance are both operative, and, if these still fall short of explaining all observations, there is another old standby to fall back on steric effects. [Pg.443]

To an experienced operator trained in the handling of industrial chemicals, the dimers present Httle cause for concern in handling or storage. The finished polymer coating presents even less of a health problem contact with the reactive monomer is unlikely. In the ancillary operations, such as cleaning or adhesion promotion, the operator must observe suitable precautions. Before using the process chemicals, operators must read and understand the current Material Safety Data Sheets, which are available from the manufacturers. [Pg.443]

Reviewing the cavitation theme, we observe tlvat the majority of eavitation is eaused or induced by operation and design. [Pg.37]

It is hoped that this volume will provide some guidance to operators, plant safety engineers and designers, and that some of the design practices are adopted particularly in older plant operations that do not apply proper pressure let down procedures and flaring practices. Many unsafe operations and even catastrophic failures have been observed by the author in overseas assignments to such countries as Ukraine and other Newly Independent States (NIS) in older plant designs. These incidents have prompted the preparation of this reference. [Pg.389]

More inclusive is Table 3.3.1 -3 which is appropriate at depth into the analysis. The major headings in this table address major hazardous subject areas,. iccideni mitigation, protection and repair. I or example, under the first major heading, "Storage of Raw Materials, Products, Intermediates," listed are confinement measures, release nicclumi.sms (valves), procedures for safe operation and limitations that must be observed for safety. [Pg.78]

After preparation, a checklist may be used by less expert engineers than the preparers for inspecting the process areas to compare the process equipment and operations with the checklist oidrcr on hardcopy or laptop computer. The analyst fills in the checklist according to observations from their inspection, process documentation, and interviews with operators and their perceptions. [Pg.78]

The experienced field operator has observed water and gas being emitted from the hydrocarbon vent at the cooling tower. The field operator shouts over the radio that a propane vapor cloud appears to be forming and moving towards the control room. [Pg.231]


See other pages where Observables and Operators is mentioned: [Pg.208]    [Pg.18]    [Pg.19]    [Pg.1702]    [Pg.22]    [Pg.302]    [Pg.76]    [Pg.771]    [Pg.96]    [Pg.208]    [Pg.18]    [Pg.19]    [Pg.1702]    [Pg.22]    [Pg.302]    [Pg.76]    [Pg.771]    [Pg.96]    [Pg.187]    [Pg.585]    [Pg.245]    [Pg.512]    [Pg.153]    [Pg.2573]    [Pg.2573]    [Pg.2573]    [Pg.107]    [Pg.116]    [Pg.109]    [Pg.158]    [Pg.654]    [Pg.179]    [Pg.432]    [Pg.215]    [Pg.362]    [Pg.365]    [Pg.146]    [Pg.39]    [Pg.22]    [Pg.178]    [Pg.1269]    [Pg.338]   


SEARCH



Observable operator

© 2024 chempedia.info