TECHNICAL APPROACHES

Evaluating Sensors for Use in Very-High-Amplitude Noise Fields 

The measurements must accurately represent the acoustic field without contamination from the measurement system. In particular, any nonlinear distortion 

Two approaches are proposed to resolve this difficulty. The first is based on generation of a high-purity acoustic field in a spherical, unharmonic resonator, and the second is based on comparison of a set of transducers with limited but overlapping dynamic ranges. In the second approach, simultaneous measurement of a broadband signal produces an accurate characterization over the entire range. Candidates for sensor fabrication include solid dielectric capacitive sensors, piezoelectric transducers, and high-temperature lithium niobate or quartz transducers. 

The discussion up to this point has neglected interactions between the sensor and the medium, other than that required to sense the sound, of course. It is anticipated that several problems not apparent in linear-acoustics sensor development will crop up at sound levels relevant to jet noise. There are two areas of initial concern (z) boundary layer interactions with the sensor surface and (it) perturbation of the acoustic and nonacoustic flow fields due to the presence of the sensor. The boundary conditions imposed on a fluid by the presence of a solid surface cause both viscous and thermal boundary layers to form in the fluid 

Perturbation of the Acoustic and Nonacoustic Flow Fields by the Sensor 

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The QRA project team can select the appropriate technical approach once you specify the study objectives, and together you can define the scope. A variety of modeling techniques and general data sources (discussed in Section 3.2) can be used to produce the desired results. Many computer programs are now available to aid in calculating risk estimates, and many automatically give more answers than you will need. The QRA team must take care to supply appropriate risk characteristics that satisfy your study objectives—and no more. 

STAHR Socio-Technical Approach to assessing Human Reliability Phillips et al.. 1983... 

Phillips, L. D., P. Humphreys, and D, E. Embrey, 1983, A Socio-Technical Approach to A Human Reliability (STAHR), TR 83-4, July,... 

The first step in minimizing accidents in a chemical phuit is to evaluate the facility for potential fires, explosions, and vulnerability to other liazards, particularly those of a chemical miture. This calls for a detailed study of plant site and layout, materials, processes, operations, equipment, and training, plus an effective loss prevention program. The technical nature of industry requires detailed data and a broad range of experience. Tliis complex task, today becoming the most important in plant design, is facilitated by the safety codes, standiu ds, and practice information available. The technical approach to evaluating die consequences of hazards is discussed later in tliis cliapter and in Part V (Chapters 20 and 21). 

Only four of tiie 10 countries— Australia, Estonia, Malaysia and the Netherlands —operate an audit system to evaluate the GMP performance of inspectors or the inspectorate. Auditing of distribution-channel inspection is carried out by Malaysia, the Netherlands, Uganda and Venezuela. In Australia, GMP audit is both internal and external, and involves an extensive review of process and technical approach. Further training, advice, revision of job description, legal proceedings and dismissal of inspectors are some of the means used to correct any weaknesses observed. 

But our approach must not conflict with the prescribed approach - where this occurs in the text, the reader s attention is drawn to it. The technical approach must complement the prescribed approach and not replace it. 

The latter comment raises a problem that should be tackled as follows. In a technical analysis, conclusions should never be in contradiction with the regulations in force. If there is such a contradiction, one should opt for the solution offered by regulation if it leads to a classification harsher than the technical approach. If on the contrary the technical approach leads to the opposite, approval is needed before an aggravated classification can be used, in our case our approach has nothing to do with this notion of threshold. In practical terms, the analyst deals with a scale that makes it easy to compare these substances with each other. It will be his knowledge about the situation in which the work with these substances would be like which will enable him to choose the measures according to the different II and H levels more than the code dictated by regulations. 

Following is the technique used by the NFPA and European Union and labour regulations in order to classify instability hazard before coming back to the technical approaches. 

Development of an industrial monitoring application for IMS requires extensive preparatory work, as well as optimal operational conditions for IMS, i.e. the nature of the reagent gas, calibration curves, evaluation of interferents, assessment of reliability. Analysis of mixtures with four or fewer components may be possible, but extension to more complex mixtures should be considered only in special cases, and generally would be unrealistic. Use of preseparators, such as GC columns, is the only known technical approach... 

