Wyniki 1-2 spośród 2 dla zapytania: authorDesc:"ADAM JAROSZ"

Calibration aided evaluation of interconnection capacitances for statistical simulation of IC’s with heterogeneous isolating materials

Czytaj za darmo! »

Growing complexity of VLSI systems causes an increase of the chip area. Simultaneously, its significant part is occupied by interconnections between rising number of blocks and devices. As a result, phenomena occurring in the metallization lines become very important and in many cases crucial to the characteristics of the circuit, so possibility to predict parameters of these lines, such as parasitic capacitances, are indispensable in the process of verification of the design. Very precise evaluations of interconnection capacitances can be provided by numerical solutions, but they are too timeconsuming, especially in the case of statistical simulations. So, analytical or empirical models, accurate as much as possible, are necessary. Usually, such models are developed for simpl[...]

Blood permeability testing of chitosan sealed polyester vascular prosthesis

Czytaj za darmo! »

The aim of the investigation was to determine blood permeability through the vascular grafts sealed with chitosan. The measurement method of water permeability of vascular grafts is specified in appropriate standard [1]. However the standard’s procedure does not reflect real prosthesis’ work conditions, particularly when it is applied as an element of heart assist system [2]. In respect of this it was intended to perform testing according to distinct procedure giving more complete representation of vascular prosthesis’ properties and taking into consideration mechanical extensibility of woven fabric during work with pulsatile pressure load. MATERIALS AND METHODS Vascular grafts The material of the investigation were BARD 004187 style 6010 vascular prosthesis of 16mm internal diameter [3]. Graft samples marked as 10 and 20 were sealed with layers based on chitosan. “10" and “20" runs was sealed with material of relative molecular mass respectively about 130 kD and 100 kD. Reference samples, marked as 0REF were not modified in any way. For testing purposes sample sets together with mounting elements and soft ring seals were prepared (Fig. 1). In such a set active graft’s length (intended for contact with blood) was 70 mm and active graft’s wall area was 35 cm2. Operating medium As an operating medium the blood collected from animals with CPDA-1 [4] anticoagulant was used. Transport of biological material to the laboratory was performed in temperature of 10°C. Time elapsed from blood collecting to beginning of the investigation was about 1.5 h. Biological material’s stability was determined by biochemical tests (hematocrit level, degree of hemolysis) [5] on the spot of drawing, directly before and during investigation. Testing methodology Vascular prosthesis’ samples were divided in three groups: a, b and c. In "a" group the grafts were subjected to the test without prelimin[...]

 Strona 1