Common algorithm of static stability estimation and computation of steady states of power systems

Generators with automatic control of excitation at studying static stability of electric system modes have been considered by transfer functions. Free number match conditions of the characteristic equation and matrix of Jacobi used in steady state calculations by the Newton method for various generator idealized models are analyzed. Features of using practical criteria of stability are examined

Protective coatings on medical implants by reactive diffusion

Wear resistant and corrosion resistant surfaces are important for medical implants. Wear resistance is especially important for articulating surfaces in load bearing applications such as total hip and total knee replacements. Metal-on- polyethylene bearings result in relative large volumetric wear, ceramics such as alumina have an excellent wear resistance but are brittle, metal-on-metal bearings have good wear resistance, but release nanometric debris and ions that may cause allergy or have toxic effects. Hard ceramic coatings on metal substrates may be a good solution: low wear and low ion release and ductile metal alloy interior—no danger of brittle fracture and easy shaping. Ti alloys such as for example Ti–6Al–4 have the best combination of mechanical properties and biocompatibility, but have very poor wear resistance, Co–Cr–Mo have good wear resistance, but may cause allergy. TiN hard coatings deposited on Ti alloys by PVD have relatively poor adhesion to the substrate as a result limited durability

Generalized static characteristics of electric power subsystems and their steepness factors

Representation of parts of electric power systems by generalized static characteristics has been considered. The design procedure of steepness factors of generalized static characteristics depending on features of equivalent subsystems is discussed. The generalized static characteristics and their steepness factors give the equivalent information on power subsystems and can be used at estimation of static aperiodic stability of power supply systems

Wavelet analysis of epileptic spikes

Interictal spikes and sharp waves in human EEG are characteristic signatures of epilepsy. These potentials originate as a result of synchronous, pathological discharge of many neurons. The reliable detection of such potentials has been the long standing problem in EEG analysis, especially after long-term monitoring became common in investigation of epileptic patients. The traditional definition of a spike is based on its amplitude, duration, sharpness, and emergence from its background. However, spike detection systems built solely around this definition are not reliable due to the presence of numerous transients and artifacts. We use wavelet transform to analyze the properties of EEG manifestations of epilepsy. We demonstrate that the behavior of wavelet transform of epileptic spikes across scales can constitute the foundation of a relatively simple yet effective detection algorithm.Comment: 4 pages, 3 figure

Consideration of Raft and Soil Interaction in Piled-Rafts Design

Based on the analysis of the piled-raft foundations, as well as experimental investigations of the geotechnical engineers, it is stated that the load of a piled-raft foundation is transferred both to a raft and a pile. When a piled-raft foundation design, the account of this factor allows the significant decrease of the foundation cost. To work out the method of a piled-raft foundation design, the experimental and numerical investigations have been carried out.The paper gives some results of the experimental and numerical investigations of piled-raft foundations. A method of the evaluation of a load part transferred to a raft and the piles is suggested. The conditions of the load transfer to a raft when a foundation loading are determined

Single Foundations of Framed Buildings and Skeleton Structures in a Compacted Base and Their Horizontal Load Resistance

In practice of construction in Russia in case of plastic soils bedding, the cast-in-place foundations are used, constructed in a compacted base in kind of tamping in the soil of the 2-4 m depth pyramidal holes with the subsequent ballast tamping into the hole bottom and placing concrete in the said hole. Such foundations are advisable under the columns of framed buildings and structures. They are significantly more effective comparing to the pile foundations with a cast-in-place raft, as without a raft the volume of excavation works and formwork decreases significantly. While design of such foundations for the framed buildings and structures, the horizontal load and bending moment calculation is of great importance. According to the above calculation, the horizontal displacements of a foundation and its reinforcing are evaluated. The aim of the given paper is to solve this problem. The complex of the experimental – theoretical investigations has been carried out by a special program and included the horizontal load static tests of the foundations in tamped holes with the parallel CPT. By results of site experiments the rules of deformation of the stressed-deformed state are obtained and the criteria of achieving the limit state of a system “foundation-soil” are revealed. In particular, it was stated that the tamped in ballast creates a zone of an increased strength in a foundation base that prevents its horizontal displacement due to the horizontal load. Based on experimental data, a design scheme was constructed and a method of such foundations horizontal load calculation was worked out including CPT

Calculation of Features of Many Row Pile Landslide Protection Structures

Results of investigation of pile many row landslide protection structures are shown. Experimental investigations of the behaviour of many row landslide protection structures are carried out on models in trays with the sandy soil under the action of the lateral landslide soil pressure. Based on results of the experimental investigations, the design scheme is improved and the method of calculation of many row pile landslide protection structures is worked out

Pierre Erny ed., Cultures et habitats. Douze contributions à une ethnologie de la maison. Paris, L'Harmattan, 1999 (« Cultures et cosmologies »).

« Si vous leur demandez pourquoi ils remuent si souvent leur ménage, ils n'ont d'autre réponse, sinon de dire qu'en changeant d'air, ils s'en portent mieux, et que s'ils faisaient autrement que leurs grands-pères l'ont fait, ils mourraient subitement. » Cette observation sur les Indiens Emérillon de Jean de Léry relatant son « voyage fait au Brésil, autrement dit en Amérique », en 1578, situe le propos général de l'ouvrage, à savoir le rapport entre l'habitat et la tradition, l'habitat ..