Many policies and practices have been adopted by European countries for the management of contaminated sites. Information about the various national polices, the technical approaches for risk assessment, and the progress of rehabilitation activities in Europe has been compiled in the framework of two European networks—CARACS (Concerted Action for Risk Assessment for Contaminated Sites) and CLARINET (Contaminated Land Rehabilitation Network for Environmental Technologies)—which were funded by the European Commission. A detailed description of European national policies can be found in relevant publications2 3 and in the CLARINET website (http //www.clarinet.at). 

The technical approach to calculate critical loads used in this research was similar to that described earlier (Posch et al., 1999 Bashkin et al., 2001a). Different biogeochemical data were used for the calculation and mapping of critical loads for acid forming and eutrophication compounds (SO2, NO ). These data were monitored... 

In the previous sections we have discussed two different applications of gas-phase catalysis. Although different in nature, both case studies had the common feature that (1) all employed educts and the obtained products were gaseous and (2) the change in volume of the gas phase resulting from the educt conversion is negligible. For a number of reactions, especially for reactions in the petrochemical industry both of the above-mentioned features cannot be neglected, we will discuss classic examples and present technical approaches to overcome the obstacles related to the chemical transformations. 

Table 11.5 Most Popular Technical Approaches for Stage l-Screening in Liquid Phase Catalysis...

The economic)technical approach focuses on the question of which occurrences can be extracted economically with today s technology. According to this approach, all occurrences that at present are economically extractable with existing available technology are classified as conventional, whereas occurrences that are not extract-able at present owing to economic or technical hurdles are considered unconventional. The physical properties of the oil are not taken into account. It is important to note that, in this approach, the boundary between conventional and unconventional crude oil is current, as it is subject to the market price of oil, the production cost and the available technology. 

The physical and economic or technical approaches made no big difference with respect to the oil that has been produced until now. According to the economic or technical approach - as advancing technology and rising prices will facilitate the economic production of new resources - the boundary will increasingly be shifted from unconventional oil towards conventional oil. This is, for instance, the case in Venezuela and Canada, where extra heavy oil and oil sands have already been economically produced for several years. According to the physical approach, however, this leads to a rise in the production volumes of unconventional oil. In this publication, the distinction between conventional and unconventional occurrences will be made according to the physical approach. 

Just as oil, natural gas is also categorised as conventional and unconventional. Unlike crude oil, however, natural gas deposits are normally classified according to the economic or technical approach, i.e., all occurrences that are currently extract-able under economic conditions are considered conventional, whereas the rest are termed unconventional. Conventional natural gas includes non-associated gas from gas reservoirs in which there is little or no crude oil, as well as associated gas , which is produced from oil wells the latter can exist separately from oil in the formation (free gas, also known as cap gas, as it lies above the oil), or dissolved in the crude oil (dissolved gas). Unconventional gas is the same substance as conventional natural gas, and only the reservoir characteristics are different and make it usually more difficult to produce. Unconventional gas comprises natural gas from coal (also known as coal-bed methane), tight gas, gas in aquifers and gas hydrates (see Fig. 3.17). It is important to mention in this context so-called stranded gas , a term which is applied to occurrences whose extraction would be technically feasible, but which are located in remote areas that at the moment cannot (yet) be economically developed (see Section 3.4.3.1). 

The development and design of the new sulphuric acid catalyst involves numerous disciplines, work tasks and methods from the field of practical catalysis and chemical engineering. The most important steps of the development process are briefly described in this section but for a deeper technical approach to the theory and methods, the reader is referred to text books within the field [1, 13-14],... 

Technical approaches must be scientifically valid and clinically relevant, and documentation that the laboratory director has reviewed all procedures on an annual basis is required. A copy of discontinued procedures is to be maintained for 2 yr thereafter, recording initial date of use and retirement date. 

This chapter discusses the features of CT imaging and outlines how the images are formed. Several different technical approaches are described along with examples. Finally, issues to be considered in designing luggage scanners are presented. 

A number of companies have made entries into the CMP waste treatment market, using a variety of technical approaches. So far there has been no... 

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