Artificial investigations

One more application area is composite materials where one wants to investigate the 3D structure and/or reaction to external influences. Fig.3a shows a shadow image of a block of composite material. It consists of an epoxy matrix with glass fibers. The reconstructed cross-sections, shown in Fig.3b, clearly show the fiber displacement inside the matrix. The sample can be loaded in situ to investigate the reaction of matrix and fibers to external strain. Also absorption and transmission by liquids can be visualized directly in three-dimensions. This method has been applied to the study of oil absorption in plastic granules and water collection inside artificial plant grounds. 

The experimental investigations are carried out in order to get an idea about the variations of the visibility of the indications during practical inspections. The specimen where a test piece with spare eroded artificial defects (Width 25 pm depth d = 30, 60, 120 pm) and other specimen with natural cracks, a forged steering lever and a weld. As an example, in Fig 4 the steering lever with 2 cracks can be seen and below the dependance on the visibilty of a weak indication and a part of the bright indications on the field strenght H. 

One of the more interesting new areas of surface science involves manipulation of adsorbates with the tip of an STM. This allows for the fonuation of artificial structures on a surface at the atomic level. In fact, STM tips are being investigated for possible use m lithography as part of the production of very small features on microcomputer chips [74]. 

Gr. technetos, artificial) Element 43 was predicted on the basis of the periodic table, and was erroneously reported as having been discovered in 1925, at which time it was named masurium. The element was actually discovered by Perrier and Segre in Italy in 1937. It was found in a sample of molybdenum, which was bombarded by deuterons in the Berkeley cyclotron, and which E. Eawrence sent to these investigators. Technetium was the first element to be produced artificially. Since its discovery, searches for the element in terrestrial material have been made. Finally in 1962, technetium-99 was isolated and identified in African pitchblende (a uranium rich ore) in extremely minute quantities as a spontaneous fission product of uranium-238 by B.T. Kenna and P.K. Kuroda. If it does exist, the concentration must be very small. Technetium has been found in the spectrum of S-, M-, and N-type stars, and its presence in stellar matter is leading to new theories of the production of heavy elements in the stars. 

The carbonated beverage has its origin in the study of mineral waters in Europe in the sixteenth century. In the late eighteenth century, artificial mineral waters were investigated for their medicinal properties both in Europe and America. The first commercial artificial mineral water was manufactured in Europe during the 1780s and in America in the early 1800s. 

This view was supported by the observation that choline on treatment with nitric acid yielded a product having a pharmacological action similar to that of muscarine as known up to that time. Comparison of the natural and artificial products by Bohm showed that the former was much more active than the latter and that its action was antagonised by atropine, whilst the artificial muscarine had a curare-like action on the atropinised frog. Later, Nothnagel investigated the action of... 

An artificial neural network based approach for modeling physical properties of nine different siloxanes as a function of temperature and molecular configuration will be presented. Specifically, the specific volumes and the viscosities of nine siloxanes were investigated. The predictions of the proposed model agreed well with the experimental data [41]. 

To investigate the connection between Ap/p and pn and the various relativistic effects two types of model calculations were performed i) the speed of light c and that way all relativistic effects have been varied artificially, ii) the strength of the spin-orbit coupling has been manipulated separately [8]. 

In the biological field, much attention has been directed toward the transport phenomena through membrane. Although the function of some natural ionophores has been known, the investigation of active and selective transport of ions using the artificial ionophores in the simple model systems may be important to simulate the biological systems and clarify the transport behaviour of natural membranes. 

Addition of suitable builders, such as sodium silicates or sodium tripolyphosphate, could increase the detergency of soap-LSDA blend even further. A systematic investigation of three-component systems, soap-LSDA builder, showed that a detergency maximum could be attained which corresponded to a certain fixed ratio of components. Maximum detergency corresponded to an approximate composition of 75% soap, 10% MES, and 15% metasilicate. The tests were carried out at 50°C and at 300 ppm water hardness which is well above that of U.S. municipal water supplies. The principle of detergency potentiation of soap by an LSDA and builder was always evident, even when using other artificially soiled cloths, such as those supplied by U.S. Testing Co. or Testfabrics Inc. 

The carbon dioxide generated by the personnel in the artificial atmosphere of submarines and spacecraft must be removed from the air and the oxygen recovered. Submarine design teams have investigated the use of potassium superoxide, K02, as an air purifier because this compound reacts with carbon dioxide and releases oxygen (Fig. 4.16) ... 

Another type of gel expands and contracts as its structure changes in response to electrical signals and is being investigated for use in artificial limbs that would respond and feel like real ones. One material being studied for use in artificial muscle contains a mixture of polymers, silicone oil (a polymer with a (O—Si—O—Si—) — backbone and hydrocarbon side chains), and salts. When exposed to an electric field, the molecules of the soft gel rearrange themselves so that the material contracts and stiffens. If struck, the stiffened material can break but, on softening, the gel is reformed. The transition between gel and solid state is therefore reversible. 

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