Refractive index sensor based on the diamond like carbon diffraction grating

In this work we present an optical refractive index (RI) sensor based on the spectral analysis of anomalies in the optical response from the diffraction grating employing polarized polychromatic light. The sensor consists of holographic diffraction grating (period 423.5 nm) coated with a thin (110 nm) SiO_x doped diamond like carbon film (DLC) that defines sensitivity of the sensor as well as the range of the spectral analysis. The deposition of the DLC film (synthesized by the direct ion beam deposition from the hydrocarbon source) has influence on the shape but not on the position of the anomalies observed in the specular reflection spectrum. From the reflection spectra the RI dispersion curve of liquid analyte-water was obtained.     

Advanced methods for the estimation of an unknown projection from a map

This article presents three new methods (M5, M6, M7) for the estimation of an unknown map projection and its parameters. Such an analysis is beneficial and interesting for historic, old, or current maps without information about the map projection; it could improve their georeference. The location similarity approach takes into account the residuals on the corresponding features; the minimum is found using the non-linear least squares. For the shape similarity approach, the minimized objective function ? takes into account the spatial distribution of the features, together with the shapes of the meridians, parallels and other 0D-2D elements. Due to the non-convexity and discontinuity, its global minimum is determined using the global optimization, represented by the differential evolution. The constant values of projection φ _k , λ _k , φ ₁, λ ₀, and map constants R,ΔX,ΔY, α (in relation to which the methods are invariant) are estimated. All methods are compared and the results are presented for the synthetic data as well as for 8 early maps from the Map Collection of the Charles University and the David Rumsay Map Collection. The proposed algorithms have been implemented in the new version of the detectproj software.     

Life margin assessment with Physics of Failure Tools application to BGA packages

Designers of electronic equipment are faced with the contractual obligation of guaranteeing that their products will fulfil the specifications on life duration. Classically, empirical methods based on databases and handbooks are used and features such as Mean Time Between Failure (MTBF) are provided. This paper presents how to use Physics of Failure (PoF) tools and results in order to provide the customer with a reliability feature, called life margin, based on Cycles To Failure (CTF) figures. The method defines and computes a life margin for 99% of the population in the given environmental life conditions. This feature is used to evaluate the different technological possibilities and decide the best trade-off to satisfy the customer’s requirement on life duration. The method has been applied to a given board and a given application, where the component, which limits reliability, has been identified as being packaged in a Ball Grid Array (BGA) package.     

Efficient collision detection for models deformed by morphing

Published online: 5 February 2003     

Indentation Thermal Shock Test for Ceramics

This paper presents an indentation-quench method to determine the resistance of ceramics to thermal cycling. The method defines a critical quench temperature difference, Δ T _c, based on a criterion which includes a minimum amount of crack growth and a minimum fraction of growing cracks. The method is applied to three different materials, which are ranked according to the individual values of Δ T _c. The variation of ΔT_c with different indentation loads and indentation positions is investigated. This technique uses a small number of specimens, avoids subsequent mechanical testing, and provides information about the ΔT C of the materials. The effect of repeated cycling on crack extension is also discussed.     

Discrete Element Method Simulation of Effect of Aggregate Shape on Fragmentation of Particle Composite

How primary particles affect the fragmentation of particle composites using discrete element method simulation is described. Disk‐shaped composite particles consisting of large aggregate particles embedded in a matrix of smaller sand particles have been impacted against a solid surface at range of collision velocities. The results have been analyzed to determine whether the shapes of the aggregates in the mixture have an influence on the fragmentation of particle composites. It has been identified that the fracture depends on the aggregate shapes of the particle composites. Liberation degrees and particle size distributions have also been found to be controlled by the shape of the primary particles. Particle shapes have a remarkable influence on the fragmentation behavior of the specimen, especially at lower velocities.     

In vitro activity of Δ6 and Δ9 desaturases in hepatomas of different growth rates

The in vitro activity of Δ9- and Δ6-desaturases was determined in the microsomal fraction of C3H/S normal mouse liver, SS1K fast growing hepatoma, and SS1H slow growing hepatoma. These tumors are two different sublines of a spontaneous hepatoma transplanted in 1949 by J.W. Wilson, Brown University, Providence, R.I., into C3H/ST W: strain. The activity of the two enzymes showed a parallel decrease in the two studied hepatomas. These alterations could be attributed to a fundamental change in structure or function in the tumors. The fatty acid desaturase activity seems to be independent of cell division in malignant tissues.