Reactions of composite structures, with concentrated and distributed parameters, to seismic action (vertical vibrations)

1976 ◽  
Vol 12 (3) ◽  
pp. 296-300
Author(s):  
I. M. Mirzaev
2017 ◽  
Vol 7 (3) ◽  
pp. 24-27
Author(s):  
Elena S. VRONSKAYA

The paper shows a possibility of including a frequency-independent viscoelastic design resistance in calculation models representing composite structures with distributed parameters. Diff erential equations of the system motion include parameters of complex rigidity. The research puts forward a solution which helps solve stationary and non-stationary dynamic problems taking internal friction into account. This solution is found by using the calculation algorithm for prismatic shells involving the use of topological matrices. In the process of separation of variables, this approach yields a diff erential equation of linear oscillator motion with frequency-independent viscoelastic resistance.


Author(s):  
Frances M. Ross ◽  
Peter C. Searson

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.


2019 ◽  
Author(s):  
Curtis Hickmott ◽  
Alireza Forghani ◽  
Victoria Hutten ◽  
Evan Lorbiecki ◽  
Frank Palmieri ◽  
...  

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