Fiducial markers for increasing the versatility of optical correlation in the measurement of faults on integrated-circuit wafers

A microscope-coherent optical processor is used for the measurement of the registration errors on integrated-circuit wafers. The measurements are obtained from the optical correlation of wafers with reference wafer patterns by use of matched spatial filters. Previously, the intricate pattern of the active circuit area of wafers has been used in the correlation process, and a new matched spatial filter had to be created for each different integrated circuit. Here, the results of using comparatively plain fiducial markers on a wafer for the registration-error measurement are presented, and these show that the measurements can be made independent of the design of the integrated circuit while maintaining the advantages and accuracy of the optical correlation technique.     

Fishtail magnetization in single crystal Tl2Ba2CuO6

We report extensive magnetization measurements on single crystals of Tl₂Ba₂CuO₆ superconductors. The fishtail magnetization is found to disappear above a characteristic temperature (60 K), which corresponds to a crossover temperature in the temperature dependence of the irreversibility line. Since the low temperature irreversibility field can be modeled by a Josephson coupled layered system, we propose that the fishtail magnetization in the Tl₂Ba₂CuO₆ system is due to dimensional crossover.     

Hardening of 316L stainless steel by laser surface alloying

The goal of this study is to investigate different hardening routes for 316L stainless steel by laser surface alloying. We have investigated the formation of iron-chromium carbides by SiC or carbon incorporation, the alloying with submicronic particles of TiC and the precipitation of titanium carbide from mixtures of Ti and SiC. For each hardening route we present the microstructures and the hardness of the processed surface alloys and the conditions leading to the best compromise between highest hardness, best homogeneity and lowest occurrence of cracks. From these results it can be reasoned that hardening by iron-chromium carbides is the best hardening route and that this surface alloy might be a good candidate for tribological applications.     

Effects of hypergravity on the cell shape and on the organization of cytoskeleton and extracelluar matrix molecules of in vitro human dermal fibroblasts

In vitro human dermal fibroblasts were submitted to normal gravity (1 g) or to chronic hypergravity ranging from 2 to 20 g for 8 days. Changes only appeared above 15 g. The majority of 20 g-subjected cells showed fine filipods in the shape of a star whereas most control cells had rounded shapes and spread by forming lamellipodia. Indirect immunofluorescence staining of vinculin, alpha-actinin and actin stress fibers showed changes of the arrangement anchoring points of stress fibers under hypergravity. Tubulin staining showed that the centrosomal material generally located above the nucleus in control cells had migrated to the nucleus side in 20 g-exposed cells. After 8 d of culture under 20 g hypergravity the thickness of fibronectin network seemed to be increased and bundles of fibrils appeared linking ordered arrays of fibers. The fibrils of collagen I formed better delimited and thicker bundles of fibers. We may assume that 20 g hypergravity can induce changes in fibroblast cell shape, migration way, and anchorage leading to a reorganization of extracellular matrix without concomitant change of cell proliferation.     

A 931 + 2T-->C transition in one COL1A2 allele causes exon 16 skipping in PRO alpha 2(I) mRNA and produces moderately severe OI

The breast clinic in the university Hospital Kuala Lumpur was started in August 1993 to cater for the increasing number of women seeking treatment for breast complaints. A four-month survey carried out from January to April 1994 found that Chinese women are more "breast conscious" than Malay and Indian women. The majority of patients were in the reproductive age group. Benign breast diseases form the majority of cases of breast diseases seen. The pick-up rate for new cases of breast cancer was 3.1%. Fine needle aspiration biopsy had a 100% sensitivity during the four-month study, and was a quick method of obtaining a diagnosis.     

Comfort of personal protective equipment

The degree of comfort of personal protective equipment (PPE) was investigated in an automobile encapsulating plant. Up to 96.2% of employees used one or a combination of PPE. Only 8% of the workers felt their respirators were comfortable, 30% tolerated their respirators, and 62% rated them as uncomfortable. The percentage of employees who rated their PPE (other than a respirator) as comfortable ranged from 32 to 52%. For comfort factor, coveralls/aprons rated 52%, safety glasses 51%, rubber gloves 42%, and hearing protectors 36%. PPE was tolerable (just acceptable) for about 30% of the employees. To increase the effectiveness and safety of PPE, the human-factor aspects of PPE design should be emphasized more and quality improvement should cover the wearability of PPE.     

Fabrication process for FEP piezoelectrets based on photolithographically structured thermoforming templates

Microsystem Technologies - Piezoelectrets fabricated from fluoroethylenepropylene (FEP)-foils have shown drastic increase of their piezoelectric properties during the last decade. This led to the...     

Induction of Superlattices for Canalized Waves in Magnetically Ordered Media by External Waves

Journal of Communications Technology and Electronics - Possible schemes for creating superlattices for channeled waves in magnetically ordered media by modulating their parameters by extraneous...     

Design and implementation of efficient QCA full-adders using fault-tolerant majority gates

The Journal of Supercomputing - CMOS technology is facing physical limitations in scaling the manufacturing process. Therefore, to deepen the development of better designs in a smaller area, it is...     

Anomalous Stokes shift of colloidal quantum dots and their influence on solar cell performance

Microsystem Technologies - We report an anomalous Stokes shift effect observed in colloidal solutions containing down-shifting Carbon quantum dots (CQDs) of different sizes that is expected to have...