Multifunctional Elements

Bossemeyer, D. The glycine-rich sequence of protein kinases a multifunctional element (1994) Trends Biochem. Sd. 19, 201-205... 

A modular concept for pre-encapsulated actuators has been developed and transferred to production by German Aerospace Center DLR Braunschweig. The multifunctional elements can be designed to meet the requirements of industrial applications. This involves for example driving voltages, size and shape of the elements and the piezoceramic material itself. Recently, modules for raised operation temperatures up to 180°C have been developed. See Fig. 9. The selected materials allow for optimum actuator performance at 180 °C, see Fig. 10. 

Functional qualities can, however, only be used in terms of adaptronics if there is success in combining the specific release phenomena with the respective desired functions. What is therefore required in the conception of multifunctional elements (level II) is the release and specific use of the material-inherent options. For this purpose it is necessary to make use of release phenomena of a physical, chemical or biological nature on material in such a way that, as necessary, several effects can be combined by taking well-directed action. For example, the application of electrorheological fluids... 

Materials represent the essential basis for all multifunctional effects. The conception of multifunctional elements is therefore mainly based on the made-to-measure production of functional materials, wherein several functions are interlinked at a molecular level. However, the fact that this is not sufficient in all cases is clearly shown by taking adaptronic shock absorbers as an example, because some effects can only be produced if several materials are combined in suitable interconnected layers or other compounds. 

Adaptronics as an overall concept for the development of adaptronic structures and systems is still a young discipline, which was only able to establish itself a few years ago. On the other hand, the research in the fields of multifunctional materials and multifunctional elements, which are the basic elements of adaptronics, started much earlier. The origins of adaptronics under a different name - go back to the early 1980s. Early progress came from the arms research sector, especially from various air forces. 

There are several possible techniques for measuring the controlled variable. For instance, one can measure the grinding forces in the normal and tangential directions to the surface of the grinding wheel by means of a multiaxis piezoelectric force measurement platform mounted beneath the grinding spindle. Since this is, however, an expensive solution, the active electrical power required by the grinding spindle serves as a control variable, making the spindle a multifunctional element [172]. 

This aspect is not included here, but is related to optical flow diagnostics. It is based again on the principle of the optical Doppler effect. Multifunctional equipment is available for noncontact measurements of flow-induced vibration on surfaces of structural elements, for acoustic measurements, and for calibration of accelerometers and vibration transducers. 

The nanostructured molecular arrangements from DNA developed by Seeman may find applications as biological encapsulation and drug-delivery systems, as artificial multienzymes, or as scaffolds for the self-assembling nanoscale fabrication of technical elements. Moreover, DNA-protein conjugates may be anticipated as versatile building blocks in the fabrication of multifunctional supramolecular devices and also as highly functional-... 

Figure 11.17. Three-dimensional multifunctional circuits on plastics, (a) Schematics and circuit diagrams of inverter (top) and floating gate memory (bottom) elements.

Many of the basic elements of enzyme catalysis have been illustrated here, including binding of substrate, multifunctional catalysis, microenvironmental effects, covalent catalysis, and strain effects. The most remarkable rate enhancements reported to date are those brought about by apolar derivatives of PEI, a polycation. These rate enhancements are very en-... 

Table 9.1 summarizes catalyst compositions and corresponding performances. The oxidation of ethane to acetic acid is now commercial an industrial plant is installed, with the technology developed by Saudi Basic. Elements that have contributed to the successful development of the process are (1) the discovery of a catalytically active compound, the multifunctional properties of which can be modified and tuned to be adapted to reaction conditions through incorporation of various elements (2) the stability of the main products, ethylene and acetic acid, which do not undergo extensive consecutive degradation reactions (3) the possibility of recycling the unconverted reactant and the major by-product, ethylene (4) the use of reaction conditions that minimize the formation of CO and (5) an acceptable overall process yield. 

Case SP Shell International Chemicals—PDC Bulk Chemical Process Design (37). This new process design consists of a multifunctional reactor, which largely combines reaction, heat exchange, and component separation in one piece of equipment. Data on energy and cost element reductions are provided. 

This ambivalent interaction behaviour can be explained by the multifunctional structure of this PEI derivative. On the one hand, the divalent metal ions can interact with the nitrogen atoms of the amino groups of the basis polymer, and one the other hand, the methylated moieties lead to an anion exchange character of the polymer. Thus, simultaneous complexation and retention of various elements are feasable with this polymer. 

Although Curran s rate data for the reduction of radicals to organosamar-iums allow for an element of predictablity,2 problems can arise when multifunctional substrates are involved. For example, in the attempted intramolecular Barbier reaction of alkyl iodide 13, treatment with Sml2 results in the formation of side product 15 in addition to the expected product cyclohexanol 14 (Scheme 3.7).8 In this case, the p-keto amide motif in 13 is reduced at a rate competitive with alkyl iodide reduction, indicating that there are likely two mechanistic pathways through which the reaction proceeds a thermodynamic pathway initiated by reduction of the R I bond providing the... 

Multifunctional Parallelism. The internal architecture of the Advanced Flexible Processor allows multiple computational streams to be constructed and executed in parallel. By way of example, one might imagine the multiply unit requesting operands from one of the memory I/O ports and one of the data memories, while at the same time an adder may be requesting the product computed by the multiplier on a previous machine cycle and another data element from one of the remaining three data memories to serve as input operands for an addition operation. 

A block diagram of the CW-NMRI system is presented in Fig. 10. The system is based around a 7T, 183 mm diameter horizontal bore superconducting magnet (Oxford Instruments, UK), with a computer (800 MHz PC) controlling certain elements of the system electronics via a GPIB IEEE 488 instrument bus and running the sequence control and data acquisition/processing software. A multifunction data... 

While the enzymatically coupled FETs described so far use separate FET chips, more advanced forms, whether monofunctional or multifunctional, use an integrated FET chip with more tham two working FET elements. The bi-functional enzymatically coupled FET described above is not truly multifunctional because it does not use an integrated FET transducer. The advanced type of FET biosensor is called a monolithic enzymatically coupled FET (43). After the bifunctional enzymatically coupled FET, we have used an integrated FET chip shown in Fig. 7, which has three independendy functioning FET elements. The dimension of the FET chip is 5 X 6.5 X 0.5 mm. The ion-sensitive gate is 0.02 mm wide and 1 mm long. 

---