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The purpose of this paper is to review the application of digital holography in studies of the corrosion of metallic materials.

Digital holography is used for in situ observation of the dynamic processes at the electrode | electrolyte interface and on the electrode surface during the corrosion dissolution of metallic materials.

Digital holography is an effect method to in situ observe the corrosion processes, and it can provide a direct experimental foundation for studying the corrosion mechanism.

Even though there are several challenges, digital holography will play a significant role in studying corrosion processes.

CURRENT methods for the analysis of stress and mode of vibration of blades, discs and small components are briefly reviewed. Alternative methods using holography are described and compared with conventional methods in terms of yield of information and ease of operation. Finally apparatus is described which will take holograms of objects up to two feet in diameter and may be operated by non‐specialist staff.

Holography is a technique which can be used to create realistic three‐dimensional images; it has attracted a great deal of public interest recently, as a result of television publicity, exhibitions in London and other centres, and a fascination with the apparently solid images seen in empty space. The intimate link between holography and the laser, the light source necessary for making a hologram, has reinforced the interest, since lasers are regarded as one of the wonders of the present day, because of their rapidly increasing applications, and of the spectacular effects that they can produce. Many people have seen displays involving the use of laser beams for entertainment or for aesthetic purposes, in Laser Light shows, or Christmas decoration, and in the concerts of some pop groups, but such applications are not strictly related to holography, and it is with the application of the three‐dimensional holographic image that this article is concerned.

Holography is a technique which can be used to create realistic three‐dimensional images; it has attracted a great deal of public interest recently, as a result of television publicity, exhibitions in London and other centres, and a fascination with the apparently solid images seen in empty space. The intimate link between holography and the laser, the light source necessary for making a hologram, has reinforced the interest, since lasers are regarded as one of the wonders of the present day, because of their rapidly increasing applications, and of the spectacular effects that they can produce. Many people have seen displays involving the use of laser beams for entertainment or for aesthetic purposes, in Laser Light shows, or Christmas decoration, and in the concerts of some pop groups, but such applications are not strictly related to holography, and it is with the application of the three‐dimensional holographic image that this article is concerned.

Holography — the method of three‐dimensional photography, using lasers, for component testing and design — is overcoming some of the practical drawbacks which have restricted its applications. General Motors, for example, are now using holography for measuring up clay models of cars prior to making press dies, and engineers are confident that this 3D technique will soon be in everyday use on the shop floor.

The purpose of this study is to measure the mass diffusion coefficient of nitrogen in jet fuel using digital holography interferometry for cost-effective designing and modeling of the aircraft tank inerting system.

The mass diffusion coefficients of N₂ in RP-3 and RP-5 jet fuels were measured by digital holography interferometry at temperatures ranging from 278.15 to 343.15 K. The Arrhenius equation is used to adequately describe the relationship between mass diffusion coefficients and temperature. The viscosities of RP-3 and RP-5 jet fuels were also measured to examine the accuracy of the Stokes–Einstein model in calculating mass diffusion coefficients.

As temperature increases from 278.15 to 343.15 K, the mass diffusion coefficients increase 4.23-fold for N₂ in RP-3 jet fuel and 5.13-fold for N₂ in RP-5 jet fuel. The value of Dµ/T is not constant as the Stokes–Einstein equation expressed, but is a weak linear function of temperature.

A more accurate diffusion model is proposed by fitting the measured Dµ/T with the temperature and calculating the mass diffusion coefficients of N₂ in RP-3 and RP-5 jet fuels within 10 per cent relative deviation.

A measurement system for mass diffusion coefficients of N₂ in RP-3 and RP-5 jet fuels was constructed based on the digital holography interferometry. The mass diffusion coefficient can be expressed by a uniform polynomial function of temperature and viscosity.

This paper seeks to present a hypothesis that is based not only on theoretical considerations, but also on experimental and clinical data. The hypothesis concerns the holographic principle as the main principle that ensures formation and functioning of any complex adaptive system (CAS).

The submitted paper represents the continuation of an article published in 2005 in Kybernetes. It substantiates the crucial role of holo‐diffraction in system‐genesis and system‐functioning. New experimental results are discussed and some parallels are also drawn between natural systems of various scales.

A new physical phenomenon of holo‐diffraction is considered as the general principle of CAS organization.

Biological holograms, emitted by various minor parts of the human body in specified conditions, allow in vivo and harmless imaging of various internal disorders. New approach to the study of complex adaptive (living) systems would help researchers to reveal some general laws and regulations of natural systems formation.

A new approach to the study of living systems that is based on parametric and visual analysis of emitted holograms is already used for medical purposes. Recently developed analytical software is being tested.

The paper contributes to the understanding of those principles which enable any CAS to integrate, control and organize its components while functioning.

Modern industry depends extensively upon the accurate conveyance of information. Much of this information, since it affects directly the quality of the products involved, requires to be precise and unambiguous. It must also be capable of interpretation by a wide range of personnel, sometimes irrespective of language barriers. The engineering drawing meets these requirements, since it is a visual system that is related directly to the shapes to be defined.

A scenario is given of a possible library of the future. Such a library might have shelves containing talking books, video cassettes, computer programs on floppy disks and the entire contents of Chemical Abstracts and Encyclopaedia Brittanica on biochips. The catalogue of the library stock and the reference books might well be stored on optical disks and viewed on flat screens. Information on the classification scheme and how to use the collection might be provided by listening to tape recordings and voice synthesisers might inform borrowers where to return items. Robots collect these items from dispensers and replace them on the shelves. Each item in the library has a barcode which is scanned by a laser to provide details of loans/returns and patrons. Terminals linked to computers via satellites enable distant files to be searched on demand for information not stored in the library. Most of the journals taken by the library will be in digital form but a touch of a button on the terminal causes the images to be printed out locally. Fact or fiction? The paper goes on to describe some of the equipment that is currently available to them in the future (such as holography, robotics and satellites). Where we are now in terms of technological developments in libraries and information centres is discussed with reference to some actual projects such as Maggie's Place and Dave's Den. Finally, the impact of such futuristic, electronic libraries on the user as well as the librarian is considered.

A Swiss research institute has developed an on‐line technique of speckle interferometry with which it is possible to examine flaws in components and study the stresses they may have to sustain